string theory

[Chaigidel]

ok from what I understand string theory states that we exist in a 3 dimensional existence but that its a membrane or a thin 2 dimensional plane, now this membrane is layed down parallel to another membrane seperated by a tiny line so to speak , all throughout both membranes there are 6 dimensions which bend the membranes around each other and have been described as strings tied on the same post so to speak with ends of each sticking out in distinct places but at any given spot the places are different

these 6 dimensions exist within every miniscule detail of every aspect of all existence so to say no matter where you look there is an infinitely small string knot which ties reality together , thats putting it very basically- :O
the 6 dimensions all exist wrapped around each other within an infinitely small point kind of like a tiny sphere ball of yarn style, as said before with the bits of string in various places on each. It is the swelling of these knots within the membrane that cause existence, the quantum foam perhaps is analagous to this concept--- you could even imagine each 6 dimensional point as tiny whirlpools around everything, considering that they are in movement, I think the idea is that this original action caused by two 3 dimensional membranes laying parrallel causes the twisting of the strings, which produces the laws of nature.

this is just what I understand of how string theory is supposed to work any corrections are welcome, I mean for this to be a explanation of the string and membrane theory and all corrections are proper :O

[DisgruntledGoat]

With all this recent talk about string theory I went did some reading. You certainly sparked my interest Chaigidel. One thing that I thought was interesting was how string theory is basically "meaningless." More explaination here:

The problem with string theory is
its a purely conjectural theory, it is not known
what the dynamical degrees of freedom or
equations governing them are.

There are no predictions of string theory,
astrophysical or otherwise, since there
is no theory. Anyone who claims otherwise
doesn't know what they are talking about,
or is using a non-standard definition of
"prediction" (as in "string theory
predicts that X may happen, but then
again maybe it won't")

You're not going to find string theorists who
know what they are talking about claiming
predictions of the theory. People like Ed
Written and David Gross are quite explicit
that the present state of the theory is such that it can't predict anything. They hope
this will change and they will find a
way to make predictions. They have been
hoping this without success for 20 years.

I always assumed string theory had a stronger foundation than basic "wishful" thinking.

[ajm317]

ok from what I understand string theory states that we exist in a 3 dimensional existence but that its a membrane or a thin 2 dimensional plane,

No, the membrane we live on would be 3 dimensional. Scientists refer to it as a sheet or membrane to make it easier to visualize.

now this membrane is layed down parallel to another membrane seperated by a tiny line so to speak , all throughout both membranes there are 6 dimensions which bend the membranes around each other and have been described as strings tied on the same post so to speak with ends of each sticking out in distinct places but at any given spot the places are different

...?

You lost me.

these 6 dimensions exist within every miniscule detail of every aspect of all existence so to say no matter where you look there is an infinitely small string knot which ties reality together , thats putting it very basically- :O

I don't believe anything in string theory is "infinitely small" rather just "really, really small."

the 6 dimensions all exist wrapped around each other within an infinitely small point kind of like a tiny sphere ball of yarn style, as said before with the bits of string in various places on each. It is the swelling of these knots within the membrane that cause existence, the quantum foam perhaps is analagous to this concept--- you could even imagine each 6 dimensional point as tiny whirlpools around everything, considering that they are in movement, I think the idea is that this original action caused by two 3 dimensional membranes laying parrallel causes the twisting of the strings, which produces the laws of nature.

I think you lost me again.

As DisgruntledGoat said, string theory is pretty shaky. Calling it a theory at this point is actually being generous. Hypothesis is more accurate. The closest that they have come to producing anything useful at this point is in regards to blackholes, where string theory appears to offer an explanation for a information paradox regarding blackholes which causes them to apparently violate the second law of thermodynamics.

There's a good article that was posted by TheKwas earlier. I suggest you read it if you haven't.

http://www.twcenter.net/forums/showthread.php?t=99217

[Chaigidel]

well I need to remind both of you it may be hard to understand but they wouldnt even call it a theory unless they had a mathematical basis for that theory... Im not a mathematician but from what I understand all scientific theory must at least have a few workable equations to even be given the title of theory, and even if one scientist considers it shakey I would encourage everyone to remember that all science that is now accepted fact began quite shakey... it will simply take time for the theory to gain more facts to support it but do not be fooled-- string theory has a basis in mathematics and in the predictable processes of the universe it is not simply a group of scientists saying what if--it is a genuine attempt to unify several theory into one.

my explanations of it of course are based on my limited understanding but I would encourage you all to read more than one article about the theory before you pass judgement.

on a personal level string theory makes perfect sense to me from what I understand of it, doesnt mean its true just means it feels right :O

[ajm317]

well I need to remind both of you it may be hard to understand but they wouldnt even call it a theory unless they had a mathematical basis for that theory... Im not a mathematician but from what I understand all scientific theory must at least have a few workable equations to even be given the title of theory, and even if one scientist considers it shakey I would encourage everyone to remember that all science that is now accepted fact began quite shakey...

First of all I am not the only one who feels calling string theory a theory is generous. Many agree with me.

Second of all string theory has some mathematical basis, what it lacks though (and what seperates it from the rest of science which you term "shakey") is any kind of falsifiable statement that could be tested. When Einstein came up with relativity, there was a test which could be done, if relativity was wrong, the experiment would have turned out one way, if it was right another. String theory has no such predictions (yet).

it is not simply a group of scientists saying what if--

At this point that is exactly what it is.

It need not always be so. Perhaps one day someone will improve string theory into something usefull, but right now it's nothing more than a neat idea on a white board.

And by the way, I've read more than one article on the subject. In fact my general relativity teacher last year was a string theorist, and I interviewed him for our seminar course. I also discussed the subject with a professor at Minnesota when I was trying to decide on my graduate school.

I am not by any means dismissing string theory. It is the most promising avenue for the "theory of everything" I'm just saying that at this point, it hasn't accomplished much. The subject appears to be too complicated for anyone to make much headway, and experimental techniques may have to improve before we get much further.

[Chaigidel]

very interesting info ajm thanks:O

[chris_uk_83]

Chaigidel

You can't just think a scientific theory is good because it "feels right" or you get into the realms of religion rather than science. I assume you have no prior physics background (i.e. a physics degree) or you probably wouldn't talk like this.

It's encouraging that you find the subject so fascinating and you want to debate it, but I would suggest getting a better understanding of it yourself first, you may find the answers you're looking for yourself. This is far more satisfying and useful than having someone else argue them with you, because in a debate you don't gain proper understanding.

In order to understand string theory you need a LOT of mathematical know-how coupled with a bit of physics (it's more of a maths thing than a physics thing as far as I know). I've completed a masters in physics and never touched on string theory, that's how advanced your knowledge has to be. If you want to know more, and understand that which you know then take a theoretical physics degree (shouldn't take more than 4 years) and do a PhD studying string theory. Then you might have a good enough understanding of what it is you're debating.

This is the reason I tend to keep out of debates regarding string theory. I know nothing about it. But I know enough to realise that I know nothing about it and that I simply couldn't talk about it with any real authority. I'm pretty sure that nobody on this forum actually has the necessary knowledge to fully understand and explain string theory (if they do, please explain it to me, along with the maths).

I don't mean to sound patronising here (and I probably do) but string theory is something you really need to fully understand before you can argue it one way or the other.

[ajm317]

(shouldn't take more than 4 years)

Pfft. I wish.

Here in the States the average time a PhD student spends in grad school (not counting undergrad) is 6 years.

[Chaigidel]

blah knowledge is not a prerequisite for arguement :O

the purpose of this discussion is exactly for that kind of information.. and my other point is that no matter what understanding of the universe exists and no matter how true it is -- most people will just never be on the level to properly comprehend it so people like me will always take what info they have and form pseudo religious conotations---

but back on string theory-- from what I understood the logic of string theory can only be properly explained mathematically because to describe it just makes little sense to our minds

Im horrible at mathematics and will never be able to gain that level of understanding , but I can appreciate the movement that the theory describes
so I have to rely on my "feeling" about the subject because I truly think thats my mind taking the info into account and producing for me a logical conclusion

to "fully" understand string theory would probably make me the smartest turd in the pocket so I know for sure Ill never do that :O

I will always find the mystery of physics endlessly fascinating but its totally beyond concrete understanding for me because I am horrible at mathematics :O/calculus fuggitaboutit

and I have talked to many many educated people on such subjects many of my close friends are pursuing doctorates of Genetics, Physics, etc I like hearing about those things, and I can only ever discuss them from my particularly "spiritual" perspective. because I dont claim that I will EVER truly be involved in the mechanics of those subjects :O

this has been informative still. I encourage further contributions if ppls find articles etc. especially about any tests that could come up to work on string theory.

[chris_uk_83]

Since you've done some reading up on string theory, I assume you've seen this site. If not, check it out; I had a read of it this morning and it seems to answer most of your questions. You might want to read the basic versions of the explanations though if your maths isn't top notch

Based on my limited knowledge of reading the site I just linked, here's my 2 cents on string theory. First you have to understand that there are a LOT of string theories, each dealing with a different way in which a string behaves (I'll come onto what a string is in a bit). Some deal with strings with fixed ends, some with loose ends, some with special cases of symmetry, etc. All are valid and belong to an overarching theory known as "M-Brane theory". Not much is known about M-Brane theory except that it involved a lot of maths and brings the different string theories together.

Right, what is a string? You know about particles right? That all matter is made up of particles, and there are different kinds of particles flying around everywhere? Well string theory seems to say that each different type of particle is simply a resonation on a string (this is particular vibration, like what a guitar string does when you pluck it). What exactly these strings are made from I don't know. The website also says that these strings are in 10 dimensions, but these 10 dimensions look like 4 from a distance (3 spatial dimensions and time). Get your head around that one if you can. Strings can apparently twist round each other, move together, attach their ends together etc. Each different variation requires another type of string theory to explain it.

Where it gets complicated is when you look at bosonic string theories and fermionic string theories (a boson is a particle in the family of protons and neutrons, and a fermion is in the family of electrons and neutrinos; google this). It turns out you need to have 26 dimensions for bosons and 10 for fermions. That's ok though because of the way the theories interact.

It's really not worth thinking about string theory on a physical level. The human brain simply cannot do it (how do you imagine 26 dimensions?). Mine has enough difficulty with quantum mechanics, and that's a far simpler thing to imagine. It's also not correct to think of strings as little bits of string floating around and getting tied in knots, in the same way it's not correct to think of electrons as little balls that orbit a nucleus, which in turn is made of little balls. It helps us mere humans to understand but it isn't what's really happening.

As for being crap at maths, I believe that anyone can do maths as long as it's explained in the right way to them. Finding the right explanation for each individual is the difficult bit.

Physics is full of interesting mysteries, and I'd be more than happy to talk to you about some of the less mentally taxing ones, as would lots of people here I believe. Let me know if you know about these for instance:
quantum tunnelling
time slowing down with high speed
quantum entanglement
time's relation to gravity (though this is a bit mathsy too)
how lasers work
There are loads more too.

[Syron]

I agree with Chris, really unless you understand the maths debating such things are pointless. trust me, there is a huge amount of difference between getting a grasp of a physical concept and actually seeing it through maths.

Personally on a non mathematical basis i find the "theories" appealing, especially M-theory not least because of their "beauty" and intricacy. They also hint at some amazing possibilities like how studying gravity could potentially lead to confirmation of a greater number of dimensions than that are currently observed.

problem is they may be a little too perfect to be true and tbh we are not really in a position to test them or even be sure it's possible. How nice a theory is is completely irrelevant.

Really you should understand that the string theories are basically all a "what if?" scenario all based around a single assumption, or rather a contradiction of one. It is often assumed that the basic units of matter are particles or "point like", or in maths terms 0-dimensional. This is just an assumption and because of Heisenbergs uncertainty principle we can't determine objects below the planck scale. All string theory is is "what if matter is made up of higher dimensional objects?", 1-dimensionals (stings), etc etc.

[Chaigidel]

I do realize that the vast majority of descriptions in hard science are merely analagous to the accepted working equations--- the example of electrons is perfect

but im willing to read or discuss any subject along these lines :o string theory was just tempting because of its pseudo mystical implications just because of its vast complexity

[Gary88]

6 sheesh i think its 4/5 here after 3/4 undergrad. string theory is definately a shakey theory some of the most eminent scientists of all time have had issues with it. the guy who came up with it was openly ridiculed by colleges at caltech even Murray Gell-Man pointed out flaws when he put his views over. (behind the scenes gell-mann was pulling strings to ensure the guy kept his job)

[ajm317]

Yeah, I was talking to a professor from France, evidently in the EU it's 4 years.

My labmate probably won't get her PhD until she's in her 7th year (currently in her 6th.)

[Gary88]

i know a girl at the charity where i work who did 3 undergrad then 4 post grad (just finished her phd) and is now doint post grad medicine

[Chaigidel]

Im glad you all see the natural attraction of such "theories" to a layman such as myself for I too can see the beauty of it and the construction may be if not in whole at least in part to the greater truth that will be one day revealed by our continuous questioning of all facets of reality.

if not that, then at least it is a beautiful construction of reasoning -- because the people who propose these things though detracted do have mathematical logics , string theory would not be mentioned at all if it was just "what if" (perhaps I trust science too much!)

and even then it is a look into another persons understanding of the world if not a true objective theory of the universe.

so the discussion of such theory is always valuable if you find value in such things. :O

[Syron]

The problem is if you just rely on the rather incomplete concepts formed from a hypothesis that has no observable evidence all you are doing is opening the door to faith and belief, which i find harmful.

The foundation of science and the reason why it is taken seriously is the skepticism at it's heart. No matter what an individuals feels for a certain idea does not change truth which is why string theory should be regarded as nothing more than a fancy idea.

string theory would not be mentioned at all if it was just "what if" (perhaps I trust science too much!)

Lol, i think you do.

The reason why it has gained notoriety is because if it is true then it would solve the problem of trying to unify general relativity and quantum mechanics which is seen as one of the biggest intellectual endevours of our time. The problem is that it is a very big (positively enormous), if.

[Simetrical]

As for string theory's meaninglessness, well, it's not testable yet. Black holes were first hypothesized in the 18th century or so, and were suitably ridiculed as being unobservable (since, after all, they gave off no light) and thus unscientific. As experimental techniques improve, we'll probably find more ways of distinguishing various theories of quantum gravity, of which string theory is the most popular.

well I need to remind both of you it may be hard to understand but they wouldnt even call it a theory unless they had a mathematical basis for that theory... Im not a mathematician but from what I understand all scientific theory must at least have a few workable equations to even be given the title of theory

Not true. The theory of evolution, for instance, isn't really expressed best as an equation, although you could construct a whole mathematical scaffold around it and people have fruitfully done so. A theory is just a set of rules, a system, that purports to explain something.

but back on string theory-- from what I understood the logic of string theory can only be properly explained mathematically because to describe it just makes little sense to our minds

The same is true of any reasonably advanced physics. Of course, some mathematical descriptions can be simple and easily understandable to a layman (the time it takes for a dropped object to fall a distance of x meters is 0.45√x seconds).

What exactly these strings are made from I don't know.

I assume nothing. What's a photon made of? What about a quark?

[chris_uk_83]

What's a photon made of? What about a quark?

I assume it's strings according to this theory .

Just to tag onto the how long it takes to get a PhD in different countries, in the UK you can do a 3 yr undergrad degree then take 3 years to do a PhD. Although it's more usual to do a masters before you do the PhD (which takes another year after your undergrad degree). In physics anyway.

string theory would not be mentioned at all if it was just "what if" (perhaps I trust science too much!)

I agree with Syron, you definately do! Also string theory is entirely based on "what if". It begins by saying that "if there were 26 dimensions, this particular maths will fit this particular situation, therefore assume 26 dimensions". At least that's what I managed to glean from the string theory website.

[ajm317]

Just to tag onto the how long it takes to get a PhD in different countries, in the UK you can do a 3 yr undergrad degree then take 3 years to do a PhD. Although it's more usual to do a masters before you do the PhD (which takes another year after your undergrad degree). In physics anyway.

So you can do in 6 years what takes me 10?

I don't usually use emoticons, but this definately deserves a .