Exit Check 8.7: The Big Bang

Front

What is the Cosmic Background Radiation?

Back

The Cosmic Background Radiation is the remaining energy from the Big Bang.

Front

What does it mean if a galaxy is redshifted?

Back

A redshifted galaxy is moving away from us.

Front

Which elements are most abundant in the visible universe?

Back

Hydrogen and Helium.

Front

What does the redshift of distant galaxies indicate about their movement?

Back

The further away galaxies are moving away faster, indicating that the universe is expanding.

Front

Why is the Cosmic Background Radiation referred to as the surface of last scattering?

Back

Photons in the early universe were scattered by electrons, making the universe opaque. When it cooled enough to form hydrogen, that last light traveled out as the CMB.

Front

What is the significance of the Cosmic Background Radiation in cosmology?

Back

It provides evidence for the Big Bang theory and the early state of the universe.

Front

How does redshift relate to the expansion of the universe?

Back

Redshift occurs because galaxies are moving away from us, which supports the theory that the universe is expanding.

Front

What is the relationship between distance and redshift in galaxies?

Back

More distant galaxies exhibit greater redshift, indicating they are moving away faster.

Front

What role do hydrogen and helium play in the universe?

Back

They are the most abundant elements, formed shortly after the Big Bang, and are essential for the formation of stars and galaxies.

Front

What does the term 'Big Bang' refer to?

Back

The Big Bang refers to the initial explosion that created the universe, leading to its expansion.