why the big bang was not a black hole? All the mass of the universe concentrated at a point? Doesn’t that sound very like a black-hole situation?

IANAC (I am not a Cosmologist), but I thought it would be fun to give this question a crack. A black hole is characterized by the presence of an event horizon, which divides space time into two distinct regions (inside & outside). The Big Bang singularity is all of spacetime itself at a single point, not a point of infinite density within spacetime, so there’s no where for an event horizon (or anything else) to be.

That’s a somewhat lame way to point out a qualitative distinction between a black hole singularity and the Big Bang singularity. You might also ask, shortly after the big bang, wouldn’t the mass/energy density within space have been large enough to form event horizons everywhere? This requires a more technical explanation.

The Schwartzchild metric describes spacetime outside of a spherical mass. The event horizon is possible because the signs of the spacelike/timelike coordinates can switch (so a black hole singularity is more properly thought of as a time, not a place).

The Friedmann (et. al.) metric describes spacetime with the mass/energy evenly spread out everywhere. Note there’s no way to change the signs, thus no event horizon possible at any mass density.

So, event horizons are only possible at local concentrations of mass. In the early universe, density fluctuations would have been very tiny, so any primordial black holes that formed would have been very tiny.

Would the universal acceptance of things only reason can establish substantially improve society? Is this the reason for this conclusion?

Actually, my conclusion is more of an observation—that people of faith often don’t grasp the nature of skepticism. The themata of faith, where believing is seeing, is projected onto all realms of thought. For instance, as far as I can tell, President Bush honestly doesn’t grasp the difference between evidence and assertion; in his mental model of the world, belief is truth. This is a direct extension of his religious faith, and has tangible consequences.

I think an atheistic society would be more likely to have fewer ills, but not because of atheism itself. If everyone were to suddenly stop believing in God, otherwise remaining the same, things wouldn’t change much. People would just find another reason to be bigots. Religion is an especially convenient means for people to express their tribalism, but Social Darwinism is evidence that (poorly understood) science can also be twisted to such ends. However, atheism is often a symptom of a healthy skepticism, of thinking critically, and an inclusive intellectual maturity. These are traits that definitely benefit society.

It’s a little awkward including quotes-within-quotes, but I’m not delusional enough to think anyone wants to scroll through old entries to make sense of replies. So, a response to smonroe:

Came across your blog. Curious entry:

…Next questions: Why does the universe look this way rather than some other way? Why does it adhere to these laws of nature rather than to some other laws?

Is it me, or does the question why imply an agent? It can be applied to cause and effect questions, but the above queries are not worded that way. This, I think, is the cause of a lot of confusion and bad philosophy. When posed with such a question, always ask: what form would the answer take? If you can’t answer that, stop wasting trees (or bandwidth) with your theories.

Given that you find the statement of the question weak, why didn’t you provide a restatement of the question that is more satisfactory?

By what line of reasoning does this imply an agent?

Second question first, an important one. When posed with such a vague question I always ask myself, what form would the answer take? If I ask: Why X? The answer could be: Because Y. For any X I can think of, what is Y like? According to Webster: be-cause: 1. for the reason that. Most often, this will take the form of a motive, thus, an agent. “Why” can be used to ask cause and effect questions, but these must be very specific: why does it take 13.6 MeV to ionize a hydrogen atom? Because [insert QM solution of H here]. Here, the answer demonstrates how an observed feature results from more fundamental assertions. “Why” asks for a cause or a reason.

Does it even make sense to ask the above questions if you don’t assume there is a motive behind universal laws? Clearly this is not worded as a cause and effect question, and could not be answered if it was. There are many trying to derive essential features of the universe from the more fundamental assertions of string theory, but this is a long, long way from being complete. And even if it proves successful, all we know is we have a self-consistent model. The ultimate nature of the universe is not a scientific question, because there could always be phenomena we haven’t observed.

It’s not that I find the statement of the question weak, but meaningless. What’s the meaning of life? A: life is not the sort of thing that has a meaning. It’s like asking: What’s the color of twelve? Not every grammatical question has an answer. I won’t come right out and say the universe does not have a reason (though I find this a radical proposition with no grounds), but we should be aware of what we’re asking for.

Also, regarding the so called “Anthropic Principle” if it is not, as you say, “even vaguely theological or creationist” then surely you have an entirely different understanding of it than many of the authors that have published books or articles on the subject. I would welcome a recommendation.

Yes, I do, but I also have the same understanding as many. Some people recognize “strong” and “weak” anthropic principles, etc. But to me, at the heart, it is simply an observation: we shouldn’t be terribly surprised the universe is capable of supporting life, or we wouldn’t be here to ponder it. One could equally speculate whether this coincidence (if it is one) is due to a clever designer or an infinite series of random experiments. The principle itself does not imply either.

Thanks for the questions. They lead me to some interesting places.