Question

1. the Hubble relation for galaxies is a relation between their

a) redshifts and distances

b) distances and colors

c) redshifts and colors

d) distances and types

e) colors and types

2. what happened to most of the primordial deuterium that the universe formed in the first few minutes after the big bang?

a) it is all still detectable today throughout the universe

b) it has slowly decayed into hydrogen

c) it was mostly converted into helium

d) it went into forming all the heavy elements (alongside helium)

3. what is the meaning of the assumption known as the cosmological principle

a) it states the universe must be locally flat, even if it is curved on large scales

b) it states the expansion of the universe would appear isotropic and identical for any two observers, even in two widely seperate galaxies.

c) it states that the universe must be expanding from a particular unique point, which was the location of the original big bang.

d) it relates the amount of material in a given region to the curvature of space measured within that region.

e)it states that theories of the universe must uniquely explain the presence of life on earth.

Answer 1

1. A. Redshifts and distance

Hubble investigated the relation between distance to galaxies and their velocity toward or away from us

2. It was mostly converted in helium

When the universe was a few minutes old (at a temperature of about one billion degrees), the protons and neutrons cooled down enough to stick together into nuclei. Each neutron found a proton partner, creating a pair called a deuteron, and almost all the deuterons in turn stuck together into helium nuclei,

3.

d) it relates the amount of material in a given region to the curvature of space measured within that region.