Leonard Susskind on String Theory

rgroom1says...

while this is scientific, it doesn't have much to do with space, other than the fact that space contains atoms, which may or may not (OR BOTH!) be made of strings.
if i were you, i'd take it out of "spacy"

9907says...

I absolutely love listening to the great modern minds of theoretical physics talk about there fields of study. We live in such an amazing time in the history of our planet, especially in regards to physics. Science in it's own right has been like a religion for so very long(there still are a good number that fall into this category) in that scientists would defend they're given theories much like an religious zealot might. But since string theory & now m-theory have become the prominent candidates for a theory of everything and the implications of higher dimensions, non locality, uncertainty principle, and the possibility of consciousness playing a role in wave collapse are driving the more open minded people in science to consider new ideas and change the landscape, to bring entirely new possibilities into the fold that have never been openly/seriously discussed before.
This new way of thinking is what hopefully 30-100yrs. down the road will change us as a civilization, instead of looking at ourselves as individuals we will begin to see how truly connected we are to everything and everyone, instead of this horrible state we are in now.

Sorry for ranking :-D, I could go on all day about this type of stuff.

13886says...

Oh my fucksticks. Um sweetiepie? That is the single most gobsmackingly scientifically moronic / clueless comment that I have ever borne witness to anywhere on the entire world wide interwebs.....Ever. It is PAINFULLY obvious that you haven't the slightest clue as to how scientific inquiry actually functions and your sciency buzzword bingo game betrays such an incredible depth of fuzzyheaded woo that it made my eyes water. Deepak Chopra is that YOUUU??! lol. Seriously someone get this man 50cc's of Carl Sagan, STAT!

gwiz665says...

Well, science is very much not like a religion, but from a personal level, a scientist can easily become attached to his or her own theory, which means they will defend it against all evidence, which is much like religion. The scientific method acts much like anti-religion, but a scientist can act against the scientific method. It's like defending your own child - you KNOW it's not ugly, stupid etc.

The distinction is important.

highdileehosays...

I got to say, Astrophysicists are the creationist of the scientific community. Almost every single modern theory regarding this subject is completly untestable. And in every other scientific discipline you cannot even create a hypothesis unless it is 'testable' let alone assert it as being a theory. Try publishing an ecological journal without signifigant testable data to back you up; It would be your last. You certainly wouldn't be visited by nerds, sipping wine at a vineyard talking about your insane ramblings. A theory based on what? the fact that another scientist cannot test it to be false simply because it is physiclly impossible? That logic is exactly aligned with religions 'faith' based principles that we all love to bash so freely. I think We can only say that certain sub-atomic and atomic particles react a peticular way. But making wild assertins as to how, why, and how we can manipulate those wild assertions is where we all went astray. I blame Einsteen, He duped the entire world, and became an icon to astrophysicists. So now they all follow his very arrogant and presumptious methodology. Being right 2 or 3 times when you were wrong hundreds is a terrible ratio for any scientist...well except for...you know fake scientists like these guys. ohhh snap, ecologists talking trash...what Son! We run this bitch!

botelhosays...

Well , it appears to me that string theory is a interesting attempt to "quantize" the space-time manifold (added with suitable supersymmetric structures ).Everything in higher dimensions become reduced to two-dimensional quantum field path integral models "living"on the string chart manifold (the intrinsic two-dimensional "string space-time").However , people impose dipheomorffism invariance on this intrinsic string parameter "space-time" which unfortunatelly get mixed with 2D conformal invariance , when one uses the sigma model Polyakov' action to assign "energy" for these "quantum -fluctuating extrinsic /observable higher dimension space-time process (quite different from the more geometrical Nambu-Goto string action ).In order to solve this problem one thus impose full sigma model conformal invariance by restricting that all strings Schwinger sources (the string higher dimensional field back grounds-including the own extrinsic space time manifold dimension!)to lead to a vanishing beta function for the sigma model Polyakov action at any perturbative order of the new universal coupling constant-the String length scale/Regge parameter.This produces an apparently well defined (?,and about the infrared 2D cut-off remotion on the perturbative Feynman calculationson the intrinsic string space-time ?) 2D Field theory for the extrinsic space-time quantum energy action, besides of fixing the string Schwinger sources to satisfy the usual Einstein-Maxwell-etc field equations at one loop and the extrinsic space-time dimension and the classical manifold topology of the extrinsic space-time to be fixed, when one has supersymmetry (Spin manifold space time structures,etc..).At this point , one has an apparently well defined quantum -mechanical framework to evaluate numerically scattering amplitudes (including quantum gravity!-the old dream ) to compare with the experimental results.That is the problem on this new quantum-mechanical framework : as far as I know nothing has been matched with the usual qed,qcd,etc results!(anomalous particle magnetic momentum, deduction of the asymptotic freedom in QCD ,The Higgs mechanism on the weak sector ,etc.

botelhosays...

Let us put in a correct perspective quantum string theory for TOE. Firstly it is important to remark that a full understanding of what is really Quantum Mechanics is far to be completely understood in its foundational aspects ,althougth its huge operational-quantitative success.For instance, even in the usual non relativistic quantum mechanics , certainly the notion of electronic orbitals in N-electron atomic physics appears to be a mathematical suitable approximation for the full N-electron atomic wave function.On the other hand in Quantum Field Theory , this ad-hoc choice of what is free and what is interaction is not so "ad-hoc", at least in the QFT (perturbative) scattering sector: free in and out fields are primary objects producing physically observables free N-particles (lorentz invariant!) wave functions-so perturbation is building around them and carrying with the formalism all notions of renormalizations , dispersions relations etc.. .Now quantum strings : Strings are supossedly observable for us mainly through scattering among its excitations by means of an already fixed sigma-model two-dimensional quantum dynamics taking place in the somewhat ficticious purely two dimensional string parameter space-time, where are operating two scales of interaction : one is entirely ruled by the intrinsic string topological genera and other governed by the extrinsic space-time coupling constant , namely : The Regge Slope parameter. So string theory for TOE is a proposal for pure S-Matrix "Heisenbergnian" on-shell "theory" for all particles scattering in Nature (including gravitons). Now the theory's "granus salis" (points not completely grasped-at least for this reader !): Back ground fields are fixed extrinsic classical field configurations fully determined by the imposition of conformal invariance for any genera (which certainly does not affects the intrinsic 2d UV-theories'behavior,but affects its IR intrinsic behavior as a 2d QFT) and at any order in the Regge Slope coupling (all these conformal invariance phenomena quite specific to Polyakov's action proposal , possibly not for a Nambu-Goto string action reformulation of TOE).And at the same time , they are expected to be Schwinger sources (even quite non linear) for the string excitations and to be functionally differentiated in the string path-integral later .Another point is related to Kaluza-Klein Theories -It appears that quantum geometrical theories appear to be trivial QFT theories when used to describe scattering in space-time extrinsic manifolds of higher dimensionality (lambda four scalar QFT is expected to be trivial for D strictly greater than four!). As a conclusion : at most Strings are useful theoretical labs for a fully understanding of what really is Quantum Mechanics (SchrodingerX HeisenbergXEinsteinXNelson) , if there are no experimental tests for its predictions .By the way,space-time supersymmetry still remains solely as a theoretical lab in Particle Physics, nothing more!.

botelhosays...

Correction to the previous comment : extrinsic backgrounds fields certainly are not Schwinger sources for the string excitations in the space-time .No problem by imposing world sheet conformal sigma model invariance and thus evaluating strings scattering amplitudes in higher dimensional critical space-time

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