The ultimate, FREE Physics club for expert Physicists, aspirant Physicists and Physics admirers!
 
HomeFAQRegisterSearchLog inLIGHTWEEKContact the ownerLink Banck to co.nr

Share | 
 

 What is string theory?

View previous topic View next topic Go down 
AuthorMessage
The Administrator
TOPC administerator
avatar

Posts : 47
Join date : 2009-07-23

PostSubject: What is string theory?   Thu Sep 03, 2009 9:09 am

String theory is a developing branch of theoretical physics that combines quantum mechanics and general relativity into a quantum theory of gravity. The strings of string theory are one-dimensional oscillating lines, but they are no longer considered fundamental to the theory, which can be formulated in points or surfaces too.

Since its birth as the dual resonance model which described the strongly interacting hadrons as strings, the term string theory has changed to include any of a group of related superstring theories which unite them. One shared property of all these theories is the holographic principle. String theory itself comes in many different formulations, each one with a different mathematical structure, and each best describing different physical circumstances. But the principles shared by these approaches, their mutual logical consistency, and the fact that some of them easily include the standard model of particle physics, has led many physicists to believe that the theory is the correct fundamental description of nature. In particular, string theory is the first candidate for the theory of everything (TOE), a way to describe the known fundamental forces (gravitational, electromagnetic, weak and strong interactions) and matter (quarks and leptons) in a mathematically complete system.

Many detractors criticize string theory as it has not provided quantitative experimental predictions. Like any other quantum theory of gravity, it is widely believed that testing the theory directly would require prohibitively expensive feats of engineering. Whether there are stringent indirect tests of the theory is unknown.

String theory is of interest to many physicists because it requires new mathematical and physical ideas to mesh together its very different mathematical formulations. One of the most inclusive of these is the 11-dimensional M-theory, which requires spacetime to have eleven dimensions, as opposed to the usual three spatial dimensions and the fourth dimension of time. The original string theories from the 1980s describe special cases of M-theory where the eleventh dimension is a very small circle or a line, and if these formulations are considered as fundamental, then string theory requires ten dimensions. But the theory also describes universes like ours, with four observable spacetime dimensions, as well as universes with up to 10 flat space dimensions, and also cases where the position in some of the dimensions is not described by a real number, but by a completely different type of mathematical quantity. So the notion of spacetime dimension is not fixed in string theory: it is best thought of as different in different circumstances.

String theories include objects more general than strings, called branes. The word brane, derived from "membrane", refers to a variety of interrelated objects, such as D-branes, black p-branes and Neveu-Schwarz 5-branes. These are extended objects that are charged sources for differential form generalizations of the vector potential electromagnetic field. These objects are related to one-another by a variety of dualities. Black hole-like black p-branes are identified with D-branes, which are endpoints for strings, and this identification is called Gauge-gravity duality. Research on this equivalence has led to new insights on quantum chromodynamics, the fundamental theory of the strong nuclear force.

_________________
- V.H.Belvadi,
Owner,
The Online Physics Club.
Back to top Go down
http://theonlinephysicsclub.clubdiscussion.net
einsteinstwin

avatar

Posts : 16
Join date : 2014-01-26

PostSubject: Re: What is string theory?   Thu Jan 30, 2014 5:59 pm

VERY WELL WRITTEN, FOR I THOUGHT I WOULD HAVE SOMETHING TO ADD BUT U COVERED EVERY GENERAL BASIS. I MEAN U NAILED IT ALL THE WAY DOWN TO BRAINS AND BRAIN-WORLDS. I COULDN'T HAVE SAID IT BETTER MYSELF LAD, MY HATS OFF!

I WOULD LIKE TO EXTEND THIS TOPIC TO THOSE PHYSICIST THAT WERE WORKING ON STRING THEORY THAT ULTIMATELY OPTED FOR A COMPLETELY NEW IDEA AS FAR AS A UNIFIED THEORY IS CONCERNED. THOSE PHYSICISTS BEING THE EINSTEIN PROFESSOR AT YALE AND ANOTHER BEING A THEORETICAL PHYSICIST AT THE MAX PLANCK INSTITUTE.

SHALL I CONTINUE....
Back to top Go down
 
What is string theory?
View previous topic View next topic Back to top 
Page 1 of 1
 Similar topics
-
» String of pearls (a.k.a. ridge dissociation)
» A wee bit of 5-string banjo Rock & Roll
» 2011: John Manning revised his '2D:4D finger length' theory!
» The Most Logical Rapture theory
» The hand of Cheiro - most famous palmist of all times! (+ his short life line theory)

Permissions in this forum:You cannot reply to topics in this forum
The Online Physics Club :: PHYSICS :: String theory-
Jump to:  
Forumotion.com | © phpBB | Free forum support | Contact | Report an abuse | Free forum