4.8.2 Red-shift

Question 1

If an object was moving towards us their line spectra would be

Answer 1

Blue shift

Question 2

If an object was moving away from us their line spectra would be

Answer 2

Red shift

Question 3

The larger the red/blue shift

Answer 3

The faster the object is travelling

Question 4

Stationary objects radiate light in….

Answer 4

All directions

Question 5

Explain red shift

Answer 5

the light waves are stretched out if the star or galaxy is moving away from us. We call it red shift because the spectrum is moved towards the red end of the spectrum.

Question 6

Red shift supports the Big Bang theory because….

Answer 6

It proves the universe is expanding

Question 7

Cosmic background radiation is….

Answer 7

Electromagnetic radiation which is equal at all points in the universe

Question 8

Cosmic background radiation supports the big band theory because….

Answer 8

It is the radiation left behind after the explosion

Question 9

what is the name of the galaxy we live in?

Answer 9

the Milky Way

Question 10

What type of galaxy is it?

Answer 10

spiral

Question 11

What is the Doppler Effect?

Answer 11

The change in observed wavelengths (and frequency) of waves due to the motion of the source towards or away from the observer.

Question 12

What does ‘receding’ mean?

Answer 12

It means moving away.

Question 13

If ALL galaxies appear to be moving away from us, what does this suggest?

Answer 13

The WHOLE universe is expanding.

Question 14

Galaxy X is 200 million light years away and galaxy Y is 4000 million light years away. Which galaxy has the bigger red shift?

Answer 14

Galaxy Y

Question 15

A blue shift in the light from a star would tell us it is ……………. .

Answer 15

approaching

Question 16

Put these in order of size
Andromeda Galaxy
Earth
Sun
Universe

Answer 16

Earth, Sun, Andromeda Galaxy, Universe

Question 17

What will happen to background microwave radiation as the Universe expands?

Answer 17

It will become more stretched and eventually become radio waves.

Question 18

Where did background microwave radiation come from?

Answer 18

It was created as high-energy gamma radiation just after the big bang. It has been travelling through space since then. As the universe expanded, it stretched out to be longer and longer wavelengths. Now it is microwaves.

Question 19

What does the future of the Universe depend on?

Answer 19

the density of the universe

Question 20

what does the big bang theory suggest?

Answer 20

suggests that the universe began from a very small region that was extremely hot and dense

Question 21

what is there about the universe that is not understood?

Answer 21

there is still much about the universe that is not understood, for example dark mass and dark energy.