Scars, acne and others: circles on the ground

Looking is never just looking. When we gaze at something, we are not passive recipients of an image, instead our brain is constantly looking for patterns. If you are drifting over the earth, whether as an astronaut or via Google Maps then a simple shape such as a circle will ‘jump out’ at you. It turns out… Continue reading Scars, acne and others: circles on the ground

Radioactivity and the earth (and moon?)

We tend to think of radioactivity as an artificial thing; some argue that the first nuclear explosions in 1945 should mark the start of a new human-dominated geological epoch called the Anthropocene. These man-made explosions have left distinctive radioactive traces that may well outlive us all.  It turns out that natural radioactivity, even fission reactions,… Continue reading Radioactivity and the earth (and moon?)