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How do fireflies glow?

For a long time their was no satisfactory explanation to why fireflies glow. A new model from quantum mechanics could solve this problem – and casually save us from loads of labwork.

The warm season is slowly ceasing and thus we also have to bid farewell to the fireflies. When they swirl around and glow on a lukewarm summer evening, everybody is fascinated.

Meanwhile it is more or less clear, why they show this behaviour – and as with a lot of strange phenomena it has to do with reproduction. The fireflies want to attract potential partners. But how exactly they glow has not been answered by physics and chemistry yet. But now a new method could bring light into this darkness.

Within the firefly moving electrons cause the lightwaves to be emitted. But thereby a so called “quantum mechanical many-body problem” is encountered. The cause is that the particles are not independent from each other in their arrangement.  If one particle changes its position, all other particles adjust accordingly. It is very difficult to calculate these processes, physicists usually approximate them by averaging. Usually the electrons are then described as being too close to each other – and thus the movement of one electron does not depend on the movement of another electron in the correct way.

Loren Greenman and David Maziotti have not come up with a new model to describe the electrons’ movement. Since it is more exact than older models it could soon provide a tool for solving chemical problems with the computer instead with expensive and laborious experiments in the lab.

Fireflies and quantum mechanics – what does the behaviour of electrons have to do with a light phenomenon on summer evenings? This is detekor.fm‘s Question of the Month. Detektor.fm posed this question to Leonie Mueck, editor of the Journal of Unsolved Questions.

Listen to the podcast here.