I recently finished watching the 3 Body Problem on Netflix so this question came to mind. Can anyone explain (in simple terms) why the 3 body problem was deemed unsolvable even by the advanced alien race in the series? Even better, can anyone here simplify what the 3 Body Problem actually is in Physics? It really got my curiosity. Thanks! 🙂
In: Physics
It’s a problem in modelling the behaviour of three or more objects interacting through gravity (but also electromagnetism).
Let’s start with the thing that isn’t a problem: Two bodies. With two bodies you can mathematically create an exact equation, with an exact solution, of how the two objects will orbit each other. The only variable left is time and you can go infinitely into to the past or future. With infinite accuracy.
When you try to do the same for three or more bodies you run into a problem. There’s more variables/unknowns than equations. In maths, this means you cannot have an exact solution where you simply go forward and backwards in time. There’s no “analytical” solution.
That’s not to say there’s no way to solve it at all. But it requires making some guesses and then running the maths over and over hoping it settles on an approximate solution. Then you advance a time step and do it again. And again.
And “approximate” and “time step” are key words here. A solution, not THE solution. An approximation. And with a resolution in time, the more resolution you want, the finer you have to make your steps, the more work you have to put in. And even then you will always eventually diverge from the true solution if you run too far into the future, as the errors accumulate.
Latest Answers