Fine Tuning, Arguments For and Against

[mistermack]

I'm going to try to give some of the argument FOR fine-tuning for balance:

The arguments made so far are all valid, I think. But the god brigade will just answer that god moves 'in mysterious ways', as they always have done.
The original fine-tuning argument was more of a physics argument, than theological. Some phyicists tried to see what the Universe would be like, if the basic constants were slightly different, and were surprised to find that even a slight difference produced a totally different Universe, in which planets and even the larger atoms like carbon could never form.
So the god squad pounced on that, and argued that god must have made it that way, because the odds against it coming about that way by chance are incredibly high. This does seem to be accepted by many phyicists, it's the reasons for it that are more strongly disputed.
My own argument, that we are like lottery winners, wondering why we have a winning ticket against such odds, isn't watertight really.
With a lottery, you can point to one winning ticket, but also to the millions of losing tickets.
But with our Universe, all we can see is our one "winning ticket", just one Universe that CAN produce life. Where are all the other "losing tickets", or barren universes?
Or do we just accept that our Universe being suitable for life was millions to one against, but it still "just happened" that way.
( Please remember I'm playing the advocate here, because we don't have a real believer posting ).
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[Coito ergo sum]

I'm going to try to give some of the argument FOR fine-tuning for balance:

The arguments made so far are all valid, I think. But the god brigade will just answer that god moves 'in mysterious ways', as they always have done.

Well, that's just another way of saying, "we don't know one way or the other - we're just replacing lack of knowledge with God."

The original fine-tuning argument was more of a physics argument, than theological. Some phyicists tried to see what the Universe would be like, if the basic constants were slightly different, and were surprised to find that even a slight difference produced a totally different Universe, in which planets and even the larger atoms like carbon could never form.

And, physicists also found that the universe could exist much the same as it does now with large changes in the fundamental forces.

So the god squad pounced on that, and argued that god must have made it that way, because the odds against it coming about that way by chance are incredibly high.

That's like saying that God must have arranged the grains of sand on the beach because the chances of them being in precisely the arrangement they are now is infinitessimally small, as would be any other arrangement they are in. But, the grains of sand must be in SOME arrangement. The chances of their being SOME arrangement of sand, given the existence of sand, is 100%. However, given the trillion trillion trillion grains of sand in the Earth, the chances of them being in just this order/arrangement is just barely above zero.

This does seem to be accepted by many phyicists, it's the reasons for it that are more strongly disputed.

Name one.

My own argument, that we are like lottery winners, wondering why we have a winning ticket against such odds, isn't watertight really.
With a lottery, you can point to one winning ticket, but also to the millions of losing tickets.
But with our Universe, all we can see is our one "winning ticket", just one Universe that CAN produce life. Where are all the other "losing tickets", or barren universes?

There may not be any. It seems more like asking where all the humans are that were never conceived. There are trillions and trillions of possible humans that could have been conceived, had one sperm been faster than another. Had two people had sex yesterday instead of today, etc. We are the lucky few who got a chance at life. Trillions of people never lived at all.

Or do we just accept that our Universe being suitable for life was millions to one against, but it still "just happened" that way.
( Please remember I'm playing the advocate here, because we don't have a real believer posting ).
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We don't know what the odds were, or even if there are odds to it. All we know is that we are here, and the universe operates according to regular laws of physics. We know that a hand of God is not necessary to keep the planets spinning or revolving, although that was once thought to be God's role. We know that a God is not necessary for a star to form, or for new species to come to be on the Earth. We know that a God is not necessary for there to be a volcanic eruption or an Earthquake, or a lightning strike. We don't need a god to create a solar system, or a galaxy. These can all come to be due to natural processes. Why then, do we feel the need to presume a creator for things we can't explain (yet)?

[mistermack]

Well, I'm not arguing for a god here. I'm really trying to tease out the facts, for and against.
I have seen claims that the universe would be much the same, without the weak force, so that would argue against any fine tuning.
But I've also seen claims that even a tiny change in some of the other physical constants would produce a Universe devoid of larger atoms, or even carbon and such that stars and planets couldn't form.
I haven't seen this claim "demolished", in fact it seems not to have been vigourously disputed. Normally these things are rubbished immediatly, but this doesn't seem to have been.
If there are millions of ways the Universe could have been sterile, and only one, or very few, in which life could have formed, then that is the essence of the 'fine tuned universe' argument. A situation that is millions to one against needs explaining. I personally suspect that it would crumble, if more in-depth study was done, but it hasn't yet, to my knowledge.
I'm not for it, but I would like to be on solid ground, if someone wants to argue for it.
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[Robert_S]

Well, I'm not arguing for a god here. I'm really trying to tease out the facts, for and against.
I have seen claims that the universe would be much the same, without the weak force, so that would argue against any fine tuning.
But I've also seen claims that even a tiny change in some of the other physical constants would produce a Universe devoid of larger atoms, or even carbon and such that stars and planets couldn't form.
I haven't seen this claim "demolished", in fact it seems not to have been vigourously disputed. Normally these things are rubbished immediatly, but this doesn't seem to have been.
If there are millions of ways the Universe could have been sterile, and only one, or very few, in which life could have formed, then that is the essence of the 'fine tuned universe' argument. A situation that is millions to one against needs explaining. I personally suspect that it would crumble, if more in-depth study was done, but it hasn't yet, to my knowledge.
I'm not for it, but I would like to be on solid ground, if someone wants to argue for it.
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Well, there might be butt-tons of other universes out there with nothing interesting at all going on and nobody in them to ask "What are the odds of such a lifeless dull universe coming into existence?"

Also, there might be other, unimagined ways for a universe to be very interesting without atoms. Imagine you are a non-atomic intelligent entity in another univers. What are the odds that, upon looking at the initial state of our own universe, you would predict life emerging?

[Coito ergo sum]

Well, I'm not arguing for a god here. I'm really trying to tease out the facts, for and against.
I have seen claims that the universe would be much the same, without the weak force, so that would argue against any fine tuning.
But I've also seen claims that even a tiny change in some of the other physical constants would produce a Universe devoid of larger atoms, or even carbon and such that stars and planets couldn't form.

Big deal? So what? Most of the universe is devoid of life. Does that indicate that the universe was not "fine tuned" for life?

When we talk of "fine tuning" we are making implicit assumptions about the nature of the "creator." Why would a creator need to "fine tune" anything? Maybe the creator is new at the creation business, and we are in a "Model-T" universe? Maybe the BMW-M5 isn't going to come out for another few universes.

Maybe there are ways to make universes come out so air and warmth fills the entire universe, so we don't have to contend with vacuums and radiation, or maybe there's a way to make humans not need to breath air or need heat to survive, etc., and so that we can just fly around the universe at will.

Even if the forces would change the universe a lot if they were changed, so what? The universe we have NOW doesn't seem to be the most "fine tuned" for any particular purpose. What's it fine tuned for? Us? We exist on one tiny planet, precariously and dangerously perched on the edge of destruction, and humans have existed on it for only a blip of time during the entire existence of that planet, and that planet is only one of hundreds of bodies in our system, which is one of 200 billion systems in the galaxy which one of another 200 billion galaxies at least, and most of it is empty space filled only with deadly cold, poisonous radiation and endless distances that we can't live long enough to traverse.

If I were fine-tuning a universe for life, I most certainly wouldn't waste all this space and time to put a few isolated humans on a small portion of a single planet nestled in a completely obscure location in a spiral arm of an ordinary galaxy......

But, then again, not being a universe-creator, I have no idea what this creator is like, and I suppose whatever this universe is could suit its purposes. Or, maybe the creator had no purpose at all, and was just fiddling around. Or, maybe the creator was doing something else, and our universe is an irrelevant by-product of what the creator was really working on. Who knows?

I haven't seen this claim "demolished", in fact it seems not to have been vigourously disputed. Normally these things are rubbished immediatly, but this doesn't seem to have been.

What, exactly? The assertion is that if you change one of the fundamental forces of the universe a completely different universe may likely have developed, one that is not able to support our kind of life? It's not that assertion that needs to be demolished - it's the conclusions being drawn from it. The assertion is correct. Remove a fundamental force, like gravity, and the universe will function completely differently. But, so? What does that tell you?

How does that make it more likely that there is a creator? Because the universe could have come about differently but didn't? The sands on the beaches could have landed in a different pattern too. So what? Does that mean that the grains were placed there purposefully? Answer: no.

If things exist, they have to be a certain way. The fact that they are a certain way doesn't imply a creator. It implies existence.

If there are millions of ways the Universe could have been sterile, and only one, or very few, in which life could have formed, then that is the essence of the 'fine tuned universe' argument. A situation that is millions to one against needs explaining. I personally suspect that it would crumble, if more in-depth study was done, but it hasn't yet, to my knowledge.
I'm not for it, but I would like to be on solid ground, if someone wants to argue for it.
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Well, nobody knows that it's millions to one against. Maybe this is the only way a universe has ever formed. So, it would be one in one.

You're assuming that because we can imagine other quantities that the forces might have and then change the equations, that they must be equally likely options, as if there was a dice roll at the big bang and the quantities were set randomly. There is no reason to think that the quantities are set randomly. All we know is that the quantities are what they are.

[lpetrich]

It's a mixed bag.

Dimensions of space-time. We live in a Universe with a 3+1 structure of dimensions -- 3 space and 1 time.

A single time dimension imposes a direction of time. More than one time dimension would allow a particle to reverse direction in time, by going in a circle in the time dimensions. It would also turn kinetic energy into a vector quantity, a vector in the time coordinates' components.

Our 3 space dimensions are the maximum that can allow stable orbits to exist. Fewer than 3 space dimensions would allow much less complexity, so we likely live in the only number of space dimensions that can allow us to exist.

Fine tuning: +

Discrepancy between gravity and nongravitational elementary-particle mass scales. The Planck mass is 1.22*1019 GeV, much, much larger than the masses and mass scales of the known nongravitational elementary particles. The largest such mass scale is associated with electroweak symmetry breaking. It is the Higgs-field vacuum expectation value, which is about 246 GeV. Supersymmetry breaking likely has mass scales of around there to 1 TeV, a tiny bit closer.

However, GUT symmetry breaking has a mass scale of about 1016 GeV, which is much closer.

This discrepancy is fortunate in some ways, because it makes the gravitational interaction very weak by elementary -particle standards, thus enabling massive objects to have large numbers of elementary particles. This makes possible the sorts of complexity that our Universe has. However, this is not tied to some small range of possible values, and we can easily have complex universes if the Planck mass is somewhat smaller than our value, or larger than our value.

Fine tuning: +?

Standard-Model multiplet structure. That's a result of GUT-scale symmetry breaking, and it looks rather byzantine, to say the least. Here are the representations of SU(3)*SU(2)*U(1) the various elementary particles fall into:

Gravity: (1,1,0) - gauge scalar
Gauge: gluon: (8,1,0), W: (1,3,0), B: (1,1,0)
Higgs: Hu: (1,2,1/2), Hd: (1,2,-1/2)
Elem. fermion: Q: (3,2,1/6), U*: (3*,2,-2/3), D*: (3*,1,1/3), L: (1,2,-1/2), E*: (1,1,1), N*: (1,1,0)

The interaction-parameter matrices for the elementary fermions and Higgses only make it even more complicated. They are 3*3 matrices because they are indexed by the three generations of elementary fermion.

It's not clear what other possible symmetry-breaking patterns there could possibly be; the string-theory landscape suggests an enormous number of possibilities.

Fine tuning: ?

Specific features of the Standard Model. Some features are rather convenient for us, like the QCD energy scale being much bigger than the masses of the electron and the up and down quarks. This makes the proton and neutron very close in mass -- and nearly 2000 times more massive than the electron. Much lower mass, and we wouldn't have much variety of nuclei, since the up-down mass difference would be much greater than the binding energy. Much higher mass, and the proton would be more massive than the neutron, with interesting alterations in nuclear physics and nucleosynthesis.

There is also the interesting coincidence that in the expansion of the Universe, neutrino freezeout occured when the Universe's temperature was about a few MeV, around the proton-neutron mass difference. If the weak interaction was weaker or gravity stronger, then the Universe would have had nearly equal numbers of protons and neutrons, meaning little surviving hydrogen. If the opposite, then the Universe would have had mostly protons and hardly any neutrons, which is much less of a calamity.

The fine structure constant is not really constrained by the physical and chemical properties of familiar materials -- those are largely due to the fermionic nature of electrons and their electromagnetic interactions.

Fine tuning: +?

Universe habitability. If the Universe had been created for the benefit of humanity, then most of it had gone to waste. Nearly all its volume is inhospitable to us. Although many stars likely have planets, many of those are also inhospitable to us. This is evident in our Solar System, where only the Earth is habitable for us -- and for just about all of its biota.

Fine tuning: -

So why the Universe is a little bit fine tuned for us, it is not very strongly fine tuned, and it's the sort of Universe that one would expect from a multiverse where most of the universes are uninhabited.

[Feck]

Birds Eggs amazing things what are the chances that something so handy reliable and nutritious would happen ?

or are we arguing with hindsight ...same with the universe .


We exist in a universe that has physical constants that allow us to exist .....WELL DUH ! that's taken as bloody obvious since we are talking about it .

the same argument is used to deny Evolution...What are the chances ????? etc

[mistermack]

I am playing the devil's advocate with this thread, I was interested in the most convincing arguments for, and the best ones against. We aren't getting many 'for', so I'm doing that bit as best I can.
I'm not too bothered what conclusions people draw from fine tuning, just whether there is anything about the universe that actually is fine tuned.

I would try to put the argument like this.
Imagine one million people bought a one-pound lottery ticket. They all congregate in a vast stadium. A huge hat in the middle has one million pieces of paper, folded, with a number inside, the numbers run from one to one million.
The winning number between one and a million is chosen by a random machine.

Now the first person walks up, picks a piece of paper out of the hat at random, opens it, and it's THE WINNING TICKET!! Would you say, well, someone has to win, or would you harbour a suspicion that it was more than mere chance?

That's what they are saying. As far as we know, this universe is the only ticket drawn, and there were millions of possible losing tickets, and only one winner.
Should we be looking for a reason? It doesn't have to be a religious one. But was it really millions to one against a Universe that could produce stars and planets.
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[Gawdzilla Sama]

You'll have to ignore the fact that I don't believe you are "impartial" here. I have too frequently seen an opening gambit like this from the wooistas.

[mistermack]

You'll have to ignore the fact that I don't believe you are "impartial" here. I have too frequently seen an opening gambit like this from the wooistas.

I am biased. I declared that in the opening post. But I'm interested in the arguments for and against, so I'm acting as an advocate FOR fine tuning, to balance the debate. I would prefer it if someone else helped me out, but it's an interesting subject to me. I don't support the fine-tuning argument, but I still haven't seen top physicists shouting that there is NO apparent fine-tuning.
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[Gawdzilla Sama]

You'll have to ignore the fact that I don't believe you are "impartial" here. I have too frequently seen an opening gambit like this from the wooistas.

I am biased. I declared that in the opening post. But I'm interested in the arguments for and against, so I'm acting as an advocate FOR fine tuning, to balance the debate. I would prefer it if someone else helped me out, but it's an interesting subject to me. I don't support the fine-tuning argument, but I still haven't seen top physicists shouting that there is NO apparent fine-tuning.
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That entire statement is what I don't believe.

[mistermack]

That entire statement is what I don't believe.

I don't believe you don't believe it.
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[Gawdzilla Sama]

That entire statement is what I don't believe.

I don't believe you don't believe it.
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I don't care.

[mistermack]

I don't care.

I doubt that very much.

[MrFungus420]

Well, the Sun rises at just the right time for us to wake up and begin our day...what are the chances that the Sun would rise at the perfect time for that?
(to paraphrase Terry Pratchett)