Quantum gravity from philosophy

From a new paper on Kant and Quantum Gravity:

In quantum gravity space and time lose their status as fundamental parts of the physical reality. However, according to Kant, space and time are the a priori conditions of our experience. Does Kantian characterization of these notions give constraints to quantum gravity, or does quantum gravity make Kantian characterization of space and time an invalid approach? This paper provides answers to these questions with a philosophical approach to quantum gravity.

You are probably going to say that this is self-evidently ridiculous, because physics is about the observable world, not the the prejudices of some silly German philosopher. Kant said a lot of stupid stuff about space and time before relativity, and there is no agreement over whether it can be reconciled with relativity.

But all quantum gravity is just philosophy. There is no data or experiment to guide the theory. Researchers are just looking for "a priori conditions of our experience", whatever that means.

Speaking of philosophy, Stanford philosophy professor Helen Longino said:

Sokal has this very sort of old-fashioned idea about science — that the sciences are not only aiming at discovering truths about the natural world but that their methods succeed in doing so.

Outside the hard sciences, I suspect that it is very common for academics to deny that science discovers truths.

Philosophers complain that they get no respect from the hard sciences. Of course they do not. Philosophers will never get respect as long as they deny the discovery of truths.

SciAm blogger John Horgan writes that the point of philosophy is not to discover truth or even to make progress:

What is philosophy? What is its purpose? Its point? The traditional answer is that philosophy seeks truth. But several prominent scientists, notably Stephen Hawking, have contended that philosophy has no point, because science, a far more competent truth-seeking method, has rendered it obsolete. ...

[David Chalmers] concedes that whereas scientists do converge on certain answers, “there has not been large collective convergence to the truth on the big questions of philosophy.” A survey of philosophers carried out by Chalmers and a colleague revealed divisions on big questions: What is the relationship between mind and body? How do we know about the external world? Does God exist? Do we have free will?

Philosophers’ attempts to answer such questions, Chalmers remarks, “typically lead not to agreement but to sophisticated disagreement.” That is, progress consists less in defending truth claims than in casting doubt on them. Chalmers calls this “negative progress.”

It appears that philosophers making negative progress are jealous of other fields that make positive progress.