Chapter 2. A View of the Origin of the Universe
1. How did Slipher and later Hubble determine that many galaxies were moving away from us?
How did they estimate the speeds of the receding galaxies?
Slipper and Hubble used telescopes to look at galaxies within their range and made
measurements and calculations showing that many galaxies were moving away from us. Hubble
used a 100-inch telescope to measure the speeds of many other spiral galaxies and confirmed
Slipher’s discovery.
2. How did Hubble estimate the distances to distant galaxies?
He first used the method of the Standard Candle, judging the distance to other galaxies by the
brightness of the stars they contained. He also used the Cepheis variable stars as comparisons.
3. What is the Hubble Law?
The farther away a galaxy is, the faster it moves
4. What is the primordial cosmic fireball radiation? What part of the electromagnetic spectrum is
the fireball radiation in now?
The primordial cosmic fireball radiation is a remnant of the original radiation from the first
moments after the big bang. It is not in the microwave region of the electromagnetic spectrum.
5. What is meant by the statement, "When you look out into space you are looking back in time?
Because of the time it takes for light in space to move, when we look at things in space we are
not seeing them as they are now.
6. What are "Dark Matter" and "Dark Energy?
Dark matter makes up most of the mass of galaxies and clusters while dark energy is the name
given to whatever influences the expansion of the universe.
7. List the three major pieces of evidence for the Hot Big Bang
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The measured abundance of elements
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Observed expansion of space
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Discovery of the cosmic microwave background
8. According to the latest information what will be the
ultimate fate of the Universe?
The ‘big freeze’ will come after the expansion of the universe continuing forever, causing the
cosmos to have a slow death drawn out for a long time.
