What issues we have in prove LQG experimentally? and It is eaiser to prove than string theory? If so , why There's a lot of string theorist than LQG?
Answers and Replies
My rudimentary understanding is that the basic issue is the same in that we need incredibly high energies for experiments to probe quantum gravitational effects, thus any theory of quantum gravity is going to run into this issue, be it string theory, LQG, etc...
This is not the be all and end all however, for example there is reason to believe that by observing evaporating black holes we may detect a certain type of radiation predicted by LQG, this experiment is only in it's very early and highly theoretical stages however.
In theory both extremely high energy experiments or possibly very large scale cosmological observations might help and it would be great fun if something truly new or unexpected are found but from a human resource perspective these extremal probings must have a practical limit and i personally think an intrigued theorist can be welll occupied for quite some time even without further data - just like some mathematicians are busy cleaning up where theoretical physicist left off.
So without more data what can we do?
1) Unify the known interactions and reduce the number of free parameters!
2) Find the right coherent reasoning that shall explain the logic of physical interactions. Information vs realism vs solipsism and all this "observerstuff".
Until i grasped these two points i see many alternative ways to spend My taxmoney. Theorist work trying to find patterns in data and theorist work trying to find patterns i the logical inference systems are quite different.
I think the latter is the task of todays theoretical physicists.