If I've got it right, it stays in orbit because the gravitational attraction pulling it down toward Earth is exactly balanced by it's tendacy to want to fly off into space [like a stone whirling round on a string when the string suddenly breaks. So the gravitational force pulling it down is exactly balanced by the centrifugal [?] force pushing it away. So far so good.
But now for the harder bit. Presumably that delicate balance of forces is somewhere influenced by the speed of motion of the moon. Our stone on its piece of string will fly twice [?] as far when the string breaks if it is whirled at twice the speed, so so should be the case for the moon. So the magnitude of one of the forces, the centrifugal pulling it away into space, is dependant upon the speed at which the moon moves aroud its orbit. Now there is no such thing as perpetual motion and the moon has no power scource. The only way it can 'top up its tanks' is via the energy it accumulates as it essentially accelerates toward the surface of the earth as it falls [for that is what I believe is actually happening isn't it - its moving forward, but instead of in a straight line it's actually continuously falling into the circular orbit it maintains, but the energy input of the fall, instead of going into a change of rate of motion, is instead brining about a 'vector' change [ie a directional change] from the straight to the circular [an infinite number of consequtive straights]. And as the moon effectively accelerates [but doesn't] toward the Earths surface, its fall is balanced by an equal and opposit increase in centrifugal force that maintains its circular orbit rather than allowing it to actually fall.........or something.
But one day surely it's luck is going to run out. Surely even the minute level of friction it experiences out in space - from say even our thinly spread atmosphere at that distance - will slow it down to the point where it can no longer resist the attractive pull of the earths gravity - and then SPLASH or CRUNCH.
But while we're on the subject, what actually is its period of orbit around the Earth; Earth takes three hundred and sixty-five [give or take] days to rotate around the Sun, but I've no idea how long it takes the moon to rotate around the Earth - no wait - isn't it one day! Isn't that the reason why we only ever see one face of the moon; No that's all wrong - we see one face of the moon because it takes the moon the same time to revolve on it's own axis as it does to orbit the earth. So I guess the moon takes around what, thirty[ish] days, There are twelve months in a year - this means twelve[ish] complete cycles from new-moon to new-moon, but does this actually equate to orbits of the earth [I guess it does - I can't see any other reason why that waxing and waning would occur in the regular way it does]. But why did we give some months thirty days and others thirty-one? But if it takes thirty days to orbit the Earth, then why is it visible in the night sky for all of us every night [except on the single nights of the new-moon]. If it took thirty days to rbit the Earth then for twelve or so days each month it should only be visible during the day [or not as the case may be] while it completes the part of it's orbit that is firmly between the Earth and the Sun; We should thus go for an extended period each month of no visible moon at night?
