This document discusses scientific perspectives on death. It begins by defining death from medical, legal, religious and cultural viewpoints. It then outlines the biological processes that occur after clinical death, including pallor mortis, algor mortis, rigor mortis, livor mortis, autolysis, putrefaction and various stages of decomposition. The document also examines perspectives on brain death and persistent vegetative states. It discusses organ donation and possibilities for the future such as neural implants, stem cell therapy, and theories of achieving immortality through technologies like brain emulation.