False choice between multiverse and design: Life determ thr?

[Lincoln]

I think it's actually simpler. There has to be a scale for length, time and mass. You can set each of these to be 1. Or, alternatively, as long as you have a logical set of combinations of these...even non-linear, you can arbitrarily set three of them to be 1 and then the rest have to compensate. For instance, in the fine structure constant, you see that the unit for charge (e) has to be the square root of the units for hbar * c.

I'd have to think a bit more to decide if this is an airtight argument, but I think that this is the deep, underlying, principle.

[jshort]

I wanna get back to Marshals original post....

Earlier that year a paper appeared arguing that string failed as a "theory of everything" because (at least in present form) it did not lead to a unique solution but instead led to millions of different versions of the universe. To put it simply, Susskind made this a virtue by promoting the idea that there WERE millions of universes but that we live in one of those favorable to life. This made string (technically "M-theory") seem very important because it was not "merely" the theory of our one universe. It was theory covering all those million of universes that were imagined to exist.

But actually this is not a real advantage. A theory must fit the universe we know (once its parameters are adjusted) so we can make predictions about the universe we have here. It needs to have a unique solution.

I find the statements in bold particularly interesting....It shows we make unproven assumptions about how the universe is governed because those assumptions would allow the universe to lend itself to our scientific analysis. Does anyone find this a little troubling?

[Paralith]

I find the statements in bold particularly interesting....It shows we make unproven assumptions about how the universe is governed because those assumptions would allow the universe to lend itself to our scientific analysis. Does anyone find this a little troubling?

I think you might be misunderstanding what Marshall was saying. All models start with certain assumptions, and an "assumption" by the very definition is not something we already know to be true. But we make assumptions because if we didn't, we couldn't make models at all. Then you take the predictions your model makes about the universe, go out to the universe, and measure those things. If what we observe and what the model says are two different things, then we know the model is wrong. Something somewhere in that model is incorrect. And it may very well be one or more of the starting assumptions. So then we can develop a different model (and really, a model is the exact same thing as a hypothesis), with different assumptions, and test it against the universe again, etc etc. The assumptions themselves are being tested as much as anything else. We don't just make them and then ignore them.

[Marshall]

...It shows we make unproven assumptions about how the universe is governed because those assumptions would allow the universe to lend itself to our scientific analysis...

How about spelling out clearly what you are talking about J?

Who is making an unproven assumption? What is the assumption?

================================

Bear in mind that there is a view of science that both Niels Bohr and Isaac Newton promoted which is that it is about INFERENCE AND PREDICTION.

Newton famously said "Hypotheses non fingo." I'm giving you a predictive law. It works. It fits the phenomena of gravity. I am not pretending to know about unseen explanatory springs and levers that the observable phenomena don't show me.

Bohr said physics is not about how nature IS. It is about how it responds to measurement. What you can measure and infer and check by further measurement. The imaginary MODELS just correspond to ways of calculating, they gain only provisional credence for as long as they work.
It is not about how nature IS, it is about what we can say about nature. (measure infer predict check.)

So that is a respectable view.
Newton "I do not feign hypotheses." I don't pretend to know an underlying explanation if it is not revealed by experiment. I don't make up stuff.

I have to go. this may have a bearing on what you are asking. Back later.

[jshort]

I find the statements in bold particularly interesting....It shows we make unproven assumptions about how the universe is governed because those assumptions would allow the universe to lend itself to our scientific analysis. Does anyone find this a little troubling?

I think you might be misunderstanding what Marshall was saying. All models start with certain assumptions, and an "assumption" by the very definition is not something we already know to be true. But we make assumptions because if we didn't, we couldn't make models at all. Then you take the predictions your model makes about the universe, go out to the universe, and measure those things. If what we observe and what the model says are two different things, then we know the model is wrong. Something somewhere in that model is incorrect. And it may very well be one or more of the starting assumptions. So then we can develop a different model (and really, a model is the exact same thing as a hypothesis), with different assumptions, and test it against the universe again, etc etc. The assumptions themselves are being tested as much as anything else. We don't just make them and then ignore them.

The reasons you gave work well most of the time. In this particular case though, the starting assumption quite possibly cannot be proven right or wrong. But if it is wrong, then we aren't going to ever solve this problem so long as we assume that its true.

[Paralith]

If the starting assumption cannot actually be tested, then your model is unscientific, uninformative, and generally should be left by the wayside. And as I understand it, this is one of the reasons why string theory has more or less fallen from grace. And I think that's what Marshall is trying to say as well.

[jshort]

Marshal, Paralith....


My issue is that your using the "predictive law" rule as a means to cast out theories that cannot adhere to it. This should only be done if another possible theory exists which can follow this law. Such a theory hasn't been found, and by throwing out all the theories that break the rule, you run the risk of never finding a "correct theory".

................................................

One more point (which is a little vague, but I hope you understand the message).

String theory says that our universe is possible. We have good reason to believe that our universe is probabilistic, not deterministic. Hence in regards to the current question being asked (ie why is the universe the way that it is?), one may not successfully be able to apply the predictive law to come to a correct measurable theory.

[Paralith]

Hmm. I've never heard of the predictive law rule before, so I'm not entirely sure exactly what you mean. But I see no reason why you should fail to throw out a soundly disproven hypothesis simply because you have not yet contrived an alternative hypothesis. Now, remember what I said earlier about models and assumptions and the predictions failing to match reality. I said that means something is wrong with your model. That could be one tiny part of it, just one assumption, or it could be whole gobs of the model. You don't know without further testing exactly what is wrong. So obviously, you shouldn't immediately throw out the entirety of the model and everything it says. But also, if large parts of the model are necessary conclusions of a single starting assumption that is inherently untestable, well. You're probably better off starting from scratch.

And in the end, I don't see any problems with any of this. I'm really not sure what your concern is. And, simply because you cannot currently think of what the answer to a certain question might look like, doesn't mean the question is unanswerable. It just means we have a lot of work to do before we get there.

[jshort]

Paralith, Marshall...

I just edited my previous post so you may want to reread...Sorry for the hasal, but I had some difficulty forming my opinion on this.

Paralith...

I'll get to your post shortly.

[jshort]

But I see no reason why you should fail to throw out a soundly disproven hypothesis simply because you have not yet contrived an alternative hypothesis.

But String theory isn't disproven as far as I know....My understanding is that it has been thrown out because it isn't predictive enough. The predictive law rule says that a theory should be able to make accurate measurable predictions in order to be accepted as a theory.

[Paralith]

But I see no reason why you should fail to throw out a soundly disproven hypothesis simply because you have not yet contrived an alternative hypothesis.

But String theory isn't disproven as far as I know....My understanding is that it has been thrown out because it isn't predictive enough. The predictive law rule says that a theory should be able to make accurate measurable predictions in order to be accepted as a theory.

Well - of course it has to make measurable predictions. Otherwise you can't test it. And if you can't test it, it's not science. We have no way of determining its veracity. Why would you be concerned about losing something that is inherently unscientific?

[Lincoln]

jshort...

Don't get hung up on the precise definitions of "theory" and "model" and stuff. While they have a specific and well-defined meaning in 8th grade science, the borders become fuzzier later in life. Language is sloppy and this just reflects that.

String theory is, in principle, verifiable. However at this time it is unverified. In the parlance of 8th grade, it's really an uber-hypothesis more than a theory. However, an enormous amount of work has been done on it and it hasn't been definitively killed yet. This is why it's called a theory before its time.

Nobody really believes string theory...even most of the theorists who have been so entranced by the theory's beauty. But neither has it been thrown out. It's just proven to be tough going and people are looking around for ideas that might bear fruit more quickly. Superstrings could be real though.

[jshort]

Paralith....

I'm sure String theory isn't completely unwarranted, otherwise no one would have bothered with it. If its not predictive enough for us, that still doesn't change the possibility that its the best we can say about the universe.

[jshort]

jshort...

Don't get hung up on the precise definitions of "theory" and "model" and stuff. While they have a specific and well-defined meaning in 8th grade science, the borders become fuzzier later in life. Language is sloppy and this just reflects that.

String theory is, in principle, verifiable. However at this time it is unverified. In the parlance of 8th grade, it's really an uber-hypothesis more than a theory. However, an enormous amount of work has been done on it and it hasn't been definitively killed yet. This is why it's called a theory before its time.

Nobody really believes string theory...even most of the theorists who have been so entranced by the theory's beauty. But neither has it been thrown out. It's just proven to be tough going and people are looking around for ideas that might bear fruit more quickly. Superstrings could be real though.

My argument was in response to the reasoning quoted in Marshals first post...I don't know anything specifically about String theory or why its been booted as a theory. I was simply challenging the logic given in that point.

[Lincoln]

I guess I haven't followed your reasoning then.

[neuro]

But String theory isn't disproven as far as I know....My understanding is that it has been thrown out because it isn't predictive enough. The predictive law rule says that a theory should be able to make accurate measurable predictions in order to be accepted as a theory.

If I may, in order to be of any use.

Possibly, the whole question lies here: you can like or dislike a theory, reject it or accept it as a working hypothesis or as a provisional truth, until disproven.

Scientifically, the only use you can do of a theory is the last one: consider it a working hypothesis and provisional truth, until disproven.
But it must be predictive in order for you to be able to disprove it.

If it is not, it might be nice, satisfying and tranquilizing, but its only use is to let you feel as if you knew (not much different from a philosophical or religious interpretation, which may have great psychological and social merit, but is of no scientific use).