Why Use Scientific Notation

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					     Exploring the Universe

           8th Grade Science
         School Year 2003-2004
         Luther Burbank School
     Mr. Frank Canzolino Room 204
                 Universe Chapter 1–Week
December, 2003            16.ppt           1
                 8 th   Grade Science



                                        Week 16.1
                                        Day 76
                                        Monday
                                        December 8, 2003



December, 2003     Universe Chapter 1–Week 16.ppt           2
                 Full Moon Tonight!

 The full moon will be in the constellation
  Taurus tonight
 Taurus may be the oldest identified
  constellation in the night sky
 To the lower left of the moon will be Gemini
 To the lower right of the moon will be Orion


December, 2003     Universe Chapter 1–Week 16.ppt   3
                 Aurora Borealis

 The Northern Lights
 This is Alaska

                                                           QuickTime™ and a
                                                  TIFF (Uncompressed) decompre ssor
                                                     are neede d to see this picture.




December, 2003   Universe Chapter 1–Week 16.ppt                                         4
                                  Aurora Borealis

                                                         During intense solar
                                                          storms, auroras can
                                                          appear anywhere, just
                QuickTime™ an d a
                                                          not in the north (This is
       TIFF (Uncompressed) decompressor
          are need ed to see this p icture .              Myrtle Beach, South
                                                          Carolina)




December, 2003                        Universe Chapter 1–Week 16.ppt              5
                                             Aurora Borealis

                                                                       The storm began when
                                                                        a coronal mass ejection
                                                                        (CME) swept past
                       QuickTime™ and a
                  YUV420 codec decompressor
                 are neede d to see this picture.
                                                                        Earth. CMEs are
                                                                        billion-ton clouds of
                                                                        gas hurled into space
                                                                        by explosions on the
                                                                        sun.


December, 2003                                      Universe Chapter 1–Week 16.ppt            6
                                  Aurora Borealis

                                                        The cloud was
                                                         propelled into space by
                                                         an M4-class explosion
                                                         on Nov. 18th near
              QuickTime™ an d a
         YUV420 codec decompressor                       sunspot 501, an active
        are need ed to see this p icture .
                                                         region that had caused
                                                         some intense space
                                                         weather back in
                                                         October, too.


December, 2003                       Universe Chapter 1–Week 16.ppt                7
                                      Aurora Borealis

                                                               When they strike
                                                                Earth's magnetic field,
                                                                CMEs sometimes spark
                                                                geomagnetic storms
                  QuickTime™ and a
               Cinepak decompressor                             and auroras. Solar
          are needed to see this picture.
                                                                winds are about 450
                                                                km/s.




December, 2003                              Universe Chapter 1–Week 16.ppt            8
                 Aurora Borealis

 In this case, however, the explosion was not
  intense. M-class means "medium-sized"—
  about ten times weaker than the much more
  powerful X-class flares feared by satellite
  operators and utility companies.




December, 2003   Universe Chapter 1–Week 16.ppt   9
                   Aurora Borealis

 Earth's magnetic field acts
  like a shield; it protects us
  from CMEs and other solar
  activity.
 M-class events happen                               QuickTime™ an d a
                                                 YUV420 codec decompressor
                                                are need ed to see this p icture .
  perhaps a dozen times each
  month; they're ordinary.
  Yet this one triggered an
  extraordinary geomagnetic
  storm. Why?

December, 2003       Universe Chapter 1–Week 16.ppt                                  10
                   Aurora Borealis

 CMEs can punch a hole in
  the shield.
 CMEs have a magnetic
  field of their own, and if a
  CME's magnetic field is                             QuickTime™ an d a
  tilted opposite Earth's                        YUV420 codec decompressor
                                                are need ed to see this p icture .
  magnetic field, the two will
  cancel out.
 This makes a hole or
  'crack' in our planet's
  shielding into which solar
  wind energy can pour.
December, 2003       Universe Chapter 1–Week 16.ppt                                  11
                  Aurora Borealis

 That's exactly what happened on Nov. 20th. In the wake of
  the CME came a south-pointing magnetic field measuring -
  50 nanoTesla—five to ten times bigger than usual. Our
  planet's magnetic defenses were breached, and the resulting
  geomagnetic storm was a whopper.
 NASA's IMAGE spacecraft and the European Space
  Agency's 4-satellite Cluster mission have recently observed
  geomagnetic cracks formed by CMEs. Some are as large as
  California and they can persist for many hours. Solar wind
  energy pours in, Earth's magnetic field shakes, and auroras
  appear where they are seldom seen.

December, 2003      Universe Chapter 1–Week 16.ppt              12
December, 2003   Universe Chapter 1–Week 16.ppt   13
                                                           The Solar System


                      The Sun


                                               Milky Way




           Galaxies



                                                           Universe

December, 2003          Universe Chapter 1–Week 16.ppt                 14
                 The Big Picture
                     The Universe

 The Big Bang theory
  has been proposed to
  explain the beginning
  of the universe




December, 2003   Universe Chapter 1–Week 16.ppt   15
                 The Big Picture
                      The Universe

 Big Bang says all
  matter and energy was
  concentrated in one
  place about 15 billion
  years ago.                                                QuickTime™ and a
                                                   TIFF (Uncompressed) decompressor
                                                      are need ed to see this picture.




 What other
  explanations can you
  imagine that started the
  universe?

December, 2003    Universe Chapter 1–Week 16.ppt                                         16
                                     The Big Picture
                                               The Universe

                                                           Closed Universe Theory
                                                           Says that the attraction of
                                                            the galaxies will slow the
                                                            expansion of the universe
                  QuickTime™ and a
         TIFF (Uncompressed) decompre ssor
                                                            that came from the big
            are neede d to see this picture.
                                                            bang
                                                           Everything will rush
                                                            together to one point where
                                                            another Big Bang occurs


December, 2003                          Universe Chapter 1–Week 16.ppt               17
                       The Big Picture
                             The Universe

                                            Open Universe Theory
                                            Galaxies will continue to
                                             separate forever
          QuickTime™ and a
                                            Stars will eventually die
TIFF (Uncompressed) decompress or            off
   are needed to see this picture.
                                            Final result is total
                                             emptiness




December, 2003           Universe Chapter 1–Week 16.ppt                  18
                 The Universe
                           Quasars

                                    If the universe is
                                     expanding, the objects
                                     near the edge should be
                                     the oldest since they
                                     took the longest to get
                                     there




December, 2003   Universe Chapter 1–Week 16.ppt            19
                 The Universe
                           Quasars

                                    The most distant
                                     objects know are
                                     quasars
                                    These star-like objects
                                     radiate mainly radio
                                     and x-rays




December, 2003   Universe Chapter 1–Week 16.ppt                20
                                     The Universe
                                              Quasars

                                                       Quasars give off the
                                                        energy of 100 galaxies
                                                        from a very small
                                                        region of space

              QuickTime™ an d a
         YUV420 codec decompressor
        are need ed to see this p icture .




December, 2003                      Universe Chapter 1–Week 16.ppt           21
                     Tycho Brahe
                           1546-1601

 Before the invention of the
  telescope, the Danish
  astronomer Tycho Brahe
  revolutionized astronomy
  by establishing the                            Q uic kT ime ™ a n d a
  importance of accurate             T IFF ( Un co m pr e ss e d) d ec o mp r es s or
                                         a re n ee d ed to s e e th is p ictu r e.
  observations.
 He invented an improved
  sextant and used it to make
  precise observations of the
  positions of stars and
  planets.
December, 2003      Universe Chapter 1–Week 16.ppt                                22
                  Tycho Brahe
                        1546-1601

                                    Spent his life
                                     producing a catalog of
                                     carefully observed stars
                                     and planets using
                                     “state-of-the-art”
                                     observatory
                                    No telescopes!



December, 2003   Universe Chapter 1–Week 16.ppt            23
                     Tycho Brahe
                           1546-1601

 Brahe completely
  recalculated Ptolemy’s
  astronomical tables, which
  contained many errors, and
  catalogued over one
                                                     QuickTime™ a nd a
  thousand stars during his                 TIFF (Uncompressed) decompressor
                                               are need ed to see this picture.
  lifetime.
 He built Europe’s first
  observatory (Denmark) and
  taught the art of
  observation to a generation
  of astronomers.
December, 2003      Universe Chapter 1–Week 16.ppt                                24
                 Tycho Brahe (1546-1601)
            Uraniborg (Castle of the Heavens)




Accurate measurements to ~1 minute of arc (1/15 the diameter of the moon)
December, 2003         Universe Chapter 1–Week 16.ppt                  25
                         Tycho Brahe
                               1546-1601
 In 1572 Brahe made careful
  observations of a “new star”
  (actually a supernova) that
  appeared suddenly in the
  constellation Cassiopeia. He
  showed that the object was not
                                                         QuickTime™ a nd a
  in the Earth’s atmosphere but                 TIFF (Uncompressed) decompressor
                                                   are need ed to see this picture.
  was actually beyond the orbit of
  the moon. This discredited the
  prevailing theory that the
  heavens are static and
  unchanging.



December, 2003          Universe Chapter 1–Week 16.ppt                                26
                                            Tycho’s Model

                                                                  Data did not fit with
                                                                   geocentric view
                                                                  Developed a new
                                                                   model that tried to keep
                                                                   the geocentric viable–
                                                                   but too complicated
                                                                  Thought that the Laws
                                                                   of nature demanded a
                                                                   geocentric cosmology
  http://es.rice.edu/ES/humsoc/Galileo/People/tycho_brahe.html


December, 2003                                 Universe Chapter 1–Week 16.ppt            27
                         Homework

 Read Section 1-2
 Page 52, Content Review
        Multiple Choice #2, #9
        True False: #1, #3, #6, #7
 Page 27, Figure 1-19, Figure Caption



December, 2003        Universe Chapter 1–Week 16.ppt   28
                 8 th   Grade Science



                                        Week 16.2
                                        Day 77
                                        Tuesday
                                        December 9, 2003



December, 2003     Universe Chapter 1–Week 16.ppt           29
                              Homework

 Page 52, Content Review Multiple Choice #2
        The shape of galaxies such as the Milky Way is
          a.) elliptical
          b.) irregular
          c.) globular
          d.) spiral




December, 2003             Universe Chapter 1–Week 16.ppt   30
                              Homework

 Page 52, Content Review Multiple Choice #2
        The shape of galaxies such as the Milky Way is
          a.) elliptical
          b.) irregular
          c.) globular
          d.) spiral




December, 2003             Universe Chapter 1–Week 16.ppt   31
                              Homework

 Page 52, Content Review Multiple Choice #9
        The most distant objects in the universe are
          a.) pulsars
          b.) neutron stars
          c.) quasars
          d.) binary stars




December, 2003          Universe Chapter 1–Week 16.ppt   32
                              Homework

 Page 52, Content Review Multiple Choice #9
        The most distant objects in the universe are
          a.) pulsars
          b.) neutron stars
          c.) quasars
          d.) binary stars




December, 2003          Universe Chapter 1–Week 16.ppt   33
                        Homework

 Page 52, Content Review True False #1
        Our sun is in the Andromeda galaxy?
          T      F




December, 2003       Universe Chapter 1–Week 16.ppt   34
                        Homework

 Page 52, Content Review True False #1
        Our sun is in the Andromeda galaxy?
          T      F    Milky Way




December, 2003       Universe Chapter 1–Week 16.ppt   35
                         Homework

 Page 52, Content Review True False #3
        A solar storm in the form of a huge bright loop is
         called a solar flare?
          T      F




December, 2003        Universe Chapter 1–Week 16.ppt      36
                         Homework

 Page 52, Content Review True False #3
        A solar storm in the form of a huge bright loop is
         called a solar flare?
          T      F     Prominence




December, 2003        Universe Chapter 1–Week 16.ppt      37
                         Homework

 Page 52, Content Review True False #6
        In an open universe, all the galaxies will
         eventually move back to the center of the
         universe?
          T      F




December, 2003        Universe Chapter 1–Week 16.ppt   38
                         Homework

 Page 52, Content Review True False #6
        In an open universe, all the galaxies will
         eventually move back to the center of the
         universe?
          T      F     Closed Universe




December, 2003        Universe Chapter 1–Week 16.ppt   39
                         Homework

 Page 52, Content Review True False #7
        The blue shift indicates that the universe is
         expanding?
          T      F




December, 2003        Universe Chapter 1–Week 16.ppt     40
                         Homework

 Page 52, Content Review True False #7
        The blue shift indicates that the universe is
         expanding?
          T      F     Red Shift




December, 2003        Universe Chapter 1–Week 16.ppt     41
                        Homework

 Page 27, Figure 1-19, Figure Caption
        This quasar, seen through an x-ray telescope, is
         some 12 billion light-years from earth. How long
         does it take the quasar’s light to reach earth?




December, 2003       Universe Chapter 1–Week 16.ppt     42
                             Homework

 Page 27, Figure 1-19, Figure Caption
        This quasar, seen through an x-ray telescope, is
         some 12 billion light-years from earth. How long
         does it take the quasar’s light to reach earth?
             12 billion years




December, 2003            Universe Chapter 1–Week 16.ppt   43
                    The Big Picture
                              Galaxies

 Galaxies contain star
  groups and are the major
  features of the universe
 Astronomers believe there
  are 100 billion galaxies
 One size (or shape) fits all
  definitely doesn’t apply to
  these huge collections of
  stars, gas, and dust.



December, 2003       Universe Chapter 1–Week 16.ppt   44
                 The Big Picture
                          Galaxies

 Galaxies are enormous swarms of stars, dust,
  gas, and dark matter held together by gravity.
 The sun is one of about 100 billion stars in
  our own galaxy, called the Milky Way.
 If you think that’s incredible, imagine this:
  The Milky Way is just one of billions of
  galaxies in the observable universe!

December, 2003   Universe Chapter 1–Week 16.ppt   45
                 The Big Picture
                          Galaxies

 Most galaxies are found in clusters of about 150
  galaxies, bound together by each other’s gravity.
 Our Milky Way is part of a small cluster of some 30
  galaxies called the Local Group.
 Clusters of galaxies are often collected in
  superclusters.
 Our Local Group is part of the Virgo Supercluster,
  which contains several thousand galaxies.

December, 2003   Universe Chapter 1–Week 16.ppt    46
                 The Big Picture
                          Galaxies

 Galaxies range in size, containing anywhere
  from 100,000 to 3 trillion stars! They also
  come in different shapes. There are three
  major types of galaxies.




December, 2003   Universe Chapter 1–Week 16.ppt   47
                      The Big Picture
                               Galaxies

 There are three types of galaxies.
        Spiral
        Elliptical
        Irregular
 Galaxies range in size, containing anywhere
  from 100,000 to 3 trillion stars!



December, 2003        Universe Chapter 1–Week 16.ppt   48
                      The Big Picture
                         Spiral Galaxies

 Spiral
        Spiral galaxies are rich
         in gas and dust. Some
         are viewed face-on so
         that the spiral arms are                     QuickTime™ and a
                                            TIFF (Un compressed) decompressor
         easily seen whereas                   are neede d to se e this picture.
         others are viewed edge-
         on.




December, 2003          Universe Chapter 1–Week 16.ppt                             49
                      The Big Picture
                          Spiral Galaxies

                                           Spiral galaxies are
                                            shaped like disks and
                                            look like pinwheels
          QuickT ime™ and a                 from above. Young
T IF F (Uncompressed) decompressor
   are needed to see this picture.          stars are found in the
                                            arms, and older stars
                                            are found in the central
                                            bulge, or nucleus.


December, 2003          Universe Chapter 1–Week 16.ppt             50
                      The Big Picture
                       Elliptical Galaxies

 Elliptical
        The majority of
         galaxies show no spiral
         features, nor are they
         flattened disks; they                        Quic kTim e™ and a
                                            TIFF (Uncompres sed) decompres sor
         take the form of                      are needed to s ee this pic ture.
         ellipsoids. Elliptical
         galaxies show only
         small evidence for
         young stars, dust or gas.


December, 2003          Universe Chapter 1–Week 16.ppt                             51
                      The Big Picture
                       Elliptical Galaxies

                                           Elliptical galaxies are
                                            the oldest and largest
                                            galaxies. They are
                                            smooth and oval and
          QuickT ime™ and a
T IF F (Uncompressed) decompressor          contain many old stars.
   are needed to see this picture.
                                            There are many more
                                            elliptical galaxies in
                                            the universe than spiral
                                            galaxies.


December, 2003          Universe Chapter 1–Week 16.ppt             52
                 The Big Picture
                  Irregular Galaxies

 Some galaxies are
  neither ellipsoidal nor
  are they spirals. Some
  have been tidally
                                             QuickTime™ and a
  distorted by the                 TIFF (Un compresse d) decompressor
                                      are needed to se e this picture.
  presence of another
  near-by galaxy some,
  such as the Large
  Magellanic have little
  symmetry to their
  structure.
December, 2003    Universe Chapter 1–Week 16.ppt                         53
                      The Big Picture
                       Irregular Galaxies

                                           Irregular galaxies don’t
                                            have a distinct shape and
                                            are not symmetrical like
                                            spiral or elliptical galaxies.
          QuickT ime™ and a                 They may be young
T IF F (Uncompressed) decompressor
   are needed to see this picture.          galaxies that have not yet
                                            formed a symmetrical
                                            shape, or their irregular
                                            shape may be caused by
                                            two galaxies colliding.

December, 2003          Universe Chapter 1–Week 16.ppt                   54
                  The Big Picture
                 When Galaxies Collide




                           QuickTime™ and a
                         Cinepak decompressor
                     are neede d to see this picture.




December, 2003     Universe Chapter 1–Week 16.ppt       55
                 The Magellanic Cloud
                   The Nearest Galaxies

 The Milky Way is part of a cluster of about 30 galaxies
  called the Local Group. Our closest neighbors in this cluster
  are two small irregular galaxies, the Large Magellanic Cloud
  and the Small Magellanic Cloud. They are known as satellite
  galaxies because they orbit the Milky Way.
 These small “star clouds” are only visible in the night sky
  from the southern hemisphere. They were named after the
  explorer Ferdinand Magellan, who spotted them in 1519 as
  he made the first voyage around the world.



December, 2003       Universe Chapter 1–Week 16.ppt          56
                 The Magellanic Cloud
                   The Nearest Galaxies

 The Large Magellanic
  Cloud is the closest of the
  two galaxies—about
  170,000 light-years away.
  Containing about 15 billion                    Quic kTime™ and a
  stars, it is about a quarter        TIFF (Unc ompres sed) decompres sor
                                         are needed to see this picture.
  the size of the Milky Way.
  The red puff seen at one
  end of this galaxy is the
  Tarantula nebula, a cloud
  of gas and dust. It is the
  largest nebula ever seen.
December, 2003       Universe Chapter 1–Week 16.ppt                         57
                 The Magellanic Cloud
                   The Nearest Galaxies

 The Small Magellanic
  Cloud is about 200,000
  light-years away and
  contains about 5 billion
                                                 Quic kTime™ and a
  stars.                              TIFF (Unc ompres sed) decompres sor
                                         are needed to see this picture.




December, 2003       Universe Chapter 1–Week 16.ppt                         58
                              Andromeda
                  The Nearest Spiral Galaxy

                                              The largest member of the
                                               Local Group is
                                               Andromeda, a spiral galaxy
                                               like ours. Andromeda is
          QuickTime™ an d a                    about 2.2 million light-
 TIFF (Uncompressed) decompressor
   are need ed to see this p icture.           years away and about one
                                               and a half times larger than
                                               the Milky Way—150,000
                                               light-years across.



December, 2003             Universe Chapter 1–Week 16.ppt                59
                              Andromeda
                  The Nearest Spiral Galaxy

                                              With about 300 billion
                                               stars, its gravitational
                                               pull causes several
                                               smaller satellite
          QuickTime™ an d a
 TIFF (Uncompressed) decompressor              galaxies to orbit around
   are need ed to see this p icture.
                                               it. Two of these
                                               elliptical satellites can
                                               be seen with a small
                                               telescope.


December, 2003             Universe Chapter 1–Week 16.ppt             60
                              Andromeda
                  The Nearest Spiral Galaxy

                                              The Andromeda galaxy
                                               is moving toward the
                                               Milky Way at about
                                               186 miles per second.
          QuickTime™ an d a
 TIFF (Uncompressed) decompressor              It would take about 2
   are need ed to see this p icture.
                                               billion years, but it is
                                               possible that the two
                                               galaxies could collide
                                               or merge into each
                                               other.

December, 2003             Universe Chapter 1–Week 16.ppt             61
                              Andromeda
                  The Nearest Spiral Galaxy

                                              Like the Milky Way,
                                               the spiral galaxy
                                               Andromeda revolves
                                               around a central
          QuickTime™ an d a
 TIFF (Uncompressed) decompressor              “bulge.” Scientists
   are need ed to see this p icture.
                                               believe this center
                                               contains a massive
                                               black hole.



December, 2003             Universe Chapter 1–Week 16.ppt            62
                  The Virgo Cluster
                  A Gallery of Galaxies

 Our own cluster of
  galaxies, the Local Group,
  is part of a larger collection
  of over one hundred
  clusters called the Local                        QuickTime™ an d a
                                          TIFF (Uncompressed) decompressor
  Supercluster. At the center               are need ed to see this p icture.

  of this supercluster is the
  Virgo cluster.




December, 2003        Universe Chapter 1–Week 16.ppt                            63
                 The Virgo Cluster
                 A Gallery of Galaxies

 The Virgo cluster is also
  the largest cluster of the
  supercluster, with over two
  thousand galaxies of
  different sizes and shapes.                     QuickTime™ an d a
  If you look closely, you’ll            TIFF (Uncompressed) decompressor
                                           are need ed to see this p icture.
  find examples of spiral,
  elliptical, and irregular
  galaxies. Three giant
  elliptical galaxies are found
  at the center of the Virgo
  cluster.
December, 2003       Universe Chapter 1–Week 16.ppt                            64
                  The Virgo Cluster
                  A Gallery of Galaxies

 At about 50 million light-
  years away, the Virgo
  cluster is the closest cluster
  to the Milky Way. And its
  mass is so great, our Local                      QuickTime™ an d a
  Group is being pulled                   TIFF (Uncompressed) decompressor
                                            are need ed to see this p icture.
  toward the Virgo cluster at
  about 168 miles per
  second.




December, 2003        Universe Chapter 1–Week 16.ppt                            65
                 Unusual Galaxies
                       Siamese Twins

 These two spiral galaxies
  are commonly known as
  the Siamese Twins. Found
  in the Virgo cluster, the
  Siamese Twins show how                         QuickTime™ and a
                                      TIF F (Uncompressed) decompressor
  gravitational pull                     are needed to see this picture.
  sometimes causes two
  galaxies to collide or brush
  against each other.



December, 2003       Universe Chapter 1–Week 16.ppt                        66
                 Unusual Galaxies
                    Sombrero Galaxy

 It’s easy to see how this
  spiral galaxy got its name.
  With a bright halo of stars
  and a large central bulge of
  stars, it looks like a hat!                   QuickTime™ and a
                                      TIFF (U ncompressed) decompressor
 Like most spiral galaxies,             are needed to see this picture.

  older stars are found in the
  nucleus, while younger
  stars are found in the dust
  rings surrounding it.

December, 2003       Universe Chapter 1–Week 16.ppt                        67
                  Unusual Galaxies
                     Sombrero Galaxy

 Scientists think an
  enormous black hole
  resides at the core—
  possibly a billion times the
  mass of our sun.                              QuickTime™ and a
 This galaxy is 50 million           TIFF (U ncompressed) decompressor
                                         are needed to see this picture.
  light-years away, but you
  can see it with a small
  telescope near the
  constellation Virgo.


December, 2003       Universe Chapter 1–Week 16.ppt                        68
                  Unusual Galaxies
                            Polar Ring

 This galaxy, 130 million
  light-years away, is one
  example of about one
  hundred known polar-ring
  galaxies which contain an                      QuickTime™ and a
  inner central disk of old           TIF F (U ncompressed) decompressor
                                         are needed to see this picture.
  stars and an outer ring of
  younger stars. Scientists
  are still researching what
  causes polar-ring galaxies,
  but one theory is that they
  result from the collision of
  two galaxies
December, 2003       Universe Chapter 1–Week 16.ppt                        69
                     Hubble Deep Field
                     Galaxies from the Past

                                              This image from the
                                               Hubble Space Telescope
                                               provides a glimpse at a tiny
                                               sliver of the universe—like
          QuickTime™ an d a                    looking at the sky through
 TIFF (Uncompressed) decompressor
   are need ed to see this p icture.           a straw. It shows at least
                                               1,500 galaxies at varying
                                               distances and at different
                                               stages of evolution.



December, 2003             Universe Chapter 1–Week 16.ppt                70
                     Hubble Deep Field
                     Galaxies from the Past

                                              Some galaxies are so
                                               far away, we see them
                                               as they were billions of
                                               years ago, representing
          QuickTime™ an d a
 TIFF (Uncompressed) decompressor              what the universe
   are need ed to see this p icture.
                                               looked like in its
                                               earliest stage—perhaps
                                               less than a billion years
                                               after the big bang.


December, 2003             Universe Chapter 1–Week 16.ppt              71
                     Hubble Deep Field
                     Galaxies from the Past

                                              To create this image,
                                               scientists pointed the
                                               Hubble Space Telescope at
                                               a single spot for 10 days to
          QuickTime™ an d a
                                               capture even the faintest
 TIFF (Uncompressed) decompressor              objects. By studying
   are need ed to see this p icture.
                                               Hubble deep field,
                                               scientists hope to answer
                                               many questions about the
                                               number, evolution, and
                                               ultimate fate of galaxies in
                                               the universe.
December, 2003             Universe Chapter 1–Week 16.ppt                 72
                    Homework

 Constellation Project due Tomorrow




December, 2003   Universe Chapter 1–Week 16.ppt   73
                 8 th   Grade Science



                                        Week 16.3
                                        Day 78
                                        Wednesday
                                        December 10, 2003



December, 2003     Universe Chapter 1–Week 16.ppt            74
                 The Big Picture
                  The Milky Way

 The home of the Big
  Blue Marble




December, 2003   Universe Chapter 1–Week 16.ppt   75
                  The Big Picture
                          Milky Way

 The band of light that we
  call the Milky Way is
  actually the plane of the
  disk of our galaxy. The
  Sun is one, rather faint,                          QuickTime™ and a
                                            TIFF (Uncompressed) decompressor
  example of approximately                     are needed to see this picture.
  200,000,000,000 stars that
  make up our galaxy.




December, 2003      Universe Chapter 1–Week 16.ppt                               76
                  The Big Picture
                          Milky Way

 If you see a creamy strip
  across the sky on a
  moonless night, you’re
  looking out at the outer
  edge of the Milky Way. (If                    QuickTime™ and a
  you lived in the southern            TIFF (Uncompressed) decompre ssor
                                          are neede d to see this picture.
  hemisphere, you’d be
  looking into the center of
  the Milky Way.)




December, 2003      Universe Chapter 1–Week 16.ppt                           77
                  The Big Picture
                          Milky Way

 When you look at the night
  sky, all the stars you see
  are a small part of our own
  Milky Way galaxy. The
  Milky Way is a spiral                         QuickTime™ and a
                                       TIFF (Uncompressed) decompre ssor
  galaxy, and the sun is                  are neede d to see this picture.

  located about 30,000 light-
  years from the Milky
  Way’s nucleus on the
  Orion arm.

December, 2003      Universe Chapter 1–Week 16.ppt                           78
                   The Big Picture
                           Milky Way

 Most of the older stars are
  found near the center
  (nucleus) of the Milky
  Way
 The density of the stars                                 QuickTime™ and a
                                                 TIFF (Un compressed) decompressor
                                                    are neede d to se e this picture.
  near the nucleus is
  thousands of times denser
  than near the arms (where
  we live)


December, 2003       Universe Chapter 1–Week 16.ppt                                     79
                    The Big Picture
                            Milky Way

                           QuickTime™ and a
                 TIFF (Uncompressed) decompressor
                    are needed to see this picture.




 Scientists estimate the diameter as 100,000 light
  years, thickness as 15,000 LY, with the nucleus
  approximately 20,000 LY
 100 billion stars

December, 2003        Universe Chapter 1–Week 16.ppt   80
                        The Big Picture
                               Milky Way

                           QuickTime™ and a
                 TIFF (Un compresse d) decompressor
                    are needed to se e this picture.


 Like all galaxies, the Milky Way is held together by gravity.
  This gravity also holds the stars, gas, and dust in orbit
  around the center of the galaxy. Just as the planets orbit
  around the sun, the sun orbits around the center of the Milky
  Way. Of course, it’s a long trip around—about 225 million
  years!
December, 2003           Universe Chapter 1–Week 16.ppt       81
                 Johannes Kepler
                         1571-1630

                                     Tycho’s assistant in
                                      Prague
                                     After Tycho’s death,
                                      succeeded Tycho’s
                                      position and had access
                                      to the excellent data
                                     How to fit the
                                      heliocentric model to
                                      data of Mars?

December, 2003    Universe Chapter 1–Week 16.ppt            82
                 Johannes Kepler
                         1571-1630

                                     There was a problem.
                                      The data was so good
                                      that it could not be fit
                                      with the heliocentric
                                      model if only circles
                                      were used.
                                     Then, he began to work
                                      with the ellipse.


December, 2003    Universe Chapter 1–Week 16.ppt            83
                             Johannes Kepler
                                        1571-1630
                                                    Armed with Tycho Brahe’s very
                                                     accurate observations of the
                                                     planets and his own painstaking
                                                     measurements, the German
                                                     astronomer Johannes Kepler
            Q uic kT ime ™ a n d a
                                                     discovered what we now call
T IFF ( Un co m pr e ss e d) d ec o mp r es s or     Kepler’s laws of planetary
    a re n ee d ed to s e e th is p ictu r e.        motion.
                                                    These three laws precisely
                                                     describe the motions of the
                                                     planets around the sun.




 December, 2003                  Universe Chapter 1–Week 16.ppt                    84
                          Johannes Kepler
                                       1571-1630

                                                Kepler’s first law states
                                                 that planets move in
                                                 elliptical orbits around
            QuickTime™ and a
                                                 the sun. This
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     are needed to see this picture.             overturned the ancient
                                                 dogma that the planets
                                                 move in perfect circles.



December, 2003               Universe Chapter 1–Week 16.ppt             85
                                   Johannes Kepler
                                                1571-1630

                                                          Using observational data of
                                                           the orbit of Mars collected
                                                           by Tycho Brahe, and after
                                                           a prodigious amount of
                 QuickTime™ an d a
        TIFF (Uncompressed) decompressor
                                                           trail and error, false starts,
           are need ed to see this p icture .
                                                           and laborious calculations,
                                                           Kepler finally determined
                                                           that planets travel in
                                                           elliptical orbits.



December, 2003                         Universe Chapter 1–Week 16.ppt                  86
                      Johannes Kepler
                               1571-1630




 Kepler’s 1st Law:
        Orbits of planets are ellipses with the Sun at one focus
        Kepler's First Law Simulation



December, 2003          Universe Chapter 1–Week 16.ppt              87
                          Johannes Kepler
                                       1571-1630

                                                His second law
                                                 describes how a planet
                                                 travels faster in its orbit
                                                 when it is closer to the
            QuickTime™ and a
  TIF F (Uncompressed) decompressor              sun.
     are needed to see this picture.




December, 2003               Universe Chapter 1–Week 16.ppt               88
                 Johannes Kepler
                         1571-1630

                                     Kepler’s 2nd law:
                                             The Line that connects
                                              the planet to the Sun
                                              sweeps out equal areas
                                              in equal time




December, 2003    Universe Chapter 1–Week 16.ppt                       89
                                   Johannes Kepler
                                                1571-1630

                                                          This is now known to
                                                           be a consequence of
                                                           the Law of
                 QuickTime™ an d a
                                                           Conservation of
        TIFF (Uncompressed) decompressor
           are need ed to see this p icture .              Angular Momentum.
                                                          Kepler's Second Law
                                                           Simulation



December, 2003                         Universe Chapter 1–Week 16.ppt             90
                          Johannes Kepler
                                       1571-1630

                                                The third law describes
                                                 how the orbital periods
                                                 of the planets increase
                                                 with the size of their
            QuickTime™ and a
  TIF F (Uncompressed) decompressor              orbits.
     are needed to see this picture.
                                                Kepler's Third Law
                                                 Simulation




December, 2003               Universe Chapter 1–Week 16.ppt            91
                                   Johannes Kepler
                                                1571-1630

                                                          This form of Kepler's 3rd
                                                           law applies to planets when
                                                           the units of time are years
                                                           and the units of distance
                 QuickTime™ an d a
        TIFF (Uncompressed) decompressor
                                                           are Astronomical Units. A
           are need ed to see this p icture .
                                                           more general form of
                                                           Kepler's Law was
                                                           developed by Newton and
                                                           applied to all closed orbits.



December, 2003                         Universe Chapter 1–Week 16.ppt                 92
                         Johannes Kepler
                                   1571-1630

 Kepler’s 3rd Law:
         The squares of the
          orbital sidereal
                                      Planet         P (yr) a (AU)    P2     a3
          periods of the planets      Mercury         0.24   0.39    0.06   0.06
          about the Sun are
          proportional to the          Venus          0.61   0.72    0.37   0.37
          cubes of the orbital
          semimajor axes
                                       Earth          1.00   1.00    1.00   1.00
 P2 = a3                              Mars           1.88   1.52     3.5    3.5
 Where P is in years                 Jupiter        11.86 5.20      141    141
  and a is in AU.                     Saturn         29.46 9.54      868    868

         Bottom line: The closer to the sun, the faster the orbit!
December, 2003              Universe Chapter 1–Week 16.ppt                    93
                          Johannes Kepler
                                       1571-1630

                                                Kepler’s laws were
                                                 based on the
                                                 Copernican view of a
            QuickTime™ and a
                                                 heliocentric universe.
  TIF F (Uncompressed) decompressor
     are needed to see this picture.             Newton relied on them
                                                 when he developed his
                                                 more general law of
                                                 universal gravitation.


December, 2003               Universe Chapter 1–Week 16.ppt           94
                 8 th   Grade Science



                                        Week 16.4
                                        Day 79
                                        Thursday
                                        December 11, 2003



December, 2003     Universe Chapter 1–Week 16.ppt            95
                                          Constellations




                          QuickTime™ an d a
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                    are need ed to see this picture .




                                                                       Constellations



December, 2003                              Universe Chapter 1–Week 16.ppt               96
                 Enrichment Day

 Teacher’s Workshop 11:15 Dismissal




December, 2003    Universe Chapter 1–Week 16.ppt   97
                 8 th   Grade Science



                                        Week 16.5
                                        Day 80
                                        Friday
                                        December 12, 2003



December, 2003     Universe Chapter 1–Week 16.ppt            98
                               Think Big

                                  QuickTime™ an d a
                        TIFF (Uncompressed) decompressor
                           are need ed to see this picture .




 Our Milky Way Galaxy is about 100,000 light-years across. Traveling at
  the speed of light, how long would it take our spacecraft to travel across
  the Milky Way?

 A.) 1.5 years     B.) 63,000 years         C.) 100,000 years



December, 2003           Universe Chapter 1–Week 16.ppt                    99
                               Think Big

                                  QuickTime™ an d a
                        TIFF (Uncompressed) decompressor
                           are need ed to see this picture .




 Our Milky Way Galaxy is about 100,000 light-years across. Traveling at
  the speed of light, how long would it take our spacecraft to travel across
  the Milky Way?

 A.) 1.5 years     B.) 63,000 years         C.) 100,000 years



December, 2003           Universe Chapter 1–Week 16.ppt                   100
                              Think Big

                                 QuickTime™ an d a
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 Way to go! And you didn’t even need to calculate. That’s one reason
  light-years are so handy in astronomy. Seeker 2000 has left the Milky
  Way and is traveling through the Local Group, a collection of galaxies
  that includes our own.




December, 2003          Universe Chapter 1–Week 16.ppt                     101
                 The Big Picture

 The word “planet”
  comes from from the
  Greek word for
  wanderers.
 On any given night,
  planets will rise with
  stars and constellations
  and move from East to
  West.

December, 2003    Universe Chapter 1–Week 16.ppt   102
                     The Sun’s Fire

 Fission
        Breaking apart of nucleus
        Chain reaction
 Fusion
        Putting two nuclei together to make one
        Takes temperatures over one million degrees



December, 2003       Universe Chapter 1–Week 16.ppt    103
                       The Sun’s Fire

 Nuclear Reactions
        Strong Nuclear Force
           Holds protons and neutrons together
           Energy to hold together called the binding energy

 Radioactivity
        Alpha particles (He nuclei)
        Beta particles (Electrons)
        Gamma rays (High energy EM)

December, 2003          Universe Chapter 1–Week 16.ppt          104
                     The Sun’s Fire

 Fission
        Breaking apart of nucleus
        Chain reaction
 Fusion
        Putting two nuclei together to make one
        Takes temperatures over one million degrees



December, 2003       Universe Chapter 1–Week 16.ppt    105
                     QuickTime™ an d a
            TIFF (Uncompressed) decompressor
               are need ed to see this p icture .




December, 2003                                      Universe Chapter 1–Week 16.ppt   106
                       Galileo Galilei
                              1564-1642
 The Italian astronomer and
  physicist Galileo is often
  credited for inventing the
  telescope. In truth, a Dutch
  optician invented the telescope
  before 1609, but as soon as                       Q uic kT ime ™ a n d a
                                        T IFF ( Un co m pr e ss e d) d ec o mp r es s or
  Galileo learned about this                a re n ee d ed to s e e th is p ictu r e.
  important new instrument, he set
  about making one of his own.




December, 2003         Universe Chapter 1–Week 16.ppt                               107
                       Galileo Galilei
                              1564-1642
 The Italian astronomer and
  physicist Galileo is often
  credited for inventing the
  telescope. In truth, a Dutch
  optician invented the telescope
  before 1609, but as soon as                           QuickTime™ and a
                                             TIF F (U ncompressed) decompressor
  Galileo learned about this                    are needed to see this picture.
  important new instrument, he set
  about making one of his own.




December, 2003         Universe Chapter 1–Week 16.ppt                             108
                       Galileo Galilei
                              1564-1642
 Galileo worked to improve his
  telescope and turned it on the
  sky. In a matter of months he
  made some astonishing
  discoveries, including mountains
  and valleys on the moon, the                          QuickTime™ and a
                                             TIF F (U ncompressed) decompressor
  phases of Venus, and the four                 are needed to see this picture.
  big moons orbiting Jupiter.




December, 2003         Universe Chapter 1–Week 16.ppt                             109
                       Galileo Galilei
                               1564-1642
 These observations supported
  the Copernican view of the solar
  system. Galileo also used the
  telescope to discover that the
  Milky Way is composed of
  countless stars too faint to be                        QuickTime™ and a
                                              TIF F (U ncompressed) decompressor
  seen with the unaided eye.                     are needed to see this picture.




December, 2003          Universe Chapter 1–Week 16.ppt                             110
                    Galileo Galilei
                            1564-1642

 Galileo’s popular advocacy
  of the Copernican system
  provoked the opposition of
  the Roman Catholic
  Church, and he was
                                                      QuickTime™ and a
  accused of being a heretic.              TIF F (U ncompressed) decompressor
                                              are needed to see this picture.
 In 1633 he was forced to
  denounce the Copernican
  system and was sentenced
  to house arrest for the rest
  of his life.

December, 2003       Universe Chapter 1–Week 16.ppt                             111
                 8 th   Grade Science



                                        Week 17.1
                                        Day 81
                                        Monday
                                        December 15, 2003



December, 2003     Universe Chapter 1–Week 16.ppt            112
                 The Big Picture

 The word “planet”
  comes from from the
  Greek word for
  wanderers.
 On any given night,
  planets will rise with
  stars and constellations
  and move from East to
  West.

December, 2003    Universe Chapter 1–Week 16.ppt   113
                 8 th   Grade Science



                                      Astronomy

                                      Supplemental
                                       Materials



December, 2003     Universe Chapter 1–Week 16.ppt     114
                              Think Big

                                 QuickTime™ an d a
                       TIFF (Uncompressed) decompressor
                          are need ed to see this picture .




 The average distance from the Earth to the sun is 93 million miles.
  Astronomers call this distance one astronomical unit (abbreviated AU).
  It’s a handy yardstick for measuring distances in the solar system.
  Neptune is 30 AU from the sun. That’s also the average distance
  between Neptune and Earth as the Earth goes around the sun. (To figure
  out how far this is in miles, multiply 30 by 93 million.)


December, 2003          Universe Chapter 1–Week 16.ppt                115
                          Think Big

                             QuickTime™ an d a
                   TIFF (Uncompressed) decompressor
                      are need ed to see this picture .




 Our spacecraft is passing Neptune. How long does a trip
  from the sun to Neptune take at the speed of light?

 A.) 25 seconds    B.) 250 minutes                  C.) 2,790 seconds


December, 2003      Universe Chapter 1–Week 16.ppt                       116
                          Think Big

                             QuickTime™ an d a
                   TIFF (Uncompressed) decompressor
                      are need ed to see this picture .




 Our spacecraft is passing Neptune. How long does a trip
  from the sun to Neptune take at the speed of light?

 A.) 25 seconds    B.) 250 minutes                  C.) 2,790 seconds


December, 2003      Universe Chapter 1–Week 16.ppt                       117
                        Think Big

                           QuickTime™ an d a
                 TIFF (Uncompressed) decompressor
                    are need ed to see this picture .




 That’s right, it would take about 250 minutes (a
  little over four hours) to reach Neptune. Seeker
  2000 has left the solar system and is soaring
  through our galaxy, the Milky Way.

December, 2003    Universe Chapter 1–Week 16.ppt        118
                               Think Big

                                  QuickTime™ an d a
                        TIFF (Uncompressed) decompressor
                           are need ed to see this picture .




 The stars are much farther away than the planets. Astronomers use light-
  years to measure big distances, where one light-year is the distance light
  travels in a year. The average distance between neighboring stars in the
  Milky Way is a few light-years. There are 5.8 trillion miles in one light-
  year. (Here’s another way to think about it: one light-year equals 63,000
  AU.)


December, 2003           Universe Chapter 1–Week 16.ppt                   119
                              Think Big

                                 QuickTime™ an d a
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                          are need ed to see this picture .




 The nearest neighboring spiral galaxy, the Andromeda galaxy, is about
  2.2 million light-years away. How far is that compared to the size of our
  Milky Way galaxy?

 A.) 2.2 times     B.) 22 times       C.) 495 times



December, 2003           Universe Chapter 1–Week 16.ppt                  120
                              Think Big

                                 QuickTime™ an d a
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                          are need ed to see this picture .




 The nearest neighboring spiral galaxy, the Andromeda galaxy, is about
  2.2 million light-years away. How far is that compared to the size of our
  Milky Way galaxy?

 A.) 2.2 times     B.) 22 times       C.) 495 times



December, 2003           Universe Chapter 1–Week 16.ppt                  121
                              Think Big

                                 QuickTime™ an d a
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 You’re right! Andromeda is 22 times farther than the size of our Milky
  Way. So unlike the stars, galaxies are large targets in terms of the
  distance between them. That’s why collisions between galaxies are
  rather common. Seeker 2000 soars into the Virgo Supercluster, a larger
  collection of clusters that includes the Local Group.



December, 2003           Universe Chapter 1–Week 16.ppt                122
                              Think Big

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                          are need ed to see this picture .




 Our Milky Way and the Local Group is part of the Virgo Supercluster of
  galaxies, which is about 150 million light-years across. How much
  farther is a trip across the supercluster compared to a trip across the
  Milky Way?

 A.) 15 times    B.) 150 times         C.) 1,500 times

December, 2003          Universe Chapter 1–Week 16.ppt                 123
                              Think Big

                                 QuickTime™ an d a
                       TIFF (Uncompressed) decompressor
                          are need ed to see this picture .




 Our Milky Way and the Local Group is part of the Virgo Supercluster of
  galaxies, which is about 150 million light-years across. How much
  farther is a trip across the supercluster compared to a trip across the
  Milky Way?

 A.) 15 times    B.) 150 times         C.) 1,500 times

December, 2003          Universe Chapter 1–Week 16.ppt                 124
                                                                           Parallax

                                                                                       A shift in the position
                                                                                        of an object when it is
                                                                                        viewed from different
                                                                                        angles
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                                                                                       Can cause error in
                                                                                        measurement
                                                                                       Can also be used to
                                                                                        measure distances

December, 2003                                              Universe Chapter 1–Week 16.ppt                    125
December, 2003   Universe Chapter 1–Week 16.ppt   126
                 In the Beginning
                 15 Billion Years Ago

 The origin of the
  Universe is unknown–
  it is the ultimate
  mystery.                                    QuickTime™ and a
                                    TIFF (Uncompressed) decompressor
                                       are neede d to see this picture.




December, 2003    Universe Chapter 1–Week 16.ppt                      127
                  In the Beginning
                  15 Billion Years Ago
 The laws of physics which
  applied in the beginning
  are not clear, so it is hard
  to guess where it might
  have come from.                               QuickTime™ and a
 There are several theories          TIFF (Uncompressed) decompressor
                                         are neede d to see this picture.
  of how the Universe began.
  What follows the
  inflationary theory of
  creation, which seems the
  most plausible.

December, 2003      Universe Chapter 1–Week 16.ppt                      128
                 In the Beginning
                 15 Billion Years Ago

 We use the word
  Macrocosmos to mean
  "everything there is".
  We will see that the
                                              QuickTime™ and a
  Cosmos and the                    TIFF (Uncompressed) decompressor
                                       are neede d to see this picture.
  Universe are just small
  parts of the
  Macrocosmos. So how
  could it have begun?


December, 2003    Universe Chapter 1–Week 16.ppt                      129
                 In the Beginning
                 15 Billion Years Ago
 Perhaps it was created out
  of nothing. To us, used to
  the idea that energy cannot
  be created, this seems
  impossible, but even today                    QuickTime™ and a
  we find two kinds of matter         TIFF (Uncompressed) decompressor
                                         are neede d to see this picture.
  (matter and antimatter)
  being created together out
  of nothing in quantum
  fluctuations.



December, 2003      Universe Chapter 1–Week 16.ppt                      130
                 In the Beginning
                 15 Billion Years Ago
 What is more, gravitational
  energy is equal and
  opposite to the matter
  energy in a closed space.
  This means that starting                      QuickTime™ and a
  from nothing gravity and            TIFF (Uncompressed) decompressor
                                         are neede d to see this picture.
  matter might have
  separated to create the
  Macrocosmos.




December, 2003      Universe Chapter 1–Week 16.ppt                      131
                        In the Beginning
                        15 Billion Years Ago
                                              The macrocosmos was filled
                                               with high energy radiation.
                                              Radiation is a mixture of electric
                                               and magnetic fields which grow
                                               and die as they move along,
          QuickTime™ and a                     swapping energy between them,
TIFF (Uncompressed) decompressor               somewhat like the two wings of
   are needed to see this picture.
                                               a strange bird which flaps first
                                               one wing and then the other,
                                               something like the picture we
                                               print here.
                                              Some radiation has more energy
                                               than others. In the young
                                               Universe the radiation mostly
                                               had very high energy.
December, 2003             Universe Chapter 1–Week 16.ppt                     132
                        In the Beginning
                        15 Billion Years Ago

                                              Some radiation has
                                               more energy than
                                               others. In the young
          QuickTime™ and a                     Universe the
TIFF (Uncompressed) decompressor
   are needed to see this picture.             radiation mostly had
                                               very high energy.



December, 2003             Universe Chapter 1–Week 16.ppt        133
                        In the Beginning
                        15 Billion Years Ago
                                                  In radiation with high energy,
                                                    the fields swap energy faster
                                                    than in low energy radiation.
                                                  Highest Energy
                                                  Gamma Rays
           QuickTime™ and a                       X Rays
TIFF (Uncompressed) decompressor
   are needed to see this picture.                Ultra Violet
                                                  Violet Light
                                                  Blue Light
                                                  Green Light
                                                  Yellow Light
                                                  Orange Light
                                                  Red Light
December, 2003                                    Infra
                              Universe Chapter 1–Week 16.pptRed                     134
                        In the Beginning
                        15 Billion Years Ago

                                               The Universe is what
                                                we can see from Earth
                                                (sometimes called the
         QuickTime™ an d a                      observable Universe).
TIFF (Uncompressed) decompressor
   are need ed to see this p icture .           The Universe is just a
                                                tiny part of the
                                                Cosmos.



December, 2003              Universe Chapter 1–Week 16.ppt           135
                         In the Beginning
                         15 Billion Years Ago
                                                  The Universe grew bigger and
                                                    cooler still. The atoms moved
                                                    slower and began to feel a weak
                                                    force called gravity pulling them
                                                    towards each other. Gravity is a
           QuickTime™ an d a
                                                    weak force of attraction between
TIFF (Uncompressed) decompressor                    every particle of matter in the
   are need ed to see this p icture .               Universe and every other
                                                    particle. It is the force which
                                                    holds us on to the Earth. Without
                                                    it none of this story would have
                                                    been possible.
                                                  The particles thought to carry the
                                                    gravitational field and give rise
                                                    to the force of gravity are called
December, 2003
                                                    gravitons. They have never been
                              Universe Chapter 1–Week 16.ppt                         136
                             In the Beginning
                             13 Billion Years Ago
                                                    Any tiny variations in the
                                                     density of energy in the
                                                     Macrocosmos was blown
                                                     up, by the process of
                                                     inflation , into large scale
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        are neede d to se e this picture.
                                                     variations in density in the
                                                     Universe . As a result, the
                                                     gas of hydrogen and
                                                     helium atoms in the young
                                                     Universe was more dense
                                                     in some places than others.


December, 2003                   Universe Chapter 1–Week 16.ppt                137
                             In the Beginning
                             13 Billion Years Ago
                                                    About 2 billion years after the
                                                     big bang the force of gravity
                                                     made the gas break up into
                                                     streams and webs of clouds,
                                                     billions of them. Each cloud of
                                                     gas shrank under gravity and
               QuickTime™ and a
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        are neede d to se e this picture.
                                                     between them. These clouds
                                                     have become clusters of galaxies
                                                     today. They measure tens of
                                                     millions of light years across.




December, 2003                   Universe Chapter 1–Week 16.ppt                    138
                             In the Beginning
                             13 Billion Years Ago
                                                    Clusters are sometimes grouped
                                                     together into superclusters. They
                                                     measure hundreds of millions of
                                                     light years across. Between the
                                                     superclusters is almost empty
                                                     space. The galaxies are arranged
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                                                     Universe. Each cluster probably
                                                     arose from a dense cloud of gas
                                                     in the big bang .




December, 2003                   Universe Chapter 1–Week 16.ppt                     139
                             In the Beginning
                             13 Billion Years Ago

                                                    Galaxies formed within
                                                     the clusters.

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                                                    The nearest galaxy
        are neede d to se e this picture.
                                                     cluster to the Milky
                                                     Way lies in the
                                                     constellation Virgo.


December, 2003                   Universe Chapter 1–Week 16.ppt             140
                              In the Beginning
                              13 Billion Years Ago
                                                      A galaxy is an island of billions
                                                       of stars, separated from other
                                                       galaxies by a vast ocean of
                                                       almost empty space. In this story
                                                       we look at one particular galaxy
                                                       (the Milky Way), since that is
               QuickTime™ and a
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                                                       where we live. But we should
                                                       not forget that, scattered far and
                                                       wide across the Universe , there
                                                       are billions of other galaxies,
                                                       probably very similar to ours.



December, 2003                     Universe Chapter 1–Week 16.ppt                     141
                              In the Beginning
                              13 Billion Years Ago
                                                      Galaxies are either spiral (about
                                                       70% of galaxies - similar to the
                                                       Milky Way ) or elliptical (about
                                                       30%). A few are other shapes. It
                                                       is not clear how the different
                                                       shapes arose. Spirals are
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                                                       ellipticals, since stars are formed
                                                       continuously in them. It is
                                                       probably this which has allowed
                                                       life to form in the spiral galaxy
                                                       where we live.



December, 2003                     Universe Chapter 1–Week 16.ppt                      142
                                 In the Beginning
                                 13 Billion Years Ago
                                                         Let's watch one young galaxy as
                                                          it shrank under the force of
                                                          gravity . The gas broke up into
                                                          hundreds of smaller clouds.
                                                          Gravity made each of these little
                                                          clouds shrink even more. Stars
                  QuickTime™ a nd a
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           are need ed to see this picture.
                                                          cloud formed millions of stars.
                                                         With a good telescope we can
                                                          still see these large ancient star
                                                          clusters today, dotted around the
                                                          outside of the Galaxy where we
                                                          live. We call them Globular Star
                                                          Clusters .

December, 2003                        Universe Chapter 1–Week 16.ppt                      143
                               In the Beginning
                               13 Billion Years Ago
                                                          In young spiral galaxies like the
                                                          Milky Way , not all the gas was
                                                          pulled into globular star clusters
                                                          . Some of it was left behind, and
                                                          gravity pulled this in a different
                                                          direction. It fell down towards
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         are need ed to see this p icture .
                                                          galaxy was slowly spinning
                                                          round, and this spin threw the
                                                          gas out into the shape of a flat
                                                          disc with a bulging center. We
                                                          do not know when the disc
                                                          formed. We guess it was around
                                                          12 billion years ago.

December, 2003                      Universe Chapter 1–Week 16.ppt                        144
                              In the Beginning
                              12 Billion Years Ago
                                                                  Looking from above the disc of
                                                                    a spiral galaxy like the Milky
                                                                    Way a new picture appears. We
                                                                    can see dense spiral arms in the
                                                                    disc of the Galaxy. We think it is
                                                                    gravity which created the spiral
                    QuickTime™ an d a
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             are need ed to see this p icture .
                                                                    not clear. The spiral arms are
                                                                    places where the gas of the disc
                                                                    is squashed together.
                                                                  Note that we have never actually
                                                                    seen our own Galaxy from the
                                                                    outside. The picture shown here
                                                                    is of another spiral galaxy, but
                                                                    we think ours is similar!
December, 2003                                                    New
                                              Universe Chapter 1–Week 16.pptand important stars form 145
                          In the Beginning
                          12 Billion Years Ago
                                                 The squashing of the gas and
                                                  dust as it enters a spiral arm of
                                                  the Galaxy makes new stars
                                                  form all the time. The gas
                                                  collects in cold dark clouds like
                                                  the one shown here, and stars
              QuickTime™ and a
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                                                  several tens of stars. It is
                                                  unfortunate that star birth
                                                  happens in these cloudy
                                                  cocoons, because they make it
                                                  difficult for us to watch what is
                                                  happening. In particular we
                                                  cannot tell how easy it is for
                                                  planets to form around new
                                                  stars.
December, 2003                Universe Chapter 1–Week 16.ppt                      146
                           In the Beginning
                           12 Billion Years Ago
                                                           Stars form in groups called open
                                                           star clusters . These are strung
                                                           out along the spiral arms like
                                                           beads in a necklace. Open
                                                           clusters are much smaller than
                                                           globular star clusters , containing
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                                                           stars.
                                                         Open star clusters are important
                                                           because planets probably form at
                                                           the same time around some of
                                                           these stars. Unfortunately it is
                                                           hard to watch open star clusters
                                                           form because spiral arms are
                                                           surrounded by clouds of gas and
December, 2003
                                                           dust.
                                     Universe Chapter 1–Week 16.ppt                         147
                             In the Beginning
                             12 Billion Years Ago
                                                               The galaxy in which we live is
                                                                 probably a typical spiral galaxy,
                                                                 although recent research shows
                                                                 it has a small bar across the
                                                                 center, making it a barred spiral.
                                                                 It is an island of tens of billions
                   QuickTime™ and a
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             are neede d to see this picture.
                                                                 dust .
                                                               It is roughly the shape of a
                                                                 "flying saucer", with a bulge in
                                                                 the middle of a flat disc. Stars
                                                                 and dust are arranged into spirals
                                                                 within the disc, which measures
                                                                 about 100,000 light years across.
                                                                 Ancient globular star clusters
December, 2003
                                                                 form a halo around the Galaxy.148
                                           Universe Chapter 1–Week 16.ppt
                              In the Beginning
                              12 Billion Years Ago
                                                     The Milky Way Galaxy can
                                                      cause some problems for the
                                                      Earth . It takes about 250 million
                                                      (a quarter of a billion ) years for
                                                      the Sun to go once round the
                                                      Galaxy. On its way it may pass
               QuickTime™ and a
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         are neede d to see this picture.
                                                      gas , dust and new stars . These
                                                      could cause problems, for
                                                      example by cutting down the
                                                      sunlight reaching the Earth. Ice
                                                      ages happen every 250 million
                                                      years or so. One theory links
                                                      them with the Sun's orbit round
                                                      the Galaxy, but this is not
                                                      generally accepted.
December, 2003                    Universe Chapter 1–Week 16.ppt                      149
                               In the Beginning
                               12 Billion Years Ago
                                                     After a while the stars formed in
                                                      an open star cluster drift apart,
                                                      probably pulled by the attraction
                                                      of passing stars. Let's focus
                                                      down on one star and see how it
                                                      works.
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          are need ed to see this picture.
                                                        A star (such as the Sun) is a ball
                                                          of gas which has, at its heart, a
                                                          nuclear fusion reactor. It is
                                                          important to know something
                                                          about how stars work, for
                                                          several reasons.
                                                        One star, the Sun , is the source
                                                          of almost all the energy used by
December, 2003                                            living
                                    Universe Chapter 1–Week 16.ppt things, including humans.150
                               In the Beginning
                               12 Billion Years Ago
                                                     More than half of all stars have
                                                      one or more close companion
                                                      stars, to which it is tied by
                                                      gravity . When there are only
                                                      two stars in orbit around each
                                                      other they are called a binary
                QuickTime™ and a
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          are need ed to see this picture.
                                                      more they are called a multiple
                                                      star.

                                                        The closer the stars are together
                                                          the faster they move. The time it
                                                          takes for them to go round each
                                                          other varies from days to years.
                                                          Some binaries are so close that
December, 2003                                            gravity
                                    Universe Chapter 1–Week 16.ppt pulls gas from one to the
                                                                                           151
                                        In the Beginning
                                       12 Billion Years Ago
                                                                  A star shines by nuclear fusion
                                                                    between particles at the center of
                                                                    the star. It is the force of gravity
                                                                    which presses the particles so
                                                                    close that they can fuse. During
                                                                    this process two positrons are
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               are neede d to see this picture.
                                                                    generated.
                                                                  The positrons travel out from the
                                                                    center of the star and soon meet
                                                                    two electrons. These are
                                                                    identical in size but opposite in
                                                                    charge. Positrons are antimatter
                                                                    electrons. When matter meets
                                                                    antimatter they annihilate each
                                                                    other, converting their mass
December, 2003
                                                                    energy into radiation.
                                              Universe Chapter 1–Week 16.ppt                           152
                             In the Beginning
                             11 Billion Years Ago
                                                                After a few billion years the
                                                                  center of a star runs out of
                                                                  protons (nuclei of hydrogen
                                                                  atoms ). What is left is a core or
                                                                  central region made of alphas
                                                                  (nuclei of helium atoms ). The
                    QuickTime™ and a
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             are neede d to see this picture.
                                                                  contain hydrogen, but they are
                                                                  not hot enough to fuse .
                                                                Because it has run out of fuel,
                                                                  the star begins to cool, and
                                                                  contract. The outer layers of the
                                                                  star fall inwards under gravity,
                                                                  and as they fall they heat up. A
                                                                  shell surrounding the central
December, 2003
                                                                  core becomes hot enough to fuse
                                            Universe Chapter 1–Week 16.ppt                         153
                                  In the Beginning
                                  11 Billion Years Ago
                                                         Some red giants die quietly. A
                                                          white dwarf is created when a
                                                          small red giant (with about as
                                                          much mass as the Sun ) runs out
                                                          of fuel, cools and begin to
                                                          contract under gravity . The
                   QuickTime™ and a
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                                                          the star releases heat which
                                                          causes the outer parts to expand
                                                          and gently get blown away. In
                                                          this way the gas of old stars is
                                                          released and can be formed into
                                                          new stars.

                                                            The inner part of the star
December, 2003                                                continues to contract until it
                                        Universe Chapter 1–Week 16.ppt                         154
                 In the Beginning
                 11 Billion Years Ago
                                     A nova is a new star which
                                      shines brightly and then fades
                                      over a period of months. What
                                      causes them?

                                     We have seen that most stars
                                      have a companion tied to it by
                                      gravity, forming a binary or
                                      multiple star. In most binaries
                                      one star is larger than the other.
                                      The large star evolves quicker
                                      than the small one, and becomes
                                      first a red giant and then a white
                                      dwarf .

December, 2003
                                      When
                  Universe Chapter 1–Week 16.ppt   the other star eventually 155
                                In the Beginning
                                11 Billion Years Ago
                                                      We have seen that a small red
                                                       giant , up to 1.5 times the size of
                                                       the Sun , turns into a white
                                                       dwarf when it dies. Larger red
                                                       giants, however, die in a more
                                                       spectacular way.
                  QuickTime™ and a
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                                                         Once the nuclear fuel is
                                                           exhausted in a red giant , the
                                                           core starts to cool and the
                                                           internal pressure falls, leading to
                                                           contraction. In large red giants
                                                           this is a sudden and catastrophic
                                                           event so that the star collapses.
                                                           As the outer layers of the star
December, 2003                                             fall they gain heat. This triggers
                                     Universe Chapter 1–Week 16.ppt                         156
                 In the Beginning
                 11 Billion Years Ago
                                  Asupernova with a mass
                                   between about 1.5 and 3 times
                                   the mass of the Sun collapses
                                   under gravity until it consists
                                   almost entirely of neutrons .
                                   Nuclear forces prevent these
                                   squashing any closer. Neutron
                                   stars are only about 10
                                   kilometers across and have a
                                   density of 1 hundred thousand
                                   billion (10 14 ) times as dense as
                                   water.

                                      Pulsars are rotating neutron
                                        stars. The rapid pulses of
December, 2003                          radiation they emit are generated
                  Universe Chapter 1–Week 16.ppt                       157
                    In the Beginning
                    11 Billion Years Ago
 A small region of space which contains so much matter and
  has such a strong gravitational field that nothing, not even
  light , can escape. The region therefore looks dark, hence the
  name. There are thought to be three kinds of black hole:

 Supermassive black holes
 These lie at the centre of quasars and certain active galactic
    nuclei that appear to be exploding. Millions or billions of
    stars together with gas ,dust and perhaps planets can fall into
    the black hole and give off enormous amounts of energy. In
    1994 the Hubble Space Telescope provided conclusive
    evidence for the existence of a supermassive black hole at
    the 2003
December, centre of the M87 galaxy. It has a mass equal to two to 158
                         Universe Chapter 1–Week 16.ppt
                         In the Beginning
                         11 Billion Years Ago
 We have seen that nova and
  supernova are major ways in
  which the new, heavy nuclei
  made in red giant stars are sent
  out into the galaxy , ready to be
  incorporated into new stars and                     Quic kTime™ and a
  planets . If this re-cycling did not      TIFF (Uncompress ed) decompres sor
  happen, planets and life could               are needed to see this picture.
  never have begun.

 As they are shot out of the star
    some atoms gain too many
    electrons (giving them a
    negative electric charge ) while
    others have too few (giving them
    a positive             Universe of
December, 2003 charge). This type Chapter 1–Week 16.ppt                    159
                      In the Beginning
                      11 Billion Years Ago
 Molecules are groups of atoms
    held together with covalent
    bonds. Molecules play a major
    part in this story.
 The first molecules were formed
    in space. Some atoms which                     QuickTime™ and a
    came out of a supernova were        TIFF (Uncompressed) decompressor
                                           are needed to see this picture.
    too light, and so moved too fast,
    to glue together with ionic bonds
    . They traveled out of the star
    until they were cool enough to
    attach to a dust grain . There
    these light atoms met and join
    together with a new type of bond
    called a covalent bond.
 Molecules are the building Chapter 1–Week 16.ppt
December, 2003              Universe                                         160
                             Stargazers
                 Famous and the Not-so-famous
                  Pioneers of the Final Frontier
 For thousands of years, people have gazed up
  at the night sky wondering about our place
  among the stars. Today, modern telescopes,
  satellites, and other powerful tools help
  answer some of these riddles, but many
  mysteries were solved by astronomers
  centuries ago.

December, 2003          Universe Chapter 1–Week 16.ppt   161
                                 Isaac Newton
                                        1642-1727

                                                    Legend has it that Isaac
                                                     Newton, an English
                                                     mathematician and
            Q uic kT ime ™ a n d a                   physicist, was led to
T IFF ( Un co m pr e ss e d) d ec o mp r es s or
    a re n ee d ed to s e e th is p ictu r e.        discover the law of
                                                     universal gravitation
                                                     when he saw an apple
                                                     fall from a tree.


December, 2003                   Universe Chapter 1–Week 16.ppt            162
                             Isaac Newton
                                      1642-1727

                                                He showed that the
                                                 same force of gravity
                                                 that pulls an apple to
                                                 the ground also holds
            QuickTime™ and a
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    are needed to see this picture.
                                                 other words, orbital
                                                 motion and falling are
                                                 exactly the same thing.



December, 2003               Universe Chapter 1–Week 16.ppt           163
                             Isaac Newton
                                      1642-1727

                                                Newton’s law of
                                                 gravitation describes a
                                                 force of attraction between
                                                 any two bodies in the
            QuickTime™ and a
                                                 universe. This force
 TIF F (U ncompressed) decompressor              increases in proportion to
    are needed to see this picture.
                                                 the mass of each body and
                                                 decreases in proportion to
                                                 the square of the distance
                                                 between them.



December, 2003               Universe Chapter 1–Week 16.ppt               164
                             Isaac Newton
                                      1642-1727

                                                That means, for example,
                                                 that if the distance between
                                                 two bodies increases by a
                                                 factor of two, the force of
            QuickTime™ and a
                                                 attraction between them
 TIF F (U ncompressed) decompressor              falls to one-quarter as
    are needed to see this picture.
                                                 much; at three times the
                                                 distance, the attraction is
                                                 one-ninth as much; at 10
                                                 times the distance, it’s only
                                                 one-hundredth as much,
                                                 etc.
December, 2003               Universe Chapter 1–Week 16.ppt                 165
                             Isaac Newton
                                      1642-1727

                                                Newton also discovered the
                                                 laws of motion. Any body
                                                 moves in a straight line at
                                                 constant speed unless an
            QuickTime™ and a
                                                 outside force acts on it.
 TIF F (U ncompressed) decompressor              Such a force produces a
    are needed to see this picture.
                                                 change in the speed or
                                                 direction, called an
                                                 acceleration.




December, 2003               Universe Chapter 1–Week 16.ppt               166
                             Isaac Newton
                                      1642-1727
                                                Newton was also a first-class
                                                 experimenter. He demonstrated,
                                                 for example, that white light is a
                                                 mixture of the entire rainbow
                                                 spectrum of colors. His study of
            QuickTime™ and a
                                                 light led him to invent the
 TIF F (U ncompressed) decompressor              reflecting telescope, which is
    are needed to see this picture.              still the basis for the design of
                                                 the large telescopes astronomers
                                                 use today.




December, 2003               Universe Chapter 1–Week 16.ppt                      167
                 Albert Einstein
                        1879-1955

 The German physicist
  Albert Einstein
  revolutionized our
  concepts of space and                       Q uic kT ime ™ a n d a
                                  T IFF ( Un co m pr e ss e d) d ec o mp r es s or
  time with his theories              a re n ee d ed to s e e th is p ictu r e.
  of relativity.




December, 2003   Universe Chapter 1–Week 16.ppt                               168
                       Albert Einstein
                               1879-1955
 In 1905 Einstein published his
  special theory of relativity. The
  foundation of the theory is the
  observation that light moves at a
  constant speed as measured by
  all observers, whatever their                         QuickTime™ and a
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  state of motion.                               are needed to see this picture.




December, 2003          Universe Chapter 1–Week 16.ppt                             169
                        Albert Einstein
                                1879-1955
 One consequence is that
  measurements of distance and
  time are not absolute quantities
  but vary relative to the motion of
  an observer. Another is that
  energy (E) can be converted into
                                                         QuickTime™ and a
  mass (m), and vice versa,                    TIFF (Uncompressed) decompressor
  according to the formula                        are needed to see this picture.

 E = mc2, where c is the speed of
  light.




December, 2003           Universe Chapter 1–Week 16.ppt                             170
                      Albert Einstein
                              1879-1955
 Ten years later, Einstein’s
  general theory of relativity
  extended this work to include
  acceleration and gravity—stating
  that the two are equivalent.
  Einstein showed that gravity is                      QuickTime™ and a
                                             TIFF (Uncompressed) decompressor
  actually the warping of space by              are needed to see this picture.
  matter.




December, 2003         Universe Chapter 1–Week 16.ppt                             171
                    Albert Einstein
                            1879-1955

 One consequence is that
  light will follow a curved
  path when it passes a
  massive body.
  Observations of a small
                                                     QuickTime™ and a
  apparent shift in the                    TIFF (Uncompressed) decompressor
                                              are needed to see this picture.
  positions of stars near the
  sun during a solar eclipse
  in 1919 showed that the
  theory was correct.



December, 2003       Universe Chapter 1–Week 16.ppt                             172
                 Albert Einstein
                         1879-1955

 General relativity was
  later used to interpret
  Hubble’s discovery of
  the expanding
                                                  QuickTime™ and a
  universe.                             TIFF (Uncompressed) decompressor
                                           are needed to see this picture.




December, 2003    Universe Chapter 1–Week 16.ppt                             173
                                Edwin Hubble
                                        1889-1953
                                                    One of the most important
                                                     figures in modern cosmology is
                                                     the American astronomer Edwin
                                                     Hubble.
                                                    He discovered a universe of
            Q uic kT ime ™ a n d a
T IFF ( Un co m pr e ss e d) d ec o mp r es s or     galaxies outside the Milky Way
    a re n ee d ed to s e e th is p ictu r e.        and showed that the entire
                                                     universe is expanding.




 December, 2003                  Universe Chapter 1–Week 16.ppt                  174
                                    Edwin Hubble
                                                 1889-1953
                                                        One of the most important
                                                         figures in modern cosmology is
                                                         the American astronomer Edwin
                                                         Hubble.
                                                        He discovered a universe of
                Qu i ckTi m e™ a nd a
    TIFF (Un co mp res se d) d ec om pres s or           galaxies outside the Milky Way
       a re ne ed ed to se e th is pi c tu re.
                                                         and showed that the entire
                                                         universe is expanding.




December, 2003                       Universe Chapter 1–Week 16.ppt                  175
                                    Edwin Hubble
                                                 1889-1953

                                                        In the early 20th century,
                                                         most astronomers believed
                                                         that the universe did not
                                                         extend beyond our Milky
                                                         Way galaxy. Then in the
                Qu i ckTi m e™ a nd a
    TIFF (Un co mp res se d) d ec om pres s or
       a re ne ed ed to se e th is pi c tu re.
                                                         early 1920s, Hubble
                                                         pointed the largest
                                                         telescope in the world (on
                                                         Mt. Wilson in California)
                                                         at the mysterious
                                                         Andromeda nebula.


December, 2003                       Universe Chapter 1–Week 16.ppt              176
                                    Edwin Hubble
                                                 1889-1953

                                                        He recognized individual
                                                         stars within the “nebula”
                                                         and concluded that it was
                                                         not a cloud of interstellar
                                                         gas within our Milky Way,
                Qu i ckTi m e™ a nd a
    TIFF (Un co mp res se d) d ec om pres s or
       a re ne ed ed to se e th is pi c tu re.
                                                         but an entire galaxy very
                                                         far away. Suddenly, the
                                                         universe was far larger
                                                         than most astronomers had
                                                         imagined.



December, 2003                       Universe Chapter 1–Week 16.ppt               177
                                    Edwin Hubble
                                                 1889-1953

                                                        Hubble continued to
                                                         find galaxies at greater
                                                         and greater distances
                                                         He developed the
                Qu i ckTi m e™ a nd a
    TIFF (Un co mp res se d) d ec om pres s or           system for classifying
       a re ne ed ed to se e th is pi c tu re.
                                                         galaxies by their
                                                         structure, which is still
                                                         used today.



December, 2003                       Universe Chapter 1–Week 16.ppt              178
                                    Edwin Hubble
                                                 1889-1953

                                                        Hubble also discovered
                                                         that the distant galaxies
                                                         are moving away from
                                                         each other and the
                Qu i ckTi m e™ a nd a
    TIFF (Un co mp res se d) d ec om pres s or           greater the distance
       a re ne ed ed to se e th is pi c tu re.
                                                         between two galaxies,
                                                         the faster they are
                                                         moving away.



December, 2003                       Universe Chapter 1–Week 16.ppt             179
                                    Edwin Hubble
                                                 1889-1953

                                                        This simple proportionality
                                                         between the distance and
                                                         the speed of galaxies
                                                         moving away from each
                                                         other, set forth in 1929, is
                Qu i ckTi m e™ a nd a
    TIFF (Un co mp res se d) d ec om pres s or
       a re ne ed ed to se e th is pi c tu re.
                                                         now known as Hubble’s
                                                         law. It shows that the
                                                         universe is expanding.




December, 2003                       Universe Chapter 1–Week 16.ppt                180
                 Georges Lemaître
                          1894-1966

 Georges Lemaître, a
  Belgian cosmologist
  and Catholic priest,
  was one of the first
                                                Q uic kT ime ™ a n d a
  scientists to use                 T IFF ( Un co m pr e ss e d) d ec o mp r es s or
  Einstein’s general                    a re n ee d ed to s e e th is p ictu r e.

  theory of relativity to
  describe the universe
  as a whole.


December, 2003     Universe Chapter 1–Week 16.ppt                               181
                 Georges Lemaître
                         1894-1966

 In 1927, he showed
  how the expansion of
  the universe, observed
  by Hubble, was a
                                            QuickTime™ and a
  natural consequence of           TIFF (Uncompressed) decompressor
                                      are need ed to see this picture.
  the equations of
  general relativity.




December, 2003    Universe Chapter 1–Week 16.ppt                   182
                 Georges Lemaître
                           1894-1966

 Lemaître also thought
  about the expansion of the
  universe in a radically new
  way. If we could imagine
  tracing the expansion                       QuickTime™ and a
  backward in time, we               TIFF (Uncompressed) decompressor
                                        are need ed to see this picture.
  would see it getting smaller
  and smaller. Wouldn’t
  there be a limit to how
  small it could get?



December, 2003      Universe Chapter 1–Week 16.ppt                   183
                 Georges Lemaître
                           1894-1966

 In 1931, Lemaître
  proposed that at some point
  in the distant past, the
  universe was compressed
  into a tiny object which he                 QuickTime™ and a
  called the “cosmic egg.”           TIFF (Uncompressed) decompressor
                                        are need ed to see this picture.
  This cosmic egg would
  have exploded—launching
  the expansion of space
  itself that we still see
  today.


December, 2003      Universe Chapter 1–Week 16.ppt                   184
                 Georges Lemaître
                         1894-1966

 This theory later
  became known as the
  big bang and provided
  the first scientific
                                            QuickTime™ and a
  description of how the           TIFF (Uncompressed) decompressor
                                      are need ed to see this picture.
  universe began.




December, 2003    Universe Chapter 1–Week 16.ppt                   185
                    Arno Penzias (1933- )
                  and Robert Wilson (1936- )
                                                    In 1964, Arno Penzias
                                                     and Robert Wilson
                                                     decided to use an
            Q uic kT ime ™ a n d a                   ultrasensitive
T IFF ( Un co m pr e ss e d) d ec o mp r es s or
    a re n ee d ed to s e e th is p ictu r e.        microwave antenna to
                                                     study natural radio
                                                     emissions from the
                                                     Milky Way.


 December, 2003                  Universe Chapter 1–Week 16.ppt          186
                   Arno Penzias (1933- )
                 and Robert Wilson (1936- )
                                                  But what they found instead was
                                                   an annoying background static.
                                                   It was there all the time, no
                                                   matter where they pointed their
                                                   antenna. They assumed that the
                                                   problem was with their
             QuickTime™ and a
   TIFF (Un compressed) decompressor               equipment and spent months
      are neede d to se e this picture.            trying to eliminate all possible
                                                   sources of the static, including
                                                   pigeon droppings inside their
                                                   giant horn-shaped antenna.




December, 2003                 Universe Chapter 1–Week 16.ppt                    187
                   Arno Penzias (1933- )
                 and Robert Wilson (1936- )
                                                  Finally they realized that
                                                   the constant static really
                                                   must be coming from the
                                                   sky.
             QuickTime™ and a                     Penzias and Wilson then
   TIFF (Un compressed) decompressor
      are neede d to se e this picture.            learned from other
                                                   astronomers that the
                                                   microwave background
                                                   radiation was an expected
                                                   consequence of the big
                                                   bang theory.

December, 2003                 Universe Chapter 1–Week 16.ppt               188
                   Arno Penzias (1933- )
                 and Robert Wilson (1936- )
                                                  According to the theory, the
                                                   universe was born in a very hot
                                                   dense fireball. As it expanded,
                                                   the fireball cooled. Today, after
                                                   billions of years of expansion
                                                   and cooling, the energy of the
             QuickTime™ and a
   TIFF (Un compressed) decompressor               original fireball remains only as
      are neede d to se e this picture.            a very faint glow of microwave
                                                   radiation coming from all
                                                   directions in the sky.




December, 2003                 Universe Chapter 1–Week 16.ppt                     189
                   Arno Penzias (1933- )
                 and Robert Wilson (1936- )
                                                  The discovery of the
                                                   cosmic microwave
                                                   background radiation was
                                                   the first evidence to
             QuickTime™ and a
                                                   support the big bang
   TIFF (Un compressed) decompressor
      are neede d to se e this picture.
                                                   theory, and it convinced
                                                   most astronomers that the
                                                   theory was correct. In
                                                   1978, Penzias and Wilson
                                                   shared the Nobel prize in
                                                   physics for their discovery.


December, 2003                 Universe Chapter 1–Week 16.ppt                190
                 Exploring the Universe
                   Vocabulary–Chapter 1

 Binary Stars (Multiple-               Spectroscope
  star systems)                         Red Shift (Doppler
 Constellations                         Effect)
 Novas                                 Big-bang theory
 Star Clusters
                                        Open universe
 Nebulae
                                        Closed universe
 Galaxies
 The Milky Way                         Quasars


December, 2003       Universe Chapter 1–Week 16.ppt           191
                 Exploring the Universe
                   Vocabulary–Chapter 1

 Stars                                   Our Sun
        Size                                     Corona
        Composition                              Chromosphere
        Surface temperature                      Protosphere
        Brightness                               Core
 Hertzsprung-Russell                             Promineces
  Diagram                                         Solar Flares
 Parallax                                        Solar Wind
                                                  Sunspots
 Nuclear fusion

December, 2003         Universe Chapter 1–Week 16.ppt             192
                 Exploring the Universe
                   Vocabulary–Chapter 1

   Protostars
   Medium-sized Stars
   White Dwarf
   Massive Star
   Supernova
   Neutron Star
        Pulsar
 Black Hole

December, 2003       Universe Chapter 1–Week 16.ppt   193
                 Exploring the Universe
                      Vocabulary–Chapter 2

 Solar Systems                                Our Solar System
        Sun formation                                 Mercury
                                                       Venus
        Planet formation
                                                       Earth
 Planetary motion                                     Mars
 Orbits                                               Asteroid belt
        Elliptical                                    Jupiter
                                                        Saturn
 Inertia and Gravity                               

                                                       Uranus
 Period of revolution                                 Neptune
 Period of rotation                                   Pluto
                                                       Planet X



December, 2003              Universe Chapter 1–Week 16.ppt              194
                 Exploring the Universe
                   Vocabulary–Chapter 2

   Meteroroids
   Meteors
   Meteorites
   Rocketry
   Escape velocity
   Space probes




December, 2003        Universe Chapter 1–Week 16.ppt   195
                 Exploring the Universe
                     Vocabulary–Chapter 3

 Earth’s Day and Night                       The Moon
 Earth’s year                                Perigee
 Earth’s seasons                             Apogee
        Summer solstice                      Phases
        Winter solstice                      Eclipse
        Vernal (Spring) equinox
                                                    Solar
        Autumnal (Fall) equinox
                                                    Lunar
 Magnetosphere                             Tides
 Van Allen Belt                                    Neap



December, 2003           Universe Chapter 1–Week 16.ppt      196
                                                                           Parallax

                                                                                       A shift in the position
                                                                                        of an object when it is
                                                                                        viewed from different
                                                                                        angles
QuickTime™ and a TIFF (Uncompressed ) decompressor are needed to se e this picture.



                                                                                       Can cause error in
                                                                                        measurement
                                                                                       Can also be used to
                                                                                        measure distances

December, 2003                                              Universe Chapter 1–Week 16.ppt                    197
December, 2003   Universe Chapter 1–Week 16.ppt   198

				
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