3.2 Describe and explain the evidence that supports the Big Bang Theory.

What is Cosmic Microwave Background Radiation (CMBR)?

Leftover heat from the Big Bang, detected as faint microwave radiation across the universe.

How does CMBR support the Big Bang Theory?

It shows that the universe was once hot and has been cooling as it expands.

What does the redshift of galaxies indicate?

Galaxies are moving away from us, with more distant galaxies receding faster.

How does Hubble’s Law support the Big Bang Theory?

It shows that the universe is expanding, meaning it must have started from a single point.

What are the most abundant elements in the universe?

Hydrogen (75%) and helium (25%).

How does the abundance of hydrogen and helium support the Big Bang Theory?

Their ratios match predictions from Big Bang Nucleosynthesis, suggesting they were formed early in a hot, dense state.