Hello HN,

42 years ago today, lieutenant colonel Stanislav Petrov chose not to launch missiles against the United States while on duty in the Serpukhov-15 missile bunker after receiving what he correctly judged to be a false alarm in a early warning system.

This hasn't been formalized into a holiday so you'll find different advice online about how to celebrate, but I intend to raise a toast to Petrov and to watch the movie WarGames released the same year.

What a real hero! Is it known why he suspected it wasn’t real?

Edit: I see it here.

>In explaining the factors leading to his decision, Petrov cited his belief and training that any U.S. first strike would be massive, so five missiles seemed an illogical start.[11] In addition, the launch detection system was new and in his view not yet wholly trustworthy, while ground radar had failed to pick up corroborative evidence even after several minutes of the false alarm.

Is there a technical write up of the false positive? I've long known about Petrov and his intuition, but eventually the error was confirmed and I haven't been able to find much detail as to the "how". Presumably the satellite system that failed had a lab twin, and the failure was reproduced there?

The reality is more complicated. I put a comment a couple of days ago: https://news.ycombinator.com/item?id=45367307

Many of us had the opportunity, at least in principle, to travel to his abode and personally thank him and bear a gift or two. I for one regret that I did not.

It is not a secret that the United States passed to the Soviets technology for PAL (permissive activation links). (Purportedly in Vienna.)

One might hope that the US has also passed the USSR/Russia technology that would make Perimeter more robust and logically airtight.