Motion
in [Physics]
|
Prev: Free fall
Next: 50% OF POPULATION BELOW AVG IQ!
From: PD on 22 Sep 2005 00:46 TomGee has made a couple of logical and semantical errors, not the result of being stupid or recalcitrant, but because of incorrect preconceptions that he has not yet abandoned. TomGee has failed to recognize that, in logic, the statement "If A, then B" is completely equivalent to the statement "If not B, then not A". Their being equivalent means that both do not need to be explicitly stated. For example, "All female mammals feed their young from mammary glands," is completely equivalent to the statement, "If an animal does not feed its young from mammary glands, then it is not a female mammal." In a similar vein, the statement "If a net force is impressed on a body, then the body accelerates," is completely, logically equivalent to "If a body is not accelerating, then there is no net force impressed on the body." TomGee feels the first can be true and the second one not necessarily be true, not realizing that the two statements are logically identical. TomGee also fails to recognize that the incompleteness of a statement does not affect its truth. For example, the statement "Some mammals ambulate on four limbs" is a true statement, even though it is also true that "Some mammals ambulate on two limbs, some mammals ambulate on two fins and a pair of flukes, some mammals ambulate on two limbs and two wings." Omitting the latter statements does not make the former statement untrue. In the same way, the statement "A body only slows down as the result of a force acting on it" is true even though it is also true that "A body only speeds up as the result of a force acting on it" and "A body only changes direction as a result of a force acting on it." Omitting the latter two statements does not make the former statement false. PD
From: Schoenfeld on 22 Sep 2005 00:48 Eric Gisse wrote: > Schoenfeld wrote: > > [snip] > > > > > s(t) = SUM{n=0}^+INF [ s^n(0) t^n / n! ] > > > > Your assumption that dg/dt = 0 reduces s(t) to: > > s(t) = s(0) + s'(0)t + 1/2 s''(0)t^2 > > > > > > Much simpler. > > I derived the solution, you reverse-engineered the solution from an > arbitrary equation. Not an arbitrary equation and no reverse engineering, just trivially true by definition. hint: all continuous n-variable functions are also functions of their derivatives. > > > > > > > > > > Don
From: PD on 22 Sep 2005 01:11 TomGee has opined that a body steadily loses kinetic energy due to drag from passage through dark matter, and that therefore an internal force is required to continue to supply energy to keep a body moving. He has also opined that the internal force pulls this energy from the very same dark energy that the body bleeds its kinetic energy into. Thus there is, he has opined, a loop of energy from the body to dark matter and back to the body, the whole mechanism operating indetectably and with perfect efficiency behind the scenes. Since this force is not an external force, he has claimed that Newton never ruled this out as a possibility. I would like to suggest a thermodynamic argument why this is probably not so. In an object at some nonzero temperature, the atoms of an object are all flying about in random directions, the individual atoms' average kinetic energy being measured by the temperature of the body. Individual atoms may have their speeds adjusted when they collide into each other, but the collisions are elastic and so the average kinetic energy would stay the same even accounting for those collisions. Note that in current models of thermodynamics, a body does not cool down on its own, losing kinetic energy spontaneously. The only time a body cools down is if it is put in thermal contact with another body at a lower temperature, transfering kinetic energy from one body to the other body until the temperatures are equal, at which time the exchange of energy from one body to the other is the same in both directions. For example, an ice cube will not cool down spontaneously unless it is in thermal contact with a colder body. However, if the atoms traveling in the body are encountering drag to dark matter between collisions, then the average kinetic energy of the atoms in the body would steadily decrease as the atoms on average slowed, and the body would continue to cool whether in contact with any other non-dark-matter body or not. This would be an easily recognized experimental signal for the presence of dark matter, the spontaneous cooling of a object isolated from all other non-dark matter. Since this is a phenomenon that is NOT predicted by the current model, then this is a testable prediction that experiment can either uphold or shoot down. The body would continue to cool until it came to the same temperature as the dark matter, at which point it would be in thermal equilibrium with the dark matter. Since TomGee is proposing that this dark matter pervades everything everywhere (as it would have to, in order to also serve the "latent photon" role he posits), then all objects everywhere would come to the same temperature as the dark matter. This is another prediction of his model that is experimentally testable, simply by looking at the temperature of two objects that are not in matter-mediated thermal contact. PD
From: jowr.pi on 22 Sep 2005 03:29 Schoenfeld wrote: > Eric Gisse wrote: > > Schoenfeld wrote: > > > > [snip] > > > > > > > > s(t) = SUM{n=0}^+INF [ s^n(0) t^n / n! ] > > > > > > Your assumption that dg/dt = 0 reduces s(t) to: > > > s(t) = s(0) + s'(0)t + 1/2 s''(0)t^2 > > > > > > > > > Much simpler. > > > > I derived the solution, you reverse-engineered the solution from an > > arbitrary equation. > > Not an arbitrary equation and no reverse engineering, just trivially > true by definition. You missed the point. I derived the equation that predicts your distance from Newton's 2nd law and knowing two initial conditions. You "derived" the same equation by picking an arbitrary series that when it is differentiated twice, is the same as the solution to a particular 2nd order ODE. They are NOT the same things. > > hint: all continuous n-variable functions are also functions of their > derivatives. > > > > > > > > > > > > > > Don
From: Herman Trivilino on 22 Sep 2005 04:13
"PD" <TheDraperFamily(a)gmail.com> wrote ... > TomGee has opined that a body steadily loses kinetic energy due to drag > from passage through dark matter, and that therefore an internal force > is required to continue to supply energy to keep a body moving. There is no difference between a state of rest and a state of uniform motion. If TomGee (or anyone else) has an explanation for what it is that keeps an object in uniform motion (an internal force, or whatever) the same explanation MUST apply to an object at rest. In other words, this same internal force that keeps an object in uniform motion also keeps it at rest. The two states are equivalent. Do you suppose that TomGee has an experimental result that distinguishes beetween a state of rest and a state of uniform motion? ----== 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 =---- |