May 18, 2023 23:00:00

Pointed out that the planetary orbit of the solar system is unstable and Mercury may collide with the sun or Venus

The planets in the solar system draw elliptical orbits around the sun. Regarding these orbits, astronomers have proposed the theory that 'sometimes they are stable and sometimes unstable,' and have set up predictions that depending on the way of thinking, collisions between planets may occur.

[2303.05979] A counterexample to the theorem of Laplace-Lagrange on the stability of semimajor axes

https://doi.org/10.48550/arXiv.2303.05979

New Math Shows When Solar Systems Become Unstable | Quanta Magazine
https://www.quantamagazine.org/new-math-shows-when-solar-systems-become-unstable-20230516/

In 2009, Jacques Lascar, an astronomer at the Paris Observatory, and others built a model of the solar system and performed a simulation, and found that if the starting point of Mercury is changed within a range of less than 1 meter, it is only a small amount of 1%. It was discovered that the orbit of Mercury changed with probability and eventually collided with the Sun or Venus.

The simplest model of the orbit of the solar system considers only the gravitational force exerted by the sun. In that model, it is thought that a stable orbit will continue forever, but when considering the gravity of the planet, etc., the result will be different.

Although simulations such as those presented by Rascal and colleagues were astronomically important, they were not mathematically proven and were not entirely accurate. There are billions of scenarios to consider when examining planetary orbits over long periods of time, taking into account factors such as gravity, and proving even the predictions that planetary collisions will occur. It's not easy to do.

Marcel Guardia, a mathematician at the University of Barcelona studying these predictions, and others will publish three papers totaling more than 150 pages in 2023, suggesting that instability will inevitably occur in models of planets orbiting the sun. proved for the first time.

Since early studies in the 18th century, the size and shape of the elliptical orbits of the planets in the solar system have been assumed to be stable, but in the late 19th century

Henri Poincaré discovered that there were only three bodies. However, I discovered that it was impossible to fit it into the existing equation, and my assumptions were shaken.

There have been previous attempts to prove that orbits can also be unstable, but no one has proven that the chaotic behavior of planets can produce large long-term changes. I couldn't do it either. In this study, Guardia and colleagues showed that instability occurs even in a planetary system in which two small objects orbit the sun.

As a result, mathematicians were able to find initial conditions for orbital instability. Instability simulations show that change accumulates very slowly but occurs faster than expected, and in realistic planetary systems, change takes hundreds of millions of years rather than billions of years. Predictions have been made that it may appear.