east

i do not undertsand the concept of multiple centers. a center is a center. if you take an atom, it has a center. if you take a neutron it has a center. it you take a quark, it has its center. the sun, the moon, milky way, all has is centers. so if you have multiple gravitional centers, there would still be a position which is the center of these centers, and that would be the true gravitional center of the earth. my original question of wether a plumbline would pass through it is i think answered, and sadly for me it's no. so now i would have to find another way to determine where the center of gravity for earth is. a plumbline just isn't enough i guess, but it was certianly a good budget science attempt for me

i need simple software tool to test circular motions or dynamics. i have seen some really higly souped up ones, but i want just a simple animation given inputs such as gravity, radius, speed etc etc. even one without the animation or graphics is fine. could someone recomend a good flexible software for this purpose please. i don't want to have to handle sophisticated CAD software. by the time i'm done learning the software i would have forgotten why i needed it in the first place.

scientist, but the word defintion is one who deals with knowledge. engineer, by the same token, is one who deals with a problem. when you try and solve a problem which is associated to knowledge, you are a scientist. when you try to solve a problem associated with existing knowledge, you are an engineer. thus as you can see, it is a rather vague line, but if you go out to seek new knowledge, you are more of a scientist than an engineer. and when a scientist uses established formulaes or methodologies to solve a problem, it is more of engineering. science is said to be the father of engineering, for without science, there can be no engineering. ( without knowlegde how can one solve problems ? ) so there is no versus really, only very different roles. perhaps the classic story is when two radio engineers were given the nobel prize for discovering background radiation from the past. they were engineers, set out to solve a real engineering problem, which is to make microwave receivers without noise, and found they just could not eliminate the noise. they do not know what they have found because they were not scientists in that capacity. but when scientists heard about it, they then realised it must be the radiation from big bang. no equipment will be able to eliminate that source of noise ! one needs another, anyone can discover anything, but no matter what, the science has to be there. if not, you would have to test several thousand materials before you get light. my 2 cents.

oh, ok, thanks.

yes, sorry, i was sleepy when typing that. you are right, there no photons as yet.

so far all arguments have been on the basis that the magnet is as it is, with no extra energy input into the system, pyramids, spheres, whatever. given an unstable arragement of magnets but with a little energy persuade it to stay, perhaps a spherical magnet is possible, a monopoled one. what if, we reverse the situation and have all magnets around and pointing to an iron sphere. would not that sphere be a monopole magnetised sphere ? Merged post follows: Consecutive posts merged probably a strong glue to hold it all together, but yes, that would be a spherical magnet equivalent. if the magnets are relatively small ( in rod diameter ), the approximation gets better. i am not sure what the resulting forces would be other than the obvious pole-pole repel, but it would be most intersting to 'see' the irong filing pattern just outside the surface. maybe we see a manetism equivalent of surface tension. extending the logic a bit, is we were to assume all the magnetic effects were to cancel out at the surface, that leaves just the ones emanating from the magnet outwards. so a cloud of non mangetic layer followed by high magetic layer just above.

which is i take to be the definitition of time within this range of measurement i.e. x number of occurences of the caesium atom. agreed. yes they may say it is fast or slow, but that is not to say that there isn't a dependable measurement unit, so perhaps not a problem. what i'm saying is that any arguments not taking this real measurement unit into consideration is perhaps not valid, by virtue of lack of real reference. in the context of the slowed down light, it is relative to this entirely separate event (i.e. the caesium atom vibes ), and hence slow. the interesting counter argument proposed is that it is not, light remains at the same speed. and my question would be relative to what ? for quite a simple requirement of measuring speed is that you need time. ( i.e. in this case a count of the number of occurences of an event ).

just maybe i am not. from point A, to point B, if light L1 takes n clock ticks, but L2 takes >>n clock ticks of the same clock as reference, you are saying light L2 is not slower than light L1 ?, that it is of the same speed ( only appearing to be slowed down ) ? c'mon. maybe light has a maximum speed, but anything in between is very possible. for a start, when you have not switched on the torch light, what is the speed of light ( of the photon ? ). curious.

ah ok, understood. it would be the case then that all these points would amount to zero gravity, neglecting for the moment other heavenly bodies. not that i know of, theoretical physics is just my hobby. i found this forum and thought it might be the right place to ask and talk about these kind of things. it if is not, i would stop. or i don't mind being reffered to another site/forum where theoritical phycics can be discussed. i just need to get these thoughts out, it is bothers me a little in the sense that it remains unsolved, like a mystery unsolved. so far it has shed better light on the center of gravity dillemma, so if possible, i'd like to go on to see what can be derived from this. thanks.

i think this is very relevant to all what is said, 'time' as we know it is measured by the natural frequency of caesium atom, but that is our own human choice of measurement. so there is no real time, there is only a series of events, of things happening. and if the event did not happen or has not happened yet, time is not and cannot be defined or perhaps defined as none. if this very real phenomena is not taken into account, all arguments about time is quite absurd. thus all formulation becomes absurd. Merged post follows: Consecutive posts merged i beg to differ. 'light' has been made to slow down in real experiments. it has also been made to 'freeze'.

just try 'slapping' hard a pool of water. it isn't as 'liquid' as you would imagine. * please do not try too hard, unless you have a black belt or something, you may injure yourself. *

is there such a thing ? has anyone made such a thing ? if not, what is the theory that explains that it canot be done ? if yes, where are the 'poles' ?

thanks for your resposes. i'll address both responses at once. ok, so we are talking of a non perfect sphere. but it isn't the shape that is so much of my concern, more of the center of gravity, the exact center. btw, it isn't the quantum of vectors that matter in this case, as in it adding up or cancelling, it is more of it meeting or not meeting/crossing each other. that it does not meet due to the shape is a temporary drawback. what i'm saying is that, if you take an object, there is what is referred to as center of gravity, where at that point, the whole object is balanced with respect to earths gravity. hence, if we can imagine 'gravitaional lines' going through this object, it must surely intersect at this point. am i right in saying so or am i missing something ? now, if we are to extend this reasoning to the earth, i am inclined to believe that it does intersect at one single point. that it does not do so due to the non spherecial shape is accepted. so each an every line will pass through, and if we make infinite lines, we would get the shape of a smaller object. now let's say we start again, with this smaller object, and repeat the whole plumbline process. again my question, would it not eventually come to a single point ? do you see any serious fault with this theory i have hanging in my head. because i certainly don't but there may just be something i might have missed.

or any planet for that matter. i have been bugging myself with this question for days, please help with some physics input, the question is perhaps on theoretical physics but it bugs me nevertheless. Q. if we draw lines towards gravity of the earth, will the lines intersect at exactly one point at the center of the earth ? a plumbline would be such a line, if we have people holding a plumbline everywhere on earth, and someone draw an accurate line through it, would they all meet at one point ? i am trying to establish if gravity is a point, a singular point. many thanks for your ideas and input.