HW 17 -- Ch 29

According to our studies of the ages of the oldest stars and the CMB, the age of the universe must be:

13.8 billion years

Which of the following statements about dark matter is FALSE?

Astronomers have a pretty good idea what the dark matter is made of

Which of the following statements about the early universe (standard model of cosmology) is FALSE?

At the very beginning, the energies were so great that the universe was actually contracting for a while

Today, we believe that only a small number of elements were actually formed during the Big Bang. Which of the following was NOT one of these

Carbon

Recent observations indicate that the universe is expanding faster today than it was a few billion years ago (that the universe is accelerating). What kind of observations have led astronomers to this surprising conclusion?

Measurements of galaxy distances using Type Ia supernovae

The two scientists/engineers who first discovered the CMB (Cosmic Microwave Background) were:

Penzias and Wilson

The satellite that has given us the most recent and precise measurements of the characteristics of the CMB is?

Planck

Which of the following is pretty good evidence that the universe begin with a Big Bang?

The Cosmic Microwave Background (CMB)

The expansion of the universe, according to astronomers, is:

a piece of established observational evidence which any theory of cosmology must include

The reciprocal of the Hubble constant (1/H0), also known as the Hubble Time (T0) is

a rough estimate of the age of the universe

According to our studies of the ages of the oldest stars we know, the age of the universe must be

about 13 - l4 billion years

According to our models of the universe, why do galaxies move apart (why do we have Hubble's Law)?

as a result of the Big Bang, space itself is stretching, and this stretching carries the galaxies away from each other

In the "closed" universe model, the universe will end by

coming together in a big crunch

Where in space did the expansion of the universe begin?

everywhere at once

In the "open" universe model, the universe will

expand forever

At about l second after the beginning of the universe, one type of particle was able to start traveling freely through the universe. These particles are still with us, but they are extremely hard to detect. They are called:

neutrinos

If we add up all the luminous matter in the universe and calculate the density of such matter, we find that it is significantly less than the critical density. Nevertheless, cosmologists who (for a variety of reasons) prefer models where the universe has the critical density have not given up in despair and gotten other jobs. Which of the following observations have given them a cause for being optimistic that we have not yet accounted for all the matter and energy in the universe?

that evidence for dark matter has been found in our galaxy, in other galaxies, and in galaxy clusters

In which model (theory) of the universe will all the galaxies eventually show a blue shift in their spectrum instead of a redshift?

the closed universe

The model of the universe that involves an enormous increase of scale during a very short time in the early universe is called:

the inflationary universe model

What causes the expanding universe to decelerate in many of our cosmological models?

the mutual gravity of the galaxies pulls them together