Is the cosmos "fine-tuned"?

[LegionOnomaMoi]

And yet it is amazingly exactly the right salinity for whales! Incredible! What are the odds?

There is no "exactly right salinity". That's the point. We would expect the same for the fundamental constants (that incredibly tiny changes to so many would ensure we wouldn't exist).

 

[shawn001]

OK, you have officially lost me. WHAT exactly is determining the way things are?

The laws of nature.

 

[LegionOnomaMoi]

But of course it is now the Higgs Boson.

Actually it is "a Higgs Boson". We still are not sure if it is the Higgs Boson.

Sure, just as the apparent design of animals was once attributed to a god, or the roll of a thunderstorm.

Really? Interesting. I wasn't aware that models in particle physics or quantum theory were used to attribute the apparent design of animals to god.

 

[shawn001]

This is still very important in the discussion.

" “weak anthropic principle” (WAP), which is essentially a tautology. It asserts that because we exist, the nature of the cosmos must have properties such that we can exist, for if it did not, we wouldn’t be here."

 

[Bunyip]

There is no "exactly right salinity". That's the point. We would expect the same for the fundamental constants (that incredibly tiny changes to so many would ensure we wouldn't exist).

Yes and obviously we do not exist in all of the universes that can not exist, or that exist but can not support life. We can only be found in the universe that fits us.

Here is the fine tuning argument in a nutshell;

Person 1: Now legs could be any length. Do you agree?
Person 2: Well sure I guess.
Person 1: Well my legs are EXACTLY the same length as the distance between my arse and the ground! What's the odds? Pretty remote huh? Must be a god, couldn't just be chance could it? If my legs were a millimeter shorter they would not reach the ground!
Person 2: **sigh**

 

[LegionOnomaMoi]

This is still very important in the discussion.

" “weak anthropic principle” (WAP), which is essentially a tautology. It asserts that because we exist, the nature of the cosmos must have properties such that we can exist, for if it did not, we wouldn’t be here."

Yes, and I should have specified that option (b) below:
"It seems that the physical laws and constants of our universe are very finely tuned to support life. How can this be accounted for? The two most popular explanations have been (a) the theistic prinicple (God created the universe) and (b) the anthropic principle"
Byl, J. (1996). On the natural selection of universes. Quarterly Journal of the Royal Astronomical Society, 37, 369.

...refers to the WAP, not stronger versions of the anthropic principle. Likewise with my comment "The anthropic principle, for example, uses the fact that we exist as a fundamental explanatory basis," although here there are exceptions.

 

[Bunyip]

Actually it is "a Higgs Boson". We still are not sure if it is the Higgs Boson.


Really? Interesting. I wasn't aware that models in particle physics or quantum theory were used to attribute the apparent design of animals to god.

They weren't you just tend to deliberately obfuscate a lot.

 

[LegionOnomaMoi]

They weren't you just tend to deliberately obfuscate a lot.

You made a bad analogy. There was nothing relevant or of import, so I didn't bother treating it seriously.

 

[Bunyip]

You made a bad analogy. There was nothing relevant or of import, so I didn't bother treating it seriously.

That is how you dismiss anything you can not respond more intelligently to. I'm used to it.

 

[Bunyip]

There is no "exactly right salinity". That's the point. We would expect the same for the fundamental constants (that incredibly tiny changes to so many would ensure we wouldn't exist).

How is that a point? Things are as they are, universes that can not exist and universes that can not support life do not have life in them. It is just a tautology, not an unlikely probability. The probability that the universal constants enable the natural formation of life remains one.

 

[LegionOnomaMoi]

Yes and obviously we do not exist in all of the universes that can not exist, or that exist but can not support life.

You are missing the important portion of your own analogy. The problem isn't that we find the that things which require salt water to live only live where there is salt water, just as it isn't that we happen to live in a habitable zone in universe that has these. It is that we wouldn't expect sea creatures that require salt water to require a salinity so precise that we couldn't keep them alive using any technology we have because we can't even begin to get near to that level of precision. And that's one constant/parameter, not ~20.

We can only be found in the universe that fits us.

Which is why Bayesian probability/reasoning is the only approach that works here. Your approach is that given that I won the lottery, the probability that I won the lottery is 1. We aren't interested in whether or not you won the lottery, but in how likely you were to win or in what other outcomes could have been. Additionally, we are interested in why it seems we can predict facts about the universe based upon the assumption that it was designed so that we could live in it.

 

[Bunyip]

You are missing the important portion of your own analogy. The problem isn't that we find the that things which require salt water to live only live where there is salt water, just as it isn't that we happen to live in a habitable zone in universe that has these. It is that we wouldn't expect sea creatures that require salt water to require a salinity so precise that we couldn't keep them alive using any technology we have because we can't even begin to get near to that level of precision. And that's one constant/parameter, not ~20.

Sorry, that was illegible - could you re-state your point please?

Which is why Bayesian probability is the only approach that works here. Your approach is that given that I won the lottery, the probability that I won the lottery is 1. We aren't interested in whether or not you one the lottery, but in how likely you were to win or in what other outcomes could have been. Additionally, we are interested in why it seems we can predict facts about the universe based upon the assumption that it was designed so that we could live in it.

No mate, in the example in question the lottery of life is already won. That the universe can support life is a given, just as my lottery winning is after the fact. It is looking at how things are now, hence a probability of one. Not a prediction of future outcomes. As I said, it is akin to believing that it is highly improbable that your legs are exactly the right distance between your arse and the ground. And postulating from that the existence of space penguins.

 

[LegionOnomaMoi]

Sorry, that was illegible - could you re-state your point please?

Our theories of the nature of the universe give us good reason to suppose that there is nothing particularly special about the fundamental constants nor any reason to suspect that they could have been quite different. Imagine each value as a single number corresponding to a coordinate. As there are ~20 constants, we'll say there are 20 values, so there are 20 coordinates, requiring 20th dimensional (Euclidean) space. This is the probability space, in that every point is a set of possible values for the constants. This space extends infinitely in 20 different "directions" (or along 20 different dimensions). We would expect that, given the enormous number of possible values, there must exist a wide range for them such that large variations wouldn't really effect much. That is to say, we would expect that the probability space of universes in which we could exist out of the total probability space would be a large region.

In other words, we expect to find what we do in your example of whales and salt water: yes, wales require salt water, but you can change an huge amount of variables by (comparatively) incredibly vast amounts and not really do much, including the salinity of the ocean. Instead we find that rather the probability space for a universe in which we could exist isn't some huge region, but more like a single point.

Not only that, but if we assume that the universe was designed for us, we can (and have) made successful predictions about its nature. Not only that, but the other alternative in that paper which mentions the two popular explanations for fine-tuning, the anthropic principle, suggests we take as fundamental not fundamental forces & particles but us. It isn't much of a leap from here to suggest that if we should do this, and it works as it has, then our status is equivalent to that of fundamental particles/forces, and as we weren't around to be fundamental anything until long after the universe began, that it was designed for us.

In essence, the ways to explain the precision of the values for these fine-tunings have been to propose that our universe is one of a vast number, to suppose that it was designed, or to suppose that we can treat it like it was designed.

No mate, in the example in question the lottery of life is already won.

Same here. The universe has the constants.

That the universe can support life is a given

The fine-tunings are not. They are given only once the universe is a given, or alternatively that granted this universe we live in has the fine-tunings it does, it has them. But it need not have them, just as you need not have one the lottery. And we have reason to suppose that it should not have them.

And postulating from that the existence of space penguins.

Why do physicists call fine-tuning a problem?

 

[Bunyip]

Our theories of the nature of the universe give us good reason to suppose that there is nothing particularly special about the fundamental constants nor any reason to suspect that they could have been quite different. Imagine each value as a single number corresponding to a coordinate. As there are ~20 constants, we'll say there are 20 values, so there are 20 coordinates, requiring 20th dimensional (Euclidean) space. This is the probability space, in that every point is a set of possible values for the constants. This space extends infinitely in 20 different "directions" (or along 20 different dimensions). We would expect that, given the enormous number of possible values, there must exist a wide range for them such that large variations wouldn't really effect much. That is to say, we would expect that the probability space of universes in which we could exist out of the total probability space would be a large region.

In other words, we expect to find what we do in your example of whales and salt water: yes, wales require salt water, but you can change an huge amount of variables by (comparatively) incredibly vast amounts and not really do much, including the salinity of the ocean. Instead we find that rather the probability space for a universe in which we could exist isn't some huge region, but more like a single point.

Not only that, but if we assume that the universe was designed for us, we can (and have) made successful predictions about its nature. Not only that, but the other alternative in that paper which mentions the two popular explanations for fine-tuning, the anthropic principle, suggests we take as fundamental not fundamental forces & particles but us. It isn't much of a leap from here to suggest that if we should do this, and it works as it has, then our status is equivalent to that of fundamental particles/forces, and as we weren't around to be fundamental anything until long after the universe began, that it was designed for us.

In essence, the ways to explain the precision of the values for these fine-tunings have been to propose that our universe is one of a vast number, to suppose that it was designed, or to suppose that we can treat it like it was designed.


Same here. The universe has the constants.


The fine-tunings are not. They are given only once the universe is a given, or alternatively that granted this universe we live in has the fine-tunings it does, it has them. But it need not have them, just as you need not have one the lottery. And we have reason to suppose that it should not have them.


Why do physicists call fine-tuning a problem?

Most of them don't. For the tiny few who do, I assume it is some sort of expression of faith.

 

[LegionOnomaMoi]

Yes and obviously we do not exist in all of the universes that can not exist, or that exist but can not support life. We can only be found in the universe that fits us.

Mostly for the sake of any tuning in (bad pun) I'm going to explain this in another way closer to physics in general. Take the big bang. It is not some finding that we can replicate, nor was it observed. Or consider the importance of reversibility in classical physics: given any state of a system, you should be able to (at least in theory) run the model backwards from the system's final state and obtain the initial state. In fact, this is one of the central ways in which models are built: we throw parameters into some system of partial differential equations (PDEs) with values determined by theory and observation, and then we run the system back and see if it gives us an actual initial state. Or, in the case of e.g., climate science, we run the model forward from some time decades ago and see if it gives us something close to the observed temperatures. If it doesn't, we adjust the parameters.

The takeaway point is simple but absolutely vital to the natural sciences: we construct models, from the climate to the universe, such that we can run them back to a starting point and explain the evolution (the change over time) via known properties of the system.

When we do this with the universe, i.e., when we run back the clock/reverse the system and get our initial point (the big bang), our model tells us that the fundamental constants should be changeable, because in addition to having no reason why they shouldn't be, we built the model such that they are "parameters" and we should be able to find out things by seeing what is or isn't changed given different values. Instead, we find that we can't treat then like parameters, because changes too small to measure drastically change (or destroy) the universe and/or ensure we could never exist. It is as if somebody already set the only possible values for the parameters and we're building a model of this designed universe without realizing it until we start to fiddle with what we thought were parameters for a non-designed universe.

 

[LegionOnomaMoi]

Most of them don't.

Given that you couldn't find any peer-reviewed literature of the kind that took me all of two minutes to find, what is your basis for this?

For the tiny few who do

i.e., those whose fields concern particle physics, cosmology, theoretical physics, quantum physics, astrophysics, and probably others I can't think of. That is the minority, true (apart from interdisciplinary fields like biophysics, there's still nuclear physics, solid state physics, materials science, etc.). However, as those physicists aren't working in relevant fields, it doesn't matter.

 

[Bunyip]

Mostly for the sake of any tuning in (bad pun) I'm going to explain this in another way closer to physics in general. Take the big bang. It is not some finding that we can replicate, nor was it observed. Or consider the importance of reversibility in classical physics: given any state of a system, you should be able to (at least in theory) run the model backwards from the system's final state and obtain the initial state. In fact, this is one of the central ways in which models are built: we throw parameters into some system of partial differential equations (PDEs) with values determined by theory and observation, and then we run the system back and see if it gives us an actual initial state. Or, in the case of e.g., climate science, we run the model forward from some time decades ago and see if it gives us something close to the observed temperatures. If it doesn't, we adjust the parameters.

The takeaway point is simple but absolutely vital to the natural sciences: we construct models, from the climate to the universe, such that we can run them back to a starting point and explain the evolution (the change over time) via what known properties of the system.

When we do this with the universe, i.e., when we run back the clock/reverse the system and get our initial point (the big bang), our model tells us that the fundamental constants should be changeable, because in addition to having no reason why they shouldn't be, we built the model such that they are "parameters" and we should be able to find out things by seeing what is or isn't changed given different values. Instead, we find that we can't treat then like parameters, because changes to small to measure drastically change (or destroy) the universe and/or ensure we could never exist. It is as if somebody already set the only possible values for the parameters and we're building a model of this designed universe without realizing it until we start to fiddle with what we thought were parameters for a non-designed universe.

Sure, I understand all that. But I can't see how it is addressing my response.

 

[Bunyip]

Given that you couldn't find any peer-reviewed literature of the kind that took me all of two minutes to find, what is your basis for this?

My basis is simply that articles in favour of fine tuning as a significant issue are as uncommon as are peer reviewed research articles in favour of creationism - and for the same reason. Few cosmologists seem to take it seriously, I did give as an example an article by one of the worlds most prominent physicists, but you completely and utterly ignored it. I am not really interested in going to the trouble of supplying more examples for you to ignore anyway,

i.e., those whose fields concern particle physics, cosmology, theoretical physics, quantum physics, astrophysics, and probably others I can't think of. That is the minority, true (apart from interdisciplinary fields like biophysics, there's still nuclear physics, solid state physics, materials science, etc.). However, as those physicists aren't working in relevant fields, it doesn't matter.

Yes, only a tiny, tiny minority within those fields also. Few physicists are so readily confused by a simple tautology. The argument from design is just an ancient fallacy - the fine tuning argument is simply a re-statement to disguise it as something new. Just as Intelligent Design is nothing more than a re-stating of creationism in order to make it seem scientific.

 

[LegionOnomaMoi]

Sure, I understand all that. But I can't see how it is addressing my response.

Your point seems to be something like "the reason we find ourselves in a universe fit for life is because were it not, we wouldn't be here". True enough, but not why "fine-tuning' is considered a problem in physics. We have a model that we obtained on the assumption that the universe wasn't designed as well as a whole slew of empirical evidence, mathematics, etc. This model allows us to do what any model should: reverse the system and evaluate our parameters (adjusting them as needed) as well as our model, and exploring the results of other allowable values for model parameters (which is what parameters are for). What we find is that this is impossible. We made a bad assumption somewhere, but it isn't a problem with the model as the model (given the extremely precise parameter values) gives us what we expect. It could be a problem with the theory (which is a problem with the model, but of a particular kind) in that we assumed things were parameters when they weren't really, but we have no basis for this position, and the model got us the right results without it. If we throw away the assumption that the universe wasn't designed, then we have a good model and we have explained why we can't fiddle with the parameters the way we thought.

 

[LegionOnomaMoi]

My basis is simply that articles in favour of fine tuning as a significant issue are as uncommon as are peer reviewed research articles in favour of creationism

Fine-tuning isn't a question. It's a fact. Every cosmologist, particle physicist, etc., knows its a fact. It's all over the literature. I gave you a quotation demonstrating that the an entire class (which includes the current model) of cosmological models, inflationary models, were developed just to address the fine-tuning "problem". This has been an issue in the literature for decades, beginning with a paper published in Reviews of Modern Physics in the 50s, and by 1961 it was already big enough to be featured in a Nature paper.

You really didn't know this?