String predicted gravity
Could you be much
much more specific about what you mean by this?
I mean sure, in a trivial sense, string theory "predicts" gravity. So do relativity, LQG, gravitons, and the old jesus-holds-the-universe-together chestnut.
But don't we usually mean something more when we talk about prediction in theories? For example, when we say General Relativity predicts black holes, we mean that first there was an analysis of the Einstein math that indicated that extremely compact masses result in singularities with specific qualities. Then, some time afterward, we found evidence in the universe that there were in fact such objects and that they did have those qualities.
Fairly often in this argument we even hear shorthand like "Inflation predicts the CMB." Really, of course, what we mean is something like, Inflation predicts continued evidence of homogenity amongst areas of the universe so distant as to be causally unrelated; and that the CMB was discovered, afterward, to provide this continued evidence.
Whereas gravity alone, isn't a thing that is discovered or proven after any of the string theories. We already have gravity, what string theory and M-theory in particular might better be said to do, is to
explain gravity without the various problems like non-renormalizability at very high energy levels, for example.
The reason I'm stressing this is because I recognize the language Izanagi is using and it reflects a real criticism of M-theory and its various predecessors / components. Here it is in a form that is either true, or else ought to be corrected:
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 - Wikipedia
This is a lot more generous than the actual statements of the detractors, in my experience. The general idea being propagated appears to be that, even if string theory were true, we would never know for sure.
Loop Quantum Gravity, by contrast, appears to predict variance of C under certain circumstances. This is something we can produce tests to check for, so it can either be supported or falsified, yes?
Loop quantum gravity - Wikipedia
What, if anything, could falsify string theory?
Edited by Iblis, : mild ststutter
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