Notes on A Universe From Nothing

The empirical validation of the big bang rests on (p. 108)

1. the observed Hubble expansion--the universe is expanding away from us and increasing in speed. 

2. observation of the cosmic microwave background

3. and the measured quantities of light elements rightly predicted to have been produced from a big bang

Our observable universe is as close to being flat as we can measure, p. 149. The newtonian gravitational energy of galaxies moving along with the hubble expansion is zero and it has to be zero. This is not arbitrary.

A universe from "nothing" would evolve into a flat universe. It is what we would expect (and by "nothing" Krauss means empty space except for energy (see p. 153))

Empty space can have a non-zero energy associated with it (what is "non-zero"?)

As the universe expands, it dumps energy into space (this is because of gravitational pressure--which I totally don't understand)

During inflation in the empty universe there are quantum fluctuations and it is these fluctuations that produce structures in the universe, p. 151

From this theory, our universe started out as a microscopic region of essentially empty space which rapidly expanded, in the process dumping energy into itself and creating quantum fluctuations which resulted in matter. This is what happens in empty space in the presence of gravity.

In the quantum world, nothing always produces something. Nothing is unstable, something is stable. Nothing has to produce something it is natural law.

Address the anthropomorphic principle (which many find completely bogus. . .):

Is physics an environmental science, and by this, Krauss means, is science dedicated to finding out why the universe is the way it is and how it came to be or are the laws of physics actually accidental, simply  necessary for our existence? That is, for humans to exist, physics had to be the way they are and there is no other, deeper reason? Or to put it another way, are there a host of choices of how the universe could be or did the universe "have" to be this way?

The universe is 13.72 billion years old