ch.29

At first, right after the Big Bang, the universe was too hot for nuclei and electrons to combine into the kinds of neutral atoms that are familiar to us today. How soon after the beginning did it become cool enough for neutral atoms to form?

a few hundred thousand years

Factoring in everything we currently know about the history of the universe, our best estimate for the age of the universe is

about 13.8 billion years

In the very distant future, given our best model of the accelerating universe, what will the universe look like?

all the stars will die and the galaxies will be dark

Which of the following statements about dark matter is FALSE:

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

Where in space did the expansion of the universe begin?

everywhere at once

Which of the following did NOT happen during the first few minutes after the Big Bang?

some very massive early stars formed

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

the 3-degree cosmic microwave background radiation

According to the most recent data from satellites making precise measurements of the properties of the cosmic background radiation (CBR),

the dark energy makes up just a little less than 70% of the density of the universe, making it the most significant constituent of the mass-energy

Astronomers have measured that there is more helium in the universe than can be explained by the fusion in stars over the last 13 billion years. How do they think the extra helium got into the universe?

the extra helium was made during the first few minutes of the Big Bang, when the entire universe was hot enough for fusion to occur briefly

Which of the following is the Earth not located in?

the globular cluster M-13