Is string theory physics on crack or does it really govern the physics at the atomic level?

Question

Basically string theory states that subatomic particles are strings whose properties are produced by vibrations in different dimensions, they could be in 11 or 12 dimensions. String theory is very complex and calls for extra dimensions that we cannot see, but it mathematically describes all occurrences in terms of vibrating strings.

Is this a dead-end field with no hope of evidence? I understand that not all physicists have a Hadron Collider available next to their workbench so they just message equations to prove theoretical concepts

Answer 1

STRINGS

There is at some indication that the theories might be true. A physicist observes a physical phenomenon and tries to figure out the mathematics that would describe the phenomena. The first place the look is in an old, dusty mathematics book. Often, because mathematicians find all sorts of equations that have interesting properties but no known practical application at the time the equations are discovered, the physicist finds an equation that EXACTLY fits the phenomena. The physicist then looks at what the equation originally described and wonders if that original thing the equation described might be a general description of reality (Theory).



String Theory and it is a good example, lets look at the birth of the theory:



Gabriele Veneziano:



The rudiments of string theory were first formulated in 1968 by Veneziano when he discovered a string picture could describe the interaction of strongly interacting particles.[4][5][6] Veneziano discovered that the Euler Beta function, interpreted as a scattering amplitude, has many of the features needed to explain the physical properties of strongly interacting particles. This amplitude, known as the Veneziano amplitude, is interpreted as the scattering amplitude for four open string tachyons. In retrospect this work is now considered the founding of string theory although at the time it was not apparent the string picture would lead to a new theory of quantum gravity.



http://en.wikipedia.org/wiki/Gabriele_Ve…



Leonard Susskind:



Susskind was one of at least three physicists who independently discovered during or around 1970 that the Veneziano dual resonance model of strong interactions could be described by a quantum mechanical model of strings,[14] and was the first to propose the idea of the string theory landscape



http://en.wikipedia.org/wiki/Leonard_Sus…



Is String Theory (M Theory aka Super Strings) true? We don't know because, so far, we have no way to test it. But, the math does sort of work.



Depends on which physicists you talk to. You get 2 answers.



"It is too elegant not to be true."



"If you cannot prove it, then no one should believe it."



The split is roughly 50 - 50.



Strings are attractive because of the depth and richness of the supporting math and that math is internally consistent. You can start from different spots and work to the same answer (Sort of like solving a motion problem in Newtonian Physics by using Energy, Momentum-Impulse, or Newton's Equations of Motion. It does not matter which you use, you get the same answer.)



A complaint against Strings is it produces strange results, which we do not understand. This may or may not be a fatal flaw. It is sort of like the equations of Electrodynamics involve square root of -1 which we know does not exist. So, is there a fatal flaw in Electrodynamics or do we just shrug our shoulders and solve for square root of -1. Electrodynamics got out of this problem by introducing a second dimension. Strings also has a CYA. Two actually. 1) Like the rest of Quantum Mechanics maybe some of the strange results apply only at the quantum level. 2) Strings is a multi-universe theory ==> Strings are more robust than we thought and the same equations apply to all universes. ===> The strange results apply not to this universe (and can be disregarded) but to others. Our problem is to figure out which results apply to our universe



http://www.ted.com/talks/brian_greene_on…

When physicists assume all the elementary particles are actually one-dimensional loops, or "strings," each of which vibrates at a different frequency, physics gets much easier. String theory allows physicists to reconcile the laws governing particles, called quantum mechanics, with the laws governing space-time, called general relativity, and to unify the four fundamental forces of nature into a single framework. But the problem is, string theory can only work in a universe with 10 or 11 dimensions: three large spatial ones, six or seven compacted spatial ones, and a time dimension. The compacted spatial dimensions — as well as the vibrating strings themselves — are about a billionth of a trillionth of the size of an atomic nucleus. There's no conceivable way to detect anything that small, and so there's no known way to experimentally validate or invalidate string theory.

Answer 2

It's very difficult to prove that any theory is true. Even the two pillars of modern physics - quantum mechanics/quantum field theory and General Relativity - are suspect under extreme conditions. However, you can pretty much tank a theory if you can disprove the underpinnings of the theory. String theory has two underpinnings that are potentially disprovable by experiment - supersymmetry and multiple extra dimensions.



Supersymmetry is pretty much required by string theory and if it doesn't exist, string theory will be in deep doo doo. One of the major goals of the LHC is to detect one of the partner particles predicted by supersymmetry. The fact that it hasn't already found partner particles is a big issue. Supersymmetry is clearly a broken symmetry so it is expected that the partner particles will be massive and hard to create. However, the more massive the particle, the less useful it is to string theory. At some point, if partner particles are not detected by the LHC, it will be a nail in string theories coffin. Not conclusive since you can claim that the LHC,doesn't have the energy, but damning none the less.



The multiple extra dimensions of string theory is potentially testable - although the LHC will not have enough energy to do,so - under a caveat. That caveat is that the gravitons predicted by string theory behave as theorized by M-theory. M-theory says that gravitons are closed strings and can be 'diluted' by their ability to travel through the extra dimensions predicted by string theory. The basis for that idea is that the 1/r^2 law for gravity is an artifact of the fact that space has three dimensions. If it has more than three dimensions, it will be dependent on higher powers of r. What this means is that at very short distances, the strength of gravity will be much higher than predicted by the 1/r^2 law which would allow micro black holes to form at much lower energies. These micro black holes would be still out of reach by the LHC, but could be within the range of more advanced colliders.



The bottom line to all of this is that while string theory cannot be proven, one shouldn't take the difficulty of proving it as a necessary negative. String theory purports to be a theory of everything, discernible from quantum mechanics and relativity only under extreme conditions that simply may not be accessible by our current technology. It took 50 years to detect the theorized Higgs boson, but we finally found it when our technology caught up with theory.

Answer 3

I think that string theory is partly right and partly wrong.



Madam Curie weighed a bottle of Radium, then let it radiate, then weighed it again, concluding that the loss of energy resulted in a loss of mass. Einstein showed that this loss was E = mc^2. Thus, mass could be converted to energy and energy converted to mass. Thus proving that mass and energy are made of the same thing (for example, an electron is made of photon(s).



An electron passing through a single slit behaves like a particle. An electron passing through a double slit passes through just one slit (as proven by a phosphorous screen), but it's field passes through the other slit, causing an interference pattern (areas of positive and negative interference, making regions of high and low probability to find the electron).



Noting this, Schoedinger proposed that particles could be described by a wave function that has both real and imaginary components.



In electronics, capacitors and inductors create imaginary numbers in Kirchoff's Current Law. That is, current obeys Kirchoff's Current Law, but reactive components, such as capacitors and inductors, create a delay. That delay is shown as a phase angle. That phase angle is the tan^-1 (imaginary/real).



Similarly, there is a phase angle in Quantum Mechanics, that apparently is due to a delay in energy entering vs. leaving an electron. That delay could be explained by a coupling of one orbit of a photon with the 2nd orbit of the same electron (and other orbits of the same electron).



String theory seems to neglect imaginary components and coupled systems, though it does show oscillatory behavior.



Several types of string theory were developed (in 10 dimensional space), and all seemed correct. One said that strings were loops, the other said that they were short segments of string that bounced energy from one end of the string to the other. The three types were merged into M-theory's 11 dimensional space (to accommodate everyone's ideas). I think that none of those three types is correct in an electron.



Quantum Mechanics shows that fields interfere, producing nodes and anti-nodes. Those are regions where electrons have higher and lower probabilities of existing.



When angular momentum and spin are taken into account for two or more particles, those regions of probability no longer form circular orbitals around a nucleus (as they do with a single electron), rather, they form lobes of probability around the nucleus, with interference patterns with nodes and antinodes of probabilily of finding the electron.



String theory doesn't take these facts into account.



Several of the dimensions of string theory apparently correspond to Maxwell's Equations. So, some of the dimensions are accounted for by known scientific theories.

Answer 4

It's physics on crack quantum mechanics is the most logical stuff