Spark of Life

An explosion of tiny sparks erupts from the egg at the exact moment of conception.

Scientists had seen the phenomenon occur in other animals but it is the first time is has been also shown to happen in humans.

The bright flash occurs because when sperm enters an egg it leads to a surge of calcium which triggers the release of zinc from the egg. As the zinc shoots out, it binds to small molecules which emit a fluorescence which can be picked up by camera microscopes.