Talk:Lagrange point
More references[change source]
Lagrange's original paper : http://www.ltas-vis.ulg.ac.be/cmsms/uploads/File/Lagrange_essai_3corps.pdf Essai sur le Problème des Trois Corps
English translation of relevant chapters : http://www.merlyn.demon.co.uk/essai-3c.htm A translation of Essai sur le Problème des Trois Corps (Chapitres I et II) by Joseph-Louis Lagrange. (Essay on the Three Body Problem) (a button must be pressed to typeset the equations)
94.30.84.71 (talk) 18:30, 3 March 2015 (UTC)
These asteroids are called Trojan asteroids.[3][change source]
The article contains "These asteroids are called Trojan asteroids.[3]". I consider that 2010 TK7 is not a good example, as it travels so far away from L4. I think it would be better to choose a better-behaved Trojan-named (i.e. not Patroclus) asteroid at Jupiter's L5. Or 624 Hektor.
By the way, I am not currently editing the article itself because I don't know Simple English well enough to write it.
94.30.84.71 (talk) 20:55, 3 March 2015 (UTC)
What Lagrange Actually Did[change source]
The article contains "It is named after the mathematician Joseph-Louis Lagrange, who wrote a paper on this in 1772". "It is" should be "They are". Lagrange's paper was on the Theory of the Moon, described in its title as the Three-Body Problem. Chapter one was rather general. Only chapter two was particularly related to what are now called the Lagrange Points. The remaining two chapters were specifically about our Moon. Lagrange's aim was to win the Paris Prize for the set topic of the "Theory of the Moon". So "a paper on this" is misleading.
Also "(long before we put satellites into orbit)" - that is irrelevant. But he did write long before the first Trojan asteroids were observed.
94.30.84.71 (talk) 11:23, 4 March 2015 (UTC)
Point / Points[change source]
The title of the article is "Lagrange Point". But its topic is Lagrange Points, so the plural should be used in general. The only time when it is right to use "Lagrange Point" is in reference to just one of the five points in a single primary+secondary system.
94.30.84.71 (talk) 11:23, 4 March 2015 (UTC)
Centripetal Force[change source]
Article has " ... and the effects of gravity from the larger objects and the centripetal forces balance out. (Centripetal force is the push outward that comes from spinning around)".
No. Consult the articles on centripetal force and centrifugal force. Use something like " ... and the effects of gravity from the larger objects provide the centripetal force needed to maintain the third object in a constant relative position".
94.30.84.71 (talk) 15:02, 4 March 2015 (UTC)
The above is correct and I fixed that part Regards EngineerSteve (talk) 02:41, 4 May 2018 (UTC)
Stability at L4 & L5[change source]
Article has "L4 and L5 are considered stable - if a satellite gets a bit out of place, it will be pushed back into place by the gravity and centripetal forces".
Use "termed stable", perhaps; it is not a matter for consideration, since it is known by observation and proved by maths. Not "gravity and centripetal forces" - it is gravity which provides the centripetal force. And the small body is not "pushed back into place"; but a small body with approximately the same position and velocity will remain near to the Point.