There's only one group of people who really know what happens when you die: the dead. And since the dead won't be revealing their secrets anytime soon, it's up to scientists to explain what happens when a person dies.
Death, just like life, is a process, scientists say. The first stage of this process is known as clinical death. It lasts from four to six minutes, beginning when a person stops breathing and the heart stops pumping blood. During this time, there may be enough oxygen in the brain that no permanent brain damage occurs. Other organs, such as the kidneys and eyes, also remain alive throughout clinical death.