A constant speed of light in all reference frames? Surely you can't be serious.
in [Relativity]
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From: PD on 4 Mar 2010 17:22 On Mar 4, 4:19 pm, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au> wrote: > "Ste" <ste_ro...(a)hotmail.com> wrote in message > > news:4563bc22-e173-4134-b524-40987e9b062c(a)g26g2000yqn.googlegroups.com... > On 4 Mar, 16:48, mpalenik <markpale...(a)gmail.com> wrote: > > > > > On Mar 4, 10:19 am, Ste <ste_ro...(a)hotmail.com> wrote: > > > > On 4 Mar, 12:19, "Inertial" <relativ...(a)rest.com> wrote: > > > > > "Ste" <ste_ro...(a)hotmail.com> wrote in message > > > > > > Not really, because if the total acceleration is small, then so is > > > > > the > > > > > speed. > > > > > That is a nonsense argument. Acceleration can be small and speeds very > > > > large. > > > > When I went to school, you could not have a large change of speed with > > > only a small amount of total acceleration. > > > The problem is your use of the term "total acceleration". If by total > > acceleration, you mean integral(a dt), then yes, you are correct. > > However, there is already a word for integral(a dt) -- it's called > > "the change in velocity". The term "total acceleration" isn't > > actually defined. Acceleration is defined, velocity is defined, > > deltav is defined. But "total acceleration is not". > > Essentially, I'm defining "total acceleration" as something akin to > total force, so that even though the force may be small, if it > continues for a long time then the total force will be the same as if > a large force was applied for a short period of time. In this way, if > the application of force is what is causing either part or the whole > of the time dilation effect, then it is the final speed that counts, > not how quickly the object reached that speed. > > ________________________ > By definition, if only the final speed counts, and not how quickly you got > there, then the acceleration doesn't matter (as the acceleration is "how > quickly you got there"). So you are saying completely disregard acceleration > or anything else except its final speed, which means a purely SR > interpretation. > > Which is exactly what you got. > > I answer to another stupid comment you made, you can have low acceleration > but achieve high speeds by simply accelerating for longer. An acceleration > of 0.01g will get you to 0.5c if you wait long enough. For a very rapid acceleration, the worldline has a sharp kink. For a slow acceleration, the kink becomes a soft bend. But the real contribution to the difference in the clock readings is how deep the "knee" in the wordline. PD
From: Bruce Richmond on 4 Mar 2010 19:55 On Mar 4, 12:10 am, "Dono." <sa...(a)comcast.net> wrote: > On Mar 3, 8:59 pm, Bruce Richmond <bsr3...(a)my-deja.com> wrote: > > > > > Well you are going to have problems with that. There is no way to > > *know* that the speed is the same both ways. > > Maybe for you. Not for the people that know physics: > > http://www.2physics.com/2009/11/testing-foundation-of-special.html Gee, should I believe Einstein or Dono? Einstein wrote: "But it is not possible without further assumption to compare, in respect of time, an event at A with an event at B. We have so far defined only an ``A time'' and a ``B time.'' We have not defined a common ``time'' for A and B, for the latter cannot be defined at all unless we establish by definition that the ``time'' required by light to travel from A to B equals the ``time'' it requires to travel from B to A." There were assumptions made during those experiments and Dono don't know it.
From: BURT on 4 Mar 2010 20:11 On Mar 4, 4:55 pm, Bruce Richmond <bsr3...(a)my-deja.com> wrote: > On Mar 4, 12:10 am, "Dono." <sa...(a)comcast.net> wrote: > > > On Mar 3, 8:59 pm, Bruce Richmond <bsr3...(a)my-deja.com> wrote: > > > > Well you are going to have problems with that. There is no way to > > > *know* that the speed is the same both ways. > > > Maybe for you. Not for the people that know physics: > > >http://www.2physics.com/2009/11/testing-foundation-of-special.html > > Gee, should I believe Einstein or Dono? > > Einstein wrote: > > "But it is not possible without further assumption to compare, > in respect of time, an event at A with an event at B. We have so far > defined only an ``A time'' and a ``B time.'' We have not defined a > common ``time'' for A and B, for the latter cannot be defined at all > unless we establish by definition that the ``time'' required by light > to travel from A to B equals the ``time'' it requires to travel from > B > to A." > > There were assumptions made during those experiments and Dono don't > know it. C is a constant in the space frame. You can travel behind light in space. Mitch Raemsch
From: Inertial on 4 Mar 2010 20:31 "Ste" <ste_rose0(a)hotmail.com> wrote in message news:8c0ae071-8d13-491b-92d0-cd2e2727af1a(a)u9g2000yqb.googlegroups.com... > On 4 Mar, 12:19, "Inertial" <relativ...(a)rest.com> wrote: >> "Ste" <ste_ro...(a)hotmail.com> wrote in message >> >> > Not really, because if the total acceleration is small, then so is the >> > speed. >> >> That is a nonsense argument. Acceleration can be small and speeds very >> large. > > When I went to school, you could not have a large change of speed with > only a small amount of total acceleration. Then you were badly taught. a) if you start at speed 0.8c and acceleration at 0.00001 m/s/s .. then your speed is still large. you claimed small acceleration means small speed b) if you start at speed 0.0 and acceleration at 0.00001 m/s/s .. then your speed after a million years will be quite fast. Yet the acceleration was small and constant. You do realize that you cannot 'total' acceleration. and acceleration of 1m/s/s followed by an acceleration of 1m/s/s is still an acceleration of 1m/s/s
From: Inertial on 4 Mar 2010 20:33
"mpalenik" <markpalenik(a)gmail.com> wrote in message news:3128a141-c953-4c0f-aca6-71773e7ea31b(a)o30g2000yqb.googlegroups.com... > On Mar 4, 12:09 pm, Ste <ste_ro...(a)hotmail.com> wrote: >> On 4 Mar, 16:48, mpalenik <markpale...(a)gmail.com> wrote: >> >> >> >> > On Mar 4, 10:19 am, Ste <ste_ro...(a)hotmail.com> wrote: >> >> > > On 4 Mar, 12:19, "Inertial" <relativ...(a)rest.com> wrote: >> >> > > > "Ste" <ste_ro...(a)hotmail.com> wrote in message >> >> > > > > Not really, because if the total acceleration is small, then so >> > > > > is the >> > > > > speed. >> >> > > > That is a nonsense argument. Acceleration can be small and speeds >> > > > very >> > > > large. >> >> > > When I went to school, you could not have a large change of speed >> > > with >> > > only a small amount of total acceleration. >> >> > The problem is your use of the term "total acceleration". If by total >> > acceleration, you mean integral(a dt), then yes, you are correct. >> > However, there is already a word for integral(a dt) -- it's called >> > "the change in velocity". The term "total acceleration" isn't >> > actually defined. Acceleration is defined, velocity is defined, >> > deltav is defined. But "total acceleration is not". >> >> Essentially, I'm defining "total acceleration" as something akin to >> total force, > > The only meaningful definition I know of total force is net force, > which is simply the sum of all the forces acting on the object. Time > doesn't enter into that. > >> so that even though the force may be small, if it >> continues for a long time then the total force will be the same as if >> a large force was applied for a short period of time. > > What you are describing is called impulse, which is the change in > momentum (integral(F*deltat)). > >> In this way, if >> the application of force is what is causing either part or the whole >> of the time dilation effect, then it is the final speed that counts, >> not how quickly the object reached that speed. > > I understand what you're saying, but we wouldn't call this "total > acceleration." We would simply call this the change in velocity. > There's nothing exactly wrong with the way you've defined total > acceleration, it's just that there is no standard definition for the > term "total acceleration" so people might infer several different > things by that term--such as the sum of the accelerations due to > several different forces acting on an object. This is the problem when trying to talk to people like STE who have no idea of the language of physics and make statements that are pure nonsense out of ignorance. If STE wants to talk physics, he first has to learn enough physics to be able to talk the talk. Otherwise he is wasting everyone's time. |