Quantum theory?

[CommodoreFluffy]

I've always thought of the world as having a predictable, mechanical, Newtonian set of laws. where everything is calculable. But unfortunately, there is too much evidence which supports quantum theory, or at least, something besides a purely Newtonian world, that it is impossible to just stick to the older schools of science.

I understand Quantum theory to some degree, but not that much. Things are changed by an observer, everything is everywhere at once, infinite possibilities, and what not. But what do you guys think about it?

[Dave Rapp]

http://i32.tinypic.com/25tuqgx.jpg

I think that pretty much sums it up. Sorry for screen stretch.

[CommodoreFluffy]

http://i32.tinypic.com/25tuqgx.jpg

I think that pretty much sums it up. Sorry for screen stretch.

Technically, it is a group of laws of physics.
Strictly speaking, Newtonian mechanics are not applicable to quantum mechanics.

[Dave Rapp]

Technically, it is a group of laws of physics.
Strictly speaking, Newtonian mechanics are not applicable to quantum mechanics.

I know. I was trying (and apparently failing) to make a joke. :smallredface:

[averagejoe]

I understand Quantum theory to some degree, but not that much.

No you don't. No one understands quantum theory. Studying for a quantum test means trying to learn the material, not reviewing the material.

So much for griping. In all seriousness, however, there is so much misinformation out there on the subject that few people who claim to understand any part of it actually do. I don't know how much you've studied, but that's what's what.

For example, everything isn't everywhere at once according to quantum theory. I wonder where you got that, and if you could elaborate further.

Or, take things being changed by an observer. To observe something is to, fundamentally, interact with it in some way. That doesn't make much difference in the Newtonian world most of the time. After all, a photon bombardment does little to divert the course of a macroscopic object. However, at the quantum level, you can't really interact with something without changing it. It's like trying to study humans by shooting cannonballs at them.

You need to know a bit of math to really do QM.

[Bitzeralisis]

It's like trying to study humans by shooting cannonballs at them.

Best. Scientific. Metaphor. Ever.

[LightWraith]

It's like trying to study humans by shooting cannonballs at them.

You need to know a bit of math to really do QM.

So you're aren't supposed to do that? :smalleek:

I think a bit of math is a gross understatement there... I've looked at enough QM stuff to know that I'm lacking several semesters worth of Mathematics before I can even bother trying to pick it up.

It is a really fascinating subject though, I will eventually learn more. I'm studying Physics for my degree, so it's almost inevitable, even if I don't decide to specialize there.

[Phae Nymna]

I'm quick to understand new theoretical stuff, but my parents are REALLY slow. It took me an hour and a half to explain Schrödinger's Cat to them, and THEN, they bothered me about the wide array of things I don't know. Philosophy and Physics and everything in between is a favourite topic of mine, but I know very little. Well... This post proves that I can't write anything coherent at one thirty. Mmph...

[CommodoreFluffy]

No you don't. No one understands quantum theory. Studying for a quantum test means trying to learn the material, not reviewing the material.

So much for griping. In all seriousness, however, there is so much misinformation out there on the subject that few people who claim to understand any part of it actually do. I don't know how much you've studied, but that's what's what.

For example, everything isn't everywhere at once according to quantum theory. I wonder where you got that, and if you could elaborate further.

Or, take things being changed by an observer. To observe something is to, fundamentally, interact with it in some way. That doesn't make much difference in the Newtonian world most of the time. After all, a photon bombardment does little to divert the course of a macroscopic object. However, at the quantum level, you can't really interact with something without changing it. It's like trying to study humans by shooting cannonballs at them.

You need to know a bit of math to really do QM.

TO SOME DEGREE I said. Nobody UNDERSTANDS quantum theory back and forth, but I get SOME concepts. And that isn't why an observer changes the effects of an experiment. Changing a wavelike interference pattern to two predictable bars by having a machine which detects particle movement is not "shooting cannonballs at the humans" I'm sure that some information I have is wrong, but you get the point.

[Player_Zero]

I understand quantum mechanics. :smallbiggrin:

I also know what's going to happen when they turn on the Large Hadron Collider, too. But it's a secret.

[mainiac]

I think the key to being able to grasp quantum theory is to REFUSE to ever bring the philosophical implications or wishy washy illusion of causation into the mix. Think of it as a set of observed phenomena. Don't think of things like quantum indeterminacy as mystical pseudo states, think of them as what you need to get past before the results you're going to observe. What you put in and what you get out isn't all that hard to understand, it's the middle stuff.

[Skippy]

http://dresdencodak.com/cartoons/a_heisenberg.jpg
[img]http://dresdencodak.com/cartoons/a_memphis.jpg

That's easy to understand...

[Jorkens]

I think the key to being able to grasp quantum theory is to REFUSE to ever bring the philosophical implications or wishy washy illusion of causation into the mix. Think of it as a set of observed phenomena. Don't think of things like quantum indeterminacy as mystical pseudo states, think of them as what you need to get past before the results you're going to observe. What you put in and what you get out isn't all that hard to understand, it's the middle stuff.
Yes, I find that it helps (or it used to help when I actually studied quantum at undergrad) to think of any scientific theory as a mathematical simulation of reality rather than as being reality. It has parameters that we plug in and makes real world predictions that we can read off, but the workings of the theory refer to the 'reality' of the mathematics not the reality of real world.

[Simius]

TO SOME DEGREE I said. Nobody UNDERSTANDS quantum theory back and forth, but I get SOME concepts. And that isn't why an observer changes the effects of an experiment. Changing a wavelike interference pattern to two predictable bars by having a machine which detects particle movement is not "shooting cannonballs at the humans" I'm sure that some information I have is wrong, but you get the point.

So, how do you think this machine detects particle movement? It can only make a measurement by somehow interacting with the particle, which is bound to affect the particle's wavefunction.

For comparison, let's look at how you might measure the location of a football: photons from the suns collide with the ball, are absorbed and re-emitted, and reach your eyes. How this change the football? Hardly at all. If you now want to detect an electron by bouncing a photon off it, this would be very much like measuring a human with a cannonball. The electron will move into higher energy states, conservation of momentum, etcetera, etcetera.

Also, quantum physics pretty much confirm Newtonian Mechanics at large scales (look up the Ehrenfest Theorem), just like GR approximates Newton at velocities close to zero. It's too bad that they don't fit together.

[averagejoe]

TO SOME DEGREE I said. Nobody UNDERSTANDS quantum theory back and forth, but I get SOME concepts. And that isn't why an observer changes the effects of an experiment. Changing a wavelike interference pattern to two predictable bars by having a machine which detects particle movement is not "shooting cannonballs at the humans" I'm sure that some information I have is wrong, but you get the point.

Eh, sorry if I offended, I wasn't really being serious.

The "shooting canonballs at humans" metaphor was only commentary on the relative magnitude of the forces at work here. When you're detecting particle movement you might not be literally shooting anything at the particles, but it changes the system in some way, and that way is significant enough to change the interfearance pattern.

[OwlbearUltimate]

This is for anyone who does not know what it is. Through quantum mechanics, in some parallel universe, I did not post this. In another universe, I flamed quantum mechanics, and yet another, I gave a huge lecture on it, the posibilities (sp) are endless. Also, all particles are made up of smaller "strings." That should explain it :smallamused:

Of course, this probably does it better. http://en.wikipedia.org/wiki/Quantum_mechanics

[CommodoreFluffy]

So, how do you think this machine detects particle movement? It can only make a measurement by somehow interacting with the particle, which is bound to affect the particle's wavefunction.

For comparison, let's look at how you might measure the location of a football: photons from the suns collide with the ball, are absorbed and re-emitted, and reach your eyes. How this change the football? Hardly at all. If you now want to detect an electron by bouncing a photon off it, this would be very much like measuring a human with a cannonball. The electron will move into higher energy states, conservation of momentum, etcetera, etcetera.

Also, quantum physics pretty much confirm Newtonian Mechanics at large scales (look up the Ehrenfest Theorem), just like GR approximates Newton at velocities close to zero. It's too bad that they don't fit together.

Well, the thing is, you could indirectly measure the path of an electron by observing things effected by electrons, which would otherwise be effected without an observer.

[Zarrexaij]

Since no one else bothered to do this, I will:

Things are changed by an observer, everything is everywhere at once, infinite possibilities, and what not.*GINORMOUS FACEPALM*

I think every damn scientist out there, whether a quantum mechanics guru or not, can tell you What the Bleep Do We Know is FULL of scientific inaccuracies and New Age BULL****. There's a reason why it's on the list (http://discovermagazine.com/2007/nov/none-found) of Five Worst Science Movies of All Time on Discover.

Seriously, if you want some insights on quantum theory and mechanics, you must read The Elegant Universe by Brian Greene. It goes over the theory, its history, and what scientists are currently believing and trying to figure it out.

I do believe one of the quantum mechanics founding fathers said if you think you understand quantum machanics, you simply don't.

[CommodoreFluffy]

Since no one else bothered to do this, I will:
*GINORMOUS FACEPALM*

I think every damn scientist out there, whether a quantum mechanics guru or not, can tell you What the Bleep Do We Know is FULL of scientific inaccuracies and New Age BULL****. There's a reason why it's on the list (http://discovermagazine.com/2007/nov/none-found) of Five Worst Science Movies of All Time on Discover.

Seriously, if you want some insights on quantum theory and mechanics, you must read The Elegant Universe by Brian Greene. It goes over the theory, its history, and what scientists are currently believing and trying to figure it out.

I do believe one of the quantum mechanics founding fathers said if you think you understand quantum machanics, you simply don't.

...What? I didn't get my information from... What the bleep do we know... I'm sure that I don't have all of my information correct, and I know that It can't be fully understood. I'm not gloating about my "Knowledge", I just simply want to know what others think

[Zarrexaij]

...What? I didn't get my information from... What the bleep do we know... I'm sure that I don't have all of my information correct, and I know that It can't be fully understood. I'm not gloating about my "Knowledge", I just simply want to know what others thinkWell, you obviously just repeated what is pretty much a summary of the "facts" that horrible fail "documentary" "contains."

[CommodoreFluffy]

Well sorry if those were the first concepts to come to my head. There so many different concepts, and I just don't know which ones are true, because many of them are false, so I just name a few. You don't need to bash me over the head if you think I was quoting something that you detest.

[Zarrexaij]

I wasn't bashing you over the head. I just see people quote that movie as fact so often I think they deserve no mercy. It happens almost EVERY time I see a quantum mechanics discussion and it never ceases to amaze me when people do that.

[averagejoe]

Also, all particles are made up of smaller "strings." That should explain it :smallamused:

String theory is a philosophy. It isn't testable or disprovable, so it isn't science.


Seriously, if you want some insights on quantum theory and mechanics, you must read The Elegant Universe by Brian Greene. It goes over the theory, its history, and what scientists are currently believing and trying to figure it out.

That was a horrible book. I would much more highly reccomend The God Particle by Leon Lederman, if for no other reason than because he's actually a good writer. Even if you learn nothing, you will probably get a good laugh out of that book. But the other reason is that string theory isn't currently real physics, so it's best for beginners to stay away from it.

I could also reccomend Richard Feynman's QED, which is about quantum electrodynamics. It would probably much more challenging than Lederman, but it is understandable by the layman, and very rewarding if you can get it. Of any other book I've read it's the best for explaining QM without using math, despite the fact that you pretty much need copious amounts of math to understand it.

[CommodoreFluffy]

That would have been justifiable If I had cited the movie or "documentary" that you have been complaining about. But I didn't, so you could have at least asked for a citation of what I have been getting my information from. I understand that I may seem extremely uneducated, or pathetically gullible in your point of view. But consider that I may simply not access the same resources as you. I'm sorry If what I said was completely incorrect.

HA: QED, quantum electrodynamics. That's hilarious.

Now that's settled:

Lets collaborate to find sources and information that we deem to be true. That would be a more constructive use of our time. So, lets see...

1:Strictly speaking, Newtonian mechanics are not applicable to the quantum level
2:Observing means interacting (therefore we are contradicting Schrödinger)
3:Steve Perry has nothing to do with quantum theory.

add or remove as you please

[averagejoe]

That would have been justifiable If I had cited the movie or "documentary" that you have been complaining about. But I didn't, so you could have at least asked for a citation of what I have been getting my information from. I understand that I may seem extremely uneducated, or pathetically gullible in your point of view. But consider that I may simply not access the same resources as you. I'm sorry If what I said was completely incorrect.

I think where he was coming from is just that all the mistaken beliefs that come from unreliable sources that put themselves out as legitimate can be frustrating. His reaction isn't really justifiable, but it is understandable. A few years ago I would have taken any half-an-excuse to rant about that movie.

Also, it is incorrect to say "everything is everywhere." Just for the record.


HA: QED, quantum electrodynamics. That's hilarious.

Yes, Feynman had quite the sense of humor. I'd actually reccomend any of his books, even the ones not about physics. He's the one who's quoted as saying, "Nobody understands quantum mechanics."


2:Observing means interacting (therefore we are contradicting Schrödinger)

I'm not sure what you mean about "contradicting Schrödinger." What about Schrödinger does it contradict?

[poleboy]

http://icanhascheezburger.files.wordpress.com/2008/05/funny-pictures-cat-kittens-fractal-schrodinger-back.jpg

Sorry, I got bored with physics halfway through and started looking at kitties. I'll just show myself out.

[CommodoreFluffy]

I meant that Schrödinger said that the very fact that something is being observed, in any manner, altered the world on a quantum level. Basically, the consciousness of an action would make that action change at the quantum level.

[Gygaxphobia]

I meant that Schrödinger said that the very fact that something is being observed, in any manner, altered the world on a quantum level. Basically, the consciousness of an action would make that action change at the quantum level.

No consciousness involved, it is about physical interaction. And no world-changing consequence, it only refers to one particular experiment.

Schrodinger's Cat is just an analogy to show the theory of quantum states - you don't know the state until you observe it, at which point you have changed the state you are observing.

Frankly, for most people it isn't worth the effort to understand the work.
Grand Unified Theory is more relevant, start with wave theory and work up. Read about one dimensional super-strings if you like n-dimensional space and imaginary mathematics :)

[CommodoreFluffy]

Thanks, I never really got the Observer thing, seemed kind of condescending and arrogant to me, the fact that a human can measure it would change it. I think that's weird.

[Jorkens]

String theory is a philosophy. It isn't testable or disprovable, so it isn't science.
That's kind of debatable. I'd say that at the moment it's more a branch of mathematics than anything else - a framework or a formalism that could be used to describe a physical theory - but that people are working hard to construct a falsifiable physical theory using it.

[CommodoreFluffy]

*UPDATE*
I just found The Very Best of the Feynman Lectures, Hopefully, after a little bit of extra research, I will be more enlightened.

[averagejoe]

That's kind of debatable. I'd say that at the moment it's more a branch of mathematics than anything else - a framework or a formalism that could be used to describe a physical theory - but that people are working hard to construct a falsifiable physical theory using it.

Right, and mathematics isn't a science. I'm not sure where the debate is. Everything you've just said seems to only confirm what I said.

However, even considering this, a lot of the funding that goes into string theory could be better spent on other things, even with the attempts to verify it experimentally. The large hadron collider is an example of this; they're building a big expensive machine whose job is basically to do one thing and nothing else, just because there are some scientists out there who can't resist the allure of being the one to discover the Next Big Thing.

Edit: @Fluffy: Studying QM doesn't really enlighten you. It just makes you confused on a much higher level than that on which most people are confused. QM still doesn't make sense to me, but I understand many of the subtle and profound reasons why no one understands it. :smallbiggrin:

[Gygaxphobia]

Science as a whole is a philosophy. Mathematics does the same thing, it responds to it's own internal rules, i.e. based on a given starting point, you can predict results. Science does exactly the same.

I'm not saying that mathematics is a philosophy, just saying that you should never forget that Science makes assumptions right at the start that are based on a philosophy.

Anyway, theorhetical science is exploring the possibilities through mathematics. It's like a brass rubbing, you use mathematics to highlight the lumps and see where the gaps are.

Mathematics moves ahead of experimental science because the apparatus does not yet exist to test the theories. Mathematics predicts what the experimental results would be.

Mathematics predicts Higgs Bosons, magnetic monopoles and supersymmetry. One day we will be able to test these theories predicted by mathematics, and then scientific laws can be created understood.

Science is nothing without mathematics, the ability to measure is fundamental.


Thanks, I never really got the Observer thing, seemed kind of condescending and arrogant to me, the fact that a human can measure it would change it. I think that's weird.

It's not just a human eye observing, it's a human poking something with a stick and observing what happens. We're talking about things so small that anything you use to measure it will affect it.
Even a thermometer put in a glass of water changes the temperature of the water...

[averagejoe]

Science as a whole is a philosophy. Mathematics does the same thing, it responds to it's own internal rules, i.e. based on a given starting point, you can predict results. Science does exactly the same.

I'm not saying that mathematics is a philosophy, just saying that you should never forget that Science makes assumptions right at the start that are based on a philosophy.

Though there are certain philisophical viewpoints that science follows, it is generally distinguished from philosophy, so I tend to differentiate the two when I speak. I could have said, "unscientific philosophy," or some such, but I generally feel the two are separated by the general methodologies.

The reason this applies to string theory is that it's something that can't be tested, nor could it be in the concievable future. Which pretty much makes it not science. Take, to contrast, quantum mechanics or general relativity, the so-called pillars of modern physics. Both theories are pretty much purely mathematical; however, they have been more extensively tested than any scientific theory before, and never been found wrong. There are experiments which can be done where if the outcome is a certain way, quantum mechanics is wrong, or at least incomplete.

Now, it isn't the existance of string theory that bugs me. Part of why science is so strong a method is because people are encouraged to come up with crazy insane stuff. String theory is quite possibly a good theory, and may even be correct; however, as of now, one might as well say that God causes atoms. That's why I call it a philosophy. One cannot set up an experiment to test whether the universe is deterministic, and it is the same for string theory.

(I would call mathematics a philosophy, by the way, at least a very specialized one, that only deals with ideal and purely logical systems.)

[CommodoreFluffy]

Well...quantum mechanics seems very iffy to me. Just because the math works, doesn't always mean it's right. But it is the best current theory, so I'll just have to go with the flow I guess.

[averagejoe]

Well...quantum mechanics seems very iffy to me. Just because the math works, doesn't always mean it's right. But it is the best current theory, so I'll just have to go with the flow I guess.

Well, it isn't just that the math works; in string theory the math works, and I think I've ranted enough that you know my opinion on that. (In fact, the prettyness of the math is a large part of the appeal of string theory.) However, it has also been tested extensively. Pretty much anything you read on the subject (written by a reputable source) has been extensively tested for over half a century. Now, strictly speaking, this doesn't prove quantum theory, it only proves that every test so far has responded exactly how quantum theory predicts. However, one might as well say the same of other theories. We have not, strictly speaking, proven that gravity accelarates objects at a rate proportional to the mass of two objects and a constant that has been well measured. However, in every observed case this has been true.

[FlyMolo]

String theory summarized.

http://xkcd.com/171/

This is all you need to know.

I have high hopes for the surfer dude theory, developed by a surfer dude. All particles are points on a 12 dimensional shape, and the lines between them (like the edges on the shape) are the forces that interact between them. It predicts things we haven't discovered yet, which makes it Science, as opposed to String Theory. It isn't science.

Rant: What's up with string theory? HOW many dimensions now? We were up to 27 a while ago, but I heard 30 something recently. 2^500 versions? No thanks. Then there were 5 versions that turned out to be 1 version viewed from several angles, or something. Unless that happened before.

And quantum mechanics makes no sense. Everyone knows this. If you understood quantum mechanics fully and why stuff only behaves that way on certain scales, you would by definition have united QM and Classical Physics, and deserve a nobel prize.

That whole entangled thing, spooky action at a distance, and the nonzero probability of something being anywhere is kinda scary. To quote somewhere:"[The Large Hadron Collider] has a nonzero probability of producing just about anything. Including man-eating dragons."

[CommodoreFluffy]

Now, strictly speaking, this doesn't prove quantum theory, it only proves that every test so far has responded exactly how quantum theory predicts. However, one might as well say the same of other theories.

Exactly, Nothing is proved, just disproved. That's what makes me so uncomfortable with the new physics, because nobody can really UNDERSTAND it, the way we can understand Newtonian physics, and planetary movement, and all that happy jazz. It kinda creeps me out.

[Gygaxphobia]

With science nothing is every proved absolutely, just "as far as we can tell". Even with Newtonian physics, which we can prove don't apply universally anyway.


There are experiments which can be done where if the outcome is a certain way, quantum mechanics is wrong, or at least incomplete.

... however, as of now, one might as well say that God causes atoms. That's why I call it a philosophy. One cannot set up an experiment to test whether the universe is deterministic, and it is the same for string theory.

You can have a theory that cannot yet be tested, it doesn't mean that it can never be tested, and it doesn't mean that it isn't science.

It's only now that we can test certain parts of QM, and we still can't test much of it. So does that mean that it was only a philosophy until we performed an experiment? Isn't that the difference between theoretical and experimental science?
I think the philosophy part is where you define what emperical evidence means and your methodology for "proving" things.

I guess I'm just saying that at this level of advanced science, it has become pure mathematics. It is no longer about a pair of googles and a bunsen burner. We aren't theorising by throwing things together in a beaker and guessing what will happen, we are theorising by playing with maths and seeing where the nodes are. And then designing rigid controlled experiments to test the theories.

I don't think that the lack of appropriate equipment to perform the experiment changes the nature of the science.

[Felixaar]

y'kno, I personally stick with the whole "The world doesnt actually make sense" theory. Rather, I make up my own idea of how physics and gravity work and just kinda hope everything works out.

And when that fails, I just try to land well.

Or learn to fly.

That'd be so awesome.

[Dallas-Dakota]

Quantum theory is untrue. Everything go's by the lore of Cookiemanjaro.

And if not that, everything resolves around Cookies and Milk. At the epicentrum of the universum a giant cookie sits, protected by pure holyness and chaos, to protect it from those stupid paladins...

[Felixaar]

A cookie-shaped universe.

That's FANTASTIC!

Man, me and D-D should NEVER be allowed onto a thread in which serious discussion is taking place.

[averagejoe]

You can have a theory that cannot yet be tested, it doesn't mean that it can never be tested, and it doesn't mean that it isn't science.

It's only now that we can test certain parts of QM, and we still can't test much of it. So does that mean that it was only a philosophy until we performed an experiment? Isn't that the difference between theoretical and experimental science?
I think the philosophy part is where you define what emperical evidence means and your methodology for "proving" things.

I guess I'm just saying that at this level of advanced science, it has become pure mathematics. It is no longer about a pair of googles and a bunsen burner. We aren't theorising by throwing things together in a beaker and guessing what will happen, we are theorising by playing with maths and seeing where the nodes are. And then designing rigid controlled experiments to test the theories.

I don't think that the lack of appropriate equipment to perform the experiment changes the nature of the science.

Well, you're not incorrect, but string theory has more problems than being untestable by any concievable device. You mentioned untestable concepts in QM. Now, I don't know what you're thinking of, but all the untestable theories I've heard of in that context have some sort of role. That is, as a theoretical framework they explain various effects or phenomena, and as such can work as a mathematical and theoretical baseline. Take the idea of the vaccum spontaneously creating electron/positron pairs. This is, as far as I know, untestable as of now; however, systems behave as if this was the case, at least as far as we can measure them. Strictly speaking, perhaps, this idea isn't scientific, any more than a particle collider is, but it's still a useful tool for scientists, and so has its place in a theoretical framework. A paintbrush isn't art, but it's good to have if you want to do art. (Well, what with post-modernism, pretty much anything is art these days, but you know what I mean.)

String theory has a place within science; however, it is not, as of now, scientific. It isn't just lack of equipment that makes it untestable, it's lack of any idea of any method of measurement that could concievably do so. It isn't like, say, the theoretical existance of certain particles, which are not testable, but one only needs to build a bigger collider for them to be so. The existance of any such equipment is purely hypothetical, and not even well speculated. To use my previous comparison, one might as well say that the existance of God is simply not yet testable, because we don't have the proper equipment, so religious speculation has a part in science, nevermind that no one could concieve of such a test.

Again, I'm not saying that string theory has no place anywhere; indeed, theoretical science depends on such things, and thrives on them. Nonetheless, it is not now scientific.

[Arioch]

You can have a theory that cannot yet be tested, it doesn't mean that it can never be tested, and it doesn't mean that it isn't science.

No, in science you can't have a theory that can't be tested. A theory, by definition, has to stand up to scientific testing and mesh with available evidence. Until these things are true, it's a hypothesis.

Evolution and continental drift are theories. String "theory" is a hypothesis, really.

[Gygaxphobia]

OK AJ I see what you're saying, and I'm half-inclined to agree with you.

Maybe we need a new branch of metaphysical mathematics?
I kind of like the idea that string theory can be classified as theology though ;)


No, in science you can't have a theory that can't be tested. A theory, by definition, has to stand up to scientific testing and mesh with available evidence. Until these things are true, it's a hypothesis.

Evolution and continental drift are theories. String "theory" is a hypothesis, really.

Well that's an interesting "theory" in itself. A theory can be a hypothetical or a model and it can be tested by mathematics instead of physical apparatus.

[FlyMolo]

String Theory is just barely science. By the skin of its teeth, it escapes being religion.

Really, The Bible makes more testable predictions than String Theory.

[Arioch]

Well that's an interesting "theory" in itself. A theory can be a hypothetical or a model and it can be tested by mathematics instead of physical apparatus.

A scientific "theory" has a very distinct meaning from "hypothesis". People often confuse the two because this division is not present in everyday language. A theory in science has to be verifiable. It's not the same as a mathematical theory either, which is why the word "theorem" is now sometimes used to differentiate.

[WalkingTarget]

The "falsifiability" bit is what a lot of String Theory bashers have problems with.

Karl Popper (http://en.wikipedia.org/wiki/Karl_Popper)'s definition: "The criterion of the scientific status of a theory is its falsifiability, or refutability, or testability."

String Theory makes the math look nice and fits the data given that you accept the existence of all of these other dimensions but since there isn't a way to test it then it doesn't qualify as "science" in these people's minds. Proponents of String Theory (or any number of other philosophers of science) might not agree with Popper and so the arguments continue.

Edit:

A scientific "theory" has a very distinct meaning from "hypothesis". People often confuse the two because this division is not present in everyday language. A theory in science has to be verifiable. It's not the same as a mathematical theory either, which is why the word "theorem" is now sometimes used to differentiate.

Doesn't a hypothesis have to be verifiable/falsifiable as well? A hypothesis is the statement one makes and then sets out to try to verify via experiment or observation. If your hypothesis holds up to enough testing it might "ascend" to Theory. Think mathematics and the difference between a conjecture and a theorem.

[Gygaxphobia]

An argument about an absolute definition seems a bit pointless.


In science, the word theory refers to a comprehensive explanation of an important feature of nature that is supported by many facts gathered over time. Theories also allow scientists to make predictions about as yet unobserved phenomena.

Meh. If it verifiable it is a law, if it's refutable then it's untrue. Surely that's all that matters.

[averagejoe]

Maybe we need a new branch of metaphysical mathematics?
I kind of like the idea that string theory can be classified as theology though ;)

Well, they do have mathematical physics, in which they try to put physics in a complete theoretical framework, but it apperantly doesn't actually take experimental evidence into account. :smallamused: (Note to mathematical physicists who may get offended by this: I don't actually know anything about this.)

To be fair, I probably wouldn't be so hard on string theory if it wasn't so big right now. The actual classification of string theory isn't as important to me; they can call themselves a science if they want, for all I care. More than anything it's a reason (among many) why string theorists don't deserve nearly the amount of funding they're getting.

On the other conversation thread, I'm pretty sure the attempt to distinguish "theory" as an idea in science from the way people use it was a response to people claiming that no one should believe in evolution because it's "just a theory," and it was important for people to understand that this meant something slightly more substantial to the scientific community. This isn't the way I've been using it; I honestly don't think it matters that much in any but semantical arguments.

[CommodoreFluffy]

String Theory is just barely science. By the skin of its teeth, it escapes being religion.

Really, The Bible makes more testable predictions than String Theory.

Yup, and many have much, much evidence against them.

[Gygaxphobia]

Well, they do have mathematical physics, in which they try to put physics in a complete theoretical framework, but it apperantly doesn't actually take experimental evidence into account. :smallamused: (Note to mathematical physicists who may get offended by this: I don't actually know anything about this.)

Well you're right in that it is not directly testable... yet.
But it is based on all the other laws and experiments we have in physics. It takes the current theories and ... extrapolates. Literally, it extrapolates the mathematics.
I'm not arguing with you AJ, I agee with you, its an interesting discussion though.

I don't know how well string theory is funded, I guess this is one thing where it's very hard to decide the priority it's given.
An awful lot of science is funded by private companies, and they decide how useful the potential outcomes are to them, so this might be one reason.

With government funding, I guess you have to fall back on that old motto, that science is there to answer the big questions. In some ways science is about the search for god... creation is about god whether you call it religion or not.

I think that's about as close as I can get to the forum rules without stepping over them.

[sikyon]

In preparation for my quantum mechanics test next week, I will now attempt to answer any questions you may have about quantum mechanics. Please don't ask me anything about, say, solutions to spin dependant Schroedinger equations.