As a kid, I loved fireflies – or lightning bugs. On humid summer evenings, as twilight deepened to dark, they rose from the marshy field across the road, making mosquitoes which flew with them bearable. I swept up the slow-flying bugs with a net or even my hands and the poor beetles spent the night in a jar at my bedside. I always released them the next morning, and most survived a brief captivity.
Now science has figured out how the firefly manufactures that magical blinking glow.
I love Jason Bittel‘s concept of the firefly as a black box. You put in enzymes and proteins, oxygen, calcium, magnesium, and the wonderfully-named chemical luciferin. You get out photons – the cold, pale light of the firefly.
Previous hypotheses didn’t fully explain the chemistry, and now a scientist has shown the bug produces a special form of molecular oxygen that contains an extra electron. Electrons can release photons when they move from one atomic orbit (or quantum state) to another. Chemistry, after all, is physics made useful.
Firefly luciferin is already proving to be a useful tool in imaging human tumors and developing cancer-fighting drugs, says lead author [Bruce] Branchini.”
But I just think it’s cool to know the little beetle is a savvy chemist.