It is 80 years since the first nuclear weapon test – codenamed Trinity – detonated above the desert in New Mexico. Today the hidden legacy of nuclear bomb tests can still be found in our cells – and is proving surprisingly useful to scientists.

It's in your teeth. Your eyes and your brain too. Scientists call it the "bomb spike" (or "bomb pulse") – and for more than half a century its signature has been present inside the human body.

On 16 July 1945, scientists of the Manhattan Project detonated the first nuclear weapon, known as the Trinity test, in New Mexico. The 18.6kt explosion lit up the sky and sent a blast of........

© BBC