Haelfix said:
Look, you keep harping on these trivialities, but understand its the same thing that quantum gravity people have been listening to for 30 years. In fact not so long ago, (say before Penzias and Wilson) the same criticisms were applied to classical cosmology.
I understand that you consider falsifiability to be a triviality. That's one perspective. I only ask that you consider that many smart people don't share this view. That doesn't make them enemies of string theory.
Haelfix said:
Unfortunately it is also ridiculously unhelpful, b/c like it or not, gravity exists, quantum mechanics exists ergo there is a system by which the two must join in some way and it is a scientists job to figure it out.
It may not be helpful but it is not the job of scientific principles to be helpful. They are there to serve as measuring sticks by which we can compare different ideas. All else being equal, a falsifiable theory that passes tests and one that predicts new phenomena which are then experimentally confirmed is far preferable to one that cannot be falsified or tested. The preference for falsifiability and for ideas with some experimental evidence may be a simple point, but it is not a triviality. I don't see how any scientist could argue this.
Haelfix said:
It is possible that QG or String theory will be a purely theoretical undertaking, with no experimental support in our lifetimes or ever. It is up to you if you think that's worthless and akin to philosophy.
This is a straw-man argument. I never said that QG or string theory was worthless and akin to philosophy.
Haelfix said:
Personally, I think the math does matter and that it will lead us eventually to the right answer, one way or the other..
This is a straw-man argument too. I never said that math doesn't matter either.
Haelfix said:
Ultimately the fact of the matter is that there are certain things that we often simply 'know' exist, without experimental support. In the 60s and 70s, theorists working on the standard model more or less knew certain particles existed before they were discovered (hence a ton of Nobel prizes that ensued from that golden age).
The way this seems to work is that many physicists predict lots of different phenomena and some of them are right. The ones that are win Nobel prizes and the ones that aren't don't and are forgotten by history.
After all, in the 19th century physicists had been predicting an aether because they just "knew" it had to exist. Then through experiment, it was eventually proven that the idea they had was wrong. Subsequently, it has been shown that they were partially correct, but not in the way that they thought. The empty vacuum is not empty but is filled with fields and warped by the presence of mass and energy, and has other traits.
I believe that most of what physicists "know" today but don't have proof for might end up like like this. Many of these ideas will turn out to be partially true and partially false when we eventually come up with a more complete theory.
Haelfix said:
Today, I can safely say that the Higgs Boson (or more precisely something responsible for ElectroWeak symmetry breaking) exists and will be discovered at the LHC. I say that with enormous 'god' or 'religous' like confidence, b/c I believe in the theoretical and mathematical structure of quantum mechanics.
Here we have a philosophical difference. I don't hold any ideas with that level of confidence unless I have seen the proof myself and understand it. I'm not saying your position is irrational. I think that it is good for science, in general, for there to be a mixture of different perspectives.
What I find puzzling is the seeming intolerance on the part of the "true believers" of string theory for the idea that others hold different opinions and have different standards for their beliefs. Luboš Motl typifies this attitude. I also find puzzling the lack of respect for the position that is possible to hold an idea in high regard while still being open to the idea that it might be flawed or incomplete in some fundamental way.
I have not found that same level of intolerance for dissent or doubt among the proponents of alternative QG ideas in my personal experience.