Paradoxes and Dilemmas

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>is the slowing in ticking in the GPS case attributed to speed or to gravitation?<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

According to GR:
-- Speed slows GPS clocks by 7200 ns/day.
-- Gravitational potential slows GPS clocks by 14.400 ns/day.
-- Gravitational potential slows ground clocks (at north pole) by 60,300 ns/day.

The net of all these effects is that GPS clocks tick faster than ground clocks by 38,700 ns/day. So they are slowed by that amount before launch, resulting in orbiting GPS clocks that are observed to tick at the same rate as ground clocks.

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>If the sats could go around faster at same orbit would that change ticking or you need to go in higher orbit?<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

Speed relative to the local gravity field slows E-M-based clocks unconditionally. Gravitational potential does likewise. The two effects are independent, and may either add to or oppose one another.

Note that "going to a higher orbit" would speed up clock ticking. -|Tom|-

See [url] metaresearch.org/cosmology/gravity/vanflandern.ppt [/url] for these details and cartoon explanations of them.

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>Did the acceleration of the rockets to get them to orbit contributed to those rates?<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

Force or acceleration as such is incapable of affecting clock rates under any circumstances. The rate before acceleration depends on the speed before acceleration, and likewise for the rates during or after acceleration. Only speed matters. When the acceleration does not change speed (as in a cyclotron), clock rates do not change.

This is explained at the link I provided.

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>Does that mean that at a GPS clock vicinity, a person ages at a 38,700 ns/day slower rate than a person on earth?<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

No. All his electrons orbit <b>faster</b> at that rate. -|Tom|-
[amended 2002/12/19 -- "faster" because of weaker gravitational potential]

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>The biggest factor seems to be the geoid slowing (60,300n/s) due to gravitational potential. The force F is not zero on the surface. ... But then later you invole the Equivalnce principle to say that acceleration does not affect rates. Is there a contradiction here? Or there is something wrong with the Alley experiment conclusions? Or something wrong with equivalence? But something is wrong...<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

One of the main points of the presentation at the link was to show that gravitational potential and gravitational force are two different phenomena, each with their own separate effects. They are related to one another the way any continuous function is related to its derivative; e.g., as velocity is related to acceleration. Just as velocity and acceleration have different properties and different physical effects despite their connection, so to do potential and force.

The presentation gives examples where force is zero and potential non-zero, or where force is large and potential constant, to illustrate the physical effects. The equivalence principle deals with force and acceleration, but not at all with potential and velocity. And only the latter pair can affect clock rates. Once this is appreciated, the theories and experiments will start to make physical sense.

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>it seems to me that the "slingshot" twin paradox can be resolved if we consider the asymmetry due to length contraction, i.e. the Gap explanation. I cannot see other asymmetry present if absolute time is present.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

I argued two points in the article in the September 15 MRB on the twins paradox.

(1) Put a GPS-type clock on board the traveling twin's spacecraft. It will have its rate pre-adjusted so as to tick at the same rate as ground clocks on Earth. This allows an Earth-synchronized clock to monitor the spacecraft's entire journey.

(2) One needs NO ASYMETRY in the twins paradox of the type you are invoking, because one can construct the entire paradox without accelerations or turn-arounds or clocks jumping into new inertial frames.

So in SR, the traveling twin really ages slower than the Earth twin. AND the Earth twin really ages slower than the traveling twin. This difference only shows up through the "time slippage" that exists in all frames when viewed from other frames.

I would add to that discussion that invoking length contraction will quickly drive you crazy because the lack of distant simultaneity in one frame relative to another in SR means that anything with extent will have its two ends existing at two different instants of time. To really understand the paradox, it is best to keep everything to its bare essence and simplest form. -|Tom|-

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>So in SR, the traveling twin really ages slower than the Earth twin. AND the Earth twin really ages slower than the traveling twin. This difference only shows up through the "time slippage" that exists in all frames when viewed from other frames.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>
I'm a little confused by this statement. In the twin paradox, the only paradox is that each observer is observing the clock in the frame of the other observer, correlating it to themselves, and then comparing it to the clock in their frame. First, the only way one could observe that the clock is slowing is to compare it to another, which is in a completely different frame. They are comparing one clock to another rather then comparing both clocks to a true constant. If they were simply observing the clock of the other they would think they have aged the same, there would be nothing else to reference, there would be no paradox.

<b>The twin paradox <u>actually uses 4 clocks</u> but only references 2.</b> There are 2 observers, each observer has a frame, each observer has a clock, and each observer has a clock from the frame of the other.(2 observers, 2 clocks each=4 clocks)
I think this is what Tom is referring to as "time slippage". However, I'm confused by the statement because it seems as though Tom is agreeing that each observer actually *<u>is</u>* younger. What the twin paradox is really about is <b>PERCEPTION</b>(does one observer believe the other is younger). It really is just a shell game and play on words, comparing 2 clocks even though there are really 4 present, it is not about what is really happening.

<b>I can create the same paradox by using (2)24hr clocks that slow at 1hr per day and (2)regular clocks. I give you one of each, the regular one on your wrist and the other on your forehead labeled "my current time". I do the same with mine. Now, if I look at you I will think you are younger when I compare "your" forehead time to the time on my wrist, if you do the same to me you will think I am younger.</b> Who's right?

In MHO, it seems as thought the twin paradox problem is simply an elaborate hoax using 2 puffs of smoke and 2 mirrors.

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>The twin paradox ... is just a shell game and play on words, ... it is not about what is really happening.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

However, orbiting atomic clocks really do slow down with speed and with deeper gravitational potential. Your "shell game" does not explain how the effect on clocks and atomic processes can be real.

I'm no fan of SR. My paper with Vigier in <i>Foundations of Physics</i> this past July claims experimental evidence that SR is now falsified. However, I have come to understand, after much struggle, that SR is an internally consistent theory and not a shell game. But I would estimate that >90% of the world's physicists do not truly understand it, and most of the books give explanations of the twins paradox that are easily shot down. It took me 25 years to finally understand the theory on its own terms myself. So even though you haven't seen it yet, there is a way out of the "shell game" you think you now see. And my present understanding of SR and the twins paradox was the subject of my Sept. 15 MRB paper. "Time slippage" (the other term in the Lorentz time transformation) is the key. If you take the time to study this paper, be prepared to be amazed. I was, because 30 years ago I would have sworn that your present view had to be correct. -|Tom|-

where can you find the paper? In thsi idea are yuo saying time is assymetrical.

The intuitive mind