Have you heard that a NASA particle detector experiment discovered a parallel universe where time runs backwards? It's all over social media, mostly with people making jokes questioning what else 2020 has in store for us, but it also seems to have piqued a lot of folks' interest. I've had many queries asking me if the story is true. Is it?
Quick answer: No.
Longer answer: No, it isn't.
More detailed answer: Well, this'll take a sec to explain. But the bottom line is this particle detector did find something really strange, but it's not clear what it is. Saying it "discovered" a parallel universe is simply not true. At best the data are consistent with this idea, but that's a long, long, looooooooong way from actually finding alternate realities.
The experiment at the heart of all this is the Antarctic Impulsive Transient Antenna, or ANITA. It's a University of Hawaii experiment funded in part by NASA and also by the DOE (so the claim that "NASA" found anything is a little misleading, though it makes for a fun clickbaity headline). What ANITA looks for is neutrinos.
A neutrino is a weird subatomic particle. It has almost no mass and ...