Question 1

Dark matter makes up _____________ of the universe.

Accepted Answer

Dark matter is estimated to constitute about 23% of the total mass-energy content of the universe, with dark energy and ordinary matter making up the rest.

Question 2

Heat death is

Accepted Answer

Heat death refers to a theoretical scenario in which the universe has reached a state of maximum entropy, where all energy is evenly distributed, and no thermodynamic free energy is available to do work, effectively leading to a state where no processes that increase entropy can occur.

Question 3

What is the difference between dark matter and dark energy?

Accepted Answer

Dark matter and dark energy are fundamentally different in their effects on the universe. Dark matter acts through gravity to pull matter together, thus slowing the expansion of the universe. On the other hand, dark energy is thought to be responsible for the accelerated expansion of the universe, working in a sense opposite to gravity.

Question 4

Based on supernova studies, it appears the universe is ____.

Accepted Answer

Studies of distant supernovae have shown that the expansion of the universe is accelerating, not slowing down. This discovery was unexpected and has led to the theory of dark energy as a driving force behind the acceleration.

Question 5

________________ is when there is no longer any source of power in the universe.

Accepted Answer

The answer of ________________ is when there is no longer...

Question 6

________________ supernovae are important standard candles in cosmology.

Accepted Answer

The answer of ________________ supernovae are important standard candles in...

Question 7

Dark energy is another name for a cosmological constant.

Accepted Answer

Dark energy and the cosmological constant (Λ) are often used interchangeably to describe the unknown force causing the accelerated expansion of the universe. The cosmological constant is a form of dark energy in the context of Einstein's theory of general relativity.

Question 8

As the expansion of the universe accelerates, parts of the universe that we cannot now see will become visible.

Accepted Answer

As the expansion of the universe accelerates, distant galaxies move away from us faster, eventually exceeding the speed of light relative to us. This means parts of the universe currently beyond our observable horizon will remain unseen, and more will become unobservable over time.

Quiz 84: Dark Energy and the Fate of the Universe