Motion
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From: Herman Trivilino on 29 Sep 2005 19:26 "TomGee" <lvlus(a)hotmail.com> wrote ... > The cause when CV exists wrt other objects is the fact that they are > all moving at the same speed and in the same direction. If you are moving with constant velocity wrt to another object, then that object is, by definition, at rest with respect to you. > Whatever > causes them to be in such a state can vary, but in our case above, the > fact that we are at rest wrt to the Earth is the cause of our CV wrt > the Earth. If we are at rest with respect to Earth, we are not movign at constyant velocity wrt the Earth. > For a sole object free of any external forces, CV is caused by the > inherent force which I claim exists in every body and which is the > total of the momentum of the mass and the energy it has due to its > motion. Can you describe an experiment you could perform that would establish whether a "sole" object is moving at constant velocity as opposed to being at rest? ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =----
From: TomGee on 29 Sep 2005 20:39 Herman Trivilino wrote: > "TomGee" <lvlus(a)hotmail.com> wrote ... > > > The cause when CV exists wrt other objects is the fact that they are > > all moving at the same speed and in the same direction. > > If you are moving with constant velocity wrt to another object, then that > object is, by definition, at rest with respect to you. > > Yes, correct. > > > > Whatever > > causes them to be in such a state can vary, but in our case above, the > > fact that we are at rest wrt to the Earth is the cause of our CV wrt > > the Earth. > > If we are at rest with respect to Earth, we are not movign at constyant > velocity wrt the Earth. > > Why not? We are moving at the same speed and in the same direction as the Earth, and that constitutes constant velocity. > > > > For a sole object free of any external forces, CV is caused by the > > inherent force which I claim exists in every body and which is the > > total of the momentum of the mass and the energy it has due to its > > motion. > > Can you describe an experiment you could perform that would establish > whether a "sole" object is moving at constant velocity as opposed to being > at rest? > > As I have mentioned before, it is not possible, with what we know about our universe, to do that because everything is in motion in the universe for a number of reasons, the most common one being that the universe is in a state of expansion. The only way for constant velocity to occur is as a comparison between two or more objects like your home and the surface of the Earth as they move through space together as one object. Newton's 1st law of motion states that a body having no external net forces working on it will achieve constant velocity by itself. However, because that body is necessarily caught up in the universal expansion process, it too is involved in it one way or another. Besides the obvious effect that everything is moving away from each other, Newton's sole body is in motion due to its own inherent force, as my model claims, or due to it needing no motive power, i.e., a force to move it, as we have always been taught. We have no way of proving Newton's 1st law, but there is no reason to think a body will not achieve CV when all net external forces are removed from it. We could send a spaceship out and shut off its motive power, then it should achieve CV if it is so that space is expanding instead of the visible matter in the universe moving away from each other. At this time we are not sure what is really happening. I tend to think now that space is what is expanding because we see galaxies move apart but yet maintain their original coordinates wrt each other. I cannot think how that can happen unless it is space doing the expansion and moving the objects apart and not the objects themselves moving apart under their net forces. Good question.
From: Herman Trivilino on 29 Sep 2005 22:07 "TomGee" <lvlus(a)hotmail.com> wrote ... >> If we are at rest with respect to Earth, we are not movign at constyant >> velocity wrt the Earth. >> > Why not? We are moving at the same speed and in the same direction as > the Earth, and that constitutes constant velocity. But when you are co-moving with another object, you are at rest wrt that object. That's what ti means when a physicist using the expression "at rest". There is no way to make it more meaningful unless you can establish a true frame of refenrence that is at rest. So far, no one has been able to do that. >> Can you describe an experiment you could perform that would establish >> whether a "sole" object is moving at constant velocity as opposed to >> being >> at rest? >> > As I have mentioned before, it is not possible, with what we know about > our universe, to do that because everything is in motion in the > universe for a number of reasons, the most common one being that the > universe is in a state of expansion. If it's not possible, based on we know, then perhaps it's not possible at all. There is no way to tell. Based on what we know now, there is no way to make the determination. > The only way for constant > velocity to occur is as a comparison between two or more objects like > your home and the surface of the Earth as they move through space > together as one object. Right. Now, take that sentence and replace the words "constant velocity" with "no velocity". Here is what you get: The only way for no velocity to occur is as a comparison between two or more objects like your home and the surface of the Earth as they move through space together as one object. > We have no way of proving Newton's 1st law, We have no way of proving ANY law. What we can do, though, is try to find exceptions to laws. In which case we can disprove them. That is all. When, despite all attempts to find an exception, we fail, it boosts our confidence in a law. That is currently the status of Newton's 1st Law. ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =----
From: Randy Poe on 30 Sep 2005 09:24 Robert Low wrote: > TomGee wrote: > > > Hey, that's my position, not yours! A derivative cannot be equal to > > the function from which it is derived! If you knew what a derivative > > is you would have known that. > > What, not even when it's the exponential function? I was wondering if Tom would muddy the waters with that one, though I already thought through my response. It's mathematically possible, but not physically possible for p to be equal to k*exp(t) on the basis of units. You don't see things like exp(t) in physics. Arguments to exponentials are always unitless. They'd better be, or the outcome would depend on the units of t. - Randy
From: Robert Low on 30 Sep 2005 09:38
Randy Poe wrote: > I was wondering if Tom would muddy the waters with that one, > though I already thought through my response. It's > mathematically possible, but not physically possible for > p to be equal to k*exp(t) on the basis of units. I tend to try not to think about this, because I get all confused, but if I'm forced to think about it, I think that the 't' there is just a number, which we interpret as the number of seconds (hours, fortnights, whatever) which have elapsed. Clearly, in this case, 'k' would have to have units of momentum. > You don't see things like exp(t) in physics. Used to see it all the time when I did damped harmonic motion. (OK, it was usually exp(-t) then.) But I suspect that I'm jumping in on a discussion and adding even more cross-purposes than were already there. Sorry about that. |