P16.5 The beginning and the future of the Universe Flashcards
What is the Big Bang theory?
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
What is the Steady state theory?
Galaxies are being pushed apart - they thought that this is caused by matter entering the universe through white holes
What evidence is needed for the big-bang theory?
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.
What can … be explained by The Big Bang Theory?
In 1965 scientists first detected microwaves coming from every direction in space
Cosmic microwave background radiation - the answer
What is cosmic microwave background radiation?
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
What is dark matter?
Matter that cannot be seen and holds galaxies together
Why can dark energy not be explained?
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
