For the first time in history, scientists managed to shoot a fireball on video and study its spectrum.
Fireball - an extremely rare natural phenomenon. For a very long time the very fact of the existence of such lightning was in doubt. No one has managed to get it in the laboratory, a few photographs and videotapes taken by random witnesses are too low quality to be of scientific value.
On January 17, an article by Chinese scientists who managed to capture a fireball during the observations of ordinary lightning in the Tibetan highlands in the summer of 2012 was published in the journal Physical Review Letters. The survey was carried out using a conventional color video camera with a resolution of 640x480 and a black and white high-speed camera with a resolution of 1280x400 and a shooting speed of 3000 frames per second, as well as two gapless spectrometers.
At the bottom left - lightning itself. On the right is its spectrum. In the middle and upper part of the frame - the spectrum of the usual linear lightning, which gave rise to the ball.
Fireball was formed near the surface of the earth at the time of the usual impact. Fireball existed for about 1.6 seconds, its apparent speed was 8.6 m / s, and the apparent diameter was a few meters. The actual speed could be higher, since the lightning could not move parallel to the camera plane. The shooting was carried out from a distance of 900 meters, so the image of a lightning consists of only a few dozen pixels, but thanks to high-speed shooting and the presence of spectrometers, these frames provide more information than all previous observations of ball lightning taken together.
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Throughout the lifetime of the ball lightning in its spectrum are clearly visible lines of iron, silicon and calcium - the main components of the soil. Another very common element in the earth's crust, aluminum, radiates outside the range that cameras used by scientists perceive, so there are no lines on the spectrum. This is a possible confirmation of the hypothesis of New Zealand scientists John Abrahamson and James Diniss, who suggested that ball lightning is a cloud of oxidized red-hot soil nanoparticles formed at the time of impact of a conventional lightning.
Ball lightning spectrum. In the left part - the lines of iron, silicon and calcium, in the right - the line of atmospheric oxygen and nitrogen
However, the only case of observation of ball lightning with the help of scientific equipment is too little to draw any conclusions. It is possible that fireballs are of different types, and have a different nature. So, there is evidence of lightning, which observed the pilots of aircraft far from the surface of the earth.
In the first moments of its existence, the lightning shone with a violet hue, then its color became white and in the end - orange. Interestingly, the lightning intensity pulsed at a frequency of 99.4 Hz. A power line with a voltage of 35 kilovolts passes 20 meters from the point of lightning strike, and this pulsation is most likely due to the interaction of the lightning electromagnetic field with the field of power transmission lines, the current in which has a frequency of 50 Hz.
On January 17, an article by Chinese scientists who managed to capture a fireball during the observations of ordinary lightning in the Tibetan highlands in the summer of 2012 was published in the journal Physical Review Letters. The survey was carried out using a conventional color video camera with a resolution of 640x480 and a black and white high-speed camera with a resolution of 1280x400 and a shooting speed of 3000 frames per second, as well as two gapless spectrometers.
At the bottom left - lightning itself. On the right is its spectrum. In the middle and upper part of the frame - the spectrum of the usual linear lightning, which gave rise to the ball.
Fireball was formed near the surface of the earth at the time of the usual impact. Fireball existed for about 1.6 seconds, its apparent speed was 8.6 m / s, and the apparent diameter was a few meters. The actual speed could be higher, since the lightning could not move parallel to the camera plane. The shooting was carried out from a distance of 900 meters, so the image of a lightning consists of only a few dozen pixels, but thanks to high-speed shooting and the presence of spectrometers, these frames provide more information than all previous observations of ball lightning taken together.
')
Throughout the lifetime of the ball lightning in its spectrum are clearly visible lines of iron, silicon and calcium - the main components of the soil. Another very common element in the earth's crust, aluminum, radiates outside the range that cameras used by scientists perceive, so there are no lines on the spectrum. This is a possible confirmation of the hypothesis of New Zealand scientists John Abrahamson and James Diniss, who suggested that ball lightning is a cloud of oxidized red-hot soil nanoparticles formed at the time of impact of a conventional lightning.
Ball lightning spectrum. In the left part - the lines of iron, silicon and calcium, in the right - the line of atmospheric oxygen and nitrogen
However, the only case of observation of ball lightning with the help of scientific equipment is too little to draw any conclusions. It is possible that fireballs are of different types, and have a different nature. So, there is evidence of lightning, which observed the pilots of aircraft far from the surface of the earth.
In the first moments of its existence, the lightning shone with a violet hue, then its color became white and in the end - orange. Interestingly, the lightning intensity pulsed at a frequency of 99.4 Hz. A power line with a voltage of 35 kilovolts passes 20 meters from the point of lightning strike, and this pulsation is most likely due to the interaction of the lightning electromagnetic field with the field of power transmission lines, the current in which has a frequency of 50 Hz.
Source: https://habr.com/ru/post/210620/
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