According to this rather fascinating Guardian article, a group of scientists now think that the flipping of the Earth’s magnetic poles about 42,000 years ago may have caused, among other things, the extinction of the Neanderthals. “The Earth’s magnetic field acts as a protective shield against damaging cosmic radiation, but when the poles switch, as has occurred many times in the past, the protective shield weakens dramatically and leaves the planet exposed to high energy particles. One temporary flip of the poles, known as the Laschamps excursion, happened 42,000 years ago and lasted for about 1,000 years.” The effects of this flip were quite severe, and the only way humans survived was to shelter in caves. Rather worrying, though, is the fact that they are due to flip again sometime soon – ie, in the next few hundred years – causing catastrophic damage to our electricity network. When I read that, my first thought was that that really would be all we need right now.