Chapter 2347: Archimedes

"Laser ignited? No, this solution has already been discussed! The laser will diffract during firing! At such a long distance, even if the laser can reach the detonation point, the light spot will diffuse due to diffraction, and the energy released per unit area will also be It will be diluted, and the energy intensity required to ignite the mixed gas will not be reached at all!" Some scientists make judgments by just glancing.
　　 is different from ordinary people's subconscious understanding. The laser is not a straight line, it is more condensed than the light emitted by the flashlight, and the degree of scattering is lower, but it is not non-scattering.
Let’s use the most common laser as an example. The laser pens on the market that are sold as toys generally use laser modules with glued crystals. They are generally green light with a wavelength of 532 nm, and the diameter of the optical port is 1.5 mm. The laser pointer, the emitted laser, and the light spot radiated five meters away will spread into a circular spot with a diameter of one centimeter.
According to this ratio, a beam of laser light is projected on the earth and projected on the moon. The distance between the earth and the moon is 384403.9 kilometers. If this laser pen can shine on the moon, we can see that the spot diameter will reach 653.4 thousand. Meters, the diameter of the moon is only 3476.28 kilometers.
The area of ​​the light spot projected by the laser pointer on the moon will become huge. Of course, this spot cannot be seen by the naked eye, because the laser light is scattered, and the visibility of the light spot projected on the moon is extremely low, which is less than 100 million. In one ten thousandth, it is no longer visible to the naked eye.
Controlled nuclear fusion requires the use of a strong laser to ignite, so the world of the wandering earth is extremely researched in the field of lasers, and people have long thought of using lasers to ignite the mixed gas between the earth and Jupiter, but even the lasers owned by planetary engines The transmitter can emit less scattered laser light, but as long as it is multiplied by the long distance that the earth reaches the detonation point, when the laser reaches the detonation point, the energy per unit area is not enough to detonate the mixed gas.
This is the same reason as the sunlight scattered by the sun. The sun is like a huge nuclear fusion reaction device. It can convert 40 billion tons of matter into energy every second, and a large part of it is converted into light energy. Without scattering and attenuation, the earth has long been evaporated by the sun.
"In addition to scattering, the atmosphere will also attenuate the power of the laser. Although the earth's atmosphere is now very thin, it will still greatly consume the energy of the laser. At the same time, the mixed gas between the earth and Jupiter will further cause energy attenuation. Therefore, even if the most powerful laser emitter developed by human beings is used, the emitted laser is not enough to ignite the gas mixture in the umbilical cord space!" the scientist shook his head and said, "We don't have much time. Wasted, let Lieutenant Colonel Liu Peiqiang continue to implement his plan!"
　　 Hearing this, Liu Peiqiang's hand was placed on the escape capsule key again, but another scientist's words made him not press the key immediately.
　　 "No, this plan does not use a laser to illuminate the tipping point!" The scientist who first saw the plan swiped the screen to the next page, and the pattern on this page revealed the truth of the plan.
　　 "This is...Archimedes?" Seeing this scene, many scientists think of the ancient Greek mathematician and physicist who lived more than 2,300 years ago.
"Yes, this plan is the same as Archimedes used to burn the Roman fleet led by Marcelas with a mirror! The energy intensity of a laser is not enough, then use a thousand or ten thousand lasers! These lasers are directed at the same area for irradiation. Thousands of laser beams are superimposed. Even if there is energy loss due to scattering and the atmosphere, the energy intensity required to ignite the mixed gas can still be achieved!" the earliest scientist shouted, "This plan must work!"
According to legend, when Archimedes was old, war broke out between his city-state Syracuse and Rome. The highest commander of the Roman army, Marcelas, led a large fleet to attack, and it was completely impossible to rely on the military power of Syracuse. Resist the army of Marcelas.
Although Archimedes did not like war, he did not want his hometown to be destroyed by the enemy, so he thought of a way to let women and children each take the mirror of their own home to the shore and let the mirror Aiming at the strong sunlight, it focused on the main sail of the enemy ship, and the reflections of thousands of mirrors gathered on a point of the sail. The sail burned, and the fire was taking advantage of the wind, and it burned more and more, Marcelas I didn't know how the sails burned. I thought that Syracuse was blessed by gods, so I dared not continue to march and quickly evacuated with the remaining fleet.
　　Of course, this is just a fable story, which can't withstand scientific verification. First of all, even if it is a bronze mirror, it is a luxury in the era of Archimedes. It is hard to say whether the ancient city of Syrah can find so many mirrors.
　　Second, the reflectivity of copper mirrors is far less than that of glass mirrors. Even if so many mirrors are found, it may be difficult to succeed.
In addition, it is not a task that can be completed by relying on the naked eye to judge many mirrors at the same time. The popular science show "Rumor Terminator" has verified this legend. UU reading www.uukanshu.com they found that when they are mirrors When it rises to twelve, it is difficult for the person operating the mirror to know exactly what light is reflected by the mirror he controls.
According to the test results of the program, at a distance of 140 feet, 300 copper mirrors were used to make the static hull smoke, and when the mirror was aimed at the sail, a large amount of heat was lost, because the sail was white, and the wind blows before it is used up .
　　 Finally, at 75 feet, the still hull was ignited with a glass mirror, but such a close distance was enough for the Romans to attack, so Archimedes’ plan did not have actual combat value.
Some people have done similar verifications in history. In 1747, Earl Dubuffen burned wood 150 feet away with 168 glass mirrors, but it was wood coated with distillate oil; in 1973, the Greek scientist Ioni-Shaka Dr. Si, he let 60 sailors hold a 6-foot-long 2-foot-wide reflector and ignited a splint nailed to the rowing boat 160 feet away, but these also did not have actual combat value.
　　 In the future, scientists of the earth have also tried similar weapons, and they finally gave up for the same reason.
However, to transfer this idea to the crisis facing the world of "Wandering Earth", it is very operable. It is impossible to accurately control so many laser emitters to be directed to an area at the same time by human power, but moss can do it, it can distinguish The landing point of each laser beam does not depend on the naked eye.
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