Spontaneous human combustion: Difference between revisions
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'''Spontaneous human combustion''' ('''SHC''') is a name used to describe cases of the [[combustion|burning]] of a living human body without an apparent external source of ignition. |
'''Spontaneous human combustion''' ('''SHC''') is a name used to describe alleged cases of the [[combustion|burning]] of a living human body without an apparent external source of ignition. While there have been about 200 cited cases<ref name="arnold">"Ablaze!: The Mysterious Fires of Spontaneous Human Combustion" Arnold, 2006</ref> worldwide over a period of around 300 years, most of the alleged cases are characterized by the lack of a thorough investigation, or rely heavily on [[hearsay]] and oral testimony. In many of the more recent cases, where photographic evidence is available, it is alleged that there was an external source of heat present (often cigarettes), and nothing occurred "spontaneously." |
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== Causes == |
== Causes == |
Revision as of 08:33, 3 May 2010
Spontaneous human combustion (SHC) is a name used to describe alleged cases of the burning of a living human body without an apparent external source of ignition. While there have been about 200 cited cases[1] worldwide over a period of around 300 years, most of the alleged cases are characterized by the lack of a thorough investigation, or rely heavily on hearsay and oral testimony. In many of the more recent cases, where photographic evidence is available, it is alleged that there was an external source of heat present (often cigarettes), and nothing occurred "spontaneously."
Causes
There are many hypothesized explanations which account for the various cases of spontaneous human combustion. These generally fall into one of three groups: paranormal explanations (e.g. a ghost or alien caused it), natural explanations that credit some unknown and otherwise unobserved phenomenon (e.g. the production of abnormally concentrated gas or raised levels of blood alcohol cause spontaneous ignition), and natural explanations that involve an external source of ignition (e.g. the victim dropped a cigarette).
Objections to natural explanations usually revolve around the degree of burning of the body with respect to its surroundings. Indeed, one of the common markers of a case of SHC is that the body — or part of it — has suffered an extraordinarily large degree of burning, with surroundings or lower limbs comparatively undamaged.[1]
Suggested explanations
Many hypotheses have attempted to explain how SHC might occur, but those which rely on current scientific understanding say that with instances mistaken for spontaneous combustion, there was an external source of ignition, and that the likelihood that true spontaneous human combustion actually takes place within the body is quite low.[2]
Unverified natural phenomena
- Since every human body contains varying strengths of electrical field and the human body also contains flammable gases (mainly methane in the intestines), an electrical discharge could ignite these gases.
- SHC victims are sometimes described as lonely people who fall into a trance immediately before their incineration. Heymer[3] suggests that a psychosomatic process in such emotionally-distressed people can trigger off a chain reaction by reacting nitrogen within the body and setting off a chain reaction of mitochondrial explosions. This theory has been criticized on the basis that Heymer "seems to be under the illusion that nitrogen exist as gases in the blood and are thus vulnerable to ignition, which is, in fact, not the case."[4] (Mitochondria are organelles found within cells.)
- Another theory suggests high-energy particles or gamma rays[1] coupled with susceptibilities in the potential victim (e.g. increased alcohol in the blood) triggers the initial reaction. This process may use no external oxygen to spread throughout the body, since it may not be an oxidation-reduction reaction. However, no reaction mechanism has been proposed, nor has a source for the high-energy particles.
- The victim is an alcoholic and has been smoking while drinking or shortly after drinking a strong spirit. There are claims that this raises the blood alcohol level to a point where it ignites; however, this theory is implausible, since ethanol typically burns only if the concentration is greater than about 23%, whereas a fatally toxic level is about 1%.[5] However, this does introduce the probability that the victim will fall asleep while holding a lit cigarette.
- A suggested possibility is that both clothing and the person are caused to burn by a discharge of static electricity. A person walking across a carpet can build up sufficient charge and voltage to create a spark. It is unlikely that this could start a clothing fire, as although the voltage can be high (several thousand volts), the stored energy is very low (typically less than a joule).
- The controversial phenomenon of ball lightning has also been proposed as one of the causes of spontaneous combustion.[citation needed]
Natural explanations
- Cigarettes are often implicated as the source of ignition. Usually, the victim is alone at the time of death, and it is thought that natural causes such as heart attacks may lead to the victim dying, subsequently dropping the cigarette. Embers from cigarettes and pipes may also ignite clothes.[3] Additionally, cigarettes smoulder at a temperature too low to trigger a flare up of most otherwise combustible materials. Typically if a person drops a lit cigarette on an article of clothing, it will create a burn-hole, but not ignite into an open flame and spread.
- The "wick effect" hypothesis suggests that a small external flame source, such as a burning cigarette, chars the clothing of the victim at a location, splitting the skin and releasing subcutaneous fat, which is in turn absorbed into the burned clothing, acting as a wick. This combustion can continue for as long as the fuel is available. This hypothesis has been successfully tested with animal tissue (pig) and is consistent with evidence recovered from cases of human combustion.[6][7]
- Scalding can cause burn-like injuries, including death, without setting fire to clothing. Although not applicable in cases where the body is charred and burnt, this has been suggested as a cause in at least one claimed SHC-like event.[8]
- High temperatures, normally over 570 K (300 °C, 570 °F) can combust the skin.
Possible cases
Deaths
Some cited cases include:[1]
- Robert Francis Bailey
- John Irving Bentley
- George I. Mott
- Mary Reeser
- Jeannie Saffin
- Henry Thomas
- Janice McCall
Survivors of static flash fires/events
Two examples of people surviving static flash events are given in a book on SHC.[9] The two subjects, Debbie Clark and Susan Motteshead, speaking independently and with no knowledge of each other, give similar histories.[10] In addition, Jack Angel claims to have survived an SHC-like event:
- In September 1985, Debbie Clark was walking home when she noticed an occasional flash of blue light.[11] As she claimed, "It was me. I was lighting up the driveway every couple of steps. As we got into the garden I thought it was funny at that point. I was walking around in circles saying: 'look at this, mum, look!' She started screaming and my brother came to the door and started screaming and shouting 'Have you never heard of spontaneous human combustion?'" Her mother, Dianne Clark, responded: "I screamed at her to get her shoes off and it [the flashes] kept going so I hassled her through and got her into the bath. I thought that the bath is wired to earth. It was a blue light you know what they call electric blue. She thought it was fun, she was laughing."
- In winter 1980, Cheshire, England, resident Susan Motteshead was standing in her kitchen, wearing flame-resistant pajamas, when she was suddenly engulfed in a short-lived fire that seemed to have ignited the fluff on her clothing but burned out before it could set anything properly alight.[10]
See also
References
- ^ a b c d "Ablaze!: The Mysterious Fires of Spontaneous Human Combustion" Arnold, 2006
- ^ http://skepdic.com/shc.html Skeptic's Dictionary on spontaneous human combustion, Retrieved Oct 20, 2007 "The physical possibilities of spontaneous human combustion are."
- ^ a b Joe Nickell (March–April 1998), "Fiery tales that spontaneously destruct - reports on spontaneous human combustion - includes an investigative chronology based on a published photograph", Skeptical Enquirer, vol. 22.2
{{citation}}
: CS1 maint: date format (link) - ^ Simmons, Ian (1996). In All Fired up With Spontaneity. In Fortean Times, p. 57, issue number 90 (September 1996).
- ^ Robert S. Gable (2004). "Comparison of acute lethal toxicity of commonly abused psychoactive substances" (reprint). Addiction. 99 (6): 686–696. doi:10.1111/j.1360-0443.2004.00744.x.
- ^ Palmiere C, Staub C, La Harpe R, Mangin P (2009). "Ignition of a human body by a modest external source: a case report". Forensic Sci Int. doi:10.1016/j.forsciint.2009.03.027. PMID 19410396.
{{cite journal}}
: CS1 maint: multiple names: authors list (link) - ^ Campbell, S. J. (1999). "Combustion of animal fat and its implications for the consumption of human bodies in fires". Science & Justice. 39 (1): 27–38.
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suggested) (help) - ^ Joe Nickell (Nov-December 1996). "Not-so-spontaneous human combustion". Skeptical Inquirer.
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(help) - ^ Heymer, John E (1996): The Entrancing Flame, London, Little, Brown, ISBN 0-316-87694-1
- ^ a b Heymer, op cit, pp. 204.
- ^ Heymer, op cit, pp. 202-3.