Guided Notes on The Universe and the Big

Guided Notes on The Universe and the Big Bang Theory Chapter 31, Section 3

1. The study of the universe, its current nature, and its origin and evolution is called cosmology.

2. In cosmology, objects that have a range of properties cannot be compared. Astronomers have only one universe to consider and nothing to compare it with.

3. The Big Bang Theory states that the universe began as a point and has been expanding ever since. It is an expansion of space with matter going along for the ride.

4. In 1965, scientists discovered a persistent background noise in their radio antenna. This noise was caused by cosmic background radiation that appeared to come from all directions in space.

5. The temperature of this radiation was 2. 735 K (-270˚C), which was very close to the temperature predicted by the Big Bang Theory.

6. There are 3 possible outcomes for the universe: (1) an open universe, in which expansion will never stop; (2) a closed universe, in which the expansion will stop and turn into contraction; and (3) a flat universe, in which the expansion will slow to a halt in an infinite amount of time.

7. When the rate of expansion of the universe is known, it is possible to calculate the time since the expansion started, or the age of the universe. This age is hypothesized to be 13. 5 billion years.