The Universe

Document Sample
The Universe Powered By Docstoc
					The Universe
              Cosmology
• the branch of astronomy that deals with
  the origin, large-scale properties, and
  the evolution of the observable universe
                The Universe
• in astronomy, the sum total of all things which
  can be directly observed or whose physical
  effects on other things can be detected
                           Can all the matter in
• in simpler terms, space and you think of something and
  energy in it              the universe that cannot be
                           seen, but its effects on other
• major components:           things can be detected?

   – galaxies
   – solar systems
   – planets
           “Big Bang” Theory
• the primeval explosion of space, time, matter and
  energy that most astronomers think gave rise to the
  universe as we see it today.
• occurred about 13.7 billion years ago
• thought to have expanded within a second from
  something the size of a spec of dust to the size of
  our solar system

                     Misconception Alert:
                  Describing this theory as
                 the “Big Bang” is a misnomer
                 because there really was not
                an explosion, just a release of
                            energy
              Edwin Hubble
• determined that other
  galaxies exist, besides
  the Milky Way
• observed that galaxies
  were moving away from
  each other
  – Hubble Law – the farther
    away a galaxy is, the
    faster it is moving away
    from us; supports the Big
    Bang Theory                             Image taken from:
                                http://apod.nasa.gov/apod/ap960217.html
Arno Penzias & Robert Wilson
• accidentally detected faint radiation on
  a radio telescope in 1965
• determined that the radiation was
  leftover thermal energy from the “big
  bang”



                                         Image taken from:

           http://www.einstein-online.info/en/elementary/cosmology/early_universe/index.html
                               Galaxy
• a large assemblage of stars (and often gas and dust), typically
  containing millions to hundreds of billions of member stars
   – Star - a large hot ball of gas which generates energy in its core by nuclear
     reactions
• around 100 billion in the universe
• held together by the gravitational attraction of all its member
  stars on one another
• formed around 200 million years after the “Big Bang”
• most large ones seem to have super-massive black holes at their
  centers
• sometimes contain very bright centers called quasars
• 3 major types:
   – Spiral
   – Elliptical
   – Irregular                         What is the name
                                        of the galaxy
                                        we reside in?
                    3 Types of Galaxies



                                                  Elliptical
          Spiral                                 shaped like                                    Irregular
have arms of stars, gas ,                     spheres or eggs;                           faint galaxies without
and dust that curve away                       have almost no                               a definite shape;
 from the center of the                          dust or gas                             smaller than the other
galaxy in a spiral pattern                     between stars;                              types of galaxies;
    Ex. – Milky Way                           contain old stars                           contain fewer stars


       The process of galaxies colliding to create a larger galaxy is known
                           as “galactic cannibalism.”

           Images taken from: http://school.discoveryeducation.com/schooladventures/universe/galaxytour/toknow.html
                    Constellation
• a group of stars that form a pattern in the sky
• stars of a constellation are often far apart from each
  other, but they appear grouped together when viewed
  from Earth
• one of 88 sectors into which astronomers divide the
  sphere of the sky – named after a traditional constellation
  in that sector
• patterns of constellations are dynamic; therefore, the
  constellations of 100,000 years ago are quite different
  from today’s
• a part of a constellation that forms its own pattern in the
  sky is known as an asterism (ex. – The Big Dipper)



        Why is it not possible to see all constellations at once?
                Solar System
 • the sun and all things orbiting around it,
   including the eight major planets, their
   satellites, and all the smaller pieces such as
   asteroids and comets
 • formed around 4.6 billion years ago

   What is
  incorrect
or misleading
 about this
    visual?


                                         Image taken from:
                http://asm.arc.nasa.gov/Gallery/images/generic/LG_Capableofeverything.jpg
            Planet
• derived from a Greek word
  that means “wanderer”
• a major object which orbits
  around a star
• in our solar system, there are
  eight such objects which are
  traditionally called “planets”
                                             Asteroids
                                                                         • small, solid, rocky
                                                                           bodies that orbit close
                                                                           to the Sun
                                                                         • most found between
                                                                           the orbits of Mars and
                                                                           Jupiter in the
                                                                           “Asteroid Belt”
                                                                         • thought to be leftover
                                                                           material from the
                                                                           formation of the solar
                                                                           system
                                                                         • range in size from
                                                                           1000 km or 621 miles
                                                                           (Ceres) to the size of
                          Image taken from:
http://www.windows.ucar.edu/tour/link=/our_solar_system/asteroids.html
                                                                           pebbles
 Meteoroid, Meteor, Meteorite
                                                   Meteoroid (asteroid)
• Meteoroid – solid debris from space
  (asteroids) that are moving
  towards Earth                                Meteor
• Meteor                               Meteorite
   – a brief streak of light produced by
     a small particle entering Earth’s
     atmosphere at high speed
   – often referred to as “shooting
     stars” or “falling stars”
   – travel at speeds between 11-72
     kilometers per second (6.8 – 44.7
     miles per second)
• Meteorite – a small object from
  outer space that passes through                                       The Earth

  Earth’s atmosphere and reaches                                       animation is
                                                                       not rotating

  the surface                                                              in the
                                                                          correct
                                              What causes a meteor       direction;

• Freehold Meteorite - MSNBC                   shower to occur?
                                                                       it should be
                                                                          rotating

• Freehold Meteorite - USA-Today
                                                                      from west to
                                                                            east
                                                              Comet
                                                                          • a small body of ice and
                                                                            dust (“dirty snowball”)
                                                                            that orbits the Sun
                                                                          • contain a head (coma)
                                                                            followed by a tail(s) of
                                                                            gas and dust
                                                                          • the tail always points
                         Image taken from:
                                                                            away from the sun and
http://www.space.com/bestimg/index.php?guid=45b0fd31f065d&cat=bestcomet
                                                                            can be millions of
                                                                            kilometers long (but the
                                                                            amount of matter it
                                                                            contains can be very
                                                                            small)
               Satellite
• an object that orbits a more massive
  object (i.e. – moons)
• probes we launch into orbit around the
  Earth are called “artificial satellites”




                                               The Earth
                                              animation is
                                              not rotating
                                                  in the
                                                 correct
                                                direction;
                                              it should be
                                                 rotating
                                             from west to
                                                   east
                    Telescope
• a device that gathers electromagnetic radiation
• Types:
  – Visible, infrared, ultraviolet – pick up visible,
    infrared, and ultraviolet waves
     • Reflecting - use mirrors that reflect the image being
       viewed

     • Refracting – using lenses, gathers light and focuses it
       near the opposite end of the tube; works like a magnifying
       glass


  – Radio - pick up radio waves emitted from space;
    not effected by variables like weather or clouds
                       Internet Telescope
     Hubble Space Telescope
• a reflecting
  telescope that was
  placed into orbit in
  1990
• sends images and
  measurements back                    Image taken from:
                                 http://hubblesite.org/gallery/


  to Earth
                               What is one of the main
  electronically         benefits of having the Hubble Space
                          Telescope in orbit, as opposed to
                               it being here on Earth?
     Astronomical Unit (AU)
• unit of distance equal to the average spacing
  between the Earth and the Sun
• equal to about 150 million kilometers (93
  million miles)
• light takes about eight minutes to cover this
  distance



                                                The Earth
                                               animation is
                                               not rotating

                        150 million km             in the
                                                  correct

                        (93 million mi.)
                                                 direction;
                                               it should be
                                                  rotating
                                              from west to
                                                    east
                   Light Year
• the distance that light travels in one year in a
  vacuum, which is about 9.5 trillion kilometers
  (6 trillion miles)
  – The Milky Way Galaxy is about 100,000 light years
    in diameter
• the speed at which light travels this distance
  is about 300,000 km/sec (186,000 mi/sec)

            The second closest star to the Earth is a
            little over four light years away. How far
                     away (in miles) is the star?
                    Parsec
• unit of distance equal to about 3.26
  light years (or 206,265 AU)



          If one parsec equals 206, 265 AU, how
                 many miles is it equal to?
                         Parallax
• the apparent shift in position of an
  object when viewed from different
  locations
• used by astronomers to measure
  distance
        Put your pointer finger in front of your face and begin
     opening and closing your eyes in an alternating manner. What
            do you notice about the your finger’s position?


                            Parallax Simulation
                          Parallax Simulation – 1
                          Parallax Simulation - 2
                Find the Distance to HT Cas Using Parallax

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:13
posted:11/24/2011
language:English
pages:21