If you’re a Friend of the IAS ($1750/year and up), you were invited to a talk last night, at which IAS member Thomas Rudelius promised to explain to you How to Test String Theory. The video of the talk is now available here.
After a long introduction involving large amounts of misleading hype, Rudelius in the last couple minutes finally gets to the promised explanation of “How to Test String Theory”. What is it? It’s his discovery that some versions of axion cosmology are incompatible with the Weak Gravity Conjecture, and thus conjecturally incompatible with string theory.
I assume that the IAS Friends in attendance, besides being financially well off, are also not so dim-witted that they wouldn’t notice that they’d been had (there’s no evidence for axion cosmology, so conjectures about whether or not various axion cosmology models are consistent or not with string theory are completely irrelevant to “testing string theory”). Any questions asked after the talk didn’t make it to the video, so it’s unclear if anyone bothered to complain about what had just been done to them.
Update: For a sensible, informative video about string theory (as opposed to the IAS one), see this from Sabine Hossenfelder.