Dark Matter and Modified Gravity Quiz

What are the two main possibilities discussed regarding the nature of dark matter?

• Dark matter is invisible and unexplained by modern physics or gravity is misunderstood.

• Dark matter is a known type of matter or a failure of gravitational theory.

• Dark matter is a form of energy or a new type of particle.

• Dark matter is a myth or a result of observational errors.

Who first noticed the effect of dark matter in the Coma Cluster?

• Vera Rubin

• Albert Einstein

• Fritz Zwicky

• Isaac Newton

What did Vera Rubin discover about spiral galaxies in the 1970s?

• They are composed entirely of dark matter.

• They have more stars than previously thought.

• Their rotation rates are too fast for their visible mass.

• They do not follow Newton's laws of motion.

What is the main idea behind modified Newtonian dynamics (MOND)?

• Gravity is weaker in the presence of dark matter.

• Dark matter is a form of energy.

• Gravity is stronger at larger distances.

• Newton's law of gravitation changes at different scales.

What evidence supports the existence of dark matter over modified gravity theories?

• The presence of black holes.

• Gravitational lensing and cosmic microwave background fluctuations.

• The discovery of new particles.

• The behavior of light in space.

What is significant about the Bullet Cluster in the context of dark matter?

• It contains no dark matter.

• It shows dark matter and baryons can be separated.

• It is the largest galaxy cluster known.

• It is the first cluster discovered.

What is unusual about the ultra diffuse galaxies (UDGs) discovered?

• They are smaller than typical galaxies.

• They have no stars.

• They are composed entirely of dark matter.

• They appear to lack dark matter.

How might the discovery of galaxies without dark matter impact our understanding of dark matter?

• It shows dark matter is only present in large galaxies.

• It indicates dark matter is a myth.

• It confirms dark matter is a form of energy.

• It suggests dark matter is not needed for galaxy formation.

What percentage of all matter in space-time is made up of dark matter?

• 50%

• 80%

• 60%

• 70%

What concept is briefly mentioned in the conclusion related to the universe?

• The multiverse theory

• The holographic universe

• The steady state theory

• The big bang theory