Victor Stenger's Cosmological Fine Tuning Counterarguments

Great Debates
1

I’m not sure where best to put it, so I’ll put it here.

For some time I’ve been hearing about the idea that the universe is “fine-tuned” for life, as claimed by various forms of christian apologists - notably creationists. The idea is that the universal constants and many of the universal formulations - if tweaked slightly - would cause the universe to be uninhabitable. I’ve been meaning for some time to read up on counterarguments and whatnot, to understand better the claims.

So reading this month’s edition of Skeptic Magazine, I came across an article by Victor Stenger on this very topic. He is a physicist who has written various articles in Skeptic and Skeptical Inquirer.

The article starts off with a brief background on fine tuning arguments, and brings up Victor’s previous book he wrote addressing the topic. He goes on to bring up the “multiverse” concept that proposes that various and sundry “universes” are in the process of being spawned and spinning off. I followed all this discussion without comment.

He then turned to addressing some specific claims regarding fine tuning. This is the part where he started saying things I didn’t follow or disagreed with.

His first class is what he calls “trivial parameters”: the speed of light in a vacuum, c, and Planck’s constant, h. He says:

He makes a similar argument for Planck’s constant, Boltzmann’s constant, k[sub]b[/sub], and Newton’s gravitational constant, G. He then states:

Now wait just a second. Yes, those constants have values that have dimensions, and thus have units. And therefore, you must pick the value that corresponds to the units you wish to use. But that doesn’t make the values arbitrary. You can’t pick any number out of a hat and call that c or h or G for the day. “Oh, I think today I’d like the speed of light to be 12 m/s.” You are constrained to the values that fit what the universe actually does.

Yes, we have come up with some special ways to define the various units in order to make them precise and consistent. But Newton didn’t make up G out of thin air. He measured it. c was a measured value. I’m baffled by Stenger’s dismissal of these properties of the universe simply because they are expressed by constants that have dimensions. Can anyone make sense of that for me?

Stenger goes on to address more parameters for life.

Ratio of electrons to protons in the universe: the creationist claim is that if the ratio were larger, there would be insufficient chemical binding; if smaller, electromagnetism would dominate gravity preventing galaxy, star, and planet formation. Stenger’s reply is that the ratio is exactly one based upon conservation of charge, on the reasonable expectation that the total electric charge of the universe is zero.

Ratio of electromagnetic force to gravity: the creationist claim is that if the ratio were larger, there would be no stars less than 1.4 solar masses and hence short and uneven stellar burning. A smaller ratio would give no stars larger than 0.8 stellar masses, and no heavy element production. Stenger’s reply includes:

Regarding comparing electromagnetism vs gravity, I think the point is that at the atomic and subatomic scale, gravity is negligible compared to EM due to the small masses versus the size of the charges involved. Maybe it’s fair for him to complain about that comparison.

The second part is a bit esoteric, but starts with the word “assumption”. That seems a reckless way to justify a strong counterargument. I’m not savvy enough to understand the relative sensibleness of that assumption or the source of the “corrections” he posits.

I’ll come back to more of his points if there’s interest.

2

I’m not a physicist or cosmologist, but I always considered that the only necessary answer to the “fine-tuning” arguments is that if the universal constants etc. did not favor life, we wouldn’t be here to wonder about it. Aren’t these arguments just post hoc fallacies (noting that it’s been 40 years since I studied logic)?

eta: I realize this isn’t exactly the subject you raised in your OP. Sorry if this consitutes a hijack.

3

Personally, I find the arguments for a “Goldilocks universe” to be very convincing. This is the first I’ve heard it was claimed by “christian apologists”; I’ve always thought it more of a “multiversian” thing.

I didn’t click the link, but the arguments you quote seem like trivia or tautologies.

For reasons similar to “K equations in K unknowns” reasoning, K parameters like c or h can be subsumed as trivial for K dimensions. But with charge and other quantum properties already quantized, the three dimensions (mass, time, distance) allow you to dispose of only three parameters. How many unexplained physical parameters are there in the present standard model? I think it’s a lot more than three!

The ratio between gravitational and electromagentic strength is an unexplained fundamental constant with a huge impact on the universe. Whether one adjusts the definitions to make that ratio “small” or “large” is beside the point.

What determines the precise rate of the 3He –> C reaction central to star longevity and element distribution? Are detailed explanations for the chemistry of water and carbon available? If the weight ratios of various quarks were tweaked very slightly would life be silicon based? Or would the universe just be a boring muddle?

4

Was. He died earlier this year.

5

Even ignoring the anthropic principle, the biggest problem I have with the fine tuning argument is that yes, if those constants were changed life as we know it wouldn’t wouldn’t be possible. Well so what? Then life not as we know might be possible.

And even if you go all the way down into the constants that make atoms possible, again, so what. Then other things, atom-like or not, might be possible.

6

I believe the Fine Tuning Argument is that if any of those constants were changed a little, then it would result in a world where life was not possible at all, because things like star formation and complex chemistry would not be possible. I have read some from Stenger that changing one constant at a time may make life impossible, but there are many combinations where you change more than one at a time and it would allow interesting properties of matter.

Out of all the religious apologist arguments for a god, I find the FTA to be (by far) their best one, not that it’s very good. We don’t know why the constants are what they are, but that’s just our current ignorance. My gut feel is that there is some physics we haven’t discovered yet that mandates their values to be what they are.

7

I agree. The number used to specify the length of my middle finger could be practically anything, depending on what units you’re using: centimenters, inches, feet, light-years, middlefingerunits… But that doesn’t make the length of my finger arbitrary.

8

As I see it, no, because us being here to wonder about it is a “special” outcome.

If I toss 200 coins, and they all come up tails, that’s a special outcome, and I’d have a really hard time believing it had happened as a result of pure chance—even though it’s no more or less likely than any other particular outcome.

9

CurtC beat me to it, but just to reiterate, the strong anthropic principle in particular isn’t an argument for “life as we know it”, it’s an argument for the structural complexity that is a prerequisite for life. Small changes to the fundamental constants would prevent stars from forming, or prevent the creation of heavier elements that are necessary for complex molecules to form, or result in a universe that was predominantly helium instead of hydrogen. At the other extreme, changes in fundamental constants would not likely result in some novel kind of atomic structure, but in almost all cases no structure at all.

That said, if creationists of any kind are trying to use the anthropic principle to bolster their crackpot beliefs, then they just don’t understand it.

10

No, the selection of units doesn’t make the length of your finger arbitrary…but the actual length of your finger in any set of consistent units is (mostly) arbitrary compared to statistics on then lengths of fingers in the overall population. Put another way, by measuring the length of your finger by itself and in absence of any other information, we cannot make any solid estimates of the lengths of other fingers or the distribution of finger length. You may have especially long fingers, or short ones, or more fingers or less fingers than other people and so forth. Without having knowledge of what determines the length that a finger will develop into the length is, in fact, arbitrary. Similarly, although we can measure the constants (which have dimensions only in relationship to one another, not to any human-created system of measurement which is actually dependent upon those constants) we can’t say anything about how “preferred” those constants are or what other functional variation they may have in other possible universes.

The outcome is only special to us, and only because we regard ourselves and the environment that supports us as being in some way special. This reflects the assumption of a necessarily anthropocentric point of view, e.g. that we are the center of some universal purpose. But in fact, there is zero objective evidence that we are in any way special or unique in the universe, or that our universe is in any way special or unique in all possible environments. Yes, we happen to have evolved in a relatively thermodynamically form (albeit non-equilibrium) based upon the electrochemical mechanics of this universe, but all of life as we understand it can be reduced to the fundamental connections and reactions that are easily modeled and understood. The overall complexity of the system (of an organism, biosystem, or evolutionary chain) is necessarily highly complex and impossible, at this point, to model in sufficient detail to predict behavior at all but the most coarse level, but that reflects our current primitive state of understanding of the world, not some inherent and insoluble mystery of it.

And while combinations of slight changes in the fundamental physical constants might make not only life as we know it but the fundamentals of chemistry (upon which our particular form of life is dependent) unworkable, or even affect the balance of other forces which allows stars and galaxies to form, this doesn’t say anything about how many chances–rolls of the dice, if you will–it took to get to our universe, or what other possible combinations of constants might create a very different, but also stable universe with some viable analogue to life based on completely different and likely incomprehensible mechanics. If we may assume that multiple universes could exist, is there any limit to how many? And if the answer is potentially infinite, then there is a subset of also potentially infinite stable, workable combinations which would create universes also capable of self-organizing, non-equilibrium thermodynamic systems which could also question the uniqueness or not of their own existence while staring up at some analogue of the Milky Way, perhaps a linear streamer of fusing neophlogiston, or a rotating ring of magnetically radiating computronium, or some other moderated power supply radiating energy to lifeforms.

There is absolutely no reason to believe that we are special or unique in our universe, or our universe is special or unique in all possibly formulations of a universe. Nor can we make any reasonable assumptions about the probability or characteristics of those formulations from our single datum.

Stranger

11

Completely agree with the first point, which touches on a discussion in another thread about the likely abundance of habitable planets in our galaxy (and by extension, in all others) and therefore the probable abundance of life, albeit at very low spatial density in terms of human metrics. But on the second point, the word “special” in the post you were responding to is perhaps a bit misleading. The physical constants are only “special” in the sense that altering them seems in the vast majority of cases to produce an uninteresting universe devoid of structure like stars and heavy elements, and therefore certainly devoid of life.

The fact that this “specialness” isn’t unique and that in a hypothetical multiverse there could be an infinite subset of universes with the same or different constants that produce complex structures and the emergence of intelligence is something that seems to me to be rather irrelevant. With infinite throws of the dice anything is possible. Somewhere in the infinite string of digits that comprise the value of pi, the complete works of Shakespeare will be found encoded, but that doesn’t diminish the value of his work. In the same way, speculation about the hypothetical multiverse should not diminish our wonder at the fact that the physical constants are what they are, and that even tiny changes would result in more or less a formless void (which is a term from Genesis but I am not in any way implying anything religious here, at all, and those who do – as I said before – don’t really understand what is meant by the anthropic principle).

A useful rough analogy would be the set of conditions that established life on earth and, ultimately, ourselves. We can speculate – as we do about the multiverse – that life is probably abundant in our galaxy and in others, but we also believe from our understanding of physics and the chemistry of complex molecules that life can only be created under a certain narrow set of conditions, and if you don’t have those conditions, you get lifeless desolation. We used to speculate about exotic forms of intelligent life on Mars and other nearby planets, and now we know better. We should value and admire the conditions on earth that are “special” in that specific context, even though informed speculation leads us to believe that there must be billions of other such conditions in the universe. In my view, in the same human or anthropocentric context it’s quite appropriate to marvel at the physical constants that allowed us to exist.

12

Or in other words, the result of changing the speed of light to 12 m/s would just be a universe that was smaller by a factor of 12/(3*10^8).

13

While I would be amazed that any given single individual (such as my bother) won the lottery, should I be amazed that the single individual on the cover of the “lottery monthly” won the lottery.

14

If the constants were different, life as know know it may not exist. And if triangles had four sides, geometry as know it may not exist.

15

Let me pick up some more, then I’ll come back and address comments.

The next topic was the expansion rate of the universe, and the mass density of the universe. The claim is that if the expansion rate of the universe (i.e. the Hubble parameter, H) were larger, there would be no galaxy formation. If smaller, the universe would collapse prior to star formation. Stenger replies that the inflationary model results in the mass density of the universe being very close to the “critical value”, which depends on H. This implies H has a critical value. He does not explain what that means.

He then basically points out that the density and the expansion rate are linked, as so only one can be freely varied, and the other would be correlated. The age of the universe is given by 1/H, and if H corresponds to the critical value, then the age of the universe is what it is, and the mass density corresponds to the age of the universe, and the expansion rate could be almost anything. It seems to me he is essentially saying that the original claim is just wrong, and that a larger expansion rate would just put us further along the curve, a smaller expansion rate not as far along the curve.

His next topic is the cosmological constant, which is equivalent to the energy density of vacuum. It is a favorite candidate for dark energy. This argument seems to boil down to the original calculations giving an absurdly large value compared to the observational results. However, there was an error in the way the calculations were made, and when that error is corrected, the results correspond to the critical density and observations.

He next turns to astronomer Fred Hoyle’s prediction of the carbon atom excited state needing 7.7 MeV (million electron-volts) above its ground state for enough carbon to be produced in stars to make life possible. Shortly after this prediction was made, it was discovered that carbon’s excited state energy is 7.656 MeV. Stenger replies that calculations show the same amount of carbon would be produced if that ranged anywhere from 7.596 to 7.716 MeV, and further, sufficient carbon would be produced if the excited state was anywhere from just above the ground state to 7.933 MeV. And finally, carbon isn’t the only element on which life could be based. That doesn’t speak of fine tuning.

He blows off in this article some parameters he already addressed in his previous book: relative masses of elementary particles, relative strengths of the forces, the decay rate of protons, and the baryon excess in the early universe.

Then he lists two more cosmic parameters: the deuterium abundance, and the lumpiness of matter. At this point he brings up something that may answer some of your previous questions:

While this answer has the dreaded “assumed” embedded in it, as well as the unexplained reference to “critical value”, it nevertheless does a good job of addressing fine-tuning complaints. Cosmologists have a model that only has six adjustable parameters, and only one of the supposed parameters proposed by the fine tuners is actually adjustable. All the others are derived from the model. That’s a pretty powerful rebuttal to fine tuning.

One more point that Stenger brings up relates to simulating universes to determine their compatibility for life. He states:

He points out one objection he received to this statement refers to criteria set by John Barrow and Frank Tipler in The Anthropic Cosmological Principle that define technical requirements for life to be possible. Stenger claims he checked and found their limit to be satisfied 91 percent of the time.

Now he does not reproduce any details of how he did these simulations, there is no data set provided or methodology, so we are taking his word for this. His book may have addressed this in more detail, I do not know.

Anyway, that is the bulk of the article.

16

Thanks for the interest in the thread.

I don’t follow. I’m not saying those values are not known. I’m saying that the values represent some characteristic about the way the universe functions, and the fact that they have units doesn’t in my mind dismiss them.

Well, I guess I can’t ask him, then.

Yes, he makes that point in the article.

Okay, so what he was trying to say is that those parameters do not seem to have any effect on the function of the universe? I’ll accept that statement for “arbitrary”, but I’d like a little more justification for his dismissal that because they have units that makes them insignificant. Now later in his article he talks about the Lambda Cold Dark Matter model, and it having only 6 parameters. Is that saying that these “trivial” constants are all outcomes from the model? That would be a better answer. But I don’t get how having units makes the constants dismissable.

17

How come everyone is missing the Nobel Prize winning discovery he made. According to him, the ratio of EM force to gravitational force equals the fine structure constant. Which - wait for it - is dimensionless.

Fine tuning = fine structure. Ta da!! Ergo God exists. Or he doesn’t. What side is Stenger on?

18

Note also that He[sup]4[/sup] has almost exactly half the energy of Be[sup]8[/sup], essential to Hoyle’s hypothesis. The reaction 3 He –> C proceeds, but at an extremely slow rate. If it were slower, elements like carbon wouldn’t form, if higher stars would be short-lived.

Why does Stenger think there are only three parameters? What about the strengths of gravitation, strong, and weak forces? Davies in The Goldilocks Enigma claims all three of these forces are fine-tuned:
[ul][li] If gravity were stronger, all stars would be “radiative” but only “convective” stars produce planets.[/li]If gravity were weaker, all stars would be convective, but only radiative stars lead to the supernovae which produce heavy elements.
Gravity has a “Goldilocks” strength which leads to both star types.
[li] If the strong force were different, carbon production wouldn’t proceed at the “Goldilocks” rate: stars would either be short-lived, or unable to produce higher elements.[/li][li] According to Davies, the weak force has a “Goldilocks” strength for two different reasons: If either smaller or larger, supernovae wouldn’t explode. Also, if smaller, the initial universe would have been almost all hydrogen; if larger, helium. Instead there is a “Goldilocks” mixture of hydrogen and helium.[/li][/ul]
One can suppose that with different parameters, different useful equilibria would be achieved. But how many could there be? If you posit a particular set of parameters perfect for nitogen-based life, and another set perfect for phosphorus, you’re going to run out of elements quickly.

We may be in agreement. I should have spoke of “degrees of freedom” rather than “unknowns.” In any event the point is that to subsume the distance/time ratio, you get one velocity for free, but any other velocities are non-free parameters. Once you’ve specified three parameters (say c, h, mass-of-electron), remaining parameters are non-free.

19

What always struck me about this argument is how it presupposes that the creator is bound by the rules of creation. It would be much stronger evidence for a god or gods if we existed in a universe that couldn’t support life–that right there would make an unambiguous case for a supernatural, miraculous being.

20

But, if we exist in a universe, then by definition that universe can support life. :confused: