The "fine tuning" argument: A "meta" look

Imagine a scientist is present at the very moment of the Big Bang. This person knows everything we now know about physics, and knows all the conditions and parameters that describe the state of energy and matter at the first moment after the BB. However, he has no knowledge about the history of the universe as it has unfolded after the Big Bang.

Would this scientist be able to predict that, 14.5 billion years after the event he has just witnessed, there will be giraffes?

If not, then why do people who use the fine tuning argument presume to know what would or would not happen in a universe in which the physical parameters are different?


Well, I’m not an expert on FTA but the idea is that even though you can’t predict what exactly would happen, it is reasonable to predict what definitely can’t happen. It’s difficult to imagine life arising in a universe where stars and galaxies can’t form, for example.


I’ve been rather skeptical about the supposed a priori predictions about what different laws of physics should be able to produce for a long time. On the one hand I can see that there are changes that would make the kind of organic chemistry that we know of impossible. Tweak the nuclear or electromagnetic forces enough and you end up with different elements and chemical bonds, and that would make life-as-we-know-it impossible.

The problem is, I’m much less persuaded that this makes life as we don’t know it impossible too.


Of course it’s difficult to imagine, because the only universe we know of is the one with stars and galaxies.

Our imagination does not limit what could exist.

Does a universe even need to have things as fundamental as energy, mass and charge? What does a universe look like in which these things are replaced with something completely different? How do we know that is not possible?


These are interesting questions, though they are talking about different things.

First, most popular versions of the FTA still assume the laws of the universe are the same, but only with different fundamental constants. In this scenario, if stars and galaxies can’t form at all, I find it hard to imagine that any sort of “life” would occur. Life doesn’t have to be carbon-based, but it has to take the form of some collection of molecules acting together to make distinct beings that move and reproduce in some way. Otherwise, we wouldn’t call it “life”. I’m genuinely interested to hear from you imaginative proposals on what non-chemistry-based life would be like.

Secondly, you can certainly imagine a universe with different physical laws than ours, such as that gravity scales as r^{-3} instead of r^{-2} for example. You can even imagine a universe where gravity scales completely differently. But this is different from a hypothetical universe where there is no such thing as energy. Energy/mass is after all just the “measure” of how much matter there is. A universe without matter would be immaterial and non-physical.

An immaterial world with immaterial beings which doesn’t follow conservation of energy? How about we also add one superpowerful Being which sustains this universe in existence and is able to create anything out of thin air? Seems like I heard that idea somewhere before… :innocent:


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Already been done, in a White Dwarf article.

( A pox on the reply clock)

Sure. But why could a universe not exist with different things entirely?

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You may find it hard to imagine, but have you actually considered the question very carefully? What life needs is something capable of forming complex structures, a stable environment, and a source of energy. But if stars are not available as a source, or their neighborhoods aren’t stable enough for long enough, are you sure there aren’t alternative structures that would form the required conditions in such a universe? How carefully have you looked at the consequences of different parameters other than to note some things that wouldn’t exist? But what about the things that would exist?

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I think we’re already making unwarranted assumptions when we presume we need to explain how “life” could come about in an alternative universe. What is so special about life? If God were to start with a completely clean slate and design a new universe completely from the ground up, without even the need to include fundamentals like “forces” “mass” “energy” “space” “time”, who knows what wonders might result? Maybe things that make a human being look mundane and childishly simple.


Let us point out that God already has a model for “life” that doesn’t need mass, energy, and so on: angels and the human souls that either do or will (depending on your theology) inhabit heaven. If we’re the point of it all, the universe itself is superfluous.


A very good question. No matter how you alter the initial conditions and physical constants, you’re going to get some particular result from that, and you can always point out after the fact that if those conditions had been different, we’d get a different result. And the particular result we get fall within some narrow range where results very much like it are found, and outside of which it becomes impossible to obtain the same or even similar results.

So now any imaginable circumstance can be subject to the same question: Why this way instead of another?

Even within our own universe, it doesn’t have to be life we focus on. Everything is the way it is because of the laws of physics and the initial conditions. Some rock outside on the ground. Some particular interstellar grain of dust 15 billion light years away. If the initial conditions would have been different, if the laws had been different, it would not exist. The universe must be made and fine-tuned for that grain of dust!

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Chaos theory says no way for any mortal, but because chaos is still deterministic, maybe for God.

However, QM says no way even for God, if He plays by the rules he set up. And Schrodinger’s cat tells us the boundary between the QM world and the macro world is fuzzy, and quantum effects would have butterfly effects - more chaos - there is no way to churn out giraffes by the big bang so that a particular region of space would condense into the right sized stars to synthesis the right amount of metals to explode the right amount of debris which would coalesce to our solar system and onwards from goo to zoo.


One problem with fine tuning is that we have no way of knowing if those variables were interdependent before the universe came to be.

My understanding is that fine-tuning is a common acknowledgement by cosmologists of various phenomena and that judgements about what would or would not happen are based on a mix of accepted theory and the results of various simulation tests run with super computers.

People seem inclined to interpret the idea of fine-tuning in light of certain theological ideas or as though it has theological connotations. However, it doesn’t seem to me that fine-tuning argument presupposes any of this at all.

I’m right with you here. My understanding is that fine-tuning as a concept is not limited to life, but also applies to other cosmic phenomena.

Where the line is drawn I don’t know. I hope to read more about this at some point in the future.

If you have some viable alternatives I’m sure there are plenty of people who would want to know :slight_smile:

Something I would like to caution here is an appeal to mysteries and seemingly unanaswerable questions as a way of disarming ideas like the FTA.

My worry is that appealing to mysteries or difficult questions under the guise of ‘being comfortable with not having to know something’ ends with us placing an unwarranted skepticism on our general abilities to make judgements about the things we do know, and from the things that we do know.

In other words, it is a break from our being committed to tentative explanations based on what we can be confident about in favour of something that very much looks like “who can really know, so why should anyone care”?

I want to emphasize that I don’t think anyone in this thread has done this, but I just think it’s worth keeping in mind that this can be a tempting strategy to turn to for the FTA. The FTA is purported by many atheists to be the best argument in natural theology precisely because it causes a lot of tension for the naturalist position.

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Where did you come by this understanding?

My point is that you haven’t even bothered to think about that.

What is this that we can be confident about that you’re referring to here? You have ignored all my objections to the fine-tuning argument, your sole argument being your claim that all the physicists and cosmologists believe in fine-tuning.

By watching interviews with cosmologists and physicists that have the relevant expertise, such as Roger Penrose, Sean Carroll and Luke Barnes.

I think it very likely that there are people that have been thinking about these things. I couldn’t tell you who, but such discussions have been referenced by the people I have observed with relevant expertise.

For one, that there does not seem to be any good reasons to think that any such alternative structures are any more probable in a universe governed by the laws of cosmology than the ones that we observe.

My intention to post was to communicate two things:

  1. People seem prone to see connotations around fine-tuning that aren’t actually there - such as to see the concept as an inherently ‘theistic’ concept

  2. That merely asking good questions about how things could have been different isn’t in itself a way to undermine fine-tuning, or diffuse the implications of fine-tuning for (a)theism.


Could you actually cite something. I will even take a video.

That’s nice, but you will understand that it isn’t a very good argument.

Is there a reason to think that they wouldn’t be?

If “fine-tuning” just means that if things were different, they’d be different, maybe it’s the wrong word to use.

Wait, what implications? I thought it wasn’t inherently theistic. And asking questions is a way to undermine the idea of fine-tuning if the questions point to holes in the idea.


The most recent video I watched was of Luke Barnes discussing fine tuning on Capturing Christianity.

The fact that we don’t see any is a prima facie reason.

I have only seen reference to the in-principle possibility of alternative structures. To my knowledge there’s no work demonstrating A) there is actually a possible alternative structure, or B) that such a structure is more probable than what we actually observe.

I don’t know what the issue is here.

Questions don’t point out holes. Arguments do.

Questions might be a shorthand or colloquial means of pointing out tension, but without there being an explication about how that tension actually undermines the argument, then there’s been no demonstration of any reasons for thinking the argument has failed.

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“Capturing Christianity” is a bit of a giveaway, no? Has Barnes published anything on this in the actual scientific literature? A little searching finds a popular book and a lot of stuff on Christian sites and philosophy conferences, but so far nothing in the literature. But I’ll look at the video. Thanks.

Would the fact that there were no stars in one of those alternate universe be evidence against the existence of stars in this one? You’re not making sense.

Is there any work at all investigating alternatives? As to what is or is not more probable, is there any work at all on the probability of particular values for universal constants? The few actual scientific papers I know of on this fine-tuning thing just assume a distribution for the sake of argument and consider the consequences. They make no attempt to justify it. And they explore only the limited question you consider: whether stars could exist.

The issue is a contradiction contained within a few lines of your post. What do you mean by “connotations around fine-tuning that aren’t actually there” and “the implications of fine-tuning for (a)theism”? Are you making a fine distinction between connotations and implications?

Perhaps if I don’t state them in question form you will actually try to deal with them. Without some idea of the possible range of variation of the values of universal constants, it’s impossible to decide whether or not they’re fine-tuned. There is no such idea that I’m aware of, and this would seem an insuperable barrier to making a fine-tuning argument. You seem to disagree, but you have never confronted the objection.

The other point, that it’s assumed that a universe like ours is the only sort amenable to life, without investigating the properties of universes unlike ours, you answered only by assuming that someone, somewhere, had done that investigation.

@ThomasTrebilco, I take it back. The video is way too long and the host spends way too much time explaining to the guest what the guest is saying, even interrupting him in mid-sentence to do so. I can’t listen to that. If all you want me to get out of that is that Barnes is an astrophysicist and he’s discussing fine-tuning, then OK. But I don’t think it says anything about whether fine-tuning is a live topic in astrophysics. This is entirely in the context of Christian apologetics.