Anthropic principle

[ImaginalDisc]

I. . .I can't take seriously, even for argument's sake, the idea that the universe is perfect for human life.

Our universe is nearly devoid of any life. Look at yourself, you weigh tens of kilograms, on a planet twelve orders of magnitude more massive than all humans combined (Assuming 6 billion humans at an average weight of 70 kilos each as a back-of-the-envelope calculation.) We live on the surface of a planet only, and the vast majority of the surface is inhospitable to human life. Our planet is a speck whem compared to the raging nuclear fireball that illuminates it, and even the size of the sun is miniscule compared to the distances of the solar system. We're so far away from the sun that light takes nine minutes to reach us from it. Consider for a moment how empty that vast distance is. This is all without going into the expanses of nothing between us and other stars, which even the most optomistic scientists believe are almost without exception lifeless.

How can you possible say the universe is designed for life when it's almost entirely empty and by any measure the overwhelming majority of what little matter there is would instantly kill life?

If you held a rock in your hand that had a single atom of carbon in it, would you call that rock a diamond?

 

[ImaginalDisc]

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.

I don't see that as a problem with science, but a problem with us. We're social animals and anyone who's ever cursed at a machine can tell you that on a fndamental level, we expect things we interact with to have minds and reasons for their actions. Like our trouble in comparing vertical and horizontal distances, paredolia, blinds spots, and other quirks of our brains and senses, asking why the universe exists is, I think, a consequence of our evolution.

 

[sol invictus]

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.

Sure - but how do you know when you've reached that point?

I. . .I can't take seriously, even for argument's sake, the idea that the universe is perfect for human life.

No one that I know of has ever made such a claim in the context of the AP. In fact to my knowledge it's only theologians twisting themselves into rhetorical knots to explain the problem of evil that say any such thing. So I'm not sure why you're knocking down that particular strawman.

The kind of issue more often discussed is whether or not it's the case that the constants of nature are finely tuned to allow stars to burn.... which they in fact appear to be. That is, take any of several dimensionless "constants" of nature (the fine-structure constant is a good example) and vary it by a few percent. A universe with a value of the FS constant which differs from ours by more than that would contain no carbon. Vary it by much more, and star ignition would never occur at all.

Question: does that require an explanation? If you think not, you accept the anthropic principle at least to some extent. If you think yes, you need to look for a better theory of physics than the one we have now.

 

[Perpetual Student]

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.".

I'm not sure what you are dubious about. Are you questioning the accuracy of the mathematics and underlying physics?
Consider the following (from a recent article in Discover Magazine):

"Consider just two possible changes. Atoms consist of protons, neutrons, and electrons. If those protons were just 0.2 percent more massive than they actually are, they would be unstable and would decay into simpler particles. Atoms wouldn’t exist; neither would we. If gravity were slightly more powerful, the consequences would be nearly as grave. A beefed-up gravitational force would compress stars more tightly, making them smaller, hotter, and denser. Rather than surviving for billions of years, stars would burn through their fuel in a few million years, sputtering out long before life had a chance to evolve. There are many such examples of the universe’s life-friendly properties—so many, in fact, that physicists can’t dismiss them all as mere accidents." Tim Folger

There are many other examples. What are you dubious about?

 

[Darat]

I'm not sure what you are dubious about.

...snip...

I explained in the rest of the post that you didn't quote and even gave a reformulation of the claim that I think removes what I am dubious about....

 

[dasmiller]

"There are many such examples of the universe’s life-friendly properties—so many, in fact, that physicists can’t dismiss them all as mere accidents." Tim Folger

There are many other examples. What are you dubious about?

I think that if we change "life-friendly" to "life-as-we-know-it-friendly", then it gets easier (for some people) to dismiss them.

Suppose that we had some marvelous computer that could model a universe with arbitrary laws of physics, fundamental constants, etc. If we ran many random cases, and some significant fraction had at least some form of self-organizing complexity that we might consider lifelike (and it's only ~10^-50 of our space/time universe), wouldn't that suggest that 'mere accidents' would work just fine? If all of the cases turned out to be homogeneous particle hazes, then that would give one pause, but I really don't know how a 'typical' universe would look and I suspect that nobody else here does, either.

What if we flip it around and try to make it into something testable? Suppose that there are 2 multiverses - one in which life is fairly likely for a random set of parameters, and one in which it's extremely unlikely. You're in a universe that's a derivative of one of those 2 multiverses, how would you figure out which? (honestly, without my "marvelous computer" above, I have no idea, but I think it's a good question)

 

[schlitt]

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.

Well put.

Unfortunately many people think "I am in the universe and I exist. This universe is here for me to exist in."

I exist within 1 out of 1 attempt.

The universe for me to exist in existed for that singular attempt.

Therefore, the universe was perfectly equipped for my existence the one only time my existence was attempted. It must be beyond coincidence that the only universe that exists was perfectly equipped for me to exist within.

1 universe, plus 1 existence = 100% perfect for existence, 100% of the time.

But this is such a narrow perspective as it fails to realise that you can only exist if preceding events permit existence. So any time something exists the conditions are of course equipped for its existence.

If our solar system were missing the earth but retained the other planets, we would not be here contemplating our existence. The fact that we are here and able to contemplate our existence only speaks to the fact that conditions were right for our existence and speaks nothing at all about the probability of the conditions arising in the first place.

The “finely tuned argument” that the religious folk like to use is nothing more than a logical miscomprehension.

 

[Darat]

Pratchett has made many amusing comments and wry observations regarding the Anthropic principle over the years, this one (from a dust jacket) always amuses me:

Terry Pratchett lives in England, an island off the coast of France, where he spends his time writing Discworld novels in accordance with the Very Strong Anthropic Principle, which holds that the entire Purpose of the Universe is to make possible a being that will live in England, an island off the coast of France, and spend his time writing Discworld novels. Which is exactly what he does. Which proves the whole business true. Any questions?​

 

[Soapy Sam]

Aye.
Since when was England an island?

Alex- just back away from the bulldozer...

 

[sol invictus]

The “finely tuned argument” that the religious folk like to use is nothing more than a logical miscomprehension.

One finds organs (like eyes) that are exquisitely adapted to their purpose. They are incredibly "fine-tuned", and we understand why - because of natural selection.

So why are people here so resistant to the idea that precisely the same logic - noticing fine-tunings and looking for a natural explanation - could be useful in physics as well?

 

[schlitt]

One finds organs (like eyes) that are exquisitely adapted to their purpose. They are incredibly "fine-tuned", and we understand why - because of natural selection.

So why are people here so resistant to the idea that precisely the same logic - noticing fine-tunings and looking for a natural explanation - could be useful in physics as well?

I am not at all resistant to the idea. I am actually quite fond of it, as i have written here previously.

http://www.internationalskeptics.com/forums/showthread.php?p=4079050#post4079050


But my issue with the finely tuned argument is this; simply to posit that because we can perceive order in existence this equates to a magical orderer (God), is to stop short of any meaningful answer.

 

[Perpetual Student]

Here is another quote from the article I mentioned above:

"Cosmic Coincidences

If these cosmic traits were just slightly altered, life as we know it would be impossible. A few examples:

• Stars like the sun produce energy by fusing two hydrogen atoms into a single helium atom. During that reaction, 0.007 percent of the mass of the hydrogen atoms is converted into energy, via Einstein’s famous e = mc2 equation. But if that percentage were, say, 0.006 or 0.008, the universe would be far more hostile to life. The lower number would result in a universe filled only with hydrogen; the higher number would leave a universe with no hydrogen (and therefore no water) and no stars like the sun.

• The early universe was delicately poised between runaway expansion and terminal collapse. Had the universe contained much more matter, additional gravity would have made it implode. If it contained less, the universe would have expanded too quickly for galaxies to form.

• Had matter in the universe been more evenly distributed, it would not have clumped together to form galaxies. Had matter been clumpier, it would have condensed into black holes.

• Atomic nuclei are bound together by the so-called strong force. If that force were slightly more powerful, all the protons in the early universe would have paired off and there would be no hydrogen, which fuels long-lived stars. Water would not exist, nor would any known form of life."

I quote this to demonstrate the basis of "anthropic" speculation. An interesting conclusion drawn in the same article is that "inflation was not a one-off event but an ongoing process throughout the universe, where even now different regions of the cosmos are budding off, undergoing inflation, and evolving into essentially separate universes ...-- called eternal chaotic inflation."

The conclusion is that "each new universe is likely to have laws of physics that are completely different from our own. The latest iteration of his theory provides a natural explanation for the anthropic principle. If there are vast numbers of other universes, all with different properties, by pure odds at least one of them ought to have the right combination of conditions to bring forth stars, planets, and living things."
Fascinating thoughts -- no?

 

[Scazon]

Just remember we have such a restricted view of what constitutes life and intelligence that we can't really sensibly comment on it. You can't sensibly extrapolate from a sample of one.

If fundamental constants were different, the universe would be different. Our life almost certainly couldn't develop. But that isn't the same as saying that a different sort couldn't develop- perhaps over a nanosecond scale in an unstable universe, or where "seconds" last a billion years in a quasi- static one- and be self- conscious. Perhaps they even do in our universe- we'd never notice them.

I'm not saying they do, and I can't think of a way to test for them. I can't even think of a way to test if another human is "genuinely" conscious. But remember that we only know about life that experiences on the scale 1 day to 1000 years (approximately): about 25 log₁₀ periods.

 

[steenkh]

If these cosmic traits were just slightly altered, life as we know it would be impossible.

This may not actually be true. A simulation using only a few constants have shown that many values were able to support hydrogen forming stars: Is our universe fine-tuned for life?.

 

[Perpetual Student]

This may not actually be true. A simulation using only a few constants have shown that many values were able to support hydrogen forming stars: Is our universe fine-tuned for life?.

Now, there's a totally different view, thanks. I will be interesting to see what physicists who believe otherwise will have to say.

 

[Wowbagger]

The anthropic principal is the insertion of human ego into Science.
Nothing less. Nothing more.


(And, therefore, not something you want your scientific ideas to rely on.)

 

[EGarrett]

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

Isn't it amazing that my cup just happens to be the perfect shape for the water that is inside it?

 

[sol invictus]

Isn't it amazing that my cup just happens to be the perfect shape for the water that is inside it?

Yes, in fact it is. If you put a chuck of rock in there, it wouldn't be the perfect shape.... which teaches you something about water, fluids in general, and the laws of physics even more generally.

Why is it so hard to understand that this same logic is useful for bigger things as well? I really don't understand the mental block people have about this...

For the fifth time - the anthropic principle, at least as it's generally applied in modern physics, has nothing to do with human ego or religion. On the contrary: it is the next step in a chain of logic which has been building throughout the history of science, each stage of which has taught us that we are less special, privileged, or unique than thought previously.

The latest realization is that the specific laws of physics we observe may be no more special or significant than the fact that we find ourselves orbiting the specific star we call Sol.

 

[EGarrett]

Yes, in fact it is. If you put a chuck of rock in there, it wouldn't be the perfect shape.... which teaches you something about water, fluids in general, and the laws of physics even more generally.

Why is it so hard to understand that this same logic is useful for bigger things as well? I really don't understand the mental block people have about this...

For the fifth time - the anthropic principle, at least as it's generally applied in modern physics, has nothing to do with human ego or religion. On the contrary: it is the next step in a chain of logic which has been building throughout the history of science, each stage of which has taught us that we are less special, privileged, or unique than thought previously.

The latest realization is that the specific laws of physics we observe may be no more special or significant than the fact that we find ourselves orbiting the specific star we call Sol.

I'm not sure if you're agreeing with me, disagreeing, getting my subtext or missing it...

 

[sol invictus]

I'm not sure if you're agreeing with me, disagreeing, getting my subtext or missing it...

I interpreted your subtext to be "the anthropic principle is empty and useless", which irritated me because I think it's false, and because I've explained why multiple times in this thread without anyone making any attempt to show why I'm wrong.

Is that not what you meant?