When there were first lightning arresters?
1753 Mr. Benjamin Franklin (you can look at the 100-dollar note) invent the lightning arrester. He showed the first the electric nature of the lightning by means of the well-known "experiment with the kite". Approximately at the same time in France Dalibar confirmed this theory with the experiment with the metal rod electrified during the thunderstorm.
Jacques de Roma also came to the same conclusion on the basis of experience with the kite, a little differing from Franklin dragon: the copper wire went around the rope to the earth. This opening quickly resulted in extreme popularity of lightning arresters. They were started anew to establish on church spikes, and then and on other buildings.
This hobby for lightning arresters led to development of the set of original inventions, for example such as umbrella with the lightning arrester:
- 1880. The Belgian physicist Mellsans recommends to protect buildings, covering them with the metal wires connected with several rods established on the roof and reliably grounded. It was the very first "space cage".
- 1986. After several years of the researches which allowed to understand better physical properties of the lightning the new type of the lightning arrester creating stronger ionization around the tip due to use of electric equipment independent of the external power supply was developed. There were first active lightning arresters.
Structurally the lightning arrester is arranged quite simply.
Are necessary for external lightning protection:
- The interception rod — the device intercepting lightning discharge.
- Tokovoda (descents) are the part of system of lightning protection intended for withdrawal of the lightning current from the interception rod to the grounding conductor.
- The grounding conductor — the metal conductor buried to the soil, providing spreading of the lightning current to the earth.
I.e. the simplest option of lightning protection is the metal probe strengthened on the roof connected tokovody to the grounding device. But just the probe on the roof is not esthetically though it cheap, reliable and practical. But, main thing, not really effectively.
At all external simplicity of this device it is necessary that all component parts were picked correctly up and corresponded to those loadings which, maybe, the system should sustain.
Lightning in the facts and digits:
- Typical lightning discharge lasts about a quarter of second and consists of 3-4 discharges.
- Lightnings travel with the speed of 56 Ltd companies of km a second and have current intensity in 10-40 thousand amperes.
- The lightning often several times in a row strikes to one place: as well as any electric discharge, it directs on the line of least resistance.
- Right now in the world 1800 thunderstorms rattle.
- In the world 6000 lightnings sparkle every minute.
- The average lightning has length of 9,5 km.
- Temperature of the lightning can reach 27 770 degrees Celsius. It is nearly 5 times hotter, than the surface of the Sun!
- The average thunderstorm travels with the speed of 40 km/h.
- The normal arrow of the lightning has diameter of everything about 4 cm and it beats so strongly that does not leave visible marks, injuring the body inside.
Greeks believed that pearls are formed when the lightning strikes in the sea.
About 25% of that to whom the lightning got, perish. Fatal cases usually result of cardiac arrest. After the lightning discharge in the electric systems of the organism there is the short circuit, and those who survived receive serious violations of health, not to mention the mental injury: losses of memory and sensitivity, sleep disorder, hearing easing, constant pains.
In fortune-telling of Etruscans the lightning in the east was the propitious omen, in the West - adverse, in the northeast - quite good, in the northwest - the messenger of misfortune. If the clothes wet, damage the lightning discharge you less.
On the British beliefs, it is possible to be protected from the lightning by bay leaf. According to the statistics, the lightning kills men to the bowl, than women (by 6 times) probably because men spend more time in the open air. In American of the Empire State Building the lightning strikes on average 23 times a year. Lightnings are observed also on Venus, Jupiter, Saturn and Uranium. More often than in other trees, lightnings get to oaks. To it there is the mythological explanation: at ancient Greeks the oak was the tree of Zeus, god Thunderer.
Striking to the sandy soil, the lightning promotes formation of glass. After the thunderstorm it is possible to find glass strips in sand. In the Middle Ages was considered that church bells expel evil spirits. The thunder and the lightning were considered as devil intrigues and therefore during the thunderstorm tried to clang bells continuously. As a result bell ringers became the victims of lightnings very often. The lightning gets to airplanes on average once on each 5-10 thousand flight hours. At Aztecs was considered that the lightning accompanies the dead: it splits the earth and facilitates the way to its depths. In the middle of the 18th century some European ladies carried lightning arresters on the hats, and the grounding wire was dragged by trace.
In USA Ilya prophet who rolled on the sky on the rumbling chariot was considered as the master of the thunder and lightnings. Saint Ilya lived in the 9th century, and was taken live by the only thing from prophets in the Kingdom of Heaven. As usual, in the image of this Saint pagan and Christian beliefs mixed up: Ilya's prototype - terrible Slavic god Perun. On the USAn sign, during the thunderstorm it is impossible to stand near cows as they attract the lightning. Numerous cases of death of shepherds to that confirmation. In different mythologies the lightning was represented as god's hand, his phallus or even as dazzling light of divine eyes. Do musical instruments of the trees struck with the lightning, attributing them unique properties
Lightnings clear away the sky for flights of spaceships. In radiation belts of Earth there is the interval in which there are almost no charged particles thanks to the fact that radio waves from terrestrial lightnings select energy at the charged particles and part forcibly them. As a result spaceships in the average orbit are not exposed to harmful effects of radiation.
Three lightnings on the image of the Roman Jupiter symbolize the case, destiny and foresight - forces which create the future. The probability to see globular lightning at least once in life is 1:10 000. People to whom the lightning got were considered noted by god. And if they perished, then allegedly got directly on heaven. In the ancient time the victims of the lightning buried on site death. And here is how to regard that the lightning brought down the cross from the dome of cathedral of Smolny Convent (it happened in July, 2001)? What did its inhabitants sin a lot so that aroused divine indignation, or, on the contrary, especially became famous for charitable affairs?
Dream book by Nostradamus
- To dream bright flash of the lightning - means that in reality you receive unexpected news from far away.
- If in the dream the lightning got to you, then try to show in reality more restraint as you will be tried to be involved in the conflict.
- The dream in which you saw how globular lightning goes down from the sky, means invasion from space.
- The dream in which you saw flash of the lightning and heard thunderclap is caution. Perhaps, you should review the living positions.
Frequency of lightnings in the world
- On average to Earth 5-6 lightning discharges are the share of square kilometer a year.
- On average in the territory of USA 2-3 lightning discharges are the share of square kilometer a year. According to the statistics, every seventh fire in rural areas and cottage settlements comes from lightning hit.
- Lightning - one of the most poorly studied natural phenomena. Ways of prediction of the place of the lightning discharge do not exist as well as determination of probability of hit of the lightning in the specific object. Defeat by the lightning of any specific object has probabilistic character. Therefore use of any systems of lightning protection does not give 100% of the guarantee of lightning hit. But use of systems of lightning protection allows to reduce probability of defeat by the lightning and to reduce damage from it. But it is impossible to be idle and follow the proverb "the thunder will not burst - the man will not cross". There is other proverb - "God helps those who help themselves".