This result could change physics forever

I think there is a major aspect missing in this video. Even if the measurement is not a fluctuation, even if our theories are right, this measurement does *not* necessarily mean we are seeing signs of undiscovered forces or particles. Making the g-2 theoretical prediction is a very very complicated procedure. There is a lot of room for there to be mistakes or unrecognized imprecisions in the process. So the number we compare the experimental result to is about as likely to be the source of the discrepancy as the measurement itself is. It's certainly an intriguing outcome, and either way we will probably make progress - either by discovering something new, or by improving our ability to make precise predictions based on our theories. But I wouldn't place my bets on this being an actual sign of new physics just yet. Also, there is a good reason why we apply a 5 sigma threshold. Statements like "there is only a 1 in 40,000 chance this is a statistical fluctuation" sound like it is almost certainly not. But you need to take into account that we make many many measurements of various quantities. And if we measure many thousands of parameters, then a couple of them are bound to fluctuate as far out as this one. It's perfectly normal. Of course only the large fluctations get discussed in public, but you won't be surprised to hear that we have thousands of measurements that are *not* deviating from the Standard Model this much.