God & Cosmology: Perceptions & Opinions

[madness]

It's one of the results that comes from string theory. If you want to argue that this proves string theory is bogus and useless, I might not agree, but I'll not object to strongly.



I don't either but, "why ask why?"

One thing that I think is happening is that people that do have science do science with very, very different philosophical ideas that just happen to be compatible with each other enough so that we don't argue over everything. If there is a lot of evidence, and if we agree on how to process the evidence, then there is nothing to argue about.

However, when we *don't* have a lot of evidence or we disagree about what it means, then sparks fly. One thing I *very* strongly object to are surveys that seem to imply "most scientists are atheists, scientists are smart, therefore atheism must be true" since that implies that scientists that believe in God like myself are stupid."

I see God right in front of me. If you don't then fine. I'm not going to even try to convince you because I know I can't and it's a waste of my time to try.

But I someone annoyed when someone calls me delusional, and I get professionally offended when someone argues that I'm less of a physicist or that I'm dumber for believe that God exists, and that seems to be the gist of a lot of articles. Also if you make a scientific argument for anything, it's my professional duty to shoot it full of holes. That's how science works.

If atheists believe that there is no God, that's fine. If atheists believe that *I* (i.e. competent scientists that do believe in God) don't exist, then we have a problem.

Until alternative universes with different laws of physics is a testable hypothesis, I see them as completely unscientific. And I can't imagine that they ever will be testable - how could test a universe with laws of physics that don't support life? I don't know a lot about string theory but I gather that it not considered scientific by most people.
I made a similar point to yours about asking "why" in my last post where I quoted Bertrand Russell - note that this point is generally to detract from the need for a God.

Personally I'm pretty agnostic about God, but what I share with the theists is a strong belief that science cannot give a final and definitive answer fundamental questions such as the origin of the universe and the reason for its existence.

 

[twofish-quant]

Therefore, to be a scientist, you had to have faith that the universe is governed by dependable, immutable, absolute, universal, mathematical laws of an unspecified origin. You've got to believe that these laws won't fail, that we won't wake up tomorrow to find heat flowing from cold to hot, or the speed of light changing by the hour.

Curiously my concept of science rejects this notion. I don't have any problems with physical laws and patterns that change over time. If the second law of thermodynamics just stops working, then oh well.

I think this may have something to do with the fact that I work in finance where the basic rules *do* change radically over time. Interest rate swap models that worked in June 2008, just will not work now, and a lot of the "fundamental laws of finance" just stopped working for a while.

I think that some people would find this disturbing, but I find it fun. What's the point in trying to figure out the rules if they don't change on you?

 

[twofish-quant]

Until alternative universes with different laws of physics is a testable hypothesis, I see them as completely unscientific.

As long as people are trying to create testable hypothesis, it's still science.

And I can't imagine that they ever will be testable - how could test a universe with laws of physics that don't support life?

Try harder. Theory is very tough, because the job of a theorist is to take a model and then try to create predictions from it. The fact that you can't think of a way in five minutes, doesn't mean very much. If you take a dozen people and try for twenty years and get nowhere, then maybe it can't be done.

Alternatively, you can try to *mathematically prove* that it can't be done. Saying something can't be done because of lack of imagination doesn't mean much. If you can create a series of rigorous steps and prove that a model will lead to no predictions, that would be a big deal, but it's really, really hard.

I don't know a lot about string theory but I gather that it not considered scientific by most people.

As long as you are still trying, you are playing the game. One thing that is important is that thirty years ago, it wasn't obvious to people that SSB would lead to these sorts of problems, and it's only by spending a lot of time trying and failing that get anywhere.

Personally I'm pretty agnostic about God, but what I share with the theists is a strong belief that science cannot give a final and definitive answer fundamental questions such as the origin of the universe and the reason for its existence.

Ummmm... "Why the universe exists, isn't a scientific question" but right now I don't see any reason to think that we can't completely understand the origin of the universe. Maybe it can't, but you don't know what you see until you try. One problem I do have is with the "God of the gaps" theology. I also have problems with a "supernatural God."

If God only exists in the unknown, then we are going to have a bigger and bigger problem as we know more about the universe. It's quite possible that someday, we'll know exactly how the universe formed. (What will be really scary is if we know enough about how the universe form to create new universes in the laboratory, which is probably another science fiction story.)

What's why it's theologically important for God to be in front of you. If you force God to be in places that we don't understand, there will be no room for God.

 

[Freeman Dyson]

Well, this is a different issue. Basically there are two schools of thought in theoretical physics. The first school of thought argues that the parameters that make up our universe could be uniquely predicted if we were to have a theory of everything before us. The second school of thought states that the universe takes on many different values for these parameters, and our region stems from one particular realization of them.

Susskind and others (including myself) argue that the fact that the physical parameters that define the properties of physics at low energies have the appearance of fine tuning is strong evidence for the second situation.

A "tuner" doesn't enter into it at all, because that proposal is a non-starter, for two main reasons.

The practical reason why proposing a "tuner" is a non-starter is just that if it were true, then there would be no further investigation to be done. So we might as well just go with those hypotheses that can be investigated and understood. This is basically the reason why science relies upon methodological naturalism: it has to, or else it'd stop.

The logical reason why it's a non-starter is that the proposal of a "tuner" is necessarily more complex than that which it is purported to explain, and thus isn't actually an explanation.


Yes. Spontaneous symmetry breaking is a mechanism that is inherent within the standard model of particle physics, and is likely to be even more significant for physics beyond the standard model. Spontaneous symmetry breaking ensures that different regions of the universe will have different parameters for what we see as physical constants. The symmetry breaking within the current standard model is pretty minimal, just relating to the properties of the weak nuclear force, but it is expected that many other parameters are a result of such events as well.

So, universe is large + spontaneous symmetry breaking = multiverse.

Well, what if there comes a time when there is no further investigation to come? Just invent something? If it's the end of the investigation, it's the end of the investigation. You don't have any say when investigation ends. It is indifferent to your wishes. Take it as it comes.

And would you stop throwing speculation upon speculation to back up the METAPHYSICAL concept of the multiverse?

Your argument basically boils down to: The universe is too tuned so I have to invent an infinite amount of other universes to make ours not seem so special. You think fine tuning=multiverse.

"the fact that the physical parameters that define the properties of physics at low energies have the appearance of fine tuning is strong evidence for the second situation."

the second situation being the multiverse. fine tuning=strong evidence for multiverse.

no, it isn't any evidence at all. much less strong evidence.

 

[GeorgCantor]

I don't "hate" people. I said that I have serious, serious problems with Dawkins. If Dawkins were speaking as a preacher or a philosopher, I wouldn't have any problems with what he says. The problem that I have is that Dawkins appears to be speaking as a ***scientist*** and claims to be using ***science*** to justify his religious beliefs. I have serious problems with that.

I totally agree with this. What would make a physicist or a scientist in general more qualified to answer fundamental questions like "Why is there something than nothing?" than say a truck driver or a bar tender? Nothing. Unscientific questions don't differentiate between professions - your untestable speculations are as good as mine. Period.

 

[madness]

As long as people are trying to create testable hypothesis, it's still science.



Try harder. Theory is very tough, because the job of a theorist is to take a model and then try to create predictions from it. The fact that you can't think of a way in five minutes, doesn't mean very much. If you take a dozen people and try for twenty years and get nowhere, then maybe it can't be done.

Alternatively, you can try to *mathematically prove* that it can't be done. Saying something can't be done because of lack of imagination doesn't mean much. If you can create a series of rigorous steps and prove that a model will lead to no predictions, that would be a big deal, but it's really, really hard.



As long as you are still trying, you are playing the game. One thing that is important is that thirty years ago, it wasn't obvious to people that SSB would lead to these sorts of problems, and it's only by spending a lot of time trying and failing that get anywhere.



Ummmm... "Why the universe exists, isn't a scientific question" but right now I don't see any reason to think that we can't completely understand the origin of the universe. Maybe it can't, but you don't know what you see until you try. One problem I do have is with the "God of the gaps" theology. I also have problems with a "supernatural God."

If God only exists in the unknown, then we are going to have a bigger and bigger problem as we know more about the universe. It's quite possible that someday, we'll know exactly how the universe formed. (What will be really scary is if we know enough about how the universe form to create new universes in the laboratory, which is probably another science fiction story.)

What's why it's theologically important for God to be in front of you. If you force God to be in places that we don't understand, there will be no room for God.

So if I say that science can't test for God do I have to try harder? By your logic we might just have not figured out how yet.
Of course "why does the universe exist" isn't a scientific question, that was my point. That doesn't mean it's an invalid one. And I completely disagree that the origin of the universe is available to scientific scrutiny. Read Kant - he said that anything which caused the universe would necessarily be outside of cause and effect, space and time. To extend the science we developed from observing our universe beyond these confines is not reasonable.

 

[GeorgCantor]

In general, physicists after around 1930's, are not determinists. Determinism is incompatible with quantum mechanics unless you start assuming either weirder stuff.

If they are not determinists, they cannot do science. Humans don't understand truly uncaused events, or do you claim to have such powers? How do you or Dave know that microscopic seemingly uncaused randomness can creep up at the macro level?? What experiment supports this? Where is the evidence that there could have been other universes besides the one we observe?

 

[Freeman Dyson]

I totally agree with this. What would make a physicist or a scientist in general more qualified to answer fundamental questions like "Why is there something than nothing?" than say a truck driver or a bar tender? Nothing. Unscientific questions don't differentiate between professions - your untestable speculations are as good as mine. Period.

I think Martin Rees, quoting Polkinghorne, said it best, "The average quantum mechanic is no more philosophical than the average auto mechanic."

 

[Phyisab****]

I think if you wonder about the effect of cosmology on faith, you are missing the idea of faith entirely. Something like twofish said. Either you know there must be something more, or you don't. There can always be god "outside" of physics.

 

[Chalnoth]

The assumption is that there are other universes (ie places with different laws of physics) that don't support life.

That's not an assumption. It's something that is necessarily true if the universe is large and there are spontaneous symmetry breaking events, both of which are strongly supported by the available evidence.

 

[Freeman Dyson]

It's one of the results that comes from string theory. If you want to argue that this proves string theory is bogus and useless, I might not agree, but I'll not object to strongly.



I don't either but, "why ask why?"

One thing that I think is happening is that people that do have science do science with very, very different philosophical ideas that just happen to be compatible with each other enough so that we don't argue over everything. If there is a lot of evidence, and if we agree on how to process the evidence, then there is nothing to argue about.

However, when we *don't* have a lot of evidence or we disagree about what it means, then sparks fly. One thing I *very* strongly object to are surveys that seem to imply "most scientists are atheists, scientists are smart, therefore atheism must be true" since that implies that scientists that believe in God like myself are stupid."

I see God right in front of me. If you don't then fine. I'm not going to even try to convince you because I know I can't and it's a waste of my time to try.

But I someone annoyed when someone calls me delusional, and I get professionally offended when someone argues that I'm less of a physicist or that I'm dumber for believe that God exists, and that seems to be the gist of a lot of articles. Also if you make a scientific argument for anything, it's my professional duty to shoot it full of holes. That's how science works.

If atheists believe that there is no God, that's fine. If atheists believe that *I* (i.e. competent scientists that do believe in God) don't exist, then we have a problem.

Well Dawkins says that religion and science are incompatible so maybe you should find a new career. Most of the best scientists in history should have too.

 

[Chalnoth]

But what constitutes "evidence".

For a classification of evidence to lead to the truth, that classification must lead to reliable results. That is to say, any sufficiently-specific statement about reality that you might make must be either true or false (another way of stating this is that it is possible to add conditions to any ambiguous statement so that it is definitively either true or false, even if we don't know which). This is basically a tautology.

Given this tautology, we can then conclude that if we are to accept a classification of evidence as being reliable, then it must consistently produce the same answers to the same questions. If it does not, then it is a bad form of evidence.

This fact is, fundamentally, why science relies so heavily upon verification of results. And it's also why there isn't any evidence for any god: the types of evidence that people attempt to use to support their beliefs are the same (revelation, personal experience, tradition), but they come to wildly different conclusions about the specifics.

First of all physicists do not *prove* anything. Mathematicians *prove* things. If you are using the word "proof" to mean anything other than a series of logical mathematical steps, you are using language in a an unforgivably sloppy way.

He's using it in the way the word is used by the general populace, however. Now, I don't do this personally, but arguing over semantics doesn't get into the meat of the article. He is quite specific about the definition that he is using in the blog post.

Last year I thought the big bang happened. May be next year I'll change my mind. If the existence or non-existence of God were really subject to scientific evidence, it would be tentative and uncertainty. Yesterday, I thought God existed, maybe tomorrow I'll see something that will make me change my mind.

I think it's typically only people that believe in a god that think that somehow the question, "Does a god exist?" is categorically different from other questions about the nature of reality. I don't. And that's what the thrust of that article was: it isn't categorically different, and so we should apply the exact same thought processes that have proven reliable time and again with other questions to the one about whether or not there is a god (or gods, for that matter).

See, I once believed in the Christian God. Then, as I learned about science and how to do science, I started applying those same thought processes to my religion (in particular after I noticed that my religion was making some claims that were distinctly opposed to reality). When I did so, I found that it was all bunk, and I really had no valid reason to believe any of it.

But I don't know of anyone that thinks of the existence of God in the same way that people think of the fine structure constant, which suggests to me that people *aren't* using scientific means to come to their conclusions, which is perfectly fine as long as people admit it.

It's only perfectly fine if you're okay with being wrong. The only limitation placed upon scientific thinking is whether or not it is fallacious. Therefore there are only two types of reasoning: scientific reasoning (i.e. non-fallacious reasoning) and fallacious reasoning.

Also, there has been a *lot* of philosophy that has contributed to the understanding of God, and even if you don't believe that God exists, it's useful to understand belief in God as a social phenonomenon. One thing that convinces me that God cannot be proved through rational means is a brilliant theologian named William of Ockham. You may have heard of him.

I find this human obsession with gods to be rather interesting. But seriously, if you're not going to demonstrate the existence of a god through rational means, then that's extremely good reason not to believe in a god.

 

[Chalnoth]

I think if you wonder about the effect of cosmology on faith, you are missing the idea of faith entirely. Something like twofish said. Either you know there must be something more, or you don't. There can always be god "outside" of physics.

That's a misuse of the word "know". If you can't demonstrate it, you don't know. You may believe very strongly, but all the belief in the world doesn't make something true.

 

[Chalnoth]

Well Dawkins says that religion and science are incompatible so maybe you should find a new career. Most of the best scientists in history should have too.

People often have little problem holding two incompatible ideas within their own heads.

 

[madness]

That's not an assumption. It's something that is necessarily true if the universe is large and there are spontaneous symmetry breaking events, both of which are strongly supported by the available evidence.

I'm not an expert on spontaneous symmetry breaking, but for the purposes of the (strong) anthropic principle you would really need enough trials (different sets of laws) that a life supporting universe becomes inevitable, or at least probable. Are you saying that this is supported by scientific evidence?
The weak anthropic principle, on the other hand, basically states that the universe supports life "because it does". I can't argue with this point of view. If you assume there's nothing special about life then there's nothing to be explained.

 

[Chalnoth]

I'm not an expert on spontaneous symmetry breaking, but for the purposes of the (strong) anthropic principle you would really need enough trials (different sets of laws) that a life supporting universe becomes inevitable, or at least probable. Are you saying that this is supported by scientific evidence?

Well, we do exist, don't we? Whatever the true theory underlying the universe actually is, it must result in our existence. If a candidate for a theory of everything doesn't predict our existence, then it's wrong.

The weak anthropic principle, on the other hand, basically states that the universe supports life "because it does".

It states nothing of the sort. It just states that if we have a theory which predicts a variety of possible universes, only those parts in which observers can exist will be observed. It's a selection effect, in other words.

If you assume there's nothing special about life then there's nothing to be explained.

That's a statement that should not be simply assumed, but investigated in detail. And it doesn't appear to be true: from what we know currently, it does appear that a large number of parameters have to take a rather narrow range of values for life to be remotely possible.

 

[madness]

Well, we do exist, don't we? Whatever the true theory underlying the universe actually is, it must result in our existence. If a candidate for a theory of everything doesn't predict our existence, then it's wrong.

You have just reapplied the anthropic principle and ignored my point. If we assume life to be something unlikely and special we either need a designer or enough different trials that it would happen eventually. Neither one of multiple sets of laws or a designer is predicted. I could equally say that if the TOE doesn't predict a designer then it's wrong.

It states nothing of the sort. It just states that if we have a theory which predicts a variety of possible universes, only those parts in which observers can exist will be observed. It's a selection effect, in other words.

That's the strong anthropic principle - you are again assuming there are multiple universes. The weak anthropic principle simply states that if it was otherwise we wouldn't exist, ie if things were different, then they would be different.

That's a statement that should not be simply assumed, but investigated in detail. And it doesn't appear to be true: from what we know currently, it does appear that a large number of parameters have to take a rather narrow range of values for life to be remotely possible.

You misunderstood my point. If life is nothing special then that narrow range of parameters is no more interesting than any other range of parameters.

 

[Chalnoth]

You have just reapplied the anthropic principle and ignored my point. If we assume life to be something unlikely and special we either need a designer or enough different trials that it would happen eventually. Neither one of multiple sets of laws or a designer is predicted. I could equally say that if the TOE doesn't predict a designer then it's wrong.

Well, no, a designer is a non-starter, for the reasons I laid out previously, so we need a large number of trials if the conditions for life are unlikely.

A large number of trials with different physical parameters is an expected consequence of inflation + high energy physics.

That's the strong anthropic principle - you are again assuming there are multiple universes. The weak anthropic principle simply states that if it was otherwise we wouldn't exist, ie if things were different, then they would be different.

Yeah, I don't think you read what I wrote. Please try again.

You misunderstood my point. If life is nothing special then that narrow range of parameters is no more interesting than any other range of parameters.

What? That makes no sense. Nobody is suggesting that this narrow range of parameters is somehow "special", only that even if other ranges of the parameter space exist, it would be impossible for anybody to observe them.

 

[atyy]

For a classification of evidence to lead to the truth, that classification must lead to reliable results. That is to say, any sufficiently-specific statement about reality that you might make must be either true or false (another way of stating this is that it is possible to add conditions to any ambiguous statement so that it is definitively either true or false, even if we don't know which). This is basically a tautology.

Given this tautology, we can then conclude that if we are to accept a classification of evidence as being reliable, then it must consistently produce the same answers to the same questions. If it does not, then it is a bad form of evidence.

This fact is, fundamentally, why science relies so heavily upon verification of results. And it's also why there isn't any evidence for any god: the types of evidence that people attempt to use to support their beliefs are the same (revelation, personal experience, tradition), but they come to wildly different conclusions about the specifics.


He's using it in the way the word is used by the general populace, however. Now, I don't do this personally, but arguing over semantics doesn't get into the meat of the article. He is quite specific about the definition that he is using in the blog post.


I think it's typically only people that believe in a god that think that somehow the question, "Does a god exist?" is categorically different from other questions about the nature of reality. I don't. And that's what the thrust of that article was: it isn't categorically different, and so we should apply the exact same thought processes that have proven reliable time and again with other questions to the one about whether or not there is a god (or gods, for that matter).

See, I once believed in the Christian God. Then, as I learned about science and how to do science, I started applying those same thought processes to my religion (in particular after I noticed that my religion was making some claims that were distinctly opposed to reality). When I did so, I found that it was all bunk, and I really had no valid reason to believe any of it.


It's only perfectly fine if you're okay with being wrong. The only limitation placed upon scientific thinking is whether or not it is fallacious. Therefore there are only two types of reasoning: scientific reasoning (i.e. non-fallacious reasoning) and fallacious reasoning.


I find this human obsession with gods to be rather interesting. But seriously, if you're not going to demonstrate the existence of a god through rational means, then that's extremely good reason not to believe in a god.

Can you prove that one should use rational thought?

Can you prove that the world was not created one second ago with everyone's memory intact as it is to give the appearance of being created a long time ago?

 

[Phyisab****]

That's a misuse of the word "know". If you can't demonstrate it, you don't know. You may believe very strongly, but all the belief in the world doesn't make something true.

Fine, but you're just arguing over semantics. You just refuted the difference above. Anyways that doesn't change the point of my post.

 

[Chalnoth]

Can you prove that one should use rational thought?

As I said, you don't have to if you don't mind being wrong.

Can you prove that the world was not created one second ago with everyone's memory intact as it is to give the appearance of being created a long time ago?

Prove? No. But if we do a quick experiment and show that it conforms to expectations based upon past experience (past meaning before this hypothetical creation event), then we have shown that it is obscenely unlikely that the universe was created at that time.

 

[GeorgCantor]

Prove? No. But if we do a quick experiment and show that it conforms to expectations based upon past experience (past meaning before this hypothetical creation event), then we have shown that it is obscenely unlikely that the universe was created at that time.

It was obscenely unkely that the world would turn to not be flat, then that the Sun is not rotating around the Earth as it seems, then it was thought obscenely unlikely that the our universe would consist of relative objects in relative space and time. It was also thought that locality would hold no matter what. It was thought that realism would hold no matter what. We've seen this approach of things being "obscenely unlikely" take the wrong turn too many times. You can't rule something out just because it looks unlikely to you or somebody else.

 

[Chalnoth]

You can't rule something out just because it looks unlikely to you or somebody else.

It doesn't just look unlikely, though. It actually is. Here's the basic argument:
1. Consider the ensemble of all possible worlds that might have formed with people that have memories of a false past.
2. Because those memories are not rooted in actual experience, the memories will be unrelated to the nature of the latter world.
3. The vast vast majority of such worlds, therefore, will prove to be completely inconsistent with peoples' memories.
4. If our experiences accord with our memories, then, the past is likely real.

You can sort of get around this by supposing a deceptive designer, but that's a self-defeating hypothesis.

 

[madness]

Yeah, I don't think you read what I wrote. Please try again.

Maybe you didn't read what you wrote - "if we have a theory which predicts a variety of possible universes, only those parts in which observers can exist will be observed. It's a selection effect, in other words.". This is clearly the strong anthropic principle. You clearly assumed the existence of a variety of universes where observers can't exist.

What? That makes no sense. Nobody is suggesting that this narrow range of parameters is somehow "special", only that even if other ranges of the parameter space exist, it would be impossible for anybody to observe them.

This is the weak anthropic principle as I stated. The weak anthropic principle assumes life is nothing special and therefore doesn't need an explanation. The strong anthropic principle assumes multiple universes. And no you haven't shown multiple universes to be any more scientific than design.

 

[Chalnoth]

Maybe you didn't read what you wrote - "if we have a theory which predicts a variety of possible universes, only those parts in which observers can exist will be observed. It's a selection effect, in other words.". This is clearly the strong anthropic principle. You clearly assumed the existence of a variety of universes where observers can't exist.

I think you misunderstood the word "if" in that sentence, and you also should look up what the strong anthropic principle means.

This is the weak anthropic principle as I stated. The weak anthropic principle assumes life is nothing special and therefore doesn't need an explanation. The strong anthropic principle assumes multiple universes. And no you haven't shown multiple universes to be any more scientific than design.

Ugh, no. Here:
http://www.merriam-webster.com/dictionary/anthropic principle

 

[madness]

It doesn't just look unlikely, though. It actually is. Here's the basic argument:
1. Consider the ensemble of all possible worlds that might have formed with people that have memories of a false past.
2. Because those memories are not rooted in actual experience, the memories will be unrelated to the nature of the latter world.
3. The vast vast majority of such worlds, therefore, will prove to be completely inconsistent with peoples' memories.
4. If our experiences accord with our memories, then, the past is likely real.

You can sort of get around this by supposing a deceptive designer, but that's a self-defeating hypothesis.

Do you realize the law of entropy is time symmetric? ie entropy should increase back in time just as much as forward. This means that it overwhelmingly more likely that the universe formed into stars and planets (and human brains) as a statistical fluctuation from disorder. This then means that all our memories are most likely imagined.
Don't worry, I'm not advocating this point of view, but it's interesting to think about. Of course, the argument undermines itself - if it is true, then our scientific reasoning on entropy is no longer valid. The solution is to assume the universe began with incredibly low entropy. This is incredibly unlikely statistically, but at least it doesn't undermine itself.

 

[madness]

I think you misunderstood the word "if" in that sentence, and you also should look up what the strong anthropic principle means.

"If" what you said isn't true, then there's no selection effort (which you said there was).


From wikipedia, 3 statements of the SAP:

"There exists one possible Universe 'designed' with the goal of generating and sustaining 'observers.'"

"Observers are necessary to bring the Universe into being."

"An ensemble of other different universes is necessary for the existence of our Universe."

The third is the one I was referring to. The other 2 are just as unscientific.

 

[Chalnoth]

Do you realize the law of entropy is time symmetric? ie entropy should increase back in time just as much as forward. This means that it overwhelmingly more likely that the universe formed into stars and planets (and human brains) as a statistical fluctuation from disorder. This then means that all our memories are most likely imagined.

This is precisely the situation I was talking about. It is trivially refuted by the reliability of past memories, because in the vast majority of such universes, past memories will be entirely unrelated to the nature of the world.

This problem is a well-known problem, and also well-known is where the solution must lie: in cosmology. Basically, the reason why we have a real past must be because there was a very low-entropy configuration in the distant past, and the laws of physics must be such that low-entropy configurations of that type are more likely than a simple thermodynamic argument would suggest.

 

[Chalnoth]

"If" what you said isn't true, then there's no selection effort (which you said there was).

The selection effect is there whether or not there are universes which don't have physical laws conducive to the formation of life.

From wikipedia, 3 statements of the SAP:

"There exists one possible Universe 'designed' with the goal of generating and sustaining 'observers.'"

"Observers are necessary to bring the Universe into being."

"An ensemble of other different universes is necessary for the existence of our Universe."

The third is the one I was referring to. The other 2 are just as unscientific.

Well, I really don't agree with Barrow and Tipler's third option there, and it's particularly telling that nobody else appears to make use of that one. But regardless, I never said that an ensemble of other different universes is necessary. I merely said that if the laws of physics are such that different regions will produce different low-energy laws of physics (which our current knowledge of high-energy physics appears to support), and if our universe is sufficiently large (which our current knowledge of inflation appears to support), then we are have a system with a large number of regions, many of which are unlikely to be habitable.

In other words, the evidence is very clearly and definitively pointing in the direction of just such a multiverse. And when evaluating any particular multiverse hypothesis, it is necessary to take into account the weak anthropic principle.

 

[madness]

Well I agree that the weak anthropic principle tells us that our observable universe is biased towards life. I don't agree that it sheds any light on why our universe supports life (although I'm not sure whether you are arguing that). I have no major problem with the strong anthropic principle on philosophical grounds, so long as it isn't couched as science.