elfmotat

That's probably the worst career advice I've ever encountered.

No, that would constitute a perpetual motion device. Plus gravity is extremely weak. Same reasons we can't do this on Earth.

What do you mean? Normal matter is electrically neutral. There's no net charge on the Moon.

Nobody is stopping them. Notice how the speculations forum is still there.

Not to mention that the "rigorous" section would get close to zero activity. Or activity that belongs there, anyway.

You can stop whenever you like. Just know that once you've left the realm of what's testable you're no longer doing science. Your question is about "why" the laws of physics are what they are. That's untestable, by every conceivable definition of the word. You can ask "how is it we know that there's no such thing as absolute velocity." The answer, of course, is that we've done a bunch of tests and there is zero evidence of any preferred frame! But when you ask "why" it should be that way, there's no way to answer.

When you ask "what causes X" in everyday circumstances, you're working under some framework in which you allow something to be true. Otherwise, you're perpetually asking "what causes the thing that causes X," "what causes the thing that causes the thing that causes X," etc. And eventually you run into the same kind of boundary you've encountered here: you're asking questions to which there are no testable answers. And if something isn't testable, it's not science - it's philosophy. You should watch the video Strange posted again, if you haven't already: https://www.youtube.com/watch?v=wMFPe-DwULM . I don't understand how you're coming to the conclusion that "science knows everything there is to know about motion." Of course that's not true. What we do know is that Newton's laws work, the principle of relativity works, special relativity works. "Why" they work is metaphysics. You either accept that they work (until experiment shows otherwise) and move on, or you get bogged down in untestable "reasons" for why they might work. MOVING IN WHICH REFERENCE FRAME!?!? This is what you're not getting. If there is some frame in which an object is at rest, then there are an infinite number of other equally valid frames in which it is NOT at rest. They are all valid descriptions of the same thing. There is no such thing as absolute movement! That's the problem! There is absolutely no test you can design to measure what your absolute velocity is. None at all. Because it doesn't exist. It's not defined. There's no such thing. I don't know how many more ways I can say it. Under an outdated definition of "mass" (called relativistic mass), this is true. But its gain in mass is only relative to some other observer. Relativistic mass is really just the total energy, and we've already established that energy is frame-dependent.

Looks like Synthesia. Also, just for fun:

That might be tough: http://www.scienceforums.net/topic/86250-goodinteresting-speculations/

You asked, "why are particles able to move?" From there, at the classical level, I can point you to Newton's laws. If you ask why Newton's laws are true, you're in the realm of metaphysics (philosophy). Stop moving according to who? The problem here is that you're still thinking in terms of something either having velocity or no velocity. When you ask a question like, "what causes motion," and we point out that there's no need for any causes by citing Newton's first law, you refuse to accept it! No. Again, Newton's first law. If an object is moving at 12 m/s in some reference frame, and I know it's never been acted on by any forces, then I know that the speed of the object has always been 12 m/s in this reference frame. There is also an equally valid frame where the object has always been moving at 5 m/s, and 108 m/s, etc. In Newtonian physics, yes, force is "absolute" in the sense that a force vector will be the same in all inertial frames. YOU said that, not me! I never said anything of the sort. I don't appreciate when people put words in my mouth. A force which, in one reference frame, will "cause movement," will also cause the object to stop moving in another frame. So the same force is both causing and stopping "movement," depending on which frame you decide to use when you analyze the problem.

Also, I thought I provided a fairly convincing argument that there can't be any "mechanisms," as you describe, which "account for motion." Place a ball on the ground, and then start driving. The ball, in your rest frame, has velocity/kinetic energy. In its own rest frame the ball has zero velocity/KE. How can any mechanism both cause something to move and not cause something to move, depending on what frame you analyze things from?

You're simultaneously saying that you're not asking philosophical questions, while at the same time asking philosophical questions. It's quite maddening. Also, congrats! You're officially the first person I've ever met who doesn't believe in Newton's first law of motion.

The fact that I addressed (or, rather, redirected) that question twice, specifically, in my previous reply should be a good hint that I wasn't referring to that one. Your question is nonsensical. I get the feeling you're just arguing for its own sake now. That is indeed how relativity works, and it has passed every experimental test with flying colors for over a century. "Mechanic causing motion" makes no sense to me. The idea of picking out a preferred reference frame instead of having the symmetry we do is a very ugly thought indeed. Plus, it ruins everything based on relativity and its symmetries.

As I said, it is better to stick to physical and mathematical questions. The type you're asking can't be answered by science. "Does motion exist when we can't measure it(?)" is a bit silly. It's one of those "if a tree falls in the forest..." type questions. The point to take home is in bold. That's exactly what we're saying. As far as us "not getting the whole picture" because there is no way to measure any absolute velocity, that's just a deep prejudice you have. It's a prejudice that exists because some of the aspects of relativity seem a bit contrary to common sense. But that's the way it works, and if you get a chance to learn the math one day you'll come to appreciate just how much more beautiful nature is this way. Thinking about it now, the idea of absolute velocity is really very ugly.

I thought his definition was rather clear. No. Set a ball down on the ground. Now get in your car and start driving at a constant velocity. Relative to you, the ball now has some velocity. Just like magic! Relative to what? That can't happen, it violates physics. You can't use physics to describe situations which violate physics. Relative to what? "Object" is not the same as "reference frame." A reference frame is just a coordinate system. There are an infinite number of coordinate systems you can use to describe a system with one object. Again, what's wrong with Strange's definition?

I don't know what this means either. It would probably be better if you asked more physical or mathematical questions. Questions about "existence" and "reality" tend to be very imprecise.

I don't understand your question. Could you try rephrasing it?

I know exactly what you're saying. All of my questions are driving at the same point: there are no special frames of reference. That's the central principle of relativity (it's actually called the principle of relativity). There is no absolute velocity, or kinetic energy, or time dilation. These things are only defined relative to a particular frame of reference. When you say "it has no velocity," you also need to specify with respect to what it has no velocity. Saying "it has no velocity" by itself is a meaningless statement. Yes, I believe somebody did mention something like that:

I don't know what "mechanisms" you're referring to, or how that answers either of my questions.

No kinetic energy according to who? No time dilation according to who?

I thought you were saying that the mass of the electron increases over time? What you're describing now (some sort of scattering process) seems completely different than what you were talking about earlier.

There's no such thing as absolute velocity. That's the whole point of relativity.

You can in principle describe any system with a single wavefunction. It has nothing to do with what I said.

Energy/momentum must be conserved at every point in space. If an electron gains energy somewhere and a proton loses energy somewhere else then conservation of energy cannot hold. In their rest frame you could say that when the electron gains energy the proton simultaneously loses energy. But in a reference frame moving with respect to the proton/electron the two event did not happen simultaneously, which means there was temporarily more/less energy then there should be, so energy conservation is violated.

That's just the weirdest train of logic I've ever seen. It doesn't even come close to making sense.