SCI - big bang + CMB + redshift

What does the Big Bang theory explain?

13.8 billion years ago, all matter, time, space, and energy were compacted together in a hot, dense state and have been expanding ever since.

What is redshift?

The stretching of wavelengths from light from galaxies that appear redder as the galaxy moves away.

What is blueshift?

The compression of wavelengths from light from galaxies that appear bluer as the galaxy comes closer.

What does redshift tell about distant galaxies?

Galaxies that display redshift signal they are moving further away from Earth in all directions, showing the universe is expanding.

What does blueshift tell about distant galaxies?

Galaxies that display blueshift mean they are moving towards the Earth from all directions.

How does redshift support the Big Bang theory?

As redshift displays galaxies are moving further away suggests the universe was once smaller, hotter, and denser.

What is the cosmic microwave background (CMB)?

The leftover light from the initial expansion of the universe from the Big Bang has cooled over time to faint microwave radiation.

Why is CMB found in the microwave part of the electromagnetic spectrum?

As the universe expanded, the initial high-energy light stretched into microwaves, lowering its energy.

How does CMB support the Big Bang theory?

CMB shows the universe started as a hot and dense state and has expanded and cooled, leaving behind microwave radiation.

What are the two main pieces of evidence for the Big Bang Theory?

Redshift from distant galaxies and Cosmic Microwave Background (CMB), both supporting the universe expanded from a hot, dense state.