Cosmology: Answers

 

What two pieces of evidence support the Big Bang theory of the formation of the Universe?

The two pieces of evidence which support the Big Band theory of the formation of the Universe are cosmic microwave background radiation (CMBR) and red-shift.

What is cosmic microwave background radiation?

Cosmic microwave background radiation is heat energy which is leftover from the big bang explosion. It has a low frequency and is emitted from all parts of the universe in all directions.

How does the frequency of emitted light change as stars move away from us?

As stars move away from us, the frequency of light that they emit decreases. The fact that light emitted from distant stars is decreasing in frequency provides evidence that the universe is expanded and provides evidence in support of the Big Bang theory.

Calculate the observed change in wavelength when light is emitted from a galaxy moving away from Earth at a speed of 5.50 x 108 m/s and a wavelength of 160 x 10-10 m. The speed of light is 3.00 x 108 m/s.

  • Change in wavelength / reference wavelength = velocity of a galaxy / speed of light
  • Rearrange to give: change in wavelength = (velocity of galaxy / speed of light) x reference wavelength
  • Change in wavelength = (5.50 x 108 / 3.00 x 108) x 160 x 10-10
  • Change in wavelength = 1.03 x 1025