P16.5 The beginning and the future of the Universe

Question 1

What is the Big Bang theory?

Answer 1

It says that the universe is expanding after exploding suddenly from a very small and extremely hot and dense region
Space time and matter were created in the Big Bang

Question 2

What is the Steady state theory?

Answer 2

Galaxies are being pushed apart - they thought that this is caused by matter entering the universe through white holes

Question 3

What evidence is needed for the big-bang theory?

Answer 3

High energy electromagnetic radiation should have been produced very soon after the universe began- This radiation would have stretched as the universe expanded and become lower-energy radiation.

Question 4

What can … be explained by The Big Bang Theory?

Answer 4

In 1965 scientists first detected microwaves coming from every direction in space
Cosmic microwave background radiation - the answer

Question 5

What is cosmic microwave background radiation?

Answer 5

It was created as high-energy gamma radiation just after the Big Bang
As the universe expanded - it has stretched out to longer and longer wavelengths and is now microwave radiation

It has been mapped out using microwave detectors on the Earth and on satellites

Question 6

What is dark matter?

Answer 6

Matter that cannot be seen and holds galaxies together

Question 7

Why can dark energy not be explained?

Answer 7

Because the only known force on the distant galaxies is gravity - it can’t be used to explain dark energy as it is an attractive force and so it acts the outward motion of the distant galaxies away from each other