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Anthropic principle

Perpetual Student

Illuminator
Perpetual Student
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Jul 8, 2008
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The fundamental quantities and constants that make the universe as we know it are numerous. The mass of the proton, electron, the gravitational constant, are just three of many examples of values that if changed slightly would dramatically alter the universe to the point that there would be no planets, no stars, no life, etc.
I am not one to accept supernatural explanations; nevertheless, the extraordinary combinations of these many values leading to the universe as we know it are a spooky coincidence.
Of course, it is possible that an alternate universe might support sentient life of a different kind. Another thought is that ours is one of many universes with many combinations of fundamental constants that do exist, either without life or with some other form of life. The most difficult question of all to ponder is why there is anything in the universe at all.
I know that these are philosophic as well as scientific speculations. Any thoughts?
http://en.wikipedia.org/wiki/Anthropic_principle
 
I'll readily admit I'm not much of a philosopher and/or a scientist, but isn't the anthropic principle a kind-of backward reasoning? Just because we're here, doesn't mean the universe was "made" or "aimed at" us. We happen to exist in it, and we're a product of it "by default", but that's just about all we can say about it. Some different sentient creature in a galaxy far, far away ;) might have the same thought. Basically, in every universe under any arbitrary set of constants and rules, should sentient life exist there, it would be able to pose the same question. The "sentient puddle" analogy comes to mind here: a sentient, liquid creature, unable to move, sitting in a hole in the ground. It might argue that the hole was made to fit its current shape, when actually it's the other way 'round: the existing hole has shaped the creature by the laws of physics.

After some pondering, I'm rating the anthropic principle to be little more than a "philosophical workout". Like I said, I'm just an amateur thinker and might be wrong here. If I mangled the "Puddle" analogy, then I claim it's because of the late-night posting which I shouldn't do :)
 
I agree with TheMark.

You can only possibly have such a thought about a universe if life exists in the first place to have such a thought.

Maybe there are many 'other' universes (parallel, subsequent, previous, different scale, who knows...) which could not support life. But there would not be any life there to have such a thought.

This universe is capable of supporting life and it does.
More than that we simply cannot say. No 'logical thought' can bring us to any conclusion regarding if this implies any sort of reason behind such a situation.
Could be God, could be incredible chance, could be an inevitable aspect of the nature of the universe... but is there any point in going too deep into something that can have no answer with the information we have now (and this is one aspect of philosophy that does annoy me - the attempt to reach conclusions based on logic when we do not have enough information to yield anything productive).

We don't know what other arrangements of the laws of physics might have thrown up - maybe unimaginable concepts far beyond 'life' and 'planets'.

Or maybe this is simply the way the universe is for no reason whatsoever.
 
The issue really is whether anthropic explanations are adequate, or whether one should spend one's time looking for a better explanation. There are many features of the universe which one might want to understand - a good example is why it is so enormously big and old in units of every fundamental constant we know of - for which the only known explanation is anthropic (if the universe were not so big or old, there would be no one in it to wonder about it).

This reasoning gains considerable leverage in theories where the laws of physics vary in different parts of the universe, or where some parts of the universe might be very "small" (meaning highly curved) or exist only for a moment. In such theories, the issue becomes both more pressing (why do we live in such an atypical region) and the answer becomes more satisfactory (once you have the "there is only one universe so what are you talking about" mental block out of the way, it's easier to see the point).
 
How is the validity, or otherwise, of the anthropic principle (AP) going to change your life? If it isn't going to do anything for you, it doesn't matter and you are wasting your neurons. AP is only philosophy, and philosophy does not settle any questions about reality.

(Philosophy can suggest questions about reality; but it cannot answer them. It proposed two competing facts for matter- it is infinitely divisible, or it is made of atoms. The prevailing, philosophical, view (for 2,000 years) was wrong.)

If you think AP suggests a "creator" or "intelligent designer," you are still stuck, like the philosophers of old, with the lack of direct (as opposed to inferential) evidence. The AP is like a (conscious) puddle, in a rut in a road, marveling that the rut is perfectly adapted to its dimensions.
 
How is the validity, or otherwise, of the anthropic principle (AP) going to change your life? If it isn't going to do anything for you, it doesn't matter and you are wasting your neurons. AP is only philosophy, and philosophy does not settle any questions about reality.
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I'm not sure what the point of that question is. How does any cosmological question change my life? We ask such questions because we think and such speculations give us pleasure and we want to understand our existence!

If you think AP suggests a "creator" or "intelligent designer," you are still stuck, like the philosophers of old, with the lack of direct (as opposed to inferential) evidence. The AP is like a (conscious) puddle, in a rut in a road, marveling that the rut is perfectly adapted to its dimensions.
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I am certainly not suggesting intelligent design or a creator. Such answers (intelligent design), in my view, merely add an unnecessary complication without a shred of scientific evidence and merely force ultimate questions of creation one more step removed.

In any case, there are so many ratios and constants that make the universe and life as we know it possible that I, for one, find it fascinating and bewildering, and -- in pursuing such thoughts -- I am certainly not alone!
 
I used to get into arguments with my father in regards to the Anthropic Principle very frequently. He always asserted that it was some sort of bullpucky reasoning that was used by Religious folks to "prove" that there must be some divine creator.

I see it more like:

I (insert your name here) exist in a universe bound by causation. Therefore the universe that I observe will be one that led to my existence... via causation.

It doesn't really say much to me at all. In fact I would find the universe very ABNORMAL if it did not display these unique properties that made my existence possible.

The anthropic principal is, if anything, an argument for there being many many many many many horrible inhospitable *universes* out there.
 
Perpetual Student said:
The most difficult question of all to ponder is why there is anything in the universe at all.
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There is something in the universe "at all", because in order for anyone to observe or understand the concept of the universe, they must exist. Thusly, the only *kind* of reality, would be one in which *things exist*, as far as any observers would be concerned.

Why does *nothing* seem more realistic than *something* when philosophically pondering these big questions?

I think of *all that is* and the keyword is *is*.

Sort of the reverse of why death isn't so scary a thing to me. Because as far as I know, I can't *be*(read: perceive being) dead.
 
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I (insert your name here) exist in a universe bound by causation. Therefore the universe that I observe will be one that led to my existence... via causation.

Nice.
 
Actually, I don't buy the argument that this universe is all that well-designed for life.

If we assume life-as-we-know-it (using liquid water, carbon, nitrogen) is the only kind in our universe - and that's a BIG assumption - then if we assume that *every* star in the Milky Way's disk has an earth-size planet with a habitable region 20 km thick, then the habitable volume of the Milky Way's disk makes up only 5E-32 of the total. For comparison, if the entire Earth was made of sand, and there was 1 purple grain (I'm guessing it to be 437 km directly below Toledo, Ohio), it's like saying, "wow, Earth must have been designed to make purple grains! We sure are lucky."

And for habitability, the galactic disk is the good part - the vast majority of the universe is much less hospitable. And most of the lifetime of the universe is apt to be much less habitable than our lush era.

Of course, we spend all our time in that purple grain, looking out, so all we see is purple, so it seems like the universe is well-suited for us.

The other view, of course, if we to look at how much of the universe isn't livable (the other 99.999999999999999999999999999995%, if I counted the 9s right), we say, "wow, look how finely balanced things have to be for us to live! We sure are lucky."

Can't win.

My personal opinion - and this isn't testable AFAIK, so it's just an opinion/philosophy - is that any combination of fundamental constants that gives a large (in space & time), internally diverse universe will have a decent shot at having "microenvironments" that would support something that we might consider lifelike. If our universe is any guide, then if you keep shovelling quintillions of different environments onto the pile, sooner or later there will be one that's usable.

Just my ramblings . . .
 
Gate2501 said:
I see it more like:

I (insert your name here) exist in a universe bound by causation. Therefore the universe that I observe will be one that led to my existence... via causation.

It doesn't really say much to me at all. In fact I would find the universe very ABNORMAL if it did not display these unique properties that made my existence possible.

I believe you have stated a variation of the "weak anthropic principle."
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Perpetual Student said:
The fundamental quantities and constants that make the universe as we know it are numerous. The mass of the proton, electron, the gravitational constant, are just three of many examples of values that if changed slightly would dramatically alter the universe to the point that there would be no planets, no stars, no life, etc.
I am not one to accept supernatural explanations; nevertheless, the extraordinary combinations of these many values leading to the universe as we know it are a spooky coincidence.
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It does certainly seem like it, and I know I have often thought this. However, Humans tend to follow a history of discovering that they are not all that important, and I often sense this will go the way of the Sun revolving around the Earth.

The problem I have with this argument (that it is too good to be true) is simply -well- what's so important about life? We only tend to think it is important because we exist.

The problem with postulating a God (I know you are not but I thought I'd bring it up) is the sense that He did an adequate job, but not a brilliant one. Why create a Universe in which Stars collapsed at all? Apart from the devastating nature of the bigger ones exploding, and the devastating effects of the black holes that follow, giving us stars that could burn forever give -quite simply- a better chance of life forming on one of its orbiting planets. He could have done better with the Human race, putting us on a K or M class star, which radiate the same heat but burn for Trillions of years. Why give us a humdrum star which only lasts 11 billion years? Why give us a Universe in which rocks are allowed to slam into planets, having the ability to destroy all life?
 
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I'm always dubious of the claim that "are just three of many examples of values that if changed slightly would dramatically alter the universe to the point that there would be no planets, no stars, no life, etc.".

All we can really say is that "our current theories indicate that if the values were changed slightly it would dramatically alter the universe to the point that there would be no planets, no stars, no life, etc. as we observe them today".

Plus I agree with dasmiller (welcome to the Forum by the way) that from what we can observe the universe does not look as if life (as we know it) is anything but a quirk.
 
Gate2501 said:
I (insert your name here) exist in a universe bound by causation. Therefore the universe that I observe will be one that led to my existence... via causation.
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As PS pointed out, that's what's known as the weak anthropic principle. It's not controversial.

dasmiller said:
Actually, I don't buy the argument that this universe is all that well-designed for life.
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No one is saying that. They're just claiming life is possible, and might not be otherwise.

Let me ask you this: Given that the universe is as it is, do you think the fact that we exist in such an incredibly special place (on the very thin crust of a small planet orbiting a star) requires an explanation? After all, nearly all of the volume of the universe is intergalactic space - so why aren't we there?

To me, it is obvious that the answer is anthropic - life probably doesn't exist in space, so we don't live there. If you agree, you accept the anthropic principle as an explanation for at least some questions. If you disagree, you believe there is a theory of fundamental physics that explains why we live on the crust of a planet.

In modern physics that's the crux of the debate - which questions need answers beyond anthropics.
 
JJM said:
If you think AP suggests a "creator" or "intelligent designer," you are still stuck, like the philosophers of old, with the lack of direct (as opposed to inferential) evidence.
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I don't understand your comment. The AP is the opposite of religion, in precisely the same sense that evolution is the opposite of intelligent design. In both cases one has a theory that explains why some seeming incredible coincidence (the conspiracy of fundamental constants that allows stars to burn or the interlocking and extremely complex structure of the mammal eye, respectively) is NOT the result of a creator's design.

At some point in human history we understood that not only was the earth not the center of the universe, it wasn't even remotely unique or special - that there are tens of billions of stars in our galaxy alone, which is one tiny mote in a giant sea of galaxies and galaxy clusters. That was a crushing blow to religion, but it is nothing compared to what comes in those models where the AP gains the most traction. In those, not only is the earth not special, the entire observable universe, along with its laws of physics, is but one an a nearly infinite array of possibilities, all embedded in an almost inconceivably large and complex higher dimensional spacetime.
 
Carter’s original postulation of the Anthropic principle (both weak and strong) were more along the lines of a tautology, since we find ourselves to exist then the universe (or this specific time and place in the universe) must be compatible with the permissibility of that existence. It was intended more as a counter argument for the Copernican Principle that our particular “position” in the universe is not “unique”. The intent was (in my opinion) to express the fact that our position is somewhat unique in that conditions to support life are not present everywhere nor at all for some time in the universe past and perhaps future.
• Carter's Weak anthropic principle (WAP): "we must be prepared to take account of the fact that our location in the universe is necessarily privileged to the extent of being compatible with our existence as observers." Note that for Carter, "location" is a space-time position.

• Carter's Strong anthropic principle (SAP): "the Universe (and hence the fundamental parameters on which it depends) must be such as to admit the creation of observers within it at some stage. To paraphrase Descartes, 'cogito ergo mundus talis est'." The Latin tag ("I think, therefore the world is such [as it is]") makes it clear that "must" indicates a deduction from the fact of our existence; the statement is thus a truism.
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Carter’s original intent has been high jacked so to speak as an argument not simply stating that our perspective on the universe is biased by the fact that we exist and therefore conditions must be suitable for that existence at this place and time, but as an assertion of that bias being a significant indication of some intent of need in the universe for life to develop, transferring our particular bias of perspective to become some specific and intentional universal bias for life.
 
I thought being Anthropocentric was believing you were the centre of the universe, whilst Anthropic was the opposite?
 
The problem is really very simple. It's all about axioms. At some point, no matter how much science advances, there will be a point where you hit something fundamental. At the moment we think that point is at electrons, quarks and a few constants, but whether that is correct or whether there are even lower levels does not matter. The point is, there really can't be an explanation for why the fundamental things are as they are. If there were an explanation, then that explanation would replace them as the fundamental thing, but you would then be left with having to explain why that explanation is at it is.

In the end, "why" is a question that science really can't answer. It can say what and how, but it can't say why. The problem is that either we reach a fundamental level, but have no way to explain why the fundamental level is the way it is, or we have a "turtles all the way down" scenario, but no way to explain where the turtles come from.

As for the anthropic principles, they don't really say anything at all. "The constants are what they are because otherwise they'd be something else." It may be true, but it's not exactly the most meaningful statement ever. It's simply a way of saying that we don't know why the answer is what it is, but if it was something else we probably wouldn't even be asking the questions.
 
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