The Theory of Everything (string theory)

[Gbl911]

Hello, if you have ever heard of the TOE then you may be able to answer my question on this theory. The theory explains that there are tiny little strings in all atoms. Imagine the universe being an atom, the stings in this atom would be the size of a tree here on Earth. That is how small they are. These strings vibrate at a certain speed. If I am correct then the speed it vibrates at decides everything of that atom. So... if we could manipulate these strings would it be possible to literally change matter itself?

 

[Timothy S]

Yes this is true, however it would take energy that is for all intents and purposes infinite to get on that scale.

 

[Gbl911]

Exactly why we can't do it.

Maybe like the energy of a black hole.

 

[phinds]

Maybe like the energy of a black hole.

What "energy of a black hole" are you talking about?

 

[Gbl911]

Black holes have immense energy

 

[bhobba]

Exactly why we can't do it.

You can in principle - but if we will ever have access to the energy and mechanisms required is another matter.

We currently can't do it and it will require great technological advancement to even attempt it - predicting technology is extremely difficult.

Thanks
Bill

 

[phinds]

Black holes have immense energy

Uh huh. What kind? How would you use it?

 

[Gbl911]

Never mind that, they just have a lot of energy.

 

[Evo]

Never mind that, they just have a lot of energy.

Please post the peer-reviewed paper in an approved journal that meets our criteria, we don't accept "just because" here.

 

[bhobba]

Never mind that, they just have a lot of energy.

Via E=MC^2 there is enormous energy all about the place, not just black holes.

Accessing it is another matter. Even Fusion power which accesses a bit of this energy has proven notoriously difficult to implement practically.

Yes - in principle if string theory is true and we can manipulate those strings we would be able to do amazing things. But doing so is way way beyond our current, of even reasonably extrapolated future technology.

Thanks
Bill

 

[phinds]

Never mind that, they just have a lot of energy.

Uh ... that's your idea of a scientific discussion? "Never mind that" ?

As Evo has pointed out, that is not an acceptable answer on PF.

 

[Edward Wij]

Quite a number of physicists dislike string theory because it can't predict the constants of nature.. but isn't it we have something like Vacuum landscapes where all constants of nature occur and we just happen to live in a universe with the right constants? Is this the primary objection to string theory? But if nature is like this. Then why can't we can say string theory is a theory of all vacuum conditions and we just happens to live in the constants we have. Can anyone list or point out to a list of other objections why string theory is not being enjoyed much nowadays with many going to LQG (like many here)?

 

[bhobba]

Quite a number of physicists dislike string theory because it can't predict the constants of nature.. but isn't it we have something like Vacuum landscapes where all constants of nature occur and we just happen to live in a universe with the right constants? Is this the primary objection to string theory? But if nature is like this. Then why can't we can say string theory is a theory of all vacuum conditions and we just happens to live in the constants we have. Can anyone list or point out to a list of other objections why string theory is not being enjoyed much nowadays with many going to LQG (like many here)?

In so far as I can get the drift of your query (vacuum landscapes where all constants occur? - I think you are referring to the large number of possible ways the extra dimensions of string theory are curled up) yes that is one view promulgated by Susskind and others - but its not the only view.

Thanks
Bill

 

[phinds]

Quite a number of physicists dislike string theory because it can't predict the constants of nature..

I think it is much more to the point to say that a number of physicists dislike string theory because it doesn't predict ANYTHING. It is not a testable theory and thus is not science, just math.

It would be terrific if string theory (or m theory) does turn out to be right because is solves some problems and would be another great step in telling us how the universe works, but it has been "showing promise" for over 30 years and the wait is getting a bit old.

 

[Edward Wij]

I think it is much more to the point to say that a number of physicists dislike string theory because it doesn't predict ANYTHING. It is not a testable theory and thus is not science, just math.

It would be terrific if string theory (or m theory) does turn out to be right because is solves some problems and would be another great step in telling us how the universe works, but it has been "showing promise" for over 30 years and the wait is getting a bit old.

Don't we have a Marcus version of Superstrings guys here who can give us summaries or updates of say the Six Themes for Superstrings in 2015 (developments to watch for)? All the papers or updates shared in this focum is about Loop Quantum Gravity. They don't unify anything except quantizing spacetime and GR doesn't even come out yet as low energy limit. Superstrings is still more interesting. What's latest with Witten?

 

[phinds]

Don't we have a Marcus version of Superstrings guys here who can give us summaries or updates of say the Six Themes for Superstrings in 2015 (developments to watch for)? All the papers or updates shared in this focum is about Loop Quantum Gravity. They don't unify anything except quantizing spacetime and GR doesn't even come out yet as low energy limit. Superstrings is still more interesting. What's latest with Witten?

You got me on all that. I don't watch string theory developments at all since (1) so far it isn't going anywhere practical and (2) the math to really understand it is way over my head.

 

[Chronos]

AFAIK this is the latest word from Witten on string theory - http://blogs.scientificamerican.com...till-thinks-string-theory-on-the-right-track/

 

[phinds]

AFAIK this is the latest word from Witten on string theory - http://blogs.scientificamerican.com...till-thinks-string-theory-on-the-right-track/

Right. Witten was extremely optimistic about it 25 years ago and he is still optimistic about it. If he lives another 25 years he will likely still be optimistic that some day it will be shown to represent reality.

I hope he's right, but I'm not holding my breath.

 

[wabbit]

Well since "There are not any interesting competing suggestions", he better be right.

 

[phinds]

Well since "There are not any interesting competing suggestions", he better be right.

Uh ... "better be right" why?

 

[Holystromboli]

Wow! This thread seems to be way off "topic"...

Speaking of things off topic, here's a fun question that I didn't think warranted a post on this forum since it was 100% pure, fresh-squeezed speculation. If string theory speculates that the universe really has multiple hidden dimensions curled up in some sort of Calabi-Yau shape, why haven't we taken that speculation to the next level and postulated that maybe the entire universe is some strangely deformed 9, 10, or 11 dimensional Calabi-Yau structure with spatial dimensions that expand outward, reach a maximum 'distention', and then collapse back down toward their curled up cousins, imparting their "momentum" to a different set of dimensions when they collapse back to sub-Planck scales, sending the next set of dimensions (made primarily of antimatter, perhaps? :p ) expanding outward, and so on and so fourth. That would be cool, huh? :)

 

[wabbit]

If string theory speculates that the universe really has multiple hidden dimensions curled up in some sort of Calabi-Yau shape, why haven't we taken that speculation to the next level and postulated that maybe the entire universe is some strangely deformed 9, 10, or 11 dimensional Calabi-Yau structure with spatial dimensions that expand outward, reach a maximum 'distention', and then collapse back down toward their curled up cousins, imparting their "momentum" to a different set of dimensions when they collapse back to sub-Planck scales, sending the next set of dimensions (made primarily of antimatter, perhaps? :p ) expanding outward, and so on and so fourth. That would be cool, huh? :)

Now look what you've done... The universe dislocated its shoulder trying to do just that.
(More seriously what does it mean to say that one dimension pushes against another?)

 

[wabbit]

NN

Uh ... "better be right" why?

Never mind, silly joke

 

[Edward Wij]

AFAIK this is the latest word from Witten on string theory - http://blogs.scientificamerican.com...till-thinks-string-theory-on-the-right-track/

This was years ago. Where is Witten now.. who is employing him? Around how old is he now? How much would it take to hire him or the like if retired already?

 

[phinds]

This was years ago. Where is Witten now.. who is employing him? Around how old is he now? How much would it take to hire him or the like if retired already?

When did 2014 get to be "years ago". Did you do any research? Even just read the Wiki entry on him?

 

[Edward Wij]

When did 2014 get to be "years ago". Did you do any research? Even just read the Wiki entry on him?

Oh sorry. I was reading his long Kyoto interview in the other thread and my head spinning with the heavy math contents and thought it was written in 2004. At the end witten says:

"But we 're still studying many different aspects of a subject whose core underlying principles are not clear". How about Loop Quantum Gravity. What are LQG core underlying principles? What is the meaning of core underlying principles?

 

[Holystromboli]

(More seriously what does it mean to say that one dimension pushes against another?)

Now that's an interesting question that I have no idea how to answer... :)

 

[Edward Wij]

Duh, isn't strings the core underlying principles of superstrings?

 

[Edward Wij]

AFAIK this is the latest word from Witten on string theory - http://blogs.scientificamerican.com...till-thinks-string-theory-on-the-right-track/

The article started with "At a 1990 conference on cosmology.." so I skipped it thinking it's ancient article.. but reading this now (after phinds emphasized its 2014). I have some questions especially since Witten links to his articles "Unravelling string theory" and "When symmetry breaks" in the page doesn't work, it says "page not found" and goggling it points to Nature paid article. Anyway. In the blog it is mentioned that

"If the landscape interpretation is correct, can we get additional clues that would make this more believable? One obvious possibility involves the outcome of Large Hadron Collider experiments. I explain why in my 2004 article, “http://www.sns.ias.edu/~witten/papers/Symmetry.pdf .” What I wrote there wasn’t original but provides a succinct explanation. The literature is filled with other suggestions about how we might conceivably get more clues about a landscape interpretation if that is correct (for example seeing a signature of a prior phase transition in the cosmic microwave radiation). It is hard to summarize these suggestions for you as it is hard to know which proposals are most worth describing.

Another possibility is that a theory that predicts a landscape would become well-established because of other predictions it made. The trouble with criticizing string theory because it plausibly predicts a landscape of vacua is that the landscape interpretation of the universe might be correct. 200 years from now, if more clues have emerged, possibly including some that are unforeseeable now, it might seem obvious that the landscape of string vacua was necessary to make string theory viable."

---
I'd like more information on this line "The literature is filled with other suggestions about how we might conceivably get more clues about a landscape interpretation if that is correct (for example seeing a signature of a prior phase transition in the cosmic microwave radiation".. what are the lists of suggestions? this is difficult to google because it would produce hundreds of articles and I can't read all of them so if you know of specific ones that list what clues to look for case the landscape interpretation is viable.. please share them because it is possible superstrings is the theory of all universes landscape and would be incredibly powerful.. thanks a lot.

 

[wabbit]

The litterature is also filled with suggestions about how faith heals. How is this different?
OK OK I'm being needlessly polemical, strike that out - but irrespective of string theory's merits, why do some of its proponents - eminent ones indeed here - at times sound almost cultish in their pronouncements about the prospects of ST?

 

[Ben Niehoff]

Don't we have a Marcus version of Superstrings guys here who can give us summaries or updates of say the Six Themes for Superstrings in 2015 (developments to watch for)? All the papers or updates shared in this focum is about Loop Quantum Gravity. They don't unify anything except quantizing spacetime and GR doesn't even come out yet as low energy limit. Superstrings is still more interesting. What's latest with Witten?

I work on string theory but I'm way, way too busy to spend time here distilling it for lay readers. But you're welcome to check hep-th on arXiv every day if you think it's important to keep up with what's being done.

 

[Edward Wij]

Thanks. I'm starting to read the book String Theories for Dummies. For any laymen here. This would be a great thing to spend the weekend with. An interesting bit inside is how LQG and Strings theory may be two sides of a more fundamental theory. Quoting it:

" One viewpoint is that both string theory and loop quantum gravity may actually represent the same theory approached from different directions. The parallels between the theories are numerous:

* String theory began as a theory of particle interactions but was shown to contain gravity. Loop quantum gravity began as a theory of gravity, but was shown to contain particles.
* In string theory, space-time can be viewed as a mesh of interacting strings and branes, much like the threads of a fabric. In loop quantum gravity, threads of space are woven together, creating the apparently "smooth" fabric of space-time.
* Some string theories believes the compactified dimensions represent a fundamental quantum unit of space, while LQG starts with units of space as an initial requirement.
* Both theories (provided certain assumptions are made) calculate the same entropy for black holes."

what else.. if you come across papers or more references on a more fundamental theory underlying the two, let me know. Thanks.