## Thursday, August 31, 2017

### Joe Polchinski's memories

While Joseph Polchinski was dealing with a brain injury – this phrase [which is probably a misspelled "surgery"] sounds much nicer than the ugly C-word – he found it an order of magnitude more difficult to work. Steve Shenker and Derek Westen have noticed that Joe's writing was crisp and excellent so he could do what a string theorist may always do even when he's temporarily reduced to 10% of his mental capacity – to become a writer.

Polchinski just published these
Memories of a Theoretical Physicist
I sincerely wish that with hindsight, the timing of these memories will be considered utterly non-essential!

If you start to read the memories, you will realize that you have already heard about the beginning. Joe Joe left his home in Tucson, Arizona, for some Californian grass.

His paternal ancestors came to the States around 1870 – from a land between Poland and Germany (the surname Polczynski is surely Polish, [it is a masculine adjective] meaning "originating from Połczyno near Gdańsk") and from Ireland. His mother ended up as a German American. Parents were unscientific (I know that background, too), Joey was keen on science already as a kid. How and Why books, Sputnik, Asimov, advanced algebra, recreational chess (I would probably never get above that level, either!), telescope.

Joe came to Caltech in the early 1970s and met three remarkable people, Richard Feynman, Kip Thorne, and Bill Zajc (yes, you know him from TRF). Bill has read Joe's memories and you can learn a lot about him from Joe's memories. Security, pranks, Feynman, Thorne. Serious physics learning in the sophomore year. QCD is being born at that time. Moving to Berkeley. Isidor Singer. Wife Dorothy. SLAC, Stanford, supersymmetry and its breaking, Susskind, D-terms.

Harvard, Mark Wise, Sidney Coleman, kids who run the circus, SUGRA, renormalization, monopoles, phenomenology. Austin, Weinberg, and the first superstring revolution explodes. In Summer 1988, Polchinski would "realize that he would never be a great scientist". As you can see, a big mistake! Fun with T-duality and the cosmological constant, Joe's students, from Austin to Santa Barbara. D-branes and orientifolds of the 1990s. Information loss, Strings 1995, D-branes.

Discretuum, anthropic stuff, plan to have no typos in his book. Joe kindly says that I sent him at least 200 errata, I believe that the number is just around 128. Proofs of finiteness of string theory. AdS/CFT. Matt Strassler and Raphael Bousso get special sections. 21st century, after the end of physics (1996). Centennial talks for founders of quantum mechanics. Cosmic strings may be out there. Interactions with Lee Smolin. Bubbles of nothing, firewalls.

The annoying "brane" cancer diagnosis in December 2015 – I knew about it with some vagueness and uncertainty. Please, Joe, never ever give up.

I think that those of you who are enthusiastic readers will love Joe's memories.

Related to firewalls: Rik van Breukelen and Kyriakos Papadodimas have released a new paper Quantum teleportation through time-shifted AdS wormholes. They construct double trace deformations optimized for thermofield states shifted by an arbitrary time translation, prove the smooth connection between two CFTs, and therefore the absence of firewalls in this setup.