Why does fine-tunning for life suggest a multiverse?

[Boltzmannbrain]

Stuart Kauffman has done many videos about the fine-tunning problem of the universe.  I have watched all of them, and I still do know exactly how it is problem. 

It has been mentioned that this universe, if it is the only universe, is improbable in various readings I have come across.  But I have yet to really understand exactly how the probability is calculated.  

This is how I am confused about why we need a multiverse.  Let's say there were x possible universes.  0.1% of them have life.  Okay, now, from our perspective, after it happened, why should this seem improbable?  it has already happened!  As an analogy, I have a glass of water.  If I point out 1 h2o molecule, and I ask what the probability of that water molecule entering my glass was when it was created, say 100 years ago, it should be quite low.  Of course I should not be perplexed in any way because it has already happened.  How is the fine-tuned universe improbable after it has already happened? 

(The first couple minutes gives a brief summary of the problem of fine-tuning.)

 

[mistermack]

The water molecule being in the glass is enormously improbable. But it's just a numbers phenomenon. 

If you have a probability of one in a thousand, but there are billions of things happening every second, then the long shot becomes less surprising. 

With the Universe, the actual conditions might look an unlikely combination. But if there were billions of possible combinations, then they were all unlikely, so whichever combination of conditions actually existed, it was always going to be unlikely. 

The conditions that ARE existing produced a Universe as we know it. If they were different, then the Universe would be different. It's our assumption that what exists is somehow SPECIAL that's misleading. It's like saying that the molecule in the glass is somehow special, and therefore everything must have been designed, so that that molecule ends up in that glass. That's the fundamental error of the fine-tuning argument.

[Genady]

7 hours ago, Boltzmannbrain said:

Stuart Kauffman has done many videos about the fine-tunning problem of the universe.  I have watched all of them, and I still do know exactly how it is problem. 

It has been mentioned that this universe, if it is the only universe, is improbable in various readings I have come across.  But I have yet to really understand exactly how the probability is calculated.  

This is how I am confused about why we need a multiverse.  Let's say there were x possible universes.  0.1% of them have life.  Okay, now, from our perspective, after it happened, why should this seem improbable?  it has already happened!  As an analogy, I have a glass of water.  If I point out 1 h2o molecule, and I ask what the probability of that water molecule entering my glass was when it was created, say 100 years ago, it should be quite low.  Of course I should not be perplexed in any way because it has already happened.  How is the fine-tuned universe improbable after it has already happened? 

(The first couple minutes gives a brief summary of the problem of fine-tuning.)

 

Can you provide something in writing? I can't discuss a video, and also the forum rules require so.

[joigus]

It's not that fine-tuning suggests a multiverse, I think. Rather, the idea of a multiverse (with different domains having different values of the physical constants) makes whatever value for the constants inescapable for some part of the multiverse where there is intelligent life, therefore supressing the need for an "outside" contrivance (creator).

There are other games in town. Eg, Smolin et al.'s idea of cosmic selection, Tim Palmer et al.'s idea of universal constants as coming from attractors of some chaotic regime, etc.

I'm not going to watch the video, sorry.

[exchemist]

10 hours ago, Boltzmannbrain said:

Stuart Kauffman has done many videos about the fine-tunning problem of the universe.  I have watched all of them, and I still do know exactly how it is problem. 

It has been mentioned that this universe, if it is the only universe, is improbable in various readings I have come across.  But I have yet to really understand exactly how the probability is calculated.  

This is how I am confused about why we need a multiverse.  Let's say there were x possible universes.  0.1% of them have life.  Okay, now, from our perspective, after it happened, why should this seem improbable?  it has already happened!  As an analogy, I have a glass of water.  If I point out 1 h2o molecule, and I ask what the probability of that water molecule entering my glass was when it was created, say 100 years ago, it should be quite low.  Of course I should not be perplexed in any way because it has already happened.  How is the fine-tuned universe improbable after it has already happened? 

(The first couple minutes gives a brief summary of the problem of fine-tuning.)

 

I tend to agree. Everything has to have some value and the fact that a constant it has the value it does is no more improbable than any alternative value.

To give a trivial example, the fact of my personal existence relies on a highly "improbable" chain of coincidences, regarding how my parents were conceived, how they happened to meet and so forth. But nobody feels the need to argue my existence must have been "designed" by some great plan, because of its intrinsically low probability.  

[Genady]

P ( A | A ) = 1

[joigus]

43 minutes ago, Genady said:

P ( A | A ) = 1

Exactly. I didn't want to open that can of worms, but I agree.

How can you get any picture at all of a sample space (and its odds) that you've never probed, and never will?

[Boltzmannbrain]

6 hours ago, Genady said:

Can you provide something in writing? I can't discuss a video, and also the forum rules require so.

From Wiki, " Theories requiring fine-tuning are regarded as problematic in the absence of a known mechanism to explain why the parameters happen to have precisely the observed values that they return. The heuristic rule that parameters in a fundamental physical theory should not be too fine-tuned is called naturalness."  Fine-tuning (physics) - Wikipedia 

[Genady]

3 minutes ago, Boltzmannbrain said:

From Wiki, " Theories requiring fine-tuning are regarded as problematic in the absence of a known mechanism to explain why the parameters happen to have precisely the observed values that they return. The heuristic rule that parameters in a fundamental physical theory should not be too fine-tuned is called naturalness."  Fine-tuning (physics) - Wikipedia 

So?

[TheVat]

“This is rather as if you imagine a puddle waking up one morning and thinking, 'This is an interesting world I find myself in--an interesting hole I find myself in--fits me rather neatly, doesn't it? In fact it fits me staggeringly well, must have been made to have me in it!' 

- Doug Adams

I know his quote has been posted here a hundred times but it bears repeating.

No cleverer statement of the observation selection effect will be found.  

I like Smolins fecund universes theory, which @joigus mentioned, which assumes universes have "offspring" through the creation of black holes whose offspring universes have values of physical constants that depend on those of the mother universe but can differ slightly.  He's made a couple of predictions from that theory which have held up.

[Boltzmannbrain]

7 hours ago, joigus said:

It's not that fine-tuning suggests a multiverse, I think. Rather, the idea of a multiverse (with different domains having different values of the physical constants) makes whatever value for the constants inescapable for some part of the multiverse where there is intelligent life, therefore supressing the need for an "outside" contrivance (creator).

There are other games in town. Eg, Smolin et al.'s idea of cosmic selection, Tim Palmer et al.'s idea of universal constants as coming from attractors of some chaotic regime, etc.

I'm not going to watch the video, sorry.

I don't understand what you are saying.  How is a multiverse and the idea of a multiverse different?

9 minutes ago, TheVat said:

“This is rather as if you imagine a puddle waking up one morning and thinking, 'This is an interesting world I find myself in--an interesting hole I find myself in--fits me rather neatly, doesn't it? In fact it fits me staggeringly well, must have been made to have me in it!' 

- Doug Adams

I know his quote has been posted here a hundred times but it bears repeating.

No cleverer statement of the observation selection effect will be found.  

I like Smolins fecund universes theory, which @joigus mentioned, which assumes universes have "offspring" through the creation of black holes whose offspring universes have values of physical constants that depend on those of the mother universe but can differ slightly.  He's made a couple of predictions from that theory which have held up.

The reason why I posted this thread is because the Doug Adams quote, or this line of thinking, is probably not an agreed upon solution.  Afterall, that line of thinking was my first reaction when I first heard of this "problem".  It just seems too obvious for the scientists out there who are contemplating this and who still call this a problem.  I have to think that there is more to this than the quote or how I am thinking about this in the OP.

[joigus]

50 minutes ago, Boltzmannbrain said:

I don't understand what you are saying.  How is a multiverse and the idea of a multiverse different?

I'm not aware of having pointed out that the idea of a multiverse is diferent from a multiverse itself. But it's obvious, isn't it? Same goes for the idea of anything compared to the thing itself. Thinking otherwise is known in philosophy as the use-mention error, which consists in ignoring the use-mention distinction. Theologists do it all the time. History of God = History of the concept of God. Not the same thing!! I'm sure Daniel Dennett has dealt with this question somewhere.

The idea of a multiverse is what our minds handle when we speculate wich such possibility. The multiverse would be what we would experience if we could travel through time and space quite freely and experience those domains directly, which we never will. I don't think we will.

 

[Eise]

On 10/2/2023 at 4:55 AM, Boltzmannbrain said:

It has been mentioned that this universe, if it is the only universe, is improbable in various readings I have come across.  But I have yet to really understand exactly how the probability is calculated.  

It is not. Nobody knows if e.g. the constants of nature can be different. So without any viable theory from which follows a 'chance distribution' of their values, it is an empty speculation. But it serves as a great escape route for string theory. Obviously, the different ways that the 6 space dimensions we cannot observe must be curled up so small that we do not notice them, counts about 10⁵⁰⁰ possibilities. Put this together with the idea of eternal inflation, which spawns endlessly bubble-universes, every bubble with its own set of constants (or even laws) of nature, then the possibility of a universe that allows for complex chemistry, and so for life will be close to one. And of course we find we are living in a universe that allows for that: we are here. In this way we do not need an explanation for the perceived 'fine-tuned' universe. 

However, the multiple universes are supposed to be causally separated from each other. So there is no way this idea can be empirically tested, and the question becomes if an idea may be called scientific, if it principally cannot be tested.

 

[Genady]

32 minutes ago, Eise said:

So there is no way this idea can be empirically tested, and the question becomes if an idea may be called scientific, if it principally cannot be tested.

I think it can be refuted in principle, for example, if ways to derive the values of constants from first principles were found.

[TheVat]

It's unclear to me how one could ever obtain definitive first principles for constants (like below) without access to other universes.

 

• The unperturbed ground-state hyperfine transition frequency of the cesium-133 atom Δν_Cs is 9 192 631 770 hertz.
• The speed of light in vacuum c is 299 792 458 meters per second.
• The Planck constant h is 6.626 070 15 × 10⁻³⁴ joule second.
• The elementary charge e is 1.602 176 634 × 10⁻¹⁹ coulomb.
• The Boltzmann constant k is 1.380 649 × 10⁻²³ joule per kelvin.
• The Avogadro constant N_A is 6.022 140 76 × 10²³ reciprocal mole.
• The luminous efficacy of monochromatic radiation of frequency 540 × 10¹² Hz, K_cd, is 683 lumens per watt.

And of course the FSC, which has to stay around a certain range to have stable matter and hence observing creatures like ourselves.

 

Value of 1/ α
137.035999084(21)

Perhaps we could develop better ways to model toy universes (or make them, haha) in order to get at such principles?  

[joigus]

15 hours ago, joigus said:

Theologists

Sorry, I meant theologians.

 

2 hours ago, Eise said:

It is not. Nobody knows if e.g. the constants of nature can be different. So without any viable theory from which follows a 'chance distribution' of their values, it is an empty speculation. [...]

2 hours ago, Eise said:

[...] However, the multiple universes are supposed to be causally separated from each other. So there is no way this idea can be empirically tested, and the question becomes if an idea may be called scientific, if it principally cannot be tested.

1 hour ago, Genady said:

I think it can be refuted in principle, for example, if ways to derive the values of constants from first principles were found.

This reminds me of comments made by @Eise on the late thread about local realism in the sense that we've reached a point where nothing but endless model-building, extrapolation and back-consistency checks --so to speak-- is possible.

[Genady]

We start with eliminating some of them. Speed of light, Planck's constant, gravitational constant, and Boltzmann constant are just unit conversion factors. They are all equal 1 in appropriate units.

(Re @TheVat's post above)

Edited October 3, 2023 by Genady

[joigus]

6 minutes ago, TheVat said:

And of course the FSC, which has to stay around a certain range to have stable matter and hence observing creatures like ourselves.

 

These are actually the significant ones, the ones that are dimensionless. Including, of course, the Planck scale.

[Genady]

23 minutes ago, TheVat said:

It's unclear to me how one could ever obtain definitive first principles for constants

I, OTOH, am unclear how values of parameters can be without a dynamic cause.

[TheVat]

What causes there to be three extended spatial dimensions?

[Genady]

2 minutes ago, TheVat said:

What causes there to be three extended spatial dimensions?

This is the only number of dimensions that makes equal the numbers of independent rotations and independent boosts, for example.

[TheVat]

Ok. Then you are saying there are equally logical bases that could potentially be uncovered for alpha, e.g.  Or elementary charge.  

 

[Genady]

Just now, TheVat said:

Ok. Then you are saying there are equally logical bases that could potentially be uncovered for alpha, e.g.  Or elementary charge.  

 

Yes.

[TheVat]

I will leave this summary of Smolin's hypothesis, just to show an alternative view where there are changeable constants.

(he sees parameters as driven by the ability to produce black holes):

 

Black holes have a role in natural selection. In fecund theory a collapsing^{[clarification needed]} black hole causes the emergence of a new universe on the "other side", whose fundamental constant parameters (masses of elementary particles, Planck constant, elementary charge, and so forth) may differ slightly from those of the universe where the black hole collapsed. Each universe thus gives rise to as many new universes as it has black holes. The theory contains the evolutionary ideas of "reproduction" and "mutation" of universes, and so is formally analogous to models of population biology.

Alternatively, black holes play a role in cosmological natural selection by reshuffling only some matter affecting the distribution of elementary quark universes. The resulting population of universes can be represented as a distribution of a landscape of parameters where the height of the landscape is proportional to the numbers of black holes that a universe with those parameters will have. Applying reasoning borrowed from the study of fitness landscapes in population biology, one can conclude that the population is dominated by universes whose parameters drive the production of black holes to a local peak in the landscape. This was the first use of the notion of a landscape of parameters in physics.

[Genady]

8 minutes ago, TheVat said:

Applying reasoning borrowed from the study of fitness landscapes in population biology, one can conclude that the population is dominated by universes whose parameters drive the production of black holes to a local peak in the landscape.

This part is not (and was not, since I've heard about this hypothesis first time) clear to me. Populations in biology are finite in size and limited by available resources, which is the cause of competition and natural selection. I don't see this kind of selection in this hypothesis.