Why is a fine-tuned universe a problem?

[mistermack]

Even the phrase "fine tuned" is rubbish, because it contains in it an unwarranted assumption. It implies that there is a tuner, which is circular reasoning right from the start. Finely balanced might be fairer, but even that implies a situation that could have been other than it is, which is not established at all. 

Imagine a grain of sand in the Sahara Desert. On it, there is a population of intelligent bacteria. They can only live under the conditions that exist at this moment in time. Any puff of wind could move the grain to a spot where they couldn't exist. Using the same logic, the Sahara must have been finely tuned, to enable them to exist. It's rubbish for them, and it's rubbish for us. 

I don't like the word constants. It really means relationships. If the various RELATIONSHIPS between forms of matter and energy in space and time had been any different, we would not exist. But that wouldn't matter in the slightest. The universe would be a bit different, that's all. There's no eveidence that life as we know it is in any way important. 

[Genady]

5 minutes ago, mistermack said:

Even the phrase "fine tuned" is rubbish, because it contains in it an unwarranted assumption. It implies that there is a tuner, which is circular reasoning right from the start. Finely balanced might be fairer, but even that implies a situation that could have been other than it is, which is not established at all. 

Imagine a grain of sand in the Sahara Desert. On it, there is a population of intelligent bacteria. They can only live under the conditions that exist at this moment in time. Any puff of wind could move the grain to a spot where they couldn't exist. Using the same logic, the Sahara must have been finely tuned, to enable them to exist. It's rubbish for them, and it's rubbish for us. 

I don't like the word constants. It really means relationships. If the various RELATIONSHIPS between forms of matter and energy in space and time had been any different, we would not exist. But that wouldn't matter in the slightest. The universe would be a bit different, that's all. There's no eveidence that life as we know it is in any way important. 

This is all correct. However, did you notice that the picture of the "fine tuned" Sahara in the example above is essentially the same as the multiverse one, i.e. there are many different environments with various conditions in them and the bacteria exist where and when the conditions are right for them?

(DISCLAIMER: I am NOT a proponent of the multiverse model, just an objective - to the best of my abilities - observer.)

[mistermack]

4 minutes ago, Genady said:

did you notice that the picture of the "fine tuned" Sahara in the example above is essentially the same as the multiverse one

It doesn't have to be. There are 700 quintillion planets in the Universe, (whatever that means), so our planet could be like a grain of sand in this Universe. 

Another way of looking at the fine tuning argument, is to look at the odds against your own existence. 

A healthy man constantly produces 1500 brand new sperm in his testicles PER SECOND !!!!! and when he ejaculates, he lets fly with 250,000,000 of the little buggers.

Only one of the 250 million would produce you. Any of the others would have produced someone quite different.
And that's just PART of the odds against your existence. So the slightest difference in the conditions of your conception could have meant that someone quite different to you would have been born. 

Then there's the odds against your parents ever meeting, or their parents meeting, or their parents meeting, or deciding that they liked each other, or feeling like sex on that specific occasion. The odds against me getting born must be more than 700 quintillion to one against, yet here I am. Therefore, all of the conditions must have been fine-tuned to produce me !!

 

 

 

[Genady]

1 minute ago, mistermack said:

It doesn't have to be. There are 700 quintillion planets in the Universe, (whatever that means), so our planet could be like a grain of sand in this Universe. 

Another way of looking at the fine tuning argument, is to look at the odds against your own existence. 

A healthy man constantly produces 1500 brand new sperm in his testicles PER SECOND !!!!! and when he ejaculates, he lets fly with 250,000,000 of the little buggers.

Only one of the 250 million would produce you. Any of the others would have produced someone quite different.
And that's just PART of the odds against your existence. So the slightest difference in the conditions of your conception could have meant that someone quite different to you would have been born. 

Then there's the odds against your parents ever meeting, or their parents meeting, or their parents meeting, or deciding that they liked each other, or feeling like sex on that specific occasion. The odds against me getting born must be more than 700 quintillion to one against, yet here I am. Therefore, all of the conditions must have been fine-tuned to produce me !!

 

 

 

Again, it is essentially the same solution, i.e. there are multitude of possibilities and the one you are in just one of them that happened to fit you. Multitude of sperm, multitude of environments on Earth, multitude of planets, multitude of universes. The model is the same: no fine tuning is required if there are many possibilities and some of them just happened to fit your existence.

[mistermack]

In 2009, a retired policeman called Geraint Woolford was admitted to Abergale Hospital in north Wales and ended up next to another retired policeman called Geraint Woolford. The men weren’t related, had never met and were the only two people in the UK called Geraint Woolford.

Must be fine tuned. 

[Genady]

4 minutes ago, mistermack said:

In 2009, a retired policeman called Geraint Woolford was admitted to Abergale Hospital in north Wales and ended up next to another retired policeman called Geraint Woolford. The men weren’t related, had never met and were the only two people in the UK called Geraint Woolford.

Must be fine tuned. 

I think we are saying the same thing, don't we?

[mistermack]

2 minutes ago, Genady said:

I think we are saying the same thing, don't we?

I think we are saying the same thing, don't we?😊

Edited February 12, 2022 by mistermack

[Genady]

Just now, mistermack said:

I think we are saying the same thing, don't we?

LOL

[34student]

21 hours ago, Genady said:

The Lambda was what led to the comparison. It was not chosen for comparison. What is your reason for comparison?

Yes I agree in the order of events.  Lambda happened, then 14 billion years later you wanted to give me an example of something that our universe has that most of the others don't.  Then you chose lambda.  These are the order of events.  

 

[Genady]

8 minutes ago, 34student said:

Yes I agree in the order of events.  Lambda happened, then 14 billion years later you wanted to give me an example of something that our universe has that most of the others don't.  Then you chose lambda.  These are the order of events.  

 

You said some time back that "it has to do with the universe existing the way that it does is too improbable".  I think that I didn't make it clear then, so I do now: I don't think that it has to do with the universe being improbable, but rather with it having improbable value of some parameter, e.g. Lambda. I said then that all universes have the same probability to exist, but the values of Lambda don't have the same probability. That's why Lambda is in the picture. I do not compare probabilities of different universes. They are equal. I compare probabilities of having various Lambdas. These are not equal.

[34student]

13 minutes ago, Genady said:

You said some time back that "it has to do with the universe existing the way that it does is too improbable".  I think that I didn't make it clear then, so I do now: I don't think that it has to do with the universe being improbable, but rather with it having improbable value of some parameter, e.g. Lambda. I said then that all universes have the same probability to exist, but the values of Lambda don't have the same probability. That's why Lambda is in the picture. I do not compare probabilities of different universes. They are equal. I compare probabilities of having various Lambdas. These are not equal.

But with so many variables that the universe has, then it should not be surprising that some of these variables are less likely.  

I could understand there being a problem if all posible variables were unlikely or something like that.

[Genady]

Just now, 34student said:

But with so many variables that the universe has, then it should not be surprising that some of these variables are less likely.  

I could understand there being a problem if all posible variables were unlikely or something like that.

That's right. Why do you expect "there being a problem?"

[34student]

43 minutes ago, Genady said:

That's right. Why do you expect "there being a problem?"

Let me explain it this way.  Scientists believe we have only one of the three choices I mentioned earlier: God, multiverse and the universe is not fine-tuned.  For me, and others on this thread, there is a very obvious - too obvious - 4th option.  The 4th option is that the universe is fine-tuned for life, so what.  I am trying to understand why they don't think this is an option.

[Genady]

3 minutes ago, 34student said:

Let me explain it this way.  Scientists believe we have only one of the three choices I mentioned earlier: God, multiverse and the universe is not fine-tuned.  For me, and others on this thread, there is a very obvious - too obvious - 4th option.  The 4th option is that the universe is fine-tuned for life, so what.  I am trying to understand why they don't think this is an option.

I think that most physicists think, this IS a valid option. Many think that one day we'll be able to derive Lambda and other numbers which today we need to put in "by hand", from some first principles. So, they are what they are because they cannot be anything else, any other numbers will lead to some inconsistencies.

[exchemist]

59 minutes ago, 34student said:

Let me explain it this way.  Scientists believe we have only one of the three choices I mentioned earlier: God, multiverse and the universe is not fine-tuned.  For me, and others on this thread, there is a very obvious - too obvious - 4th option.  The 4th option is that the universe is fine-tuned for life, so what.  I am trying to understand why they don't think this is an option.

I do not think what you say it true.

Most scientists, it seems to me,  don't give a moment's thought to the question and simply accept the values of the fundamental constants are what they are.  So in effect your "so what" option is what they subscribe to, by default.

I think you are making a fuss about nothing, to be honest. 

[joigus]

I'm aware of two fine-tuning problems in theoretical physics. One is related to the vacuum energy. We need something to correct for the "offset" of 120 orders of magnitude in its estimate coming from quantum field theory.

The other is related to the cancellation of huge radiative corrections to the mass of the Higgs up to the order of such mass.

As far as I know, they are very different. No consistent theory of quantum gravity has been formulated, so I think it's difficult to conceive of a mechanism that cancels those discrepancies while leaving a ridiculously small vacuum energy. The Higgs problem has been treated in the context of supersymmetry. No luck so far.

Why that is a problem has to do with a concept that's very deeply rooted in the history of physics. Miraculous coincidences are very difficult to believe, and generally not a sound heuristic approach. It's possible that the idea of our universe being embedded in a much, much bigger multiuniverse in which the laws of Nature play with what we call universal constants (and we happen to live in a region in which they have the right value) cannot be easily dismissed. You can dismiss it only on the bases of unfalsifyability and/or (perhaps) non-simplicity.

But I tend to look at the history of physics for inspiration, and when some exceedingly complicated adjustment has been necessary (think of the Ptolemaic tweakings to adjust the motion of the planets, complicated hypotheses about moving bodies before relativity), a much simpler solution always has arisen that had to do with a valiant re-thinking of the principles, rather than patching up the model. 

[OldChemE]

 "How can so many numbers of nature, the constants and relationships of physics, be so spot-on perfect for humans to exist?

Because they provide the boundary conditions that happened (by chance) to allow humans to exist.  If nature were different, likely any life that evolved would also be different-- and some of those living beings would likewise be amazed that nature just happened to be perfect for them to exist.

[Genady]

1 hour ago, exchemist said:

I think you are making a fuss about nothing, to be honest. 

I couldn't say it better. +1

58 minutes ago, joigus said:

I'm aware of two fine-tuning problems in theoretical physics. One is related to the vacuum energy. We need something to correct for the "offset" of 120 orders of magnitude in its estimate coming from quantum field theory.

The other is related to the cancellation of huge radiative corrections to the mass of the Higgs up to the order of such mass.

As far as I know, they are very different. No consistent theory of quantum gravity has been formulated, so I think it's difficult to conceive of a mechanism that cancels those discrepancies while leaving a ridiculously small vacuum energy. The Higgs problem has been treated in the context of supersymmetry. No luck so far.

Why that is a problem has to do with a concept that's very deeply rooted in the history of physics. Miraculous coincidences are very difficult to believe, and generally not a sound heuristic approach. It's possible that the idea of our universe being embedded in a much, much bigger multiuniverse in which the laws of Nature play with what we call universal constants (and we happen to live in a region in which they have the right value) cannot be easily dismissed. You can dismiss it only on the bases of unfalsifyability and/or (perhaps) non-simplicity.

But I tend to look at the history of physics for inspiration, and when some exceedingly complicated adjustment has been necessary (think of the Ptolemaic tweakings to adjust the motion of the planets, complicated hypotheses about moving bodies before relativity), a much simpler solution always has arisen that had to do with a valiant re-thinking of the principles, rather than patching up the model. 

Another fine-tuning problem, in cosmology, is related to the flatness problem, i.e. the degree of the current flatness of the universe requires incredible closeness of the initial energy density to a critical value at the start of the universe expansion. The inflation model solves this one.

[erik]

5 hours ago, 34student said:

For me, and others on this thread, there is a very obvious - too obvious - 4th option.  The 4th option is that the universe is fine-tuned for life, so what.  I am trying to understand why they don't think this is an option.

At last you clarify your question.

The idea that the constants could have been different is not part of science, it can not be tested, it can not be falsified, it predicts nothing. It is just a "what if" fantasy. It's just like wondering what if Thanos won. It's not part of science. It's just fantasy.

Since the constant couldn't have been different, the universe was not fine tuned for life, it was not fine tuned at all.

Due to our natural anthropocentrism, we could believe that life is a special thing, but it is not. Your body is made from the exact same atoms as those found in a stone. Life is nothing more than a byproduct of natural selection. Much like symmetry, commutativity or entropy, what we know as natural selection is a set of mathematical concepts which are deeper that the constants of the universe. These concepts don't require any fine tuning in order to exist.

[joigus]

10 hours ago, Genady said:

I couldn't say it better. +1

Another fine-tuning problem, in cosmology, is related to the flatness problem, i.e. the degree of the current flatness of the universe requires incredible closeness of the initial energy density to a critical value at the start of the universe expansion. The inflation model solves this one.

Well, yes. As to the flatness problem, it does. Also regarding the causal paradox and the absence of monopoles. But at what price? Introducing another bunch of arbitrary parameters (number of e-foldings, hypothesis concerning the shape of an arbitrary curve!! --the inflaton field.)* It doesn't look like leading us in the direction of "naturalness" or less ad hoc, or less fine-tuned. You have to tune it too, don't you?

Don't get me wrong. I'm all in favour of inflationary scenarios, and I have defended them here frequently.

* Neil Turok is one of the interesting cosmologists to listen to in this respect.

[Genady]

19 minutes ago, joigus said:

Well, yes. As to the flatness problem, it does. Also regarding the causal paradox and the absence of monopoles. But at what price? Introducing another bunch of arbitrary parameters (number of e-foldings, hypothesis concerning the shape of an arbitrary curve!! --the inflaton field.)* It doesn't look like leading us in the direction of "naturalness" or less ad hoc, or less fine-tuned. You have to tune it too, don't you?

Don't get me wrong. I'm all in favour of inflationary scenarios, and I have defended them here frequently.

* Neil Turok is one of the interesting cosmologists to listen to in this respect.

I should've put the last statement in that post in parentheses, like this: (The inflation model solves this one.) I wanted to bring another example of a fine-tuning problem in physics. Inflation is interesting in this respect as a way of eliminating a need of fine-tuning dynamically, in principle. One of possible ways.

Edited February 13, 2022 by Genady

[joigus]

On 2/12/2022 at 1:34 PM, mistermack said:

Even the phrase "fine tuned" is rubbish, because it contains in it an unwarranted assumption. It implies that there is a tuner, which is circular reasoning right from the start. Finely balanced might be fairer, but even that implies a situation that could have been other than it is, which is not established at all. 

I agree with this. Fine-tuned seems to re-invent a concept that was already there, with much less anthropomorphic/deistic implications: ad hoc.

I myself would like to see more and more people resisting the temptation to use these anthropomorphic/deistic words: created, tuned, etc.

[Genady]

17 minutes ago, joigus said:

I agree with this. Fine-tuned seems to re-invent a concept that was already there, with much less anthropomorphic/deistic implications: ad hoc.

I myself would like to see more and more people resisting the temptation to use these anthropomorphic/deistic words: created, tuned, etc.

You mean, we shouldn't say that particles are created? shouldn't call 'a⁺' a creation operator?  

[joigus]

2 minutes ago, Genady said:

You mean, we shouldn't say that particles are created? shouldn't call 'a⁺' a creation operator?  

No, I meant it more in relation to "how the Earth was created" or "made", "the Himalayas were created by such and such process," etc. You know what I mean.

But now that you mention it, I remember there was a pseudo-religious-whatever people that played with the idea of creation and annihiliation operators as the two versions of the Hindu gods.

Brahma was the creator (a⁺)

Shiva was the destroyer (a)

I assume the number operator aa⁺+a⁺a was supposed to be Vishnu, "the keeper." 🤣

[Genady]

1 hour ago, joigus said:

No, I meant it more in relation to "how the Earth was created" or "made", "the Himalayas were created by such and such process," etc. You know what I mean.

But now that you mention it, I remember there was a pseudo-religious-whatever people that played with the idea of creation and annihiliation operators as the two versions of the Hindu gods.

Brahma was the creator (a⁺)

Shiva was the destroyer (a)

I assume the number operator aa⁺+a⁺a was supposed to be Vishnu, "the keeper." 🤣

I know, let's use German, erstellen. Sounds just like eigen and gedanken.