Anthropic Principle

[otseng]

This topic is an offshoot from Does God exist or not? Since this topic is a huge area of debate, I'm making this have it's own thread.

So, the question of debate is...
Does the Anthropic Principle point to the existence of God?

First, let's give some definitions of the Anthropic Principle (AP).

Wikipedia:
"Any valid theory of the universe must be consistent with our existence as carbon-based human beings at this particular time and place in the universe."

Philosophy Pages:
"Belief that the existence of human life entails certain features of the physical world. In a minimal form, this view merely points out that we would not be here to observe natural phenomena were they not compatible with our existence. Stronger versions of the anthropic principle, however, seem to rely upon the idealistic notion that the universe could not exist without intelligent observers."

Augustine Fellowship:
"The observation that the universe has all the necessary and narrowly-defined characteristics to make man and his sustained existence possible. The view that the universe is conspicuously 'fine-tuned' for human existence. "

[otseng]

To use the Anthropic Principle to state that this planet is "fine tuned" uses a presupposition that there surely IS NOT other life on other planets that is different than life here.

It's not a presupposition. It's a conclusion that can be drawn from the scientific evidence that I have presented already from light and water. And there are other things also that I hopefully can get to (carbon, oxygen, et al).

You're trying to use circular logic to confuse the issue.

Circular logic? All I ask is how else can life evolve? When that question is answered, then there is a basis for arguing that there is a selection effect.

[perspective]

Circular logic? All I ask is how else can life evolve? When that question is answered, then there is a basis for arguing that there is a selection effect.

The basis for the argument that there is a selection effect is our admission that we do not know if life exists elsewhere. The selection effect exists regardless of evidence to support the existence of theoried unknowns. The fact that we know that there are unknowns is all that is needed as a basis for the selection effect.

We can all agree that we don't know if life has evolved on other planets. We can agree that even within our close range of space, we don't know if life has evolved on any of those close-range planets. Until we can go to planets and inspect, we can't say that life does or does not exist on those planets. You claim that -- when we look at a planet from very far off -- it is permissible to decide that no life could possibly evolve on that planet just because the life that evolved on this planet couldn't evolve on that planet. This is an error. Unless we can actually touch down on that planet and inspect not only its surface, but its entirety, we cannot assume that nothing lives there. We cannot assume that something lives there. We just don't know. Regardless of evidence of life existing elsewhere - the selection effect still does exist. Until we can know for sure that no other life in this universe has evolved (not just at the present time, but EVER - and not just close to here, but ANYWHERE), can we use the Anthropic Principle to support the claim that this planet is supernaturally engineered. So that makes it - uh - never. Never will you be able to use the Anthropic Principle to support the claim that this planet is supernaturally engineered. Because never will we know for sure that no other life in this universe has evolved in the past or present. Unless you are god.

You can still claim that this planet is supernaturally engineered, but you can't use the Anthropic Principle to logically support that theory. Selection effect prevents the logic from being sound.

[otseng]

The basis for the argument that there is a selection effect is our admission that we do not know if life exists elsewhere. The selection effect exists regardless of evidence to support the existence of theoried unknowns. The fact that we know that there are unknowns is all that is needed as a basis for the selection effect.

Yes, we do not know if life exists elsewhere. But, that fact in itself doesn't show that the selection effect is present. It might be present, but then again, it might not be present.

Taking your earlier example. If the sample of people we survey were all conservatives, we can say that the survey could be affected by the selection effect. It would be shown with certainty that the selection effect was true if non-conservatives were found in the country. But, what if the rules of the country itself says that only conservatives can live in the country? And therefore only conservatives in fact did populate the country. Then the survey would be representative of the entire country and would not be subject to the selection effect.

[perspective]

Yes, we do not know if life exists elsewhere. But, that fact in itself doesn't show that the selection effect is present. It might be present, but then again, it might not be present.

I will concede the selection effect might not be present. But it still weakens the anthropic principle significantly. Again, we're back to un-agreed upon rules and standards associated with debating religion. In anything else in this world (medicine, legality, physics, chemistry), we would use an educated guess to deal with the unknowns in the world around us. We know that of all the planets in the solar system, we've only been able to closely examine two - ours and Mars, and even Mars I wouldn't call completely examined. Out of examining 2 planets for life, I wold call it bad science to conclude that the million others surely couldn't produce life of some sort. But that would be my opinion. And that of statisticians in this world. But that obviously wouldn't be bad science to religious people who are trying to prove that a god exists.

Unless it was in relation to something else, non-religious - like me making the claim that because I've never seen lights on in the houses down the road from mine, it's likely that no one lives on my street because I can't see them. I've never gone there and looked in the windows. I've never knocked on the door or called these people. I can't walk and I don't have a phone - so it's ok for me to conclude that no one lives anywhere on my street except in my own house. Surely you'd see the selection effect that makes that conclusion illogical.

[otseng]

Unless it was in relation to something else, non-religious - like me making the claim that because I've never seen lights on in the houses down the road from mine, it's likely that no one lives on my street because I can't see them. I've never gone there and looked in the windows. I've never knocked on the door or called these people. I can't walk and I don't have a phone - so it's ok for me to conclude that no one lives anywhere on my street except in my own house. Surely you'd see the selection effect that makes that conclusion illogical.

I understand what you're saying. However, I'm not making my judgements based on the fact of what might or might not exist on other planets. It's totally immaterial to my argument for the Anthropic Principle. My arguments are based on the properties of the universe as we understand it. These properties are undisputable. What is in dispute is can these properties produce life besides life as we know it?

[perspective]

However, I'm not making my judgements based on the fact of what might or might not exist on other planets. It's totally immaterial to my argument for the Anthropic Principle. My arguments are based on the properties of the universe as we understand it. These properties are undisputable.

I don't know which properties you are referring to, but I'm pretty sure they are not undisputable. Your listing the specifics of how this particular world evolved does not preclude the possibility that had this world been composed differently that some life form still could have evolved. So if that's what you mean - that we're so fine tuned that any little thing could have prevented life - that is disputable.

[otseng]

I don't know which properties you are referring to, but I'm pretty sure they are not undisputable.

So far, I've presented the electromagnetic specturm and water.

The properties that I've outlined on these two are undisputable.

[veritas]

I don't know which properties you are referring to, but I'm pretty sure they are not undisputable.

So far, I've presented the electromagnetic specturm and water.

The properties that I've outlined on these two are undisputable.

The properties are, indeed, indisputable. WHat perspective is arguing is that your conclusion that "we see that life can only evolve to be one certain way" is not.

Is it possible that life on other planets (assuming there is any--as far as I'm concerned, the jury is still out) could have evolved so as to not use water? :shrug: I guess. Is it possible that life could have evolved to use (or, at least, to survive) a higher or lower portion of the spectrum? :shrug: Dunno--that one would probably be a bit tougher, if (and note please that it is a very big if) we assume that "life" everywhere must consist of large, carbon-based molecules. But that's the problem: the assumtion that life consists of "large, carbon-based molecules" is just that--an assumption, based on only one planet (our own).

We know that mammals (and most, if not all, surface-dwelling animals)require iron-based hemoglobin for oxygen transfer--so do all large, relatively complex animals require this? No--for instance, the octopus uses a copper-based protein to accomplish oxygen transfer. But for a moment, let's assume that we were not aware of that fact. What Perspective is trying to say is that, if you just go on surface-dwelling creatures, you'd never be able to simply "guess" that the octopus does not have iron-based blood.

In a similar fashion, perspective is trying to say that we cannot even guess what life on other planets is like. Does it require water? Does it require the same narrow band of EM radiation that we do? Who knows? I don't, perspective doesn't--but your statements make that base assumption.

Justin

[otseng]

WHat perspective is arguing is that your conclusion that "we see that life can only evolve to be one certain way" is not.

Yes, that is what is up for dispute.

Is it possible that life on other planets (assuming there is any--as far as I'm concerned, the jury is still out) could have evolved so as to not use water? :shrug: I guess. Is it possible that life could have evolved to use (or, at least, to survive) a higher or lower portion of the spectrum? :shrug:

That is part of the problem. We cannot guess how (complex) life can form without water or without using energy from stars.

As a side note, so ingrained is our concept of water being essential to life, that just by thinking there's water on Mars, people have speculated life exists there.

Dunno--that one would probably be a bit tougher, if (and note please that it is a very big if) we assume that "life" everywhere must consist of large, carbon-based molecules.

I'll present later why carbon is the optimal element to base life on.

We know that mammals (and most, if not all, surface-dwelling animals)require iron-based hemoglobin for oxygen transfer--so do all large, relatively complex animals require this? No--for instance, the octopus uses a copper-based protein to accomplish oxygen transfer. But for a moment, let's assume that we were not aware of that fact. What Perspective is trying to say is that, if you just go on surface-dwelling creatures, you'd never be able to simply "guess" that the octopus does not have iron-based blood.

Sure, but iron-based hemoglobin is not anything I'm arguing about.

In a similar fashion, perspective is trying to say that we cannot even guess what life on other planets is like. Does it require water? Does it require the same narrow band of EM radiation that we do? Who knows? I don't, perspective doesn't--but your statements make that base assumption.

My argument is - what are the alternatives?

[veritas]

Is it possible that life on other planets (assuming there is any--as far as I'm concerned, the jury is still out) could have evolved so as to not use water? :shrug: I guess. Is it possible that life could have evolved to use (or, at least, to survive) a higher or lower portion of the spectrum? :shrug:

That is part of the problem. We cannot guess how (complex) life can form without water or without using energy from stars.

Well, as a side note, we do already know of one form of (terrestrial) life that does not use energy from light: the whateveritis at the deep-ocean volcanic vents. (I don't have the article handy, and I'm too darn tired to google it. ) The only energy they take in is the heat energy of the vents they live near.

Dunno--that one would probably be a bit tougher, if (and note please that it is a very big if) we assume that "life" everywhere must consist of large, carbon-based molecules.

I'll present later why carbon is the optimal element to base life on.

Oh, I already agree--as long as you can also agree that "optimal" doesn't necessarily mean "only."

We know that mammals (and most, if not all, surface-dwelling animals)require iron-based hemoglobin for oxygen transfer--so do all large, relatively complex animals require this? No--for instance, the octopus uses a copper-based protein to accomplish oxygen transfer. But for a moment, let's assume that we were not aware of that fact. What Perspective is trying to say is that, if you just go on surface-dwelling creatures, you'd never be able to simply "guess" that the octopus does not have iron-based blood.

Sure, but iron-based hemoglobin is not anything I'm arguing about.

It's not the specific topic, it's the parallel. In the case of our hypothetical biologist (the one who has never seen sea life and thinks that all complex life requires iron-based blood), he made a guess based on insufficient data--an illustration of perspective's "selection effect," in that he only had data from land-based animals to work with.

My argument is - what are the alternatives?

Alternatives to carbon-based biology? Oh, heavens, if I knew that, I'd be going to pick up my nobel prize!

There are some possibilities: sulphur replaces some functions of carbon in the volcanic vent ecology (not all, but some). Scientists have been speculating for years if life on other planets could be based on silicon--I don't happen to believe so, as silicon is not nearly reactive enough, but like I said before, I'm not a Nobel-laureate scientist. Chlorine, long a standard of science fiction, is right out (too simple chemically, and it makes too strong a bond). Like you, I think that carbon is the best bet, but like you, I just don't know what else could be out there.

But just because I don't know doesn't mean that there's not something out there that is outside of my specific guesses. "Absence of evidence," and all that, y'know.

Justin