Israeli scientists solve physics' 'three-body problem'

The three-body problem, which has been a focus of scientific study for over 400 years, represented a stumbling block for famous astronomers such as Isaac Newton and Johannes Kepler.

Earth from space (photo credit: NASA)
Earth from space
(photo credit: NASA)

Scientists at Technion-Israel Institute of Technology have found a solution to one of physics' greatest questions in a paper published this month.

The paper, published in Physical Review X, focuses on the three-body problem, which concerns the orbits of the Sun, Earth, and the Moon.
While in a binary orbit system consisting of two celestial bodies, the orbits can be accurately predicated mathematically, while the complex interactions of a three-body problem are chaotic and unpredictable.
The three-body problem, which has been a focus of scientific study for over 400 years, represented a stumbling block for famous astronomers such as Sir Isaac Newton and Johannes Kepler.
Up until now, scientists could only predict what happens in a three-body system by using computer simulations. When simulating the three-body problem, they found two phases occur.
First, a chaotic phase occurs when all three bodies pull on each other violently, until one star is ejected far from the others, yet still on a bound orbit. In the second phase, one of the stars escapes on an unbound orbit, never to return.
Prof. Hagai Perets and PhD student Barry Ginat of the Technion found a way to calculate a statistical solution to the random two-phase process. Instead of predicting the actual outcome, they calculated the probability of any given outcome.
The entire series of calculations is modeled after a certain type of mathematics known as the theory of random walks, called "drunkard’s walk."
"The random walk model accounts for such phenomena naturally,” said Mr. Ginat. "This has important implications for our understanding of gravitational systems, and in particular in cases where many encounters between three stars occur, like in dense clusters of stars," noted Prof. Perets.