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**Flat Earth General / Re: Anyone for a public discussion?**

« **on:**November 13, 2017, 04:32:43 PM »

imagine you bring a pebble inside and drop it from some height. you make a plot of its position over time (its lateral motion, let's say) and you get a straight line. neat! there is a mathematical function that describes straight lines. you have an analytic solution for the object's position with respect to time or displacement or something.

now imagine you bring a leaf inside and drop it from some height. you plot its position over time, but now the plot is all messy, like graph #2 from my previous post. damn. there is no analytic solution that describes this motion.

where did the failure of physics happen? you didn't do any physics. you just plotted the position of an object over time. one of them

now imagine that i have a phd in fluid dynamics or something, and i simulate your leaf-dropping in a computer. i tell it how to update the position of the leaf over time using equations of motion from physics. if my code makes correct predictions, then it's asinine to say "your solution isn't analytical therefore it's wrong and/or meaningless." the opposite is true. i've used the laws of physics to get a numerical solution to an analytically unsolvable problem. that's a success, not a failure.

you are completely misunderstanding both what this paper is saying, and what an analytic solution represents. and what a function is, if i'm being completely honest.

also i did not say that the solution from that paper is not very useful. i said that there do exist analytic solutions to 3bp, but they are not useful. numerical solutions are useful and make accurate predictions. numerical solutions are computationally expensive (you're iterating lots of tiny time-steps, for example), but they're not less useful/accurate/valuable than analytic solutions.

now imagine you bring a leaf inside and drop it from some height. you plot its position over time, but now the plot is all messy, like graph #2 from my previous post. damn. there is no analytic solution that describes this motion.

where did the failure of physics happen? you didn't do any physics. you just plotted the position of an object over time. one of them

*happened to be describable by well-known analytic functions*. the other did not. nothing failed at anything. it's just that lots of stuff can't be described analytically.now imagine that i have a phd in fluid dynamics or something, and i simulate your leaf-dropping in a computer. i tell it how to update the position of the leaf over time using equations of motion from physics. if my code makes correct predictions, then it's asinine to say "your solution isn't analytical therefore it's wrong and/or meaningless." the opposite is true. i've used the laws of physics to get a numerical solution to an analytically unsolvable problem. that's a success, not a failure.

In the article you linked the authors basically created a scenerio where three bodies moved around each other and decided that they solved the three body problem. When you make a graph with a function you are computing a pattern.

Solving the three body problem is actually much more complicated than that; it's providing a solution that will allow us to solve the problems in space and physics, where we do not know the exact "function" that brings the scenerio to its conclusion. You admitted yourself that the solution of the page was not very useful.

you are completely misunderstanding both what this paper is saying, and what an analytic solution represents. and what a function is, if i'm being completely honest.

also i did not say that the solution from that paper is not very useful. i said that there do exist analytic solutions to 3bp, but they are not useful. numerical solutions are useful and make accurate predictions. numerical solutions are computationally expensive (you're iterating lots of tiny time-steps, for example), but they're not less useful/accurate/valuable than analytic solutions.