It's a typical day for any scientist or engineer. You're doing some calculations while playing around with the fundamental forces of nature and... you suddenly realize that what you're doing could have fatal consequences. As in the potential death toll starts in the dozens, if not hundreds or thousands. Worst case, you find what you're doing could cause the apocalypse.
Movie fans who hung around after watching Barbie to also watch Oppenheimer as part of the "Barbenheimer" social media-inspired double feature craze recently become aware that's a thing the people that do this kind of work deal with on a daily basis. Admittedly, for many of these fans, seeing the main character of Oppenheimer getting all worked up over results of math that suggested a runaway nuclear reaction could end the world could be a real consequence of detonating an atomic bomb caused a real head rush.
So what's in the math that Robert Oppenheimer did that made him think the proverbial end of the world was something that had a non-zero chance of happening because of the work he was doing? Welch Labs explains the math Oppenheimer did in the following short video:
We now return you to the world that continued muddling through when the invention of the atomic bomb didn't cause it to end.