The Min Min Mystery

By Dr Karl Kruszelnicki | August 9, 2018

An Australian neuroscientist has solved the mystery of Min Min lights.

Contributor

Dr Karl Kruszelnicki

Dr Karl is a prolific broadcaster, author and Julius Sumner Miller fellow in the School of Physics at the University of Sydney. His latest book, Karl the Universe and Everything is published by Pan MacMillan. Follow him on Twitter at @DoctorKarl

THE MYSTERIOUS Min Min lights appear after dark, of course. Weirdly, when you approach them, they always retreat. They were first noted near the now-abandoned western Queensland settlement of Min Min.

A typical Min Min light is circular, about one-quarter the size of the full Moon and has fuzzy, moving edges, like a buzzing bee swarm. Min Min lights are usually white, but can be green, yellow, red or rarely blue. The fuzzy orbs can dance around erratically left to right, up and down and back and forth. Occasionally, a single Min Min light can suddenly split into two separate lights.

Australian polymath and neuroscientist Professor John Pettigrew says he’s solved the mystery. Indeed, he was even able to create his own Min Min light.

He says they are real, but distant, lights – a fire, or bright headlights. Normally, you can’t see them, because they’re over the horizon, and too faint. But Professor Pettigrew has proved that a layer of cold air, sitting just above the ground, between the distant light and the observer, can trap light. This layer bends the light and keeps it close to the ground, so it can be seen over great distances. This layer of cold air can also concentrate the distant light and stop it from spreading – so it doesn’t get weakened by extreme distance.

John Pettigrew used geometry to show a Min Min light was actually very bright truck headlights – 300km away! Another time, he drove 10km away and shone his headlights at the campsite. His companions reported via radio seeing a bobbing light just above the horizon, half the size of the full Moon, changing from vivid red, to orange, yellow then green. As Pettigrew switched his headlights on and off, the Min Min light disappeared and returned.

So these floating orbs aren’t combusting marsh gas, swarming bioluminescent insects, or even aliens. But light trapped in cold air is spooky enough.