The "three-body problem" can be traced back to the 1980s in 17, when isaac newton, a British physicist and mathematician, correctly predicted the motion laws of two mutually attractive celestial bodies (such as the sun and the earth), and their orbits were basically elliptical. But if there are three celestial bodies, the sun, the earth and the moon, what are their orbits? Newton failed to give a universal and special answer.
Simply put, the "three-body problem" is to discuss the motion law of three celestial bodies with arbitrary mass, arbitrary initial position and arbitrary initial velocity under the action of universal gravitation, and these three celestial bodies can be regarded as particles.
In the following 200 years, scientists racked their brains to solve this problem, until Heinrich bruns, a German mathematician and astronomer, pointed out in 1887 that it was doomed to be useless to find the general solution of the three-body and only the special solution that was established under certain conditions could exist.
1889, Henri Poincare, a French mathematician and celestial mechanic, simplified the complex three-body to the so-called "restricted three-body". However, he found that even for the simplified restricted three-body near homoclinic orbit or heteroclinic orbit, the shape of the solution will be so complex that it is almost impossible to predict the final fate of this orbit when the time tends to infinity under given initial conditions. This uncertainty about the long-term behavior of orbit is called "chaos" phenomenon. It shows that the solution of three-body is generally aperiodic.
It is not easy to find the periodic special solution of the three-body problem-only three groups of periodic special solutions have been found in the more than 300 years since the "three-body problem" was proved.
French mathematician and physicist Joseph Lagrange and Swiss mathematician and physicist leonhard euler got some results in the18th century. In 1970s, American mathematician Roger Brooke and French astronomer Michel Hennon got more results with the help of computers. 1993, American mathematician and physicist Chris Moore discovered a strange phenomenon-the motions of three celestial bodies in the special solution seem to chase each other in the figure-eight orbit. All the above special solutions can be summed up in the following three families: Lagrange-Euler family, Brooke-Hennon family and Figure-8 family. The solution of Lagrange-Euler family is relatively simple, that is, three celestial bodies move in a circular orbit at equal intervals, just like a merry-go-round. The solution of the Brook-Henon family is complicated, with two celestial bodies rampaging inside and a third celestial body orbiting around them.
You know, it is not easy to find a new special solution: the distribution of three celestial bodies in space can be infinite, and it is necessary to find suitable initial conditions-starting point, speed, etc. So that the system can return to the initial state after a period of movement, that is, carry out periodic movement.
In 20 13, Serbian physicists Milovan Suvakov and Dimitra Snovic discovered a new special solution of the 13 family. They published a paper in the famous academic journal Physical Review Express, describing their search method: using computer simulation, starting with a known special solution, and then constantly adjusting its initial conditions slightly until a new movement pattern is discovered. The special solution of the 13 family is very complex, and it is like a loose line group in the abstract space "shape ball".
The family number of the three-body special solution has been extended to 16 family. This new discovery inspired the scientific community. Robert Vanderbilt, an American scientist who has studied three-body for many years, said, "I like this result very much." Richard montgomery, another American scientist, said: "These results are wonderful and the description is wonderful." Zhou Haizhong, a scientist from China, said that their achievements have deepened people's understanding of celestial motion, promoted the further development of celestial mechanics and mathematical physics, and especially helped people to study the orbit of space rockets and the evolution of binary stars.