Saturday, April 23, 2016

The fine-tuning of the universe

1. If the initial explosion of the big bang had differed in strength by as little as one part in 10\60, the universe would have either quickly collapsed back on itself, or
expanded rapidly for stars to form. In either case, life would be impossible.
2. (An accuracy of one part in 10 to the 60th power can be compared to firing a bullet at a one-inch target on the other side of the observable universe, twenty billion light years away, and hitting the target.)
3. Calculations indicate that if the strong nuclear force, the force that binds protons and neutrons together in an atom, had been stronger or weaker by as little as five percent, life would be impossible.
4. If gravity had been stronger or weaker by one part in 10\40, then life-sustaining stars like the sun could not exist. This would most likely make life impossible.
5. If the neutron were not about 1.001 times the mass of the proton, all protons would have decayed into neutrons or all neutrons would have decayed into protons, and thus life would not be possible.
6. If the electromagnetic force were slightly stronger or weaker, life would be
impossible, for a variety of different reasons.
7. Either this is an accident, or a design. Or perhaps there is a multiverse, and we just happen to be in the universe that has life in it.



24 comments:

John Moore said...

Another option besides accident or design is necessity. Why do we assume gravity or the strong force etc. could ever have been different? Maybe there's just one way a universe can possibly be.

entirelyuseless said...

I keep seeing these claims, but I have never seen someone justify claims like 1. or 4. I do not think those can be known to be true, because I do not think that anything has been measured to that accuracy. And you would have to measure it to that accuracy to be sure that a change that small would make a big difference. For example, Wikipedia says that the gravitational constant has a "relative standard uncertainty 4.7×10−5." That does not seem consistent with number 4.

entirelyuseless said...

I've searched for the text of the first claim, and it appears to go back to an argument by Robin Collins, but it misinterprets what he said. He doesn't say that anything is so precise that you can't change it by 1 in 10^60 without messing things up. He says that the range that he considers reasonable for that value if you chose it randomly is 10^60 (actually he says 10^53) times as large as the kind of range which would have produced life -- the exact values are not known nearly well enough to say what would happen "if the initial explosion of the big bang had differed in strength by as little as one part in 10\60." Most likely things would have been basically the same.

It is a kind of argument for fine tuning, but much weaker than saying that the constant is actually that precise and has to be that precise.

Victor Reppert said...

On P1, see Paul Davies, The Accidental Universe, (Cambridge, 1982).

Mr. Green said...

John Moore: Maybe there's just one way a universe can possibly be.

Except that's quite obviously false. What could that even mean? There is no logical necessity for the laws of physics to be what they are or fundamental constants all to have the values they do, as opposed to, say, the necessity of the angles of a triangle adding up to 180°. There isn't even any logical necessity for a universe to exist at all.

John Moore said...

It's not obviously false at all. We really have no idea what an alternate universe could be like, since we've never seen one. It's entirely possible that no alternate universes can exist at all. How would you ever know?

It's exactly like the triangle with angles adding to 180 degrees. Think about it this way: If the universe started out as a zero-dimensional singularity, then there's only one way for it to expand.

Also, when you say there's no logical necessity for a universe to exist, you're implicitly assuming there was a time before the universe existed, a time at which the universe might or might not have started to exist. I'd simply say that such a time does not exist.

Joe Hinman said...






Paul Davies:Templeton prize address

"You might be tempted to suppose that any old rag-bag of laws would produce a complex universe of some sort, with attendant inhabitants convinced of their own specialness. Not so. It turns out that randomly selected laws lead almost inevitably either to unrelieved chaos or boring and uneventful simplicity. Our own universe is poised exquisitely between these unpalatable alternatives, offering a potent mix of freedom and discipline, a sort of restrained creativity. The laws do not tie down physical systems so rigidly that they can accomplish little, but neither are they a recipe for cosmic anarchy. Instead, they encourage matter and energy to develop along pathways of evolution that lead to novel variety-what Freeman Dyson has called the principle of maximum diversity: that in some sense we live in the most interesting possible universe."

"Some scientists have tried to argue that if only we knew enough about the laws of physics, if we were to discover a final theory that united all the fundamental forces and particles of nature into a single mathematical scheme, then we would find that this superlaw, or theory of everything, would describe the only logically consistent world. In other words, the nature of the physical world would be entirely a consequence of logical and mathematical necessity. There would be no choice about it. I think this is demonstrably wrong. There is not a shred of evidence that the universe is logically necessary. Indeed, as a theoretical physicist I find it rather easy to imagine alternative universes that are logically consistent, and therefore equal contenders for reality." First Things: Physics and the Mind of God: The Templeton Prize Address (1999)



Joe Hinman said...


April 24, 2016 2:44 AM



Blogger John Moore said...
It's not obviously false at all. We really have no idea what an alternate universe could be like, since we've never seen one. It's entirely possible that no alternate universes can exist at all. How would you ever know?


That would be a cogent criticism of old style design arguments because they didn't have a control on what is design they basically just said "it looks right." We have a control with FT: whatever is not the target level is undersigned, why because its so vastly unlikely. when you consider the vast array of possible plank lengths or other such things every actually represents a contradiction to millions of possibilities.

It's exactly like the triangle with angles adding to 180 degrees. Think about it this way: If the universe started out as a zero-dimensional singularity, then there's only one way for it to expand.

No it's nothing like that. Because within the range of possibility it could fail to manifest life at all or produce a universe teaming with life.


Also, when you say there's no logical necessity for a universe to exist, you're implicitly assuming there was a time before the universe existed, a time at which the universe might or might not have started to exist. I'd simply say that such a time does not exist.

The difference between some universe and none does not require a time before. that is going to depend upon weather or not you keep the singularity. with a singularity you can have one that doesn't expand or one that does the inflation thing then never forms any sgtars.

Joe Hinman said...

My FT argument 2cpges but page 2 is my answers on Multiverse

Mr. Green said...

John Moore: We really have no idea what an alternate universe could be like

Sure we do: like anything (that doesn't contain a logical contradiction).

It's exactly like the triangle with angles adding to 180 degrees.

Really? This exact universe is the only possible way things could be? So John Moore is a logical necessity? Wow!

How would you ever know?

Because if no other universe were logically possible, then every other universe would be logically self-contradictory. But since it's trivial to think up self-consistent sets of universe-descriptions, that's false.

Think about it this way: If the universe started out as a zero-dimensional singularity, then there's only one way for it to expand.

"If" it did... then that's one kind of possible universe. If it didn't, then that's another kind. And obviously there isn't only one way for it to expand — because "not at all" is another possibility. Or expand a little bit and then stop. Or expand in one dimension but no others. Or expand in a million dimensions.

Also, when you say there's no logical necessity for a universe to exist, you're implicitly assuming there was a time before the universe existed

I'm assuming no such thing.

Aragorn said...

Weisberg

John Moore said...

You guys keep saying it's easy to have alternate universes, but you really don't know what you're talking about. Mr. Green said, "It's trivial to think up self-consistent sets of universe-descriptions," but how do you know they are self-consistent? Just because you don't see the logical contradiction, that doesn't mean it's not there.

Paul Davies said, "I find it rather easy to imagine alternative universes that are logically consistent," but again I think he's just imagining they are logically consistent. He doesn't want to see logical contradictions in his fantasy worlds, so he doesn't look for them.

Joe Hinman spoke of "the vast array of possible plank lengths," but you're just assuming such an array exists. I honestly don't see how the Planck length could possibly be any different than it is.

----

OK, here's a kind of far-out theory for why the universe can't be different:

See, if the universe started out as a zero-dimensional singularity "without form, and void," then the Planck length is the result of the very first emergence of dimensionality. From ultimate oneness, there was suddenly twoness. The question is how far apart the first two things were, and the answer is that there's no possible way to measure. The first two particles in existence were just as far apart as they were, and there's nothing more we can say about that. This is the Planck length. So it's incoherent to imagine the Planck length being different.

What if all the other constants of nature derive from the Planck length? That way, it doesn't matter precisely what the constants are, but everything just depends on the relative values. You couldn't change one constant without all the others adjusting appropriately, and the reason is because they all derive from the same zero-dimensional origin.

Legion of Logic said...

If there is one way things can be, what are the odds that things would be that way?

Legion of Logic said...

If there is one way things can be, what are the odds that things would be that way?

Joe Hinman said...

John Mooore:"Joe Hinman spoke of "the vast array of possible plank lengths," but you're just assuming such an array exists. I honestly don't see how the Planck length could possibly be any different than it is.
"

John if you look at the link I put up there you will see that argument is made by Andre Linde, atheist, physicist one of the authors of inflationary theory. He said it was a formidable problem that made FT argument hard to answer. I got the argument from him.

Joe Hinman said...

more "Paul Davies said, "I find it rather easy to imagine alternative universes that are logically consistent," but again I think he's just imagining they are logically consistent. He doesn't want to see logical contradictions in his fantasy worlds, so he doesn't look for them."

Let's see who do we listen to? Templeton prize guy or someone on one knows? Maybe that is unfair let's do it this way: Linde backs up Davies in that assessment and he's trying to beat the FTA. I mean he's article lists several issues where the FT argument has a point that needs answering.

Problem is another major physicist pulled out of his defemnse of strking theroyu because hev sakid to push inflation they had to use fine tuning anywal


Physicist Paul Steinhardt, one of the originators of the theory, had doubts about it as early as his first paper on the subject (1982). He admits that the point of the theory was to eliminate fine tuning (a major God argument), but the theory only works if one fine tunes the constants that control the inflationary period. “The whole point of inflation was to get rid of fine-tuning – to explain features of the original big bang model that must be fine-tuned to match observations. The fact that we had to introduce one fine-tuning to remove another was worrisome. This problem has never been resolved.”i Nor is inflationary theory backed by observation. Many great observations have been made to back up the original theory. But as Steinhardt points out the theory has evolved such that, “we no longer believe that inflation makes any of those predictions so that none of the magnificent observations made over the last 30 years can be viewed as supporting inflation.”ii What's more one prediction that has not worked out is gravitational waves, predicted before '83, that should have been detected by WMAP and Planck satellites and was not.iii


John Horgan, “Physicist slams Cosmic Theory he Helped Conceive,” Scientific American Blogs, December 1, 2014. on line, URL http://blogs.scientificamerican.com/cross-check/physicist-slams-cosmic-theory-he-helped-conceive/ accessed 10/5/15.
Horga

Joe Hinman said...

here's another problem with John Moore's thinking, on the necessity of the universe. Lot's of atheists are pretty stuck on multiverse. I told DC not get rid of it. Anyway, the idea that we have unlimited boundless sea of alternate universes and they are exactly like this one, that's worse than Nkietzsche's eternal return.

Gyan said...

VR,
Science is not competent to pronounce upon "initial explosions". You are still relying upon naive, popular presentations. This is entirely one piece with your misrepresentations of science ---re: your confusion of Methodological naturalism for one.

planks length said...

What if all the other constants of nature derive from the Planck length?

Hey, guys! Don't start blaming all this stuff on me now!!

Joe Hinman said...

LOL

Mr. Green said...

John Moore: Mr. Green said, "It's trivial to think up self-consistent sets of universe-descriptions," but how do you know they are self-consistent?

By using logic. It really isn't hard. And your slam against Davies is entirely unwarranted, with no evidence to support it.

I honestly don't see how the Planck length could possibly be any different than it is.

Didn't someone once say, "Just because you don't see, that doesn't mean it's not there"??

See, if the universe started out as a zero-dimensional singularity

"If". And if not?

So it's incoherent to imagine the Planck length being different.

You mean, if one accepts all your 'if's about the universe being a certain way, then on that particular view Planck-length is fixed. Great, so what? The problem is not that there may be a coherent possible universe in which it cannot "be different", the problem is that that whole universe is only one possibility. There are other possible universes in which Planck-length can be different. There are other possible universes — infinitely many — in which there isn't anything even corresponding to Planck-length in the first place.

What if all the other constants of nature derive from the Planck length?

Who cares? We're not talking about the way the actual universe really is, we're talking about the infinity of ways it could have been. Even if it turned out that there is only one way to get a universe just like this one, that says nothing about universes that are completely different. Nothing you have said even addresses that question. (Other than suggesting that anyone who disagrees with you is too thick to recognise a logical contradiction.)

Mr. Green said...

Joe Hinman: Lot's of atheists are pretty stuck on multiverse. I told DC not get rid of it.

Hah! (Yeah, the problem with multiverses is that to make sure they work, they have to have certain properties, and then all you've done is push the fine-tuning up a level.)

Joe Hinman said...

true

planks length said...

It's turtles all the way down!