Origin of the UNIVERSE

Question 1

The universe seems to be expanding.

Answer 1

All galaxies seem to be moving away from each other.

Question 2

Light from other galaxies is red-shifted.

Answer 2

Different chemical elements absorb different frequencies of light.
Each element produces specific pattern of dark lines at the frequencies that is absorbs in the visible spectrum.
We look at light from distant galaxies we see the same patterns but slighlt lower fe=requencies that they should be- shifted towards red end of the spectrum.
Called redshift.

Question 3

eg of doppler effect.

Answer 3

EG Car.

Engine sounds lower pitched when the car’s gone past you and is moving away from you.

Question 4

Describe the doppler effect.

Answer 4

Emits waves towards you or away from you, wavelengths and frequenices of the waves seem different.
frequency of a source moving towards you will seem higher and its wavelength will seem shorter.
Frequency of a source moving away from you will seem lower and wavelength longer.
Happens to both longitudinal and transverse waves.

Question 5

The futher away a galaxy is the greater its red shift.

Answer 5

Measurements of redshift suggest all galaxies are moving away from us quickly.
More distant galaxies = greater redshift than nearer ones.
More distant galaxies = moving away from us faster than nearer ones.
Provides evidence of the whole world expanding.