Bucha effect
Encyclopedia
The Bucha effect is a disorientation-, vertigo
-, and nausea
-inducing effect of a strobe light
flashing at 1 Hz
to 20 Hz, approximately the frequency of human brainwaves. The effects are similar to seizures caused by epilepsy
(in particular photosensitive epilepsy
), but are not restricted to people with histories of epilepsy.
The effect is named after a Dr. Bucha who identified the phenomenon in the 1950s when called upon to investigate a series of similar and unexplained helicopter
crashes. Those pilots who had survived reported sudden onset of dizziness and confusion, causing them to lose control of their aircraft. Dr. Bucha found that helicopter rotor
blades, when turning at certain speeds, could cause flashes of sunlight at frequencies coinciding with the electrical frequencies of the central nervous system (brainwaves), inducing symptoms similar to epileptic
seizure
s, including disorientation, nausea, etc.
The Bucha effect has been considered as a principle for various forms of non-lethal weapon. A related crowd-control
device was invented by Charles Bovill, which "employed a combination of ultra-sonic waves and strobe lights to induce acute discomfort, sickness, disorientation and sometimes epilepsy."
Vertigo (medical)
Vertigo is a type of dizziness, where there is a feeling of motion when one is stationary. The symptoms are due to a dysfunction of the vestibular system in the inner ear...
-, and nausea
Nausea
Nausea , is a sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit. It often, but not always, precedes vomiting...
-inducing effect of a strobe light
Strobe light
A strobe light or stroboscopic lamp, commonly called a strobe, is a device used to produce regular flashes of light. It is one of a number of devices that can be used as a stroboscope...
flashing at 1 Hz
Hertz
The hertz is the SI unit of frequency defined as the number of cycles per second of a periodic phenomenon. One of its most common uses is the description of the sine wave, particularly those used in radio and audio applications....
to 20 Hz, approximately the frequency of human brainwaves. The effects are similar to seizures caused by epilepsy
Epilepsy
Epilepsy is a common chronic neurological disorder characterized by seizures. These seizures are transient signs and/or symptoms of abnormal, excessive or hypersynchronous neuronal activity in the brain.About 50 million people worldwide have epilepsy, and nearly two out of every three new cases...
(in particular photosensitive epilepsy
Photosensitive epilepsy
Photosensitive epilepsy is a form of epilepsy in which seizures are triggered by visual stimuli that form patterns in time or space, such as flashing lights, bold, regular patterns, or regular moving patterns.-Symptoms:...
), but are not restricted to people with histories of epilepsy.
The effect is named after a Dr. Bucha who identified the phenomenon in the 1950s when called upon to investigate a series of similar and unexplained helicopter
Helicopter
A helicopter is a type of rotorcraft in which lift and thrust are supplied by one or more engine-driven rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forwards, backwards, and laterally...
crashes. Those pilots who had survived reported sudden onset of dizziness and confusion, causing them to lose control of their aircraft. Dr. Bucha found that helicopter rotor
Helicopter rotor
A helicopter main rotor or rotor system is a type of fan that is used to generate both the aerodynamic lift force that supports the weight of the helicopter, and thrust which counteracts aerodynamic drag in forward flight...
blades, when turning at certain speeds, could cause flashes of sunlight at frequencies coinciding with the electrical frequencies of the central nervous system (brainwaves), inducing symptoms similar to epileptic
Epilepsy
Epilepsy is a common chronic neurological disorder characterized by seizures. These seizures are transient signs and/or symptoms of abnormal, excessive or hypersynchronous neuronal activity in the brain.About 50 million people worldwide have epilepsy, and nearly two out of every three new cases...
seizure
Seizure
An epileptic seizure, occasionally referred to as a fit, is defined as a transient symptom of "abnormal excessive or synchronous neuronal activity in the brain". The outward effect can be as dramatic as a wild thrashing movement or as mild as a brief loss of awareness...
s, including disorientation, nausea, etc.
The Bucha effect has been considered as a principle for various forms of non-lethal weapon. A related crowd-control
Crowd control
Crowd control is the controlling of a crowd, to prevent the outbreak of disorder and prevention of possible riot. Examples are at soccer matches, when a sale of goods has attracted an excess of customers, refugee control, or mass decontamination and mass quarantine situations . It calls for gentler...
device was invented by Charles Bovill, which "employed a combination of ultra-sonic waves and strobe lights to induce acute discomfort, sickness, disorientation and sometimes epilepsy."
External links
- "LED-based incapacitating apparatus and method", filed in 2005 — a patent for a device based on this phenomenon.
- "New Robo-Weapon: Paralyzing Floodlight", Wired Danger Room blog, February 20, 2007 — a description of a weapon based on a similar phenomenon.