Three Body Problem

The Three Body Problem is a four hundred year old problem of mathematics which has its roots in the unsuccessful attempts to simulate a heliocentric Sun-Earth-Moon system.

Due to the nature of Newtonian Gravity, a three body system inherently prefers to be a two body orbit and will attempt to kick out the smallest body from the system—often causing the system to be destroyed altogether. There are a limited range of scenarios in which three body orbits may exist. It is seen that those configurations require at least two of the three bodies to be of the same mass, can only exist with specific magnitudes in specific, sensitive, and highly symmetrical configurations, and exhibit odd loopy orbits that look quite different than the systems of astronomy proposed by Copernicus. The slightest imperfection, such as with bodies of different masses, or the effect of a gravitational influence external to the system, causes a chain reaction of random chaos which compels the entire system to fall apart

—Paul Trow, Chaos and the Solar System (Archive)

400 Years of Defiance
In The Physics Problem that Isaac Newton Couldn't Solve (Archive) physics and astronomy professor Robert Scherrer tells us:

Newton's Solution
Mathematician and astronomer Issac Newton is credited to have "brought the laws of physics to the solar system."1 To solve the multi-body problems of his system Newton famously invoked divine intervention (Archive):

1The University of California San Diego credits Newton with providing the laws of physics for the Solar System (Archive):

Henri Poincaré
http://n.ethz.ch/~stiegerc/HS09/Mechanik/Unterlagen/Lecture13.pdf (Archive)

Ask A Mathematician
https://www.askamathematician.com/2011/10/q-what-is-the-three-body-problem/ (Archive)

No General Solutions
Physics Professor Richard Fitzpatrick at the University of Texas says (Archive):

Science China Press says:

From The Three-Body Problem (Archive) by Z.E. Musielak and B. Quarles we see:

As we read above, there are no general solutions to the Three Body Problem. As the authors of "Ask A Mathematician" related, the only solutions require very specific and odd scenarios.

A Thousand New Solutions
In 2017 researchers used a supercomputer to test various configurations and reported over one thousand new solutions to the Three Body Problem. We read an account from a New Scientist article titled Infamous three-body problem has over a thousand new solutions (Archive) :

As suggested, the field of Celestial Mechanics is still on step zero—the stone age. The found orbits are nothing like heliocentric astronomy and there will be an attempt to use them as a skeleton to "build the whole system up from."

Two Bodies of Equal Mass
The research group with the super computer published another study titled: Over a thousand new periodic orbits of a planar three-body system with unequal masses (Archive). The group found only configurations where two bodies had the same mass.

Hill's Region
Astronomer and mathematician George William Hill studied the Three Body Problem. The only way Hill was able to make any progress at all was by using the Restricted Three Body Problem, where one of the bodies was of zero or negligible mass. Even then, the body was still chaotic. The benefit of the Restricted Three Body Problem and the Mass-less moon meant that that the moon would be no longer ejected from the system, as it would usually be. It is confined to what is known as "Hill's Region".

From http://www.scholarpedia.org/article/Three_body_problem (Archive):



The above depicts a crazy and chaotic moon which even makes a u-turn in mid orbit.

From the text that accompanies the image:

"Zero mass body" -- One of the bodies in the restricted three body problem is of zero mass.

"Nevertheless this does not prevent collisions with the earth" -- It's still chaotic, even in that simplified version.

One might observe that Newtonian Mechanics most certainly does not naturally default to the heliocentric system of Copernicus.

Poliastro
Poliastro, an astrodynamics software developer, shares several numerical methods for the restricted three body problem:

https://twitter.com/poliastro_py/status/993418078036873216?lang=en (Archive)



Arenstorf orbits are the knotted closed trajectories which are the result of Restricted Three Body Problem solutions.

Chaos Theory: A Demo
The available solutions to the Three Body Problem, beyond being unlike anything seen in Heliocentric Theory, are so sensitive that the slightest change or imperfection will tear the entire system apart. From 'Mathematics Applied to Deterministic Problems in Natural Sciences' we read another account of Poincaré's discoveries:

The orbits are incredibly sensitive. As a very illustrative demonstration, take a look at this online Three Body Problem simulator that uses the simplest possible figure eight pattern, which requires three identical bodies of equal mass which move at very specific momentum and distance in relation to each other.

Demo: Figure-Eight Three Body Problem



Adjust the slider values in the upper left of the simulation to something very slight to find what happens. What you will see is a demonstration of Chaos Theory. Any slight modification to a perfect system creates a chain reaction of random chaos.

This is precisely the issue of modeling the Heliocentric System, and why its fundamental system cannot exist. Only very specific, sensitive, and highly symmetrical configurations may exist. The slightest deviation, such as with a system with unequal masses, or the minute influence from a gravitating body external to the system, will cause the entire system to fly apart. The reader is invited to decide for his or her own self whether those scenarios would occur in nature as described by popular theory.

N-Body Solution Galleries
Below are links to galleries of various Three Body Problem solution galleries. One should note the lack of heliocentric orbits and mass restrictions.

Wolfram Science

https://www.wolframscience.com/nks/notes-7-4--three-body-problem/ (Archive)



Institute of Physics Belgrade

http://three-body.ipb.ac.rs/ (Archive)

n-Body Choreographies

http://rectangleworld.com/demos/nBody/ (Archive)

Scholarpedia.org

http://www.scholarpedia.org/article/Three_body_problem (Archive)

Euler Math Toolbox

http://euler.rene-grothmann.de/Programs/Examples/Three-Body%20Problem.html (Archive)

Supercomputing Challenge
Programming students participated in the New Mexico Supercomputing Challenge to simulate the solar system and found issues with creating basic orbits:

Simulation of Planetary Bodies in the Universe (N-Body) (Archive) (Source Code)

The PDF report explains with additional details that all attempts at observing orbit were unsuccessful.

Universe Sandbox 2
Universe Sandbox 2 (Universe Sandbox ²) is a physics based space simulation developed and published by Giant Army. It has often been claimed that this simulation provides evidence that the Sun-Earth-Moon System and the Solar System are able to be simulated with Newtonian Gravity.

Read the following from a developer blog post and decide whether the program is using a full simulation of gravity:

Working Through the N-Body Problem in Universe Sandbox ² (Archive)

Despite any fanciful allusions that it might be possible if we waited for the "Sun to evolve," that there are not enough steps, or reassurances that our solar system is stable despite the inability of simulating it—all common statements to excuse away the problems of simulating bodies in heliocentric orbits—its developers freely admit that the program is not using a full simulation of gravity. The article states "By default, the simulations in Universe Sandbox ² try to set an accuracy which prevents orbits from falling apart due to error".

Sean Carrol
Caltech physicist Sean Carrol (bio) restates the same as all of the above on his page N-Bodies (Archive), starting with the history of the problem.

Sean Carrol describes the three body problem orbits as chaotic and classifies the special available orbits as "highly-symmetric." Dr. Carrol proceeds to give animations of figure eight configurations and other symmetrical orbits which have been discovered.



Readers should decide for themselves whether the Sun-Earth-Moon system or other systems proposed by contemporary Astronomy are "highly symmetric" systems. Recall, also, what happened to the interactive figure eight demo when a slight modification to the masses or velocity was made: The slightest imperfection to the perfect system caused a chain reaction of chaos which caused the entire system to fly apart.

Analytical Vs. Numerical
Q. I think those quotes are talking about analytical solutions. There are working numerical solutions... A. This is a misconception which stems from some sources which state that there are no analytical solutions, only numerical solutions. This might cause a casual reader to assume that there must be solutions in which the systems of astronomy work. While it is true that the analytical approach of predicting position based on initial conditions is much more difficult, and that the available solutions were numerically (computationally and systematically) determined, the working 'numerical solutions' are the special cases described above -- the figure eight and other highly symmetric configurations. The above quotes and sources do not specify analytical versus numerical at all in their depictions of the issue. Nor do they describe that there are alternative ways to get orbits to work. Feel free to read the sources for context. Those classifications are not described. Like the context reads, the sources are talking about the chaotic nature and very limited solutions for the Three Body Problem.