Some interviews that readers of this blog may find of interest:

- David Zierler at the AIP interviews Lee Smolin (April 1, 2021).
- David Zierler at the AIP interviews Stephon Alexander (June 7, 2021).
- Alexis Papazoglou at IAI News interviews me (hot off the press).

I think you missed this interview of Andrew Strominger?

https://youtu.be/y3cw_9ELpQw

In other news: https://www.quantamagazine.org/physicists-use-quantum-mechanics-to-pull-energy-out-of-nothing-20230222/

Dilawar Singh,

Hard to get excited about teleportation in quantum devices unless it’s through a wormhole…

In his interview Smolin says:

“These very rough models [of quantum gravity] predict noise at the square root of the Planck frequency. Interestingly enough, that’s where LIGO has some sensitivity to noise.”

“So, there’s a story about this. The GEO down in Hannover, I don’t know if it was ever actually published, but there were talks where they showed graphs of this noise, and Giovanni got very excited about it, and I got very interested in it. Again, since they didn’t publish, we didn’t publish. Now, the LIGO people seem to be saying that there’s some inexplicable noise in the detector. Again, I’m told this second hand. I don’t think they’ve published.”

Does anyone here know anything about “inexplicable noise” in the gravitational wave detectors LIGO or GEO600?

@JB WP has some info on it: GEO600: Claims on holographic properties of spacetime.

I learned a lot of things from Lee’s wonderful interview, things he never included in his previous books, which are very important for the younger generation. I wish he would one day publish personal memoires in which he would elaborate more on his academic journey and those personal matters. One thing in particular is the contrast between the two portraits of Witten, the one found in his interview and the one found in your book Peter.

Thanks, Martin S! With an apparatus so exquisitely delicate as LIGO or GEO600, the battle against noise is an endless one, and I imagine at any particular stage of this battle there will be “inexplicable noise” – or more accurately,

not yet explainednoise. So I would be very reluctant to jump to the conclusion that this not yet explained noise is due to innate properties of spacetime. But I was very curious to hear what rumors Smolin was alluding to.Even assuming that the noise was in fact there, and would in fact be due to some aspect of Planck scale physics, I am skeptical how much you can learn from it about any specific model.

All models I know of that attempt to make some predictions for effects like noise or decoherence are at some point putting the Planck scale in by hand – e.g. setting some arbitrary length scale in the model to be equal to the Planck length. Hence, I don’t find it very astonishing if one gets results of order 1 in Planck units as phenomenological predictions. It’s what I would expect from most models of quantum theory + gravity.

Prof Woit, I was impressed by your interview. I’m not a professional scientist (just an MSc opto-quantum physics), but I was always intrigued by the Twistor theory of Penrose. Ironically, I first heard about it, if I remember, in a String Theory book. That same book made me a big string theory enthusiast, until I eventually realised it was a dead end. I only realised that after I bought “Not Even Wrong”. (Later I read “the trouble with physics”, a great book. But your book was more to the point, to me.)

I agree that String Theory has been a boon to mathematics. But for physics, ST has set physics back 20 or 30 years, I think. Perhaps I forgive string theory, a little, due to the incredible group-theory Moonshine mathematics. >smile< I'm a fan of group theory, of John Conway RIP, Richard Borsherds, and co.