Docstoc

Light

Document Sample
Light Powered By Docstoc
					Speed of light
      A race to compare the speed of
      light to other things
         A quick comparison of how far things can
          go in 1 second.
             Start
Fastest Athletes         10 m
Cheetah                             25 m
Fastball                             45 m
Drag racer
Bullet
Supersonic Jet
Crack of thunder
Flash of lightning
   Most are still going
We will continue these throughout the presentation!
They are roughly to scale.
                  Drag Racer                          175 m

              Bullet (still going)


        Supersonic Jet (still going)

           Crack of thunder

          Flash of lightning
      Astronomical Distances
   Light takes 8 minutes to get from the Sun to the
    Earth.
   It takes 4 years to get here from the next nearest
    star aside from the sun, Proxima Centauri which
    is 4 light years away.
   Light year-The distance light travels in one year
   9.5 x1015 m (a really big distance)
Space travel problems

   Since we can’t even get close to the speed
    of light deep space travel would take
    extreme amounts of time.



     crack of thunder (340 m)
Looking into the past
   Every time you look at the stars you are
    looking at the distant past.
   If you see a star that was 100 light years
    away blow up (supernova) it actually blew
    up 100 years ago.
   It just took the light that long to get to you.
Speed of light in things other
than a vacuum
   Whenever light hits a medium it slows it
    down.
   The more dense the material the slower
    light can travel.
   Therefore light tends to travel faster in a
    gas, and slowest in a solid.
   It travels fastest in a vacuum (nothing)
Speed of light in different
substances
Vacuum    2.99792458 x 108 m/s
Air       2.9970 x 108 m/s
Water     2.26 x 108 m/s
Glass     1.97 x 108 m/s
Diamond   1.24 x 108 m/s

                                 Bullet (780 m)
It may slow down but…
   It is still unbelievably fast compared to
    everything else.
   You can not travel faster than the speed of
    light. Several interesting things happen
    when you get close.


                          Supersonic Jet (900 m)
  How far will that light go




If I had 15,000 more slides just like this one, I could cover the
distance light would travel (300,000,000 m)

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:6
posted:7/1/2012
language:
pages:10