Understanding Dark Energy and the Universe's Expansion

What was the problem with the universe being both infinitely expanding and geometrically flat?

• It required the introduction of a new type of energy.

• It implied the universe was static.

• It contradicted the laws of thermodynamics.

• It suggested the universe was shrinking.

How can the past expansion history of the universe be determined?

• By counting the number of galaxies.

• By measuring the redshift-distance relationship.

• By calculating the universe's temperature.

• By observing the color of stars.

Why is it challenging to measure distances in astronomy?

• Because the universe is too small.

• Because the universe has expanded significantly over time.

• Because light travels too fast.

• Because stars are too dim.

What is a 'standard candle' in astronomy?

• A type of star that never changes brightness.

• A celestial object with a known intrinsic brightness.

• A planet that reflects light consistently.

• A black hole with a constant mass.

What did the discovery of the universe's accelerating expansion lead to?

• The idea that the universe is static.

• The conclusion that the universe is shrinking.

• The discovery of dark energy.

• The rejection of the Big Bang theory.

What does the cosmological constant represent?

• A constant speed of light.

• A measure of the universe's temperature.

• A property of space itself.

• A type of dark matter.

What is the significance of the Hubble Parameter?

• It measures the density of dark matter.

• It shows the speed of light.

• It indicates the rate at which the universe doubles in size.

• It measures the universe's temperature.

What does a positive cosmological constant imply for the universe's future?

• The universe will continue to expand exponentially.

• The universe will eventually stop expanding.

• The universe will become static.

• The universe will collapse into a singularity.

Why is the universe's flatness difficult to confirm?

• Because the universe is too dark.

• Because the universe is too bright.

• Because the universe is constantly changing shape.

• Because we can only observe a small part of it.

How do galaxy surveys help in understanding the universe's density?

• By observing the color of galaxies.

• By counting the number of black holes.

• By sampling a large enough fraction of the universe.

• By measuring the temperature of stars.