Tuesday, May 7, 2019

How string theory changed Physics

Lubos Motl still defends string theory:
To make it brief, string theory has been rather essential to realize – and make explicit – all the ideas that we call the holography of quantum gravity.

There's no qualitative difference between elementary particles and black hole microstates

Black holes look like qualitatively different, large "beasts" that differ from the elementary particles. But string/M-theory has shown us that the black hole microstates – there are many microstates because the black hole entropy is large for a large black hole – are nothing else than the "very massive" counterparts of elementary particle species.

The qualitative difference between an electron and a black hole could have looked – and arguably did look to most people – "obvious" but we already know it's wrong. ...

The idea that physicists will "return" to an epoch in which string theory and its lessons may be ignored is as childish as the idea of a "return" to the Flat Earth. Science just doesn't work like that.
Wow, thanks to string theory we now know the difference between an electron and a black hole, and this knowledge cannot be unlearned. Because ... that's how science works!

I thought that science worked by testing hypotheses. The ancient Greeks disproved the Flat Earth hypothesis by watching ship go over the horizon, by watching lunar eclipses, and by measuring how the Sun was higher in the sky at lower latitudes.

Lubos is so ridiculous here that I wonder if he is just trolling us.

A century ago, the Bohr atom made some analogies between electron and larger objects. But the model made some testable quantitative predictions, and some of those were confirmed.

Analogizing an electron with a black hole has gone nowhere. Neither has quantum gravity holography or any of the other string theory nonsense.


  1. Dear Roger,

    Honestly, once again, I didn't know how to think about it, though I did have some vague feelings about it. But you bring those points under the lens of clarity, once again!

    Thanks, and best!

    PS: I do think LuMo got a bit carried away by the suggested analogy between the two singularities---that of the electron and of the black-hole---as suggested by several hobbyists of physics. ... A bit of a fault, but nothing compared to how illuminating he has been, otherwise, on so many fora over such a long period of time...

    Anyway, time to call it a day...



  2. Super Strings are what you get when you wish to magically grant yourself degrees of freedom because your crappy particle theory is based on non-physical points carrying mass and anything else you can wave your hands vigorously about.

    There is nothing empirical whatsoever about Super Strings, they are not informed by measurement or observation, and in turn they do not inform anything observable or measurable...not surprising as they aren't science or even good metaphysics...

    but they DO keep certain people funded in grant money and allow many papers to be published in order for certain folks to keep score of their untestable non accomplishments and hopefully get cited in other useless papers.

    The world needs garbage collectors, electricians, engineers and plumbers as they are very useful, Superstring scientists not so much.