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rogerl
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True Background-Independent String Theory/Particle Physics
Lee Smolin mentions in Trouble with Physics:
"... it is not enough to have a theory with gravitons made from strings wiggling in space. We need a theory about what makes up space, a background-independent theory. As described earlier, the success of general relativity demonstrates that the geometry of space is not fixed. It is dynamical and it evolves in time. This is a basic discovery that cannot be reversed, so any further theory must incorporate it. String theory does not, so if string theory is valid, there must lie behind it a more fundamental theory - one that is background independent. In other words, whether string theory is valid or not, we still have to discover a background-independent theory of quantum gravity"
Questions:
1. Is it really a requirement that any quantum gravity must be background independent (context of this meaning space and time must arise from it, and not serve as a backdrop for the actions of strings)? Or is it only Smolin bias that it has to be so?
2. If string theory really needs to be background independent, how come string theorists don't work toward that end? Maybe because it is not necessarily a requirement?
3. If it is really required for string theory to be background independent, what groups and how many percentage of string theorists are working on it?
4. Is Background Independence not only important in Quantum Gravity but in any particle interaction as well even if strings are not involved? Meaning the particles in QFT like the electrons and quark being thousand of times larger than the Planck scale needs also to be background independent? I think String theory treat electron as strings in Planck scale.. but what if they are not strings.. then electrons are much bigger in size than the Planck.. in this case... do we need them to be background independent too?
5. What would happen if our QFT were adjusted to become background independent. How current experimental results be affected or what new results can the theory predicts?
Lee Smolin mentions in Trouble with Physics:
"... it is not enough to have a theory with gravitons made from strings wiggling in space. We need a theory about what makes up space, a background-independent theory. As described earlier, the success of general relativity demonstrates that the geometry of space is not fixed. It is dynamical and it evolves in time. This is a basic discovery that cannot be reversed, so any further theory must incorporate it. String theory does not, so if string theory is valid, there must lie behind it a more fundamental theory - one that is background independent. In other words, whether string theory is valid or not, we still have to discover a background-independent theory of quantum gravity"
Questions:
1. Is it really a requirement that any quantum gravity must be background independent (context of this meaning space and time must arise from it, and not serve as a backdrop for the actions of strings)? Or is it only Smolin bias that it has to be so?
2. If string theory really needs to be background independent, how come string theorists don't work toward that end? Maybe because it is not necessarily a requirement?
3. If it is really required for string theory to be background independent, what groups and how many percentage of string theorists are working on it?
4. Is Background Independence not only important in Quantum Gravity but in any particle interaction as well even if strings are not involved? Meaning the particles in QFT like the electrons and quark being thousand of times larger than the Planck scale needs also to be background independent? I think String theory treat electron as strings in Planck scale.. but what if they are not strings.. then electrons are much bigger in size than the Planck.. in this case... do we need them to be background independent too?
5. What would happen if our QFT were adjusted to become background independent. How current experimental results be affected or what new results can the theory predicts?
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