<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Remind Jonlear (from the open minds forum) that the values he input into his formula are quite simply wrong. The formula he is using is for 2 static objects. The values he input are more closely related to the Lagrange point (L1). The formula for L1 is far more complicated and involves things like the Hill Sphere, orbital velocities, centripetal forces, momentums and other stuff. It's part of the n-body solutions which is more complicated than I'm prepared to deal with. Factor in the trajectory of the craft only adds to the complication.The formula I used previously to come up with 26,500 miles from the moon is for 2 static objects. Should he use the correct values in his fomula, he will probably come up with with about 1/6th. I don't feel like doing it for him, but I'm pretty confident that's what it will show.Zorgon (from the open minds forum) wrote: "Why are skeptics always so insecure that they need to play a game and keep score... a score that they set the rules for?"Remind him that us "skeptics" didn't write the rules... Laws of physics wrote the rules.infotech (from the open minds forum) wrote: "Then you show the formula you've been given matches the result you've been given. Cool. Now prove it. And please no "Nasa films this or that. Show me how you can personally measure the amount of gravity on the moon and prove the formula is right. A calculator can be worked by a monkey - it doesn't demonstrate proof or knowledge."Formulae derived from observations or, conversely, observations that confirm formulae are both proof the formulae are correct. Not really sure at what he's grasping at here. Monkeys may be able to operate a calculator, but when they input the wrong value, they get the wrong answer.He then goes on to state: "I know card tricks which can pull the card you've picked based on math. Does that mean I'm magic?"Nope... not magic. The moment he pulls the correct card confirms the formula he used is correct. Funny how he uses an analogy that answers his own demands for proof. <br />Posted by derekmcd</DIV></p><p>If you really want to get into the details of the Lagrange libration points L1, L2, ...L5, you might look in <em>An Introduction to the Mathematics and Methods of Astrodynamics</em> by Richard H. Battin. But it gets pretty complicated. If you think you can use the derivation associated with the libration points to change the mind of someone who rejects F=ma, then all I can do is wish you luck and moral support from the sideliines. Given that the post that originated this thread came from another, very different (thank God), forum I fear that you may be either preaching to the choir (here) or talking to yourself (there). <br /></p> <div class="Discussion_UserSignature"> </div>