One of the best tricks of making a horror movie is not to show too much, allowing the imagination to create the monster. We can’t see molecules, which is what makes them scary. We fill this vacuum with fairy stories about what molecules are. We stereotype them as toxic, or dangerous.
To say chemicals are toxic is rather like saying people are bad. Some are. Most aren’t. It depends. Most molecules you meet are not dangerous, which helps explain why you’re alive.
My students and I work with molecules every day: we study what they do, and how to make them. None of us has ever seen a molecule with our naked eyes, but we know they’re there, and what they look like. Understanding molecules is like learning a language: it takes time, but eventually you come to see the beauty.
Just as a language can be used to create things that are beautiful, or ugly, inspiring or harmful, so atoms can be arranged to form molecules that are tasty or toxic, fragrant or explosive.
“Molecule” is another word for “chemical”. Typically we talk about a molecule as a single thing, and a chemical as a collective – rather like a person is part of a population. The whole world consists of molecules – we are immersed in them. But never is our relationship as intimate as when we eat them.