What is the current status on super strings?

  • Thread starter Thread starter modmans2ndcoming
  • Start date Start date
  • Tags Tags
    Current Strings
AI Thread Summary
The current status of superstring theory shows promise in addressing aspects of general relativity (GR), particularly with the calculation of Hawking-Beckenstein entropy for extremal black holes, which aligns with thermodynamic state counting. However, superstring theory has not yet achieved background independence, a critical criterion for theories aspiring to match GR. While it has made progress in describing gravitational phenomena, it still lacks experimental testability and a complete definition of its non-perturbative aspect, M-theory. Discussions suggest that GR may not adequately classify extremal black holes, potentially limiting its ability to identify certain quantum characteristics. Ongoing research continues to explore these intersections between quantum mechanics and gravitational theories.
modmans2ndcoming
Messages
150
Reaction score
0
how serious is this theory? has it been used to define GR or SR yet or even parts of it?

it is exciting, actualy, because as a student of Mathmatics with an interest in physics, I have come to think that a theory of the universe that allows for mathmatical solutions dealling with infinity are inherently flawed at those points.

just like Newton's theories were shown to be flawed when maxwell applied them to magnatism and found that they had results that were inconsistent with what was observable, we have seen that GR has the same limitations, where as QM is much more robust.

I am confident that when we can explain GR in terms of some form of Quantum effects that we will see that all those infinities are not really there, though the barriors those infinities present are most certainly in existence, they will probably be explainable through a more advanced version of the uncertainty principle.
 
Physics news on Phys.org
Superstrings has made baby steps in describing general relativity. They have a graviton which behaves much like Einstein's curvature tensor, but they haven't succeeded in making their theory background independent, which has gradually grown into a criterion for general relativity wannnabes that even the superstring community now acknowledges.

A big success was the superstring calculation of the Hawking-Beckenstein entropy of a black hole. They reproduced the numbers that Hawking and Beckenstein got (those two used a half-and-half "semiclassical" approach), and it's important to state that they did it with true and proper thermodynamic state counting. The only bad news is that this wonderful result is limited to a particular class of black holes, "extremal" black holes that have the most electric charge they can hold (or so I understand the distinction. If someone has a better definition, perhaps they will contribute it).

String physics still hasn't produced any results testable by experiment or astronomical observation. Nor has it succeeded in completely defining its non-perturbative part, M-theory. Work goes on.
 
Last edited:
here is a question then

are we able to make accurate idetifications of the type of black holes with GR?\

could Hawking's Black hole entropy have been calculated for just the type of black hole that SS has reproduced numbers for but that GR is just not accurate enough to identify that fact?
 
I don't believe GR has a class for "extremal" black holes. In GR black holes are characterized by their angular momentum, mass, and charge. I am not sure, but I think the classification as extremal may bring in quantum considerations.
 
Thread 'Motional EMF in Faraday disc, co-rotating magnet axial mean flux'
So here is the motional EMF formula. Now I understand the standard Faraday paradox that an axis symmetric field source (like a speaker motor ring magnet) has a magnetic field that is frame invariant under rotation around axis of symmetry. The field is static whether you rotate the magnet or not. So far so good. What puzzles me is this , there is a term average magnetic flux or "azimuthal mean" , this term describes the average magnetic field through the area swept by the rotating Faraday...
Back
Top