Chapter 7 Short Answers

What is Olbers paradox? How is it resolved?

"Why is it dark at night?" Resolved because all four assumptions on which it is based are wrong. The universe is not infinite, eternal, static, uniformly filled with stars.

Give three reasons why travel to the stars will be extremely difficult.

-Distance: 500,000 as far as mars -Speed: Can't travel faster than light -Fuel: 400x us around energy to go to nearest star.

Fermi's paradox says if aliens exist, they should be here now. Give three reasons why this need not be so.

-Maybe space travel is too difficult -Maybe they haven't found us yet -Maybe they have a prime directive -Maybe they aren't interested in us -Maybe they are here

State and briefly discuss the main idea behind Darwin's theory of evolution.

A beneficial trait will be inherited by the offspring of an organism and eventually becomes the norm. This is called natural selection.

What is meant by the term "irreducible complexity"? Give an example of an irreducible complex system.

All parts must be present and working for the object to function, as in a mousetrap or a bacterial flagellum.

State two types of evidence that support the theory of evolution.

DNA, fossil record, artificial selection, current examples such as AIDS, unifying theory of biology.

If they early universe was very hot, why is the current temperature of the Big Bang radiation just about 3 degrees above absolute zero?

Expansion cooled the universe and the waves were greatly red shifted.

Why should we be extra cautious about believing UGO's are extraterrestrial space craft?

Extraordinary claims like that require extraordinary evidence and we have none.

What is the 2.7 K radiation and why is it important?

It is microwaves radiation coming almost equally from all directions in space. It was predicted by the Big Bang theory and strongly supports it.

Do you believe some UFOs are space ships from other worlds? Defend your answer.

No- No convincing evidence Yes-Some UFO sightings can't be reasonably explained.

Can Darwin's theory of evolution explain the origin of life? Why or why not?

No. Darwin's theory requires reproduction, which non-living things can't do.

What is the theory of "inflation" in cosmology? Name one property of the universe is explains.

The universe expanded from atom to solar system size in a tiny fraction of a second. This explains flatness, uniform temperature, and structure.

No elements more massive than Helium were created in the Big Bang. Why not?

There was not enough time, only five minutes to make elements heavier than He.