Wednesday, December 23, 2009 From Skeptics Say How Blog
For any of you who have ever braved a psychic fair, you will have seen the booths inviting you to have a photograph of your aura. This aura is supposedly connected to the activity of your chakras (vortices of energy permeating from certain points of our bodies), and is able to reflect a person’s quality of consciousness, emotional state, thoughts and well-being (i).Throughout history people have continued to claim that they can see and interpret a person’s aura, including Buddhist monks, Native American Shamans and Christian Priests, whose Saints were depicted with glowing halos. In the 20th century an aura was supposedly captured on film by two Russian scientists, Semyon and Valentina Kirlian. This was done by passing high voltage, high frequency electricity through an object resting on photographic film. The process is now referred to as Kirlian photography.
The rest of the article will be in three parts. The first describing the mechanism behind Kirlian photography and what is actually being captured on film, the second giving some possible medical explanations for how people might see an aura and the third explaining how aura photography at psychic fairs work.
Kirlian Photography
As stated above, Kirlian photography is achieved by passing high voltage, high frequency electricity through an object resting on photographic film. Below is a link to a site outlining how you could build your own simple Kirlian photography device.
http://www.imagesco.com/articles/kirlian/kirlian-photography-device.htmlThe ‘aura’ captured on film shown emanating from the object is actually a corona discharge, where the surrounding air becomes ionised allowing it to conduct electricity (ii) . This same principle can be seen in action around the toroid of a Tesla Coil. Testing whether this ‘aura’ is linked to the life force, emotional state or health of an object is a simple enough test, place any non-organic object that will conduct electricity (such as a key or coin)on the film and you will see the same corona discharge around the object.
Many believers in Aura photography will claim that it produces an effect dubbed the “Phantom Limb Effect”, where any recently removed parts of an organic object will still appear on film with an aura surrounding them. The following is an excerpt from a paper outlining Dr. Harry Oldfield’s (a Homeopathic Physician) process for capturing the “Phantom Limb Effect” in potato leaves.
Unfortunately there is a mundane answer for this effect; it is just the result of sloppy experimentation and a lack of understanding of the physics behind Kirlian photography. Kirlian photography works on organic objects due to their water content. This water allows the object to conduct electricity. By first placing the entire leaf on the photographic film and then removing part of it, you are leaving a water residue on the film which will still conduct electricity and emit a corona discharge. The “Phantom Limb Effect” disappears when the ‘limb’ is removed before placing on the film.
Aura’s in Medicine
People throughout history have claimed that they could perceive an individual’s aura without the aid of any modern technology. Whilst many of these people might be fraudsters and charlatans, a few may legitimately perceive some form of ‘aura’ at times. Around 1/5 of migraine sufferers have symptoms that include visual auras as well as auditory and olfactory hallucinations. These visual auras can manifest as flashes of black, white and occasionally colour (photopsia) or zigzagging lines (scintillating scotoma) (iv). Before migraines were properly understood it is easy to understand how people might believe that they were witnessing a divine act (followed by a severe headache) instead of visual hallucinations due to hyper-activity of brain cells.
Another possible explanation for perceived visual auras is synaesthesia. Synaesthesia is loosely defined as when one sense activates another unrelated sense. Synaesthesia can take many forms but the most common sub-sets are colour-graphemic; where numbers and/or letters (occasionally shapes) produce colours and simple patterns, and colour-auditory; in which auditory input, including voices, music, and random noise, produces colours, textures, and shapes (v). This could also be interpreted by those ignorant of the medical research as anecdotal evidence for the existence of auras.
Aura Photography
The aura photography you will see at psychic fairs is often thought to be Kirlian photography but it is actually nothing of the sort. For those of you not familiar with the process, you are asked to place both of your hands on metal plates, which are connected to a ‘black box’ and a Polaroid camera. Your photo is then given to you with bright colourful lights surrounding you, and a leaflet describing the meaning of all the different colours.
The metal plate you’re placing your hands on is actually a galvanometer and is simply measuring the skin resistance of your hands. This information is then fed into the ‘black box’ where it lights up a series of coloured LEDs to different intensities, which are then superimposed over the image of you. When pressed (give a man enough rope and...) the practitioners of this art will tell you that skin resistance measured at the different locations on the hand represent different organs/emotional states/states of being etc. There are no published peer-reviewed studies that show any correlation of this sort. A simple enough test would be to have two of these photographs taken, one with very dry hands and another after you have wet them. Both photos should turn out dramatically different due to the substantial difference of resistance between wet and dry hands.
Conclusion
Neither Kirlian photography nor Aura photography have stood up to any claims that they can capture someone’s aura on film. It is just another fancy light show designed to fool those that don’t question the scientific mechanisms behind such processes.
The rest of the article will be in three parts. The first describing the mechanism behind Kirlian photography and what is actually being captured on film, the second giving some possible medical explanations for how people might see an aura and the third explaining how aura photography at psychic fairs work.
Kirlian Photography
As stated above, Kirlian photography is achieved by passing high voltage, high frequency electricity through an object resting on photographic film. Below is a link to a site outlining how you could build your own simple Kirlian photography device.
http://www.imagesco.com/articles/kirlian/kirlian-photography-device.htmlThe ‘aura’ captured on film shown emanating from the object is actually a corona discharge, where the surrounding air becomes ionised allowing it to conduct electricity (ii) . This same principle can be seen in action around the toroid of a Tesla Coil. Testing whether this ‘aura’ is linked to the life force, emotional state or health of an object is a simple enough test, place any non-organic object that will conduct electricity (such as a key or coin)on the film and you will see the same corona discharge around the object.
Many believers in Aura photography will claim that it produces an effect dubbed the “Phantom Limb Effect”, where any recently removed parts of an organic object will still appear on film with an aura surrounding them. The following is an excerpt from a paper outlining Dr. Harry Oldfield’s (a Homeopathic Physician) process for capturing the “Phantom Limb Effect” in potato leaves.
“His original research with Kirlian photography focused on the phantom leaf effect: organic potato leaves were set up for Kirlian photography but then the leaves were removed from the stem. In many cases the energy outline showed the whole leaves, ie including the portions removed, thus showing a natural energy field corresponding to the physical structure and molecules of the leaf.” (iii)
Unfortunately there is a mundane answer for this effect; it is just the result of sloppy experimentation and a lack of understanding of the physics behind Kirlian photography. Kirlian photography works on organic objects due to their water content. This water allows the object to conduct electricity. By first placing the entire leaf on the photographic film and then removing part of it, you are leaving a water residue on the film which will still conduct electricity and emit a corona discharge. The “Phantom Limb Effect” disappears when the ‘limb’ is removed before placing on the film.
Aura’s in Medicine
People throughout history have claimed that they could perceive an individual’s aura without the aid of any modern technology. Whilst many of these people might be fraudsters and charlatans, a few may legitimately perceive some form of ‘aura’ at times. Around 1/5 of migraine sufferers have symptoms that include visual auras as well as auditory and olfactory hallucinations. These visual auras can manifest as flashes of black, white and occasionally colour (photopsia) or zigzagging lines (scintillating scotoma) (iv). Before migraines were properly understood it is easy to understand how people might believe that they were witnessing a divine act (followed by a severe headache) instead of visual hallucinations due to hyper-activity of brain cells.
Another possible explanation for perceived visual auras is synaesthesia. Synaesthesia is loosely defined as when one sense activates another unrelated sense. Synaesthesia can take many forms but the most common sub-sets are colour-graphemic; where numbers and/or letters (occasionally shapes) produce colours and simple patterns, and colour-auditory; in which auditory input, including voices, music, and random noise, produces colours, textures, and shapes (v). This could also be interpreted by those ignorant of the medical research as anecdotal evidence for the existence of auras.
Aura Photography
The aura photography you will see at psychic fairs is often thought to be Kirlian photography but it is actually nothing of the sort. For those of you not familiar with the process, you are asked to place both of your hands on metal plates, which are connected to a ‘black box’ and a Polaroid camera. Your photo is then given to you with bright colourful lights surrounding you, and a leaflet describing the meaning of all the different colours.
The metal plate you’re placing your hands on is actually a galvanometer and is simply measuring the skin resistance of your hands. This information is then fed into the ‘black box’ where it lights up a series of coloured LEDs to different intensities, which are then superimposed over the image of you. When pressed (give a man enough rope and...) the practitioners of this art will tell you that skin resistance measured at the different locations on the hand represent different organs/emotional states/states of being etc. There are no published peer-reviewed studies that show any correlation of this sort. A simple enough test would be to have two of these photographs taken, one with very dry hands and another after you have wet them. Both photos should turn out dramatically different due to the substantial difference of resistance between wet and dry hands.
Conclusion
Neither Kirlian photography nor Aura photography have stood up to any claims that they can capture someone’s aura on film. It is just another fancy light show designed to fool those that don’t question the scientific mechanisms behind such processes.
References
(i)http://www.auraimaging.com/fundementals/whatis.shtml(ii)David G. Boyers and William A. Tiller (1973). "Corona discharge photography". Journal of Applied Physics 44 3102-3112(iii)http://www.healthseminarsonline.com/attachments/583_dr_harry_oldfield_inventor.pdf(iv)http://en.wikipedia.org/wiki/Aura_%28symptom%29(v)http://www.bu.edu/synesthesia/faq/index.html#q3
http://www.imagesco.com/articles/kirlian/kirlian-photography-device.htmlhttp://www.webmd.com/migraines-headaches/what-is-a-migraine-with-aurahttp://en.wikipedia.org/wiki/Synesthesia#Grapheme_.E2.86.92_color_synesthesia
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