The video discusses the Big Bang theory, focusing on the cosmic Microwave Background (CMB) radiation as key evidence. It explains how the universe was once smaller and denser, and how CMB photons traveled through an expanding universe. Two challenge questions are presented: one conceptual and one mathematical, with instructions for submission. An announcement is made about a seminar on gravitational waves at Lehman College.

What is the most significant evidence supporting the Big Bang theory?

• The existence of black holes

• The cosmic Microwave Background radiation

• The expansion of the universe

• The presence of dark matter

How old was the universe when the CMB photons were released?

• 10 billion years

• 13.7 billion years

• 380,000 years

• 1 million years

What was the initial distance between the blobs of plasma and the future Milky Way?

• 43 million light years

• 93 billion light years

• 1100 light years

• 380,000 light years

By what factor has the universe expanded since the CMB light was emitted?

• 2000 times

• 100 times

• 500 times

• 1100 times

What was the universe primarily composed of just before the CMB was created?

• Dark matter and dark energy

• Protons, electrons, and helium nuclei

• Neutrons and neutrinos

• Stars and galaxies

What event allowed the universe to become transparent to photons?

• The Big Bang

• Recombination

• The cooling of the universe

• The formation of black holes

What is the subject line required for submitting answers to the quiz?

• Gravitational Waves Seminar

• CMB Quiz

• CMB challenge

• Space-time Challenge