The idea of using the energy of the Sun as a weapon first came to man's mind, perhaps back in the Stone Age, but for the first time it was embodied by none other than the famous Archimedes.
The inhabitants of Syracuse, of which he was a citizen, were much more grateful to him for this than for the exact value of the number "pi" and the calculation of the volume of the displaced liquid combined. And it was like this …
In 215 BC. e. King Syracuse Hieron II died at the age of 90, having transferred power to his grandson Hieronymus. In the course of palace intrigues, he took a course of separation from the hitherto friendly Rome and soon concluded a treaty with Carthage, which, as you know, must be destroyed. The logical result of such a policy was the Second Punic War of the Carthaginians with the Romans, which began in the year 218 don. e. In 212 BC. e. Roman general Mark Claudius Marcellus laid siege to Syracuse from sea and land.
Sixty quinkyrems (heavy ships with five rows of oars) approached the city walls within an arrow's flight distance, and archers and slingers began to shower the defenders with their deadly shells. However, the city was helped to defend himself by Archimedes, who put into action everything he could think of - giant iron paws hooked 45-meter ships and overturned them, catapults threw monstrous boulders, and the most unusual thing was that with the help of a huge mirror, the scientist set fire to Roman quinciremes!
Having lost several ships in such an unusual way, Marcellus took the fleet away, but this did not help either - the 75-year-old Archimedes built another mirror and continued to shoot deadly sunbeams. True, this did not make it easier for the townspeople: although the scientist thwarted the assault on Syracuse, he could not save him from the siege, so in the end the city fell. Archimedes himself was killed by a simple legionnaire in a patchwork of street fighting.
Pros and cons
In the Middle Ages, a strong blow to the possibility of using mirrors in battle was struck by the French philosopher and mathematician Rene Descartes, who convincingly proved in his Diopter that it is impossible to set fire to a ship with the help of the sun's rays: 32, then any point of the mirror reflects not a ray, but a cone of rays coming from different points of the solar disk, having an angle of 32 degrees at the apex. An incendiary mirror, the diameter of which is less than a hundredth of the distance between it and the place where the sun's rays are concentrated … even if polished by an angel, it cannot … heat that place more than the rays emitted directly by the Sun.
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The French naturalist and inventor Georges Louis Buffon (world renowned for his work "Natural History"), who built a system of 128 flat mirrors in 1747, restored Archimedes' reputation as the world's first combat laser operator. With its help, he not only ignited a tarred board at a distance of 50 meters, but also managed to melt lead and silver.
At the end of the 20th century, a man was found who decided to once again put the experiment, so to speak, in nature. This time it turned out to be the Greek mechanical engineer Ioanis Sakas. Having recruited 70 assistants in November 1973, he placed them on the shore of the bay with shield-like mirrors measuring 91 by 50 centimeters. At Sakas's command, the assistants raised their mirrors several times, trying to focus the sunbeams on the boat loaded with resin. Finally, when the rays were able to combine at one point, the boat started to smoke in this place and burst into flames three minutes later!
A similar experiment (albeit on land) on September 30, 2005 was conducted by students and professors of the Massachusetts Institute of Technology. True, things did not go as smoothly as among the Greeks: the students could not point all 129 square mirrors purchased for the experiment at one point. Soon the sky was covered with clouds, and the continuation of the experiment became impossible.
The second attempt was crowned with complete success - this time the professors decided to do without the muddle-headed students and did everything themselves. With the help of a mirror giving a cross-shaped "bunny-target" to the model of a Roman ship, they alternately pointed all 129 mirrors, previously draped with a cloth, into one place (so that the light of one mirror did not interfere with directing the other).
The tests were successful
Finally, when everything was in focus, the scientists removed the covers. A few minutes later, thick smoke poured from the red oak mockup, and then a flame burst out at the focus point. Having admired their handiwork and extinguished the fire, the scientists discovered that their giant solar "hare" had burned through a 2.54 centimeter thick board.
On the whole, the experiments carried out at different times have convincingly proved that Archimedes could well have used a system of mirrors of his own design to set fire to Roman quincire.
The brilliance and poverty of the heliograph
Today the prototype of the invention of the great Greek is used exclusively for peaceful purposes. A signal mirror (or, scientifically, a heliograph) is included in many rescue kits for military, travelers and athletes. A flash of a heliograph on a sunny, cloudless day is detected from an aircraft flying at an altitude of 1-2 kilometers, from a distance of 20-25, and in some cases even up to 40 kilometers! Moreover, the signal mirror can give signals even at full moon night or in foggy haze.
However, the military is haunted by the colossal energy of the Sun, which, in fact, is wasted. Calculations show that the brightness of the beacon at a sun angle of 90 is nearly seven million candles, and the temperature in the center of the focused light flux can reach several thousand degrees!
It is easy to imagine what one such mirror placed in orbit can create - the reflected rays of the Sun will easily melt not only the tank armor or the bunker wall, but also the covers of intercontinental missile silos. A constellation of such satellites can burn an entire city. And this despite the fact that the military will not spend a cent on the energy expended for the "shot" - our light will give everything away for free.
Of course, "war bunnies" are not an absolute weapon: firstly, thick smoke or fog will weaken their effect, and secondly, why do the winners need the land of the vanquished, scorched and caked from the terrible heat? But as giant spotlights or heaters, projects like these probably have a more realistic future.
Evgeny VASILIEV