As a kid, we all heard the story about Sir Isaac Newton being inspired to come up with his theory of gravity after being brained by an apple. We're led to believe that had the apple not whacked him on the head, it might have been a lot longer before we ever discovered a theory of gravity. That story, as with so many things we learn as kids, turns out to most likely to have been bullshit. (Newton probably made it up, to claim primacy over others who'd come to similar conclusions.) With nearly every other discovery, there are often multiple individuals working along the same lines, so even if, for example, Newton had died before he'd worked out his theory of gravity, someone else would have published the same theory in the same time frame. I was listening to a podcast today on famous tumors, which talks about Henrietta Lacks, and her tumor, which not only aided in the development of a polio vaccine, but has led to something like 11,000 patents, and it got me to thinking. Here we have something which lead to tremendous scientific breakthroughs, and unlike the theory of gravity, evolution, or the lightbulb (to name but a few examples), there's no way that someone else could have come up with the same results. It took Mrs. Lacks' DNA, her exposure to different illnesses, and the random mutation that caused her fatal tumor, to give us the first human cells that could be kept alive indefinitely in the lab. With the knowledge gained from her cells, we were able to develop other human cell cultures that could be kept alive for long periods of time, but it took another 20 years to come up with the techniques. Who knows how long it might have taken us had she not developed cancer? I can't think of any other moment so unique in science, where a breakthrough came about from happenstance. Presumably, there must be others, but I don't know if any of them would have had the same kind of payoff (in terms of discoveries that hinged off the first one). Anybody else have any nominations for such singular moments?