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33 Cards in this Set

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What is the Big Bang Theory?
a theory that all the matter and energy in the universe must have been compressed into a very small space , then exploded from a singularity point and started expanding
How old is the universe and how do we know?
around 14 billion years old, we use the current rate of expansion to estimate this.
What is the 'Steady State' theory?
a theory that the universe has always existed as it is now
What is the Steady State theory based on?
The idea that that the universe appears pretty much the same everywhere
What does the Steady State theory explain?

the apparent expansion by suggesting that matter is being created in the spaces as the universe expands.


There are big problems with this theory.

What evidence is there to support the Big Bang theory?
Cosmic Microwave Background Radiation (CMBR) which was produced just after the Big Bang and continues to expand with the universe
What is Cosmic Microwave Background Radiation (CMBR)?
A low frequency electromagnetic radiation coming from all parts of the universe, coming from the microwave part of the EM spectrum
Where did Cosmic Microwave Background Radiation (CMBR) come from?

Just after the Big Bang, while the universe was still extremely hot, everything inside it emitted very high frequency radiation.



What happened to the Cosmic Microwave Background Radiation (CMBR) as the universe expanded?
the universe cooled and the radiation dropped in frequency - it is now known as Microwave radiation.
What is a limitation from the Big Bang theory's predictions?
it predicts that the universe's expansion should be slowing down but as far as we can tell it's speeding up.
What is a good and two bad factors of the Big Bang?

-Explanation for the universe's expansion


-Explanation for what actually caused the explosion


-what the conditions were like before the explosion, if there was abefore

What do different chemical elements do?
absorb different frequencies, each producing a specific pattern of dark lines at the frequencies it absorbs in the visible spectrum
How do we know the universe is still expanding?
through Red Shift
how is redshift shown in the light from distant galaxies?
the same patterns are shown but from slightly lower frequencies so are shifted to the red end of the visible spectrum are absorbed
what is the Doppler effect?
the change in frequency of sound, light or other waves as the source and observer move towards or away from each other


How do the sound waves change when a car moves away from the observer
the frequency will seem lower and its wavelength will seem longer