Researchers made an exciting discovery they called “breathtaking” and gives added meaning to the phrase “spark of life.” Researchers watched through a microscope the moment of fertilization, when the sperm connects with the egg—the beginning of human life. What surprised them was a burst of light from each human egg as it transformed into a human embryo. What caused it? They believe fertilization generates a surge of calcium which triggers the release of zinc from the egg. When the zinc is expelled, it connects to molecules and emits a fluorescent light. They’d seen this in mice but never in humans. Instead of thanking God for this visual sign of precious life, they plan to use it to identify healthy embryos who they think give off more light and discard the others.