If ever hostile aliens arrive on Earth, then all of us will end. And this is a logical conclusion, because the species traveling between stars and galaxies must surpass us in intelligence and technological development. So, they can perceive us as backward beings with whom it is not worth negotiating. How do we protect ourselves?
If you can not win, then hide! This idea was proposed by astronomers from Columbia University. They propose to create a giant laser camouflage device to hide the entire Earth from the aliens. Yeah, that's not a joke.
That is, they conceived to take the technique that is used to search for aliens, and use it with the opposite value. Now, to search for other worlds, we direct our giant telescopes in the direction of distant stars and check the level of incidence of light during the passage of the planet. If there is a constant surge, then there is an alien world in orbit.
In mid-August 2010, Yuri Beletsky took this amazing photo from the Paranal Observatory. A group of astronomers observed the center of the Milky Way with the help of a laser guide at a star station, which is one of four telescopes in the Very Large Telescope system. The laser beam crosses the southern sky and creates an artificial star at an altitude of 90 km. The “laser star” is part of an adaptive optical system and is used to correct the atmosphere blur effect on images. This method has allowed to find thousands of exoplanets over the past few decades. Therefore, we hope that one day we will find another planet with life. It is clear that the aliens can use the same technique to try to find another life — us. In the end, they can actually discover the Earth and fly in for the invasion. Therefore, we must make sure that our passage in front of the Sun will not be noticed.
The exit from the situation will be a large laser, whose beam is directed directly at the star, near which aliens can live. When flying in front of the Sun, we simply turn on the laser and mask it. Scientists believe that a continuous 30-megawatt laser operating for 10 hours once a year will cope with this task. This is the same amount of energy that the ISS solar cells collect each year.
To cover all the bases, you can create a whole laser system that emits light at all effective wavelengths. But it is necessary to increase the power to 250 megawatts. If we talk about an alternative option, then you need to hide hints of biological activity on Earth. Such a laser needs power up to 160 kilowatts. If we understand that the aliens are peaceful, then the lasers will notify us of our presence. Scientists are still arguing about whether we need to reveal ourselves and broadcast about our existence to the entire galaxy. In fact, a new scientific work offers a choice: declare oneself or hide. Some even believe that you should not worry. If the newcomers are reasonable, then they will refuse to contact themselves with earthlings.