P1.6.4 The Expanding Universe

HideShow resource information
  • Created by: Maddi
  • Created on: 03-05-14 10:27
What is the Doppler effect?
The change of wavelength (and frequency) of the waves from a moving source due to the motion of the source towards or away from the observer.
1 of 9
When the source moves towards the observer, what happens to the observed wavelength and frequency?
The observed wavelength decreases and the observed frequency increases.
2 of 9
When the source moves away from the observer, what happens to the observed wavelength and frequency?
The observed wavelength increases and the observed frequency decreases.
3 of 9
What do we mean by red-shift of a light source?
The red-shift of a distant galaxy is the shift to longer wavelengths of the light from it because the galaxy is moving away from us.
4 of 9
How do we know the distant galaxies are moving away from us?
All the distant galaxies show a red-shift. The further away a distant galaxy is from us, the greater its red-shift is
5 of 9
How does red-shift show that the universe is expanding?
The furthest galaxies are moving the fastest so everything is expanding outwards.
6 of 9
How does red shift depend on speed?
The faster a distant galaxy is moving away from us, the greater its red-shift is.
7 of 9
What did Hubble discover?
1. the light from distant galaxies was red-shifted. 2.the further a galaxy is from us, the bigger its red-shift is.
8 of 9
What did Hubble conclude?
The distant galaxies are moving away from us. The greater the distance a galaxy is from us, the greater the speed is at which it is moving away from us.
9 of 9

Other cards in this set

Card 2

Front

When the source moves towards the observer, what happens to the observed wavelength and frequency?

Back

The observed wavelength decreases and the observed frequency increases.

Card 3

Front

When the source moves away from the observer, what happens to the observed wavelength and frequency?

Back

Preview of the front of card 3

Card 4

Front

What do we mean by red-shift of a light source?

Back

Preview of the front of card 4

Card 5

Front

How do we know the distant galaxies are moving away from us?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Physics resources:

See all Physics resources »See all Electromagnetic waves resources »