Mathematical Obscurities in Special Relativity

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20 years 5 months ago #4152 by DAVID
Replied by DAVID on topic Reply from
<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by kc3mx</i>
<br />Another point is that I dont think Lorentz derived a time dilation in an 1895 book. What book are you citing here? I would like to look this up. My understanding is that Larmor was the first to derive a time dilation using a theory of the ether. This point is not clearly resolved for me. Most books make the incorrect claim that Einstein was the first to derive time dilation. But this is not correct.
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See:

<b>“Versuch Einer Theorie Der Elektrischen Und Optischen Erscheinungen In Bewegten Körpen”</b>

By H.A. Lorentz, 1895, page 49:

im1.shutterfly.com/procserv/47b4dd37b312...de74a31ada0000001610

In a 1907 paper, Einstein credits this specific book with introducing him to time dilation, which Lorentz called “local time”.

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20 years 5 months ago #9406 by DAVID
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<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Jan</i>
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I firmly believe that relativistic phenomena can be perfectly explained without rescaling dimensions and time. Process slowing/speeding is a prefectly natural phenomenon, showing that the objects interact with an ambient environment such that any changes to that environment will obviously change the game. These changes can be induced by motion and this is nothing special, contrary to what other people want us to believe.


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Of course. Exactly.

The well-known fact that pendulum clocks slow down at higher elevations, in weaker gravitational fields, led many 19th Century geographers to used portable pendulum clocks to measure the altitudes of mountain peaks. The changing rate of the pendulum clock with gravity potential was much more reliable than using the barometer method, and easier than using the direct-survey method.

Nearly everybody has used a 4-D “space time” coordinate system to arrange meetings and appointments. This has been going on for at least the past 50,000 years, maybe longer. If you say, “Meet me on the observation deck of the Empire State Building on New Year’s eve, 2004,” you are using a 4-D space-time coordinate system. Longitude, Latitude, altitude, and time. All of the x, y, z, and t coordinates.

Mainly what is “curved” about “space” is the curved gravity fields that curve around spherical astronomical bodies.



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20 years 5 months ago #9407 by DAVID
Replied by DAVID on topic Reply from
<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by kc3mx</i>
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The basic issue is the following. Does the derived time dilation reflect a fundamental property of time,ie, that time actualy slows down?
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I say “NO”, absolutely not. I say it is the “clock” that is “slowing down”, with “the clock” being anything that moves, hums, vibrates, etc.

Time is a progressive numerical counting of repetitive “events” and a comparing of the duration between events with the duration between other kinds of repetitive events. But we can’t say that any particular kind of clock represents all of “true time”, since, for example, an atomic clock slows down at gravitational potentials where pendulum clocks speed up. So which represents “true time”? I say “both”, for the “type” of time they measure and, in fact, they “generate”. But the slow-down in one kind of clock does not represent the slow-down of all of "time itself" in the place where that clock is located.

How do you know what a “mile” is? You’ve got to measure it out with a tape measure. How do you know what a “foot” or a “meter” is? You’ve got to have an international convention and have a lot of nations agree, and you have to compare a “foot” and a “meter” to some other length.

I think the same principle applies to time. What is a “second”, some fraction of a day or a year. What is a year? Well, there are two kinds of astronomical time "years", for our planet, so which kind do we want to use for a "second"? Do we want a more scientific sounding “second” definition? Ok, let’s compare it to the number of oscillations of a certain kind of atom at mean sea level. But, let's don't go moving that atom up or down in elevation, because if we do, its oscillation rate will change. And by the way, we had better compare its oscillation rate to the ancient astronomical "second" so our vibrating atom won’t get out ahead of our revolving or rotating earth.

So “time” is a sequence of events, of any kind. The more stable the “duration” is between events, the better the “clock” is considered to be.

What causes time? Energy. Kinetic energy causing things to move. Every thing that moves, hums, vibrates, oscillates, etc. is a “clock”.

What is “space”? I’d say an “empty” 3-D coordinate system. We’ve got “space” inside a box, inside a room, between the earth and the sun, and even “space” inside atoms. In fact, atoms partially fill “space”, but the “space” they fill is still there, just like the “space” inside a box is still there, even if you fill it up with something.

Yes, yes, I know that these are very simple fundamental definitions, but I don’t care.



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20 years 5 months ago #4153 by DAVID
Replied by DAVID on topic Reply from
<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by kc3mx</i>
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When a clock runs slow because the ambient temperature changes, we don't conclude that heat caused time to change, we conclude that heat changed the physical process by which time is measured and that the clock no longer correctly measures time relative to the time standard.
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Uhh, I believe there are different kinds of time and different kinds of clocks. Study the growth and bloom rates of daffodils. They are good examples of “thermodynamic” clocks.

I don't think Einstein ever had any clue as to what "time" was.



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20 years 5 months ago #4154 by Jan
Replied by Jan on topic Reply from Jan Vink
DAVID,


Perhaps the reason why the space-time paradigm has been so successful up to now is that it actually deals with two important basic units, being "length" and "time". Scaling these two basic units readily gives us considerable freedom to geometrically "fit" many processes that require these basic units.

Now, it is all nice and dandy to claim that matter warps space-time, but this tells us diddly-squat about what really happens to light when it approaches an astronomical object. So, can GR be claimed to be real physics? Geometrically fitting the bending of light may enable us to predict its behavior for many cases, but there is no implication that the warping of space-time does represent the actual mechanism behind the bending. We just need to wait for the results of Gravity probe B, which is being launched soon I think.

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20 years 5 months ago #4156 by altare
Replied by altare on topic Reply from Astrid Lindholm
Clocks are used to meaure time - they don't determine it. Mechanical processes may be altered by gravitational fields because these fields influence whatever it is that is doing the time-keeping (a pendulum, an atomic process, whatever) This change has no deep mystery - it doesn't say anything about spacetime physics - it is merely a local effect consequent to a local force field.

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