[melodysquare (OP)]

My first post on here, /bow. I'm sure this has been discussed, now to go through and open each thread to find out which after deciding what title it may apply to is hard, so if someone finds a link and just posts it as a reply id be happy with just that.

My question is obvious with its title, is string theory philosophy more so than science at this stage? What experiment can validate string theory? I know a lot of people when confronted with the idea of multiverse being just as plausible as God as an explanation (both things we could never actually "observe") will state, o but the difference with multiverse, (as in that which makes it scientific over God) is the math. But does finding equations that fit correctly into a puzzle really magnify the reality of what is there? For example a valid question for me would be, do the extra dimensions imposed only exist or were thought to exist because they fit an equation into another piece of the puzzle? I'd feel more comfortable with the ideas of strings, and extra dimensions, if they were observed (science), not worked in because of the math.

The problem this could create if I am right I think is obvious - The problem of quantum mechanics is being replaced by creating imaginary things to throw the problem in (extra dimensions, strings, etc). In so that mathematically it works out, but skips over whatever is reality.

[abacus9900]

"The problem this could create if I am right I think is obvious - The problem of quantum mechanics is being replaced by creating imaginary things to throw the problem in (extra dimensions, strings, etc). In so that mathematically it works out, but skips over whatever is reality."


It is the study of quantum mechanics itself that has caused scientists to re-evaluate what reality is. Things like extra dimensions, strings and so on have been conceptualized as a way of attempting to encompass a grand unified theory of all the known forces, which theories such as Relativity do not achieve. People have to engage their imaginations in forming ideas about the way reality is because commonsense is no longer adequate to account for the deeper aspects of the universe. We have evolved as a species to deal with everyday 'big' objects in four dimensional spacetime, but the greater reality seems to insist we go beyond this model and use things like maths to try to provide an underlying foundation to account for both classical physics and quantum mechanics. It is always a mistake to rely on one's senses to describe how the universe really is.

[yor_on]

Seems a valid question to me. Against it you might state the fact that we expect all things to be able to describe and define mathematically, giving mathematics an universal approach. If mathematics can do so, does it implicate that all its solutions exist? Don't know, but the better it describes nature the closer we expect it to be to the 'real thing'. And as far as I understand string theory, how ever weird it might be for me, succeeds in this, able to describe what we already know as well as some things we only can guess on, like what's inside a black hole.

So, don't count out string theory, even though I find it hard to melt myself
Any 'philosophy' succeeding in accurately describing all states in the universe will get a vote from me, well possibly so Not that I'm saying that string theory is there yet. Because, as you say, to really validate a theory it will need to create an answer to a formerly unsolved mystery, or even better, create a new puzzle that only can be explained out of the new theory happening in the 'real world', not only on paper.

[abacus9900]

  Because, as you say, to really validate a theory it will need to create an answer to a formerly unsolved mystery, or even better, create a new puzzle that only can be explained out of the new theory happening in the 'real world', not only on paper.

Of course, but it is important to have in place ideas that, pehaps one day, will be amenable to testing. After all, this is how science got started in the first place, i.e. from philosophical questions that were speculated about and later subjected to testing. In this way science progresses. I suppose it's all an evolving process but you have to evolve slowly.

[LeeE]

I would say that String/Superstring/M-Theory is definitely science, but it is synthetic rather than analytic.

[melodysquare (OP)]

It is the study of quantum mechanics itself that has caused scientists to re-evaluate what reality is. Things like extra dimensions, strings and so on have been conceptualized as a way of attempting to encompass a grand unified theory of all the known forces, which theories such as Relativity do not achieve. People have to engage their imaginations in forming ideas about the way reality is because commonsense is no longer adequate to account for the deeper aspects of the universe. We have evolved as a species to deal with everyday 'big' objects in four dimensional spacetime, but the greater reality seems to insist we go beyond this model and use things like maths to try to provide an underlying foundation to account for both classical physics and quantum mechanics. It is always a mistake to rely on one's senses to describe how the universe really is.

Sure, you could argue what reality really is, is string theory and thus we should accept seemingly illogical things to be real because, well, they are, thus it sort of, in a way, changes the definition of everything, even common sense. I get that, but this is all believed because of what? Because its what satisfied an equation in the end? Or was it something that was actually observed?

[graham.d]

It is the study of quantum mechanics itself that has caused scientists to re-evaluate what reality is. Things like extra dimensions, strings and so on have been conceptualized as a way of attempting to encompass a grand unified theory of all the known forces, which theories such as Relativity do not achieve. People have to engage their imaginations in forming ideas about the way reality is because commonsense is no longer adequate to account for the deeper aspects of the universe. We have evolved as a species to deal with everyday 'big' objects in four dimensional spacetime, but the greater reality seems to insist we go beyond this model and use things like maths to try to provide an underlying foundation to account for both classical physics and quantum mechanics. It is always a mistake to rely on one's senses to describe how the universe really is.

I think you have stated this well, Abacus.

Melody, the objective of science is to try to see how the world (the universe) works. It seems to be the case that our brains are not equipped to deal with the visualisation of many of the underlying mechanisms (why should they be?). So we rely on more abstract ideas that fit the mathematical descriptions - string theory being one such concept. It is not very meaningful to think that there are really things like vibrating strings in any sense that we could "see" them, but it is a helpful analogy and there is correlation in the mathematics with the behaviour of vibrating strings at the macro level. The test we have to make, in all science, is whether the theories we have are able to make predictions about behaviour that we are able to observe and verify. String theories (there are a few) have been able to make such predictions and the goal is to keep testing the theories until we have one that survives. Undoubtedly the theory will be found to be wrong in some respect at some point in the future but that does not mean it has not been useful.

[melodysquare (OP)]

It is the study of quantum mechanics itself that has caused scientists to re-evaluate what reality is. Things like extra dimensions, strings and so on have been conceptualized as a way of attempting to encompass a grand unified theory of all the known forces, which theories such as Relativity do not achieve. People have to engage their imaginations in forming ideas about the way reality is because commonsense is no longer adequate to account for the deeper aspects of the universe. We have evolved as a species to deal with everyday 'big' objects in four dimensional spacetime, but the greater reality seems to insist we go beyond this model and use things like maths to try to provide an underlying foundation to account for both classical physics and quantum mechanics. It is always a mistake to rely on one's senses to describe how the universe really is.

I think you have stated this well, Abacus.

Melody, the objective of science is to try to see how the world (the universe) works. It seems to be the case that our brains are not equipped to deal with the visualisation of many of the underlying mechanisms (why should they be?). So we rely on more abstract ideas that fit the mathematical descriptions - string theory being one such concept. It is not very meaningful to think that there are really things like vibrating strings in any sense that we could "see" them, but it is a helpful analogy and there is correlation in the mathematics with the behaviour of vibrating strings at the macro level. The test we have to make, in all science, is whether the theories we have are able to make predictions about behaviour that we are able to observe and verify. String theories (there are a few) have been able to make such predictions and the goal is to keep testing the theories until we have one that survives. Undoubtedly the theory will be found to be wrong in some respect at some point in the future but that does not mean it has not been useful.

Do you have a reference to any of these predictions?

[Geezer]

Do you have a reference to any of these predictions?

I suspect String Theory is more at the stage of trying to tie things together than making exciting new predictions. I think that's appropriate.

[graham.d]

Do you have a reference to any of these predictions?

I suspect String Theory is more at the stage of trying to tie things together than making exciting new predictions. I think that's appropriate.

 [] []

I think this is actually about right. It's not really my field, but I think the various string theories are able to be consistant with existing knowledge but have yet to be able to differentially tested with any experiment that is within the capability to be carried out. There are other theories that can rival string theories too. My point is really that it does not matter too much whether these theories actually represent reality as long as the maths works out and they can enable some sort of aid to understanding the maths in a form the brain can cope with. Another theory in a similar class is Garrett Lisi's predictions of fundamental particles based on the E8 lie group. I don't think that anyone is saying that this gives any physical view of the sub-nuclear world but it does allow a pattern to be produced (allbeit a complicated multidimensional one) which seems to correspond to fundamental particle existence and their behaviour. I think it maybe analogous to how the periodic table evolved in chemistry - it was many years before anyone understood why there was such a pattern of behaviour but this did not stop it being useful. Basically any theory which gives insight to the mathematics helps.

[abacus9900]

 

Do you have a reference to any of these predictions?

The problem is these ideas are essentially mathematical in nature so you would have to have some familiarity with advanced maths to understand them. The analogies given in language are to make the ideas involved easier to visualize. However, you could take a look at the following link, which serves as an introduction to M-theory and strings, etc.: http://en.wikipedia.org/wiki/Introduction_to_M-theory [nofollow]

[abacus9900]

I think you have stated this well, Abacus.

Thanks, graham.d, and I think we should make it clear that any ideas will evolve over time to (hopefully) attain the status of a predictive theory. You have to begin somewhere, of course.

[Geezer]

I suspect String Theory is more at the stage of trying to tie things together than making exciting new predictions.

Maybe it was a subliminal thing. Believe it or not, I didn't see the funny side of my post until Yoron pointed it out to me!!

[melodysquare (OP)]

Well the reason I ask for references is that I don't see how a theory that postulates multiverses exist can have any predictions (or maybe it can but not in reference to that aspect of it). I don't see how it can be possible to prove an event happens that corresponds to the fact of quantum mechanics in another universe without having to first take on the assumption that other universes do exist in order for the event to take place aka the experiment to make sense.

On the existence of extra dimensions im also confused, where these postulated to exist because they helped/help in understanding other aspects of the universe outside of assuming string theory is true (this is the same problem i have with multiverse stated right above in a sense, taking in an assumption to prove a math)? IE could these extra dimensions stand up on their own accord vie a proof and help explain an aspect of the universe? Or must we first assume either the strings exist or the extra dimensions exist in order to justify the other one vie a math?

[Geezer]

Re. the extra dimensions, I'm no expert on String Theory, but as I understand it, the additional dimensions are necessary to construct a model that does not contradict the existing math that predicts and describes observed phenomena. If the math holds up, it would seem to confirm the existence of the other dimensions and, of course, experimental evidence should also be sought, although that might turn out to be more than a bit tricky (to put it mildly!)

It may also turn out that ST will predict some sort of anomaly that we already observe, like, for instance, the so called "dark energy". If something like that were to happen, it would certainly add an enormous amount of weight to the theory.

The notion of additional dimensions does seem a bit bizarre, but just about everything we now accept as reality seemed pretty bizarre when it was first described. I always think it's funny that we tend to think of ourselves as rather substantial objects living on a very substantial planet. If you take an atomic perspective, there's almost nothing there at all!

[yor_on]

S000 Mr Atomic?
Are we not substantial?

As i look at myself in the mirror I wish I could agree
More is less I say

[Geezer]

S000 Mr Atomic?

Rats! My cover has been blown. There won't be much point in wearing my Spandex suit now.

[JP]

Re. the extra dimensions, I'm no expert on String Theory, but as I understand it, the additional dimensions are necessary to construct a model that does not contradict the existing math that predicts and describes observed phenomena. If the math holds up, it would seem to confirm the existence of the other dimensions and, of course, experimental evidence should also be sought, although that might turn out to be more than a bit tricky (to put it mildly!)

I'm no expert either, but from what I've heard in popular science accounts, it does ok with the descriptions of current phenomena, but it doesn't do much in terms of predicting measurable results that differ from current models.  It also apparently introduces many (infinitely, I think?) possible universes, of which we live in only one.  Although I don't find that particularly objectionable (the anthropic principle helps in my opinion), some people really don't like that, and think a theory of everything should explain why our universe has the laws it does without relying on the anthropic principle.

[LeeE]

Actually, an infinite number of dimensions makes more sense than a finite number of them, for if there is only a finite number then there must be a reason why it's that particular finite number and not another finite number i.e. why do we have only three spatial dimensions instead of four or five, or any other number?

There may be an energy relationship between different numbers of dimensions though.  For example, the inverse square law whereby the strength of a field reduces with the square of the distance from its source, that we're familiar with, wouldn't work with just two spatial dimensions and the relationship would be linear instead of squared, and if you went down to just a single spatial dimension there would no reduction in strength with distance from source at all.  Conversely, with one more spatial dimension we might expect to see an inverse cubed law instead.

So while there might be no intrinsic limit to the number of possible spatial dimensions, you'd need infinite energy for them to be expressed.  Actually, this is one of those areas where you have to deal with different sizes of infinity too, for the energy required would increase exponentially with the number of dimensions; the infinite amount of energy would need to be exponentially greater than the infinite number of dimensions.

[melodysquare (OP)]

Re. the extra dimensions, I'm no expert on String Theory, but as I understand it, the additional dimensions are necessary to construct a model that does not contradict the existing math that predicts and describes observed phenomena. If the math holds up, it would seem to confirm the existence of the other dimensions and, of course, experimental evidence should also be sought, although that might turn out to be more than a bit tricky (to put it mildly!)

It may also turn out that ST will predict some sort of anomaly that we already observe, like, for instance, the so called "dark energy". If something like that were to happen, it would certainly add an enormous amount of weight to the theory.

The notion of additional dimensions does seem a bit bizarre, but just about everything we now accept as reality seemed pretty bizarre when it was first described. I always think it's funny that we tend to think of ourselves as rather substantial objects living on a very substantial planet. If you take an atomic perspective, there's almost nothing there at all!

Its not exactly that I have a problem with "Bizarre" here or not wanting to change what may seem like common sense, im fine with that, and a lot of these posts (at least first ones), seem to tell me i just need to let go of what was previously thought, and thats fine and all like i said i have no problem with that, what I am trying to do is decipher the original question or title of this thread. Lets take for granted the argument for instance, lets say somehow we know multiverse is the reality in which we live, there are an infinite number of universes out there, now, is it plausible to discover that by scientific means? Maybe I mean to ask, how does the math imply multiverse? And just how reasonable is it for us to conclude other universes exist simply because of this?