red shift & big bang

• what do chemicals from the sun absorb?

  different variations of light
• what happens when the light from the sun reaches earth?

  certain wavelengths are missing and the absorption spectrum ends up with dark lines
• what is light from distant galaxies shifted towards of the absorption spectrum?

  the red end. this is red shift.
• why do we get red shift?

  because light waves get stretched as they make their way towards the earth. in simpler terms, the light from distant galaxies are moving away from us so the light waves get stretched.
• how are the galaxies moving away?

  the space in between us and the galaxies is expanding
• how can you explain red shift with a balloon and markers?

  1. balloon represents universe and makers represent the galaxies
  2. as we blow up the balloon (representing the universe expanding) the galaxies all get further apart.
  3. this happens because the space between them gets stretched (the markers aren't moving away the space is just getting bigger)
• the further away from us a galaxy is, the more ______ it appears to be moving away


  quickly
• what is the Big Bang theory?

  1. the theory that initially all the matter in the universe occupied a really tiny space (unimaginably dense and hot)
  2. all of a sudden it exploded
  3. space itself started to expand which is still continuing to this day