4.8.2 Red-shift Flashcards
If an object was moving towards us their line spectra would be
Blue shift
If an object was moving away from us their line spectra would be
Red shift
The larger the red/blue shift
The faster the object is travelling
Stationary objects radiate light in….
All directions
Explain red shift
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.
Red shift supports the Big Bang theory because….
It proves the universe is expanding
Cosmic background radiation is….
Electromagnetic radiation which is equal at all points in the universe
Cosmic background radiation supports the big band theory because….
It is the radiation left behind after the explosion
what is the name of the galaxy we live in?
the Milky Way
What type of galaxy is it?
spiral
What is the Doppler Effect?
The change in observed wavelengths (and frequency) of waves due to the motion of the source towards or away from the observer.
What does ‘receding’ mean?
It means moving away.
If ALL galaxies appear to be moving away from us, what does this suggest?
The WHOLE universe is expanding.
Galaxy X is 200 million light years away and galaxy Y is 4000 million light years away. Which galaxy has the bigger red shift?
Galaxy Y
A blue shift in the light from a star would tell us it is ……………. .
approaching
Put these in order of size Andromeda Galaxy Earth Sun Universe
Earth, Sun, Andromeda Galaxy, Universe
What will happen to background microwave radiation as the Universe expands?
It will become more stretched and eventually become radio waves.
Where did background microwave radiation come from?
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.
What does the future of the Universe depend on?
the density of the universe
what does the big bang theory suggest?
suggests that the universe began from a very small region that was extremely hot and dense
what is there about the universe that is not understood?
there is still much about the universe that is not understood, for example dark mass and dark energy.
