2. Exactly why we get old and die is still a puzzle. One hypothesis is that because most creatures are killed or die of disease before they can get old, evolution doesn't weed out the mutations which hurt us in old age.
3. "Death", the word, comes from the Old English deað (that symbol on the end is known as "eth" and is pronounced "th"). It is related to the German Tod, the Old Norse dauði, the Danish død, and the same concept in other Germanic languages.
4. "Mortality" and "mortal" come to English through Old French and stem from the Latin mors, meaning death.
5. Only about 93.5% of humans have died. (Of the 108 billion people estimated to have lived since the emergence of anatomically modern human beings, 7 billion are still alive.)
7. The Zoroastrian Parsi community in India offers its dead to vultures rather than burying them. However, in recent decades, the vulture population has collapsed.
11. Every year, about 8 out of every 1,000 people die, according to the Population Reference Bureau and the CIA's World Factbook.
12. That's about 55.3 million people per year. Or: 151,600 people a day; 6,316 people an hour; 105 people a minute; nearly two people a second.
15. On some bodies, a waxy substance called "adipocere" forms in the first few days after death, covering the skin. It is also known as "corpse wax" and can preserve the rest of the remains for years.
16. Rigor mortis, a stiffening of the body, sets in between three and four hours after death. It's caused by chemical changes in the muscles that force them to contract.
18. Forensic scientists can tell roughly how long it has been since death by looking at the species of insect on the body.
20. Brain cells die within a few minutes of the heart stopping. Skin cells can survive for up to 24 hours.
21. "Brain death", the loss of all functions of the brain, including those of the brain stem, is diagnosed by coma, absence of brainstem reflexes, and apnoea (stopping breathing).
22. The intestines are full of digestive bacteria, which live on after death. They begin to digest the dead tissues of the gut, and then break out into the rest of the body.
23. After death, the pancreas and other places that are filled with digestive enzymes just sort of digest themselves, and then the rest of the body, in a process called autolysis.
24. Fingernails and toenails do not continue to grow after death. The skin dries and contracts around them, making it look as though they have grown.
25. Dead bodies swell up like balloons after about four days, due to the gases and liquids released by autolysis. This stage is called "bloat".
26. Of the 55 million deaths per year, about 9.5 million are Chinese.
28. Livor mortis, a purplish or reddish discoloration caused by the blood settling within the body, can set in within 20 minutes.