Imagine a universe where mixed-material objects only stay together if they have the spark of life. No matter how hard we try, we can’t make allows, mixtures, and so on. As soon as a living object dies, it immediately falls apart into it’s component elements.
It would be difficult to support life in that universe, and yet here we are! What is it about life that allows it to stay together? Pretty amazing!
One cannot meaningfully speak of the speed of light, or Planck’s constant, changing. If you speak of the speed of light being 12 m/s, all you’re doing is re-defining the meter and/or the second. Well, we humans can certainly do that: We invented those units, after all. But merely changing the definitions of the units doesn’t do a thing to the existence or nonexistence of life.
The only physical constants one can truly speak of as changing, or as having different values, are the dimensionless ones. Some of those, of course, are interdependent, so you can’t pin down exactly which constants are the “fundamental” ones, versus which ones are just algebraic combinations of the fundamentals. For instance, one could speak of the ratio of the electron mass to the proton mass, and the ratio of the electron mass to the Planck mass, and the ratio of the proton mass to the Planck mass… but that’s only two independent numbers, since once you have any two, you can determine the third.
So far as we know, there are two dozen independent parameters. As said, which two dozen you pick is flexible, but one possible set follows:
The masses of 14 different particles, relative to the Planck mass.
The W/Z mixing angle
3 quark mixing angles
3 neutrino mixing angles
Coupling constants for the strong, weak, and electromagnetic forces
There may be more that govern physics we don’t yet know about. And there may be less, if it turns out that some of those constants actually relate to each other in some way. It’s conceivable that there might not even be any: They might all turn out to be calcualable mathematical constants, in which case the Universe isn’t “tunable” at all.
I’m not entirely sure that’s right. One can imagine our universe, with no other changes, save that the speed of light is 1,000,000 times greater. What other changes would have to occur to accommodate this? I don’t suppose anyone can know for sure, but the notion is meaningful in the abstract.
If the strong nuclear force were a little weaker than it is, large nuclei couldn’t form. If a little stronger, Uranium might be a stable atom, not a radioactive one.
This isn’t a nonsensical avenue for speculation, just one that is somewhat unproductive.
I can just imagine another parallel universe built on different physical constants like where its sentient life (maybe silicon-based salamanders breathing HF gas) is arguing how life could not form if the physical constants were different than theirs.
Stenger is definitely anti-fine tuning.
Let me see if I understand. You see it coming from people who propose there are dozens/hundreds/thousands of universes and we just happen to be in the “just right” one? Yes, that is a form of the argument, but Stenger is concerned with creationists who talk about fine tuning as proof of God. Multiverse is one option to allow “fine tuning” without God. Discrediting fine tuning is a different approach.
Stenger’s approach to these types of claims is to look at just how finely tuned these characteristics are. How large of a range of values allows that Goldilocks zone? The larger the zone, the less fine tuned, the less convincing the argument. If the values are locked to 15 decimal places, then you have a much more convincing argument than if the values can range 15%.
I have no idea why he only mentioned three parameters. For the Lamda Cold Dark Model, he discusses 6 parameters.
In his summary section, he states:
Yes, that makes sense. That fits with points Stenger makes, that many parameters are interrelated and that changes to one parameter can be offset by changes to another parameter to make the viable universe options larger.
I’m not even sure what that would mean. It would basically be saying “magic works”.
Wouldn’t we analyze and study this “spark of life” to understand how it works? Apply scientific scrutiny. You’re proposing some inexplicable and completely undetectable “force” that has no mechanism and only can be observed via a rule of behavior (kinda like gravity to Newton). Either we can come up with some way to understand it, or magic works.
This doesn’t make sense to me. The speed that light propogates is a certain speed, regardless of the units chosen and the value that corresponds to those units. Doesn’t inflation propose the speed of light changing rapidly during that period? What makes the value of c unchangeable in the sense it is a locked parameter whereas the strength of gravity is not locked?
Why? This is what I don’t understand.
Do we have any reason to believe that “changing the fundamental constants of the universe” is even a coherent concept? It seems like this is an assumption at the base of the fine-tuning argument that is completely unsupported.
As I understand it, no: it proposes that the cosmos itself expanded much faster than the speed of light, but that the speed of light itself was still the same old familiar comfortable constant, at least in the region of space that is causally connected to us. “Our” region of space.
One possible outcome of this is that there may be regions within our universe, causally isolated from the region we inhabit, and the physical constants might vary slightly from one region to another.
It’s a slight variation on the multiverse idea.
We’re still exploring what it means for these parameters to have the values they have, and why they are what they are. So far, we can determine values. We can evaluate what different values might mean. Without an underlying theory and complete model on how they are all connected, we can’t know that they are constrained, so we think what the changes could mean. My quote from Stenger in the last response indicates the models are tightening such that the values may be constrained.
An argument against the “need” for fine-tuning is the phenomenon known as self-organized criticality, where the critical parts of physical systems tend to occupy phase transitions. I wonder if claims like Davies’ that a mixture of both radiative and convective stars is improbable ignore that principle.
But there are “magical” properties of some chemical or thermonuclear reactions that do depend on specific tuning. I still think the reaction 3 He –> Be[sup]8[/sup] + He –> C[sup]12[/sup] is a particularly good example.
This was responding to the energy of a C[sup]12[/sup] state in the above reaction. But it is the mass-energy of Be[sup]8[/sup] which is more interesting. On a scale where C[sup]12[/sup] is 12.0000, twice the mass of He[sup]4[/sup] is 8.0052, while the mass of Be[sup]8[/sup] is 8.0053; the former is 99.999% of the latter – very precise fine-tuning – and, according to Hoyle, this is the reason carbon can be produced in the Sun. (But if this peculiar resonance could be bypassed, carbon would be produced much faster and stars would be short-lived.)
I hope physicists comment on whether this closeness (2 He[sup]4[/sup] <–> Be[sup]8[/sup]) follows from principles, or is just a coincidence?
Perhaps you should think of it as analogous to the proposition that the length of a second changes—what could that mean? Nothing, because time always passes at a rate of one second per second; if the second were twice as long, it would still pass at that same rate, and nothing would change.
The same thing goes for the (unfortunately-named) speed of light, c (I’ll from now on adopt the convention that I use c when speaking about the fundamental speed limit, and c[sub]L[/sub] when talking about the spead at which light propagates, which may well differ from c). It’s essentially a conversion factor between units of length and units of time: thus, when you talk about c changing, you’re making merely a statment about the system of units you have elected to use. If you say that c is 12 m/s, then that tells you merely what a meter is—the distance light covers in vacuum in 1/12 the time it takes the cesium 133 atom to transition between the hyperfine levels of its ground state 9192631770 times (or whatever else your definition of ‘second’ is). In these units, the moon would be something like 15 m away.
That’s why we can get away with setting the speed of light to one—it’s just choosing a convenient system of units. If you say that the speed of light is some other value, what you’re really saying is ‘I want to use this other system of units’, which you’re free to do, but which doesn’t change anything about the physics.
Now, a priori, there’s a difference between c and c[sub]L[/sub]—counterfactually, it’s certainly possible for light to propagate at some other speed than c. Indeed, there are situations where it propagates both slower (in any material optically denser than the vacuum) and faster (Casimir effect) than that. In fact, if light were massive, it could propagate at any speed smaller than c; if it were tachyonic, it could propagate at any faster speed. But this does not impinge on the fact that c[sub]L[/sub] is always equal to one, up to redefinitions of units, anymore than the possibility that 9192631770 oscillations between the hyperfine levels of the Cs-133 groundstate could take less or more time than a second impinges on the fact that time always flows at one second per second.
Let me phrase this a different way.
The Fine Tuning argument presupposes humans are special–that is, the fact that the universe supports our existence is a significant and meaningful observation.
However, I would argue that the fine-tuning argument is counterproductive to the theistic (read: Christian) argument. The fact that we need an universe fine-tuned for us suggest we are not special. The clumps of atoms that make up our minds and bodies follow the same rules as every other clump of atoms in the universe.
Compare that to the actual creation myth. In that universe, we are dust with God’s breath animating us. The “rules” of that universe don’t allow for life–put dust together all you want, you won’t get Adam II. Only a miracle by God allowed us to come into being. And I’ve seen it argued (though I don’t know if the Bible supports this) that each conception is another miracle from God.
So, given that an infinitely powerful God could miraculously create and sustain us on any universe, why should a universe that supports us without miraculous intervention constitute any proof of God?
One could suggest that God is parsimonious. This is why animals and humans have so much in common: bone structures, muscles, internal organs, etc. The creationist can say, “No, we didn’t come from animals; God just used parts of the same blueprints when creating us from nothing.” God could have created the universe to be habitable to life, as a simplifying process.
Now, the problem with this reasoning is that it is ad hoc. It serves only to defend the conclusion desired. It’s fallacious. But that doesn’t quite mean that it isn’t true…
(In mathematics, there are any number of invalid, true propositions!)
…immediately raising the question of the reason for the sextillion stars not essential to our existence 
It’s beyond my ability to address.
Ah, but you see you are missing the point. I could define the second to be longer, but I have not changed the property of the universe by doing so. Correct.
But why does time flow at the rate it does? Regardless of how I define a second, that rate of time passage is the inherent property of the universe that I am talking about being able to vary as a parameter. Why not? It’s really hard to talk about the parameter of timerate without mentioning the units we use.
The same thing goes for the (unfortunately-named) speed of light, c … It’s essentially a conversion factor between units of length and units of time: thus, when you talk about c changing, you’re making merely a statment about the system of units you have elected to use. If you say that c is 12 m/s, then that tells you merely what a meter is—the distance light covers in vacuum in 1/12 the time it takes the cesium 133 atom to transition between the hyperfine levels of its ground state 9192631770 times (or whatever else your definition of ‘second’ is). In these units, the moon would be something like 15 m away.
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I see what you are saying, but you are missing my point. I am not picking a number and saying “how to I apply that value to what the universe is doing?”. I am saying “make the universe work differently”. When I said “12 m/s”, I was trying to say something about the parameter c. Why is that the cosmic speed limit? Why is that the value that plugs into E=mc[sup]2[/sup]? Why is that the value that fits the Lorentz transformations? But more importantly, what if that relationship was different?
Instead of saying I’m changing the definition of the meter and the second, keep those the same and tell me about the parameter of how the universe behaves.
Are you trying to tell me that that principle is, instead, embedded in other parameters like the Hubble parameter?
Thank you for clarifying. Their proposition seems to be “There are any number of possible variations to make types of universes, but only one in which we could be here. Therefore, God did it.” Your approach seems to be “this universe allows us to exist as naturally functioning components without anything special or new added just for us. Therefore, we got lucky that we have our universe, but God didn’t do anything to make us special.”
I suppose I see your point. The counterargument would be, I think, the “soul”. Our spirit, the divine spark that sets humans above animals and lets us go to heaven and all that jazz.
In which case my argument has accomplished its goal:forcing the theist to abandon the pretense of science and to admit their beliefs are based on unfalsifiable faith claims.
To the extent that it’s meaningful to talk that way, there is only one ‘rate’ at which time can possibly flow. Consider your measuring the duration something takes, say, the time it takes for the moon to complete a full revolution. For one revolution, your clock makes n ticks. Now speed up the flow of time, say, double it. What changes? Well, nothing: for one revolution, your clock still ticks n times. The revolution of the moon is now ‘twice as fast’; but likewise, your clock ticks n times twice as fast.
If the above doesn’t make things clearer, consider that a ‘rate’ is the change of something with time; thus, speaking of the rate of time passing simply is incoherent.
Whenever you’re saying that there could be some other value to plug into the energy-mass equivalence, or the Lorentz transformation, or something else, all you’re saying is that there could be another system of units you’re using, which is of course true.
Consider two ‘universes’, one with fundamental speed c[sub]1[/sub], the other with fundamental speed c[sub]2[/sub]. In one, the energy-mass equivalence would be E = mc[sub]1[/sub][sup]2[/sup], in the other, E = mc[sub]2[/sub][sup]2[/sup]. You allege that there would be a fundamental difference between both. But consider that a physicist in either universe could choose different units, in which c[sub]1[/sub] = 1, and respectively c[sub]2[/sub] = 1. This does not change anything about the physics; all they’ve done is use another system of standard clocks and measuring sticks. But then, in both universes, the energy-mass equivalence would be E = m, making clear that their physics is actually the same.
What really makes a difference physically are the dimensionless ratios of dimensionful quantities. Take, for instance, the fine-structure constant α: its value is approximately 1/137, independently of the units you use. If you change its value, then you get genuinely different physics—stronger or weaker electromagnetic forces, for instance.
Another way to think about this is to note that the values dimensionful quantities take is merely an accident of how we have chosen to define our measuring system—they’re purely anthropocentric. We can always choose units such that c = 1, and other dimensionful constants likewise; their values are just accidents of how we’ve chosen to quantify things, not properties of the universe.
I was just trying to come up with a universe that doesn’t support life, and yet here we are. Reyemile did a better job of working that out than I did.
Your first point is correct: we cannot meaningfully talk about different rates of time.
But we can meaningfully talk about different speeds. 186,282 miles per second is different than 500,000 miles per second. We live in a universe where the former is observed, but there is no philosophical reason we might not live in a universe where the latter is observed.
It would be pointless to argue, “If I measure my weight in kilograms instead of pounds, I weigh less, since 115 is less than 250.”
But it is perfectly valid to wonder what might happen if the charge on the electron were twice what it is, since it is measureable as a ratio of forces. It isn’t a “naked” unit, but can be observed by the force of repulsion (dynes) between two charged objects. If the unit charge were twice what it is, that physical repulsion would be twice what it is, and that would be a real difference in the cosmos.
Not quite. What must change in order to make an observable difference is the dimensionless ratio between electron and Planck charge, which ratio happens to be the square root of the fine structure constant. In Planck units, the Planck charge is one, and thus, you could there talk about changing the electron charge; however, in atomic units, the electron charge is one, and you’d have to talk about changing the Planck charge instead. The point is that talking about changing the ratio of electron to Planck charge has operational meaning across all possible systems of units, while changing the electron charge doesn’t.
My guess is that simply something other than stars, or just very different stars, would form. Also very different chemistry.
The problem is they are working backwards from the way things are now, so of course if anything is different, what we see now will be impossible. What they fail to imagine is what might arise under the different conditions. Yes, complex chemistry, as we know it, would be impossible. But we don’t know what would result in its stead, and they are, IMHO, fallaciously assuming it’s nothing.