3 ms·

Well, isn’t the UV catastrophe very similar in spirit to the renormalizability of quantum gravity? :-) They both correspond to UV behavior of the only massless

Well, isn’t the UV catastrophe very similar in spirit to the renormalizability of quantum gravity? :-) They both correspond to UV behavior of the only massless degrees of freedom possible. Due to electromagnetism being a free theory, we don’t need to worry about loops, and the particle nature provides the UV cutoff for on-shell/external photons. Gravity, being nonlinear, has loops with off-shell graduations which need to be handled consistently. Also, I would put IR problems on similar footing as UV (soft photon theorems, transformations at infinity, etc.) If we reason strictly by analogy (with the UV catastrophe being considered relevant to the observable word), quantum gravity has such a gaping loophole that it cannot explain how we can have simple empty space — the kind we see all over the place! Otherwise largely agree with your previous point about the lack of easily measurable effects pointing to the low likelihood of technological consequences. It’s an under-appreciated intuition! Oh, btw (as a fellow physicist) what did you work on? Inspire link? :-)

exmadscientist 7y ago
I mean, sure, you're absolutely right: the fundamentals are kind of a mess, especially with respect to quantum gravity. (But not cosmological gravity!) In many ways the Standard Model is a mixed blessing: it works really, really well... right up until it has nothing at all to offer. If it didn't work quite so well, things would be more interesting. It doesn't help that there aren't all that many experiments left to do (in the fundamentals realm). Either they're likely to be uninteresting, or they're currently beyond our reach. I think there are going to be many lean years ahead for fundamental particle physics. I used to work on neutrino experiments, but (as the username indicates), don't do that stuff any more. I could link my publication record, but all that's really there is a bunch of nitty-gritty detector characterization, plus a few blockbusters that my name got on because, well, I helped build the bloody detector :) Turns out that if you can build neutrino detectors that work, there are plenty of other things you can do with your life....

exmadscientist 7y ago

I mean, sure, you're absolutely right: the fundamentals are kind of a mess, especially with respect to quantum gravity. (But not cosmological gravity!) In many ways the Standard Model is a mixed blessing: it works really, really well... right up until it has nothing at all to offer. If it didn't work quite so well, things would be more interesting. It doesn't help that there aren't all that many experiments left to do (in the fundamentals realm). Either they're likely to be uninteresting, or they're currently beyond our reach. I think there are going to be many lean years ahead for fundamental particle physics. I used to work on neutrino experiments, but (as the username indicates), don't do that stuff any more. I could link my publication record, but all that's really there is a bunch of nitty-gritty detector characterization, plus a few blockbusters that my name got on because, well, I helped build the bloody detector :) Turns out that if you can build neutrino detectors that work, there are plenty of other things you can do with your life....