Lagrange point: Difference between revisions
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(Created page with "<!-- A Lagrange point is a point where the gravity between bodies balances out to be nothing. : ...assuming we are dealing with just two bodies heavy enough that any others areound have negligible effect. : This is often true enough, but you can make things more complex if you want - [https://en.wikipedia.org/wiki/N-body_problem n-body problems] just get involved ''fast'' Also, note that while you could consider this to be about objects sitting in space, we more usual...") |
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A Lagrange point is a point where the gravity between bodies balances out to be | A Lagrange point is a point where the gravity between bodies balances out to make for a stable place to be. | ||
This is usually simplified to assume we are dealing with just two bodies heavy enough that any others around have negligible effect. | |||
Which, given the distances involved, and/or the other influences being fairly constant, is often close enough. | |||
...yet you can make things more accurate and complex if you want - [https://en.wikipedia.org/wiki/N-body_problem n-body problems] just happens to get very involved very quickly. | |||
Also, note that while you could consider this to be about objects sitting in space, | Also, note that while you could consider this to be about objects sitting in space, | ||
we more usually talk this in the context of orbits -- because | we more usually talk this in the context of orbits -- because without the relative speeds that make for (potential) orbits, | ||
those bodies will soon smash into each other. | |||
So it's about bodies that move, which also means that Lagrange points will move. | |||
Read or watch enough sci fi and the term will pop up ("our FTL is dangerous to do in gravity, so our clever cowboy of a captain timed it right in the Lagrange point" type thing), and you'll have an awareness of these things. | |||
Which leads to the intuition is that these are the points where gravity balances out to be zero. | |||
Yet there are a few reasons this can be as confusing as it can be helpful. | |||
An arguably better intuition is that Lagrange points are the points where the balance of forces can | |||
happen to make for another potentially-stable place to be (another orbit of sorts). | |||
I'm also pushing this angle because what they tend to not mention is that for two orbital bodies | |||
there is not ''a'' Lagrange point, there are actually '''five Lagrange points''. | |||
If you only ever heard of the one, this seems a little weird, because surely there's just one point things balance out? | |||
Turns out they are all slightly different in nature, and this comes largely from the "because moving / because orbits" part. | |||
(In one view - if they weren't moving they'd all overlap) | |||