5Louis Fieser

You’re going to find a common thread here, which is that most of these scientists weren’t pure murder-makers. A lot of the time, they are also credited with discoveries that have kept people alive, whether pursued out of guilt or just pure happenstance and curiosity. The chemist Louis Fieser has a couple helpful compounds under his belt, like blood-clotting agent vitamin K and cortisone, which is probably floating around your dad’s arthritic knees as we speak.

It’s something else that hangs over his head a little more unpleasantly, however. Fieser is also sometimes called “the father of napalm.” Most famously used in Vietnam, it was an answer to some psychopath’s complaint that when people caught on fire, they were too easy to put out. Napalm is fuel mixed with gelling agents, forming an incendiary substance that sticks to targets, whether architectural or human and screaming.

It’s a highly controversial weapon, in that most countries find it abhorrent and cruel, and the U.S. was still using it in Iraq in the aughts. Fieser isn’t full “I am become death” about it, though. He does say he was “outraged” to find it was being used on people, as he thought it was only going to be used on buildings. Which makes sense, if you think a Harvard chemist isn’t aware of what lives in buildings.

4Fritz Haber

Again, with German chemist Fritz Haber, let’s look at the good before we look at the very, very bad. Haber is credited with figuring out how to synthesize ammonia from hydrogen and nitrogen. This, combined with the work of Carl Bosch, led to the Haber-Bosch Process, which skyrocketed the world’s ability to produce crops through more effective, mass-produced fertilizers. It, in fact, landed him a Nobel Prize in chemistry in 1918.

Usually, if you put a dent in literal world hunger, you’d think you’d be one of history’s all-time good guys. One of his other projects, though, was the exact opposite. Haber also developed chemical weapons (yikes) for the Nazis (double yikes). Most notably, his research led to the development of Zyklon B, the gas infamously used to exterminate groups of Jews in Nazi concentration camp showers. This was despite the fact that Haber was Jewish himself. I think we can all agree: what a fucking putz.