luvluv

eh, am I wrong in my understanding that Hawkins discovered that time, like the physical universe, had a begining?

I realize that there are some things about the issue that I don't know. However, you'll excuse me if I'm wrong, but I get the feeling you're taking advantage of this by withholding knowledge that you are aware exists but will not divulge because it supports my argument. It's not really a problem, because it isn't your job to do my research for me. But if your position is as strong as you make it out to be I don't see why it would be necessary to withhold anything. Again, perhaps this is all a work of my imagination and if so I apologize.

eh

Why are you asking that, when I just posted the very Hawking quote in question? What exactly do you not understand about it? It seems simple enough.

Vorkosigan

This latter is part of an anthropic argument of the bass-ackwards variety. What exactly is wrong with it?

Nothing. It's just not the Anthropic Principle I'm attacking. You're defending the Weak Anthropic Principle (as we call it around here), but I'm discussing the Strong Anthropic Principle. The claims of each are different. The WEAK one says "We're here!" Then Strong one says "We're the reason everything is here!" Really, we're discussing two different things.


An origin producing many universes + selection of this one by the need for our existence is one candidate explanation. Your position, as I understand it, is that you already know it's not right.

No, my position is that there is no data currently known that can confirm or deny this possibility. Misreading me again.

In the science that I was taught, you can't deduce anything from a population of 1.

Then I'm afraid your science education was incomplete. Perhaps what they meant was that you can't deduce a general principle from one example, which is true. In fact, anthropic arguments try to show us cases where you can't infer a general principle even from lots of consistent results.

No, in the science of stats, a population of one is pretty much worthless for inferring the kind of probablity claims Strong Anthros have made. That's what I was referring to.

When you say the anthropic princple no longer applies, you are in fact saying that the planet we observe is randomly selected from all planets. That Earth is typical, not of planets sustaining multicellular life or life or intelligent life or life with wings, but of all planets erverywhere.

There's a massive error here. A randomly selected planet is NOT NECESSARILY a "typical planet." I could walk into a room and randomly select one of the people in it. If she was left-handed, she would be non-typical, but she would still be randomly-selected.

You might not intend this, but that's what the words mean. That's why I keep repeating this point.

No, like I said, you have a lot of misconceptions and confusions about this problem. Like confusing "randomly-selected" with "typical." The reason you keep repeating this point is that you have not yet sorted out what we are discussing.

In fact, the anthropic principle is a fancy way of reminding us that inferences we make from our observing position are not random samples of the universe (or universes).

You know this how? What information do you have about other universes?

There's nothing supernatural about an anthropic argument - why do you think there is?

About the Weak Anthropic Principle[/i], no. The Strong Anthropic Principle is usually held by people advocating some supernatural belief. I don't know of anyone who advocates a naturalistic explanation for the Strong Anthropic claims.

Before moving on to the the substantive point, I'd like to point out that you're confusing probabilities before and after the fact. Before I toss a coin the probability of heads is 0.5, after it has fallen heads it is 1. At some early time by which the parameters were set, we think the probability that our universe would develop life was high, whereas we now know that the probability of life in the universe is 1.

No. According to the Strong Anthropic Principle, the probability of our universe developing life like ours is 1. That's because under that principle, we're the reason for the existence of the universe. This is an entirely different principle than the Weak one that you are discussing here.

Back to the issue, your problem here is that you think the anthropic principle applied to the universe makes a claim. All it does is describe our knowledge at present of how the universe formed and note that it need not be representative of the universe formation process, just as the events in the origin of the Earth are not all representative of the planet formation process.

The WEAK one. The STRONG one is a different case. It makes a claim.

'supporting intelligent life' (to the best of our knowledge) selects a subset of universes with certain properties. We can only exist in one of these.

Again, you know this how? I don't know any other universe than this, and neither does anyone else!

It is a selection principle - the anthropic principle reminds us that our planet is not typical of planets.

It is certainly not typical of the planets we know. All what -- twenty of them? In any case, that's the WEAK Anthropic Principle....

It makes us wonder if our unvierse is typical of universes. Musings from there onwards try to account for the exitence of a universe that can sustain life. In these musings, the parameters don't rely on life/observers per se.

Then what do they rely on? You seem to think they rely on some principle other than a subjective and ultimately arbitrary feeling of human beings. If so, what is it?

To the best of our current knowledge it's small. Best we can do. That's science, I'm afraid.

I agree, the range of parameters that can produce observers like us may well be small. Anything else is your speculation. And no science.

'Misreading' - pot - kettle. I'll use the argument about planets since it's clearer. Anthropic principle arguments tell us that our planet is not typical of planets since it supports us - this doesn't endow us with mystical status.

WEAK Anthropic Principle. This IS NOT the principle I was responding to.

Lots of planets support ice - so the parameters that support us are a subset of those that support ice. I was pointing out that you don't allow any continuum. It is not true that exactly the same range of parameters allow us to exist as allow stars to exist.

Never did I make this claim. However, snowflakes exist in a much narrower range of temperatures and pressures than life....additionally, you have shifted the goalposts. The issue is not the number of planets but the range of parameters.

Observers are the interesting thing about anthropic principles in general because the principles deal with the generalisability of observations and hence of theories deduced from them.

In the Strong case, observers are the reason the universe was created. That is what I am responding to.

Vorkosigan