Question 1

Einstein's original theory of general relativity predicted this, but Einstein could not believe it was true, and added the cosmological constant to his theory to prevent this prediction.&#10;A) a static universe&#10;B) the existence of dark matter&#10;C) motion of the universe&#10;D) creation of helium

Accepted Answer

Einstein's original equations of general relativity predicted an expanding or contracting universe, which he found unsettling, as he believed in a static universe. To counteract this, he introduced the cosmological constant to allow for a static universe.

Question 2

The value of omega which gives you a recollapsing universe is ____.&#10;A) >1&#10;B) =1&#10;C) <1&#10;D) <0

Accepted Answer

The value of omega (Ω) greater than 1 indicates a universe with enough mass density to stop its expansion eventually, leading to a recollapse. This scenario corresponds to a closed universe.

Question 3

In which type of universe would the angles of a triangle add up to more than 180 degrees?&#10;A) Positive curvature and closed&#10;B) Positive curvature and open&#10;C) Negative curvature and closed&#10;D) Negative curvature and open

Accepted Answer

In a universe with positive curvature and a closed geometry, the angles of a triangle would add up to more than 180 degrees. This is characteristic of spherical geometry, where the surface's curvature causes the sum of the angles in a triangle to exceed the flat space sum of 180 degrees.

Question 4

The factor needed to find out if the universe expands forever or recollapses is the ____.&#10;A) critical density&#10;B) supernova 1a&#10;C) nuclear constant&#10;D) gravitational constant

Accepted Answer

The critical density of the universe determines whether it will expand forever or eventually recollapse. If the actual density is greater than the critical density, the gravitational attraction will eventually stop the expansion and cause the universe to recollapse. If the actual density is less than the critical density, the universe will expand forever.

Question 5

Omega is the ________.

Accepted Answer

The answer of Omega is the ________....

Question 6

A Big Crunch will occur if omega is _______________.

Accepted Answer

The answer of A Big Crunch will occur if omega...

Question 7

If omega is greater than 1, then the universe is open.

Accepted Answer

If omega is greater than 1, it means the density of the universe is greater than the critical density, leading to a closed universe, not an open one.

Question 8

If omega is 1, then the universe is at critical density.

Accepted Answer

When omega (Ω) is equal to 1, it means the density of the universe is exactly the critical density, which is the density required for the universe to be flat.

Deck 82: The Curvature and Expansion of Universes