KEY POINTS:
It is macabre reading and will appeal to those with a morbid streak, but New Scientist magazine has published a report on what it is like to die.
This week's edition discusses various ways of dying, from being burned alive to drowning and decapitation.
Evidence of death experience
came from advances in medical sciences and accounts from lucky survivors, the report said.
Whatever the mode of death, it was usually a lack of oxygen to the brain that delivered the "coup de grace".
* Drowning: Victims first panic and try to hold their breath, usually for 30 to 90 seconds.
Survivors describe a "tearing and burning" sensation as water enters the lungs, followed by a feeling of calmness and tranquillity.
Oxygen deprivation results in loss of consciousness, the heart stopping, and brain death.
* Heart attack: A "squeezing" chest pain or feeling of pressure are the most common symptoms as the heart muscle struggles for oxygen.
Disruption of the heart rhythm stops the heart beating. Loss of consciousness can occur in about 10 seconds, and death follows minutes later.
* Loss of blood: Marked by several stages of "haemorrhagic shock".
Anyone losing 1.5 litres of blood felt weak, thirsty and anxious.
By the time two litres were lost, people experienced dizziness, confusion and eventual unconsciousness.
* Electrocution: A household electric shock might stop the heart, leading to unconsciousness after about 10 seconds. Higher currents through the heart or brain can produce almost immediate unconsciousness.
It has been claimed that prisoners executed in the electric chair may have died from heating of the brain or suffocation.
* Fall from a height: Survivors of great falls often reported the sensation of time slowing down.
A study of 100 suicide jumps from San Francisco's 75m high Golden Gate Bridge found many cases of instantaneous death involving collapsed lungs, exploded hearts or damage to organs from broken ribs.
* Hanging: Hanging suicides and old-fashioned executions cause death by strangulation.
This can lead to unconsciousness in 10 seconds, but a poorly placed noose may result in many minutes of suffering. "Long drop" hangings were intended to break the neck, but a study of 34 prisoners executed this way found four-fifths died partly from asphyxiation.
* Fire: Burns inflict intense pain and boost the skin's pain sensitivity. As superficial nerves were destroyed, some feeling was lost but not much, experts said.
Most people who died in fires were actually killed by inhaling toxic gases and asphyxiation.
* Decapitation: Beheading can be swift and painless, but consciousness is believed to continue for a short time after the spinal cord was severed.
Experts have calculated that the brain might remain functioning for seven seconds.
Reports from guillotine executions in post-revolutionary France cited cases where movements of the eyes and mouth were seen for up to 30 seconds after the blade struck.
* Lethal injection: Introduced in the US in 1977 as a humane alternative to the electric chair, it involves three drug injections - an anaesthetic, a paralytic agent and potassium chloride which stops the heart.
Some prisoners are thought to have felt the burning pain of the potassium chloride injection but paralysis prevented them showing it.
* Explosive decompression: Survivors of rapid depressurisation include pilots and a Nasa technician who had a vacuum chamber accident.
They often reported initial pain, like being hit in the chest, and sometimes the feeling of air escaping from the lungs.
Loss of consciousness generally occurred in less than 15 seconds.
