This plan is totally unreliable in science? After seeing Hawking’s laser pointer plan, some people said that this time Hawking was talking crazy again. In fact, what Hawking said was not crazy. At least in theory, this plan is feasible.
First of all, the “nano aircraft” is getting closer and closer to us. In recent years, nanotechnology has made rapid progress. Nano-scale machines and devices and their energy supply methods have become popular research fields in the world, and some substantial breakthroughs have been made. Nano-scale machines will appear in front of us in the near future. Naturally, it also includes “nano-aircraft.”
In addition, Hawking’s conception is indeed based on the development of existing physics and the progress of the exploration of the human universe. Pang Zhihao, an expert in space technology and the deputy editor-in-chief of “Space International”, said that compared with Hawking’s aerospace vision of using ground-based lasers to continuously act on windsurfing, the two existing programs have great similarities: one is a solar sail spacecraft, and the other is a solar sail spacecraft. It’s a photon rocket. But these two aspects are currently unable to achieve interstellar navigation.
The concept of solar sails appeared very early. It was born in the 1920s. Since light is composed of photons with no static mass but momentum, when the photons hit a smooth surface, they can bounce off the wall like a bounce. Like table tennis, it changes the direction of movement and applies a corresponding force to the impacting object. This is the principle of the development of solar sails.
The solar sail needs a huge reflector to shine the sunlight on a large enough sail board. If the diameter of the solar sail is increased to 300 meters, its area will be 70,686 square meters, and the thrust obtained by light pressure will be 0.034 tons. According to theoretical calculations, this thrust can enable a spacecraft weighing about 0.5 tons to reach Mars in more than 200 days. If the diameter of the solar sail increases to 2,000 meters, the 1.5 tons of thrust it obtains can send a green laser pointer spacecraft weighing about 5 tons outside the solar system.