View Full Version : About the gravity on the moon (and possibly other scientific subjects)

14th July 2011, 12:05
Hey all!

I have a nice opportunity during this summer which is to spend some time with very clever people. I'll quickly explain this to you: my sister is working to get a doctorate (in mathematics - game theory) and spends most of her time working at the university. I'm a student. Not a very good one: I missed 7 exams and have to take them again in late august-early september. In order to motivate myself and to be in a good studying environment, my sister told me I could go work at the university.

So here I am, spending most days with (mostly) guys who are supposedly good theoricists and getting to ask them questions. (I've only met mathematicians, informaticians and physicists until now)

My first question to a physicist was about the John Lear's words about the gravity on the moon. So I showed the demonstration that implies Von Braun's neutral point, and I came out of his office nearly the same as when I entered: unsure.
He says that the demonstration is correct, but if there's a mistake, it's the position of the neutral point. So I googled a little bit about Von Braun and the position, but I did not find any good scientific article that might convince him.

Maybe you could help me on that? If you have good resources I might show him, I'd be glad to 'interfere' with his ideas and his knowledge.

Also, the way we usually calculate the gravity on the moon is by using the masses of earth(?)/moon. I assume that if that way is wrong, it's the masses that are wrong. Do you have an idea on how we estimate the mass of the earth/moon ? And do you have (again) any resources on how we do it and why it's not correct?

Thank you !

Oh and also, they all are very kind and patient so if you have some scientific stuff (yep, it has to imply long equations and to be incomprehensible... ^^ nah, just kidding.. but..) that is interesting but not commonly admitted, I'd be glad to ask clarifications!

[EDIT] Maybe this should be moved to the science subforum?