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Some troubling assumptions of SR



 
 
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  #581  
Old March 25th 07, 12:39 PM posted to sci.physics,sci.astro,sci.physics.relativity
Mitchell Jones
external usenet poster
 
Posts: 67
Default Some troubling assumptions of SR

In article ,
"George Dishman" wrote:

"Mitchell Jones" wrote in message
...
In article .com,
"George Dishman" wrote:
On 20 Mar, 21:21, Mitchell Jones wrote:
In article ,
"George Dishman" wrote:
"Mitchell Jones" wrote in message
...

...
***{Let's get concrete. Suppose we start with three identical
digital
clocks, all set to keep standard time here on Earth. Call them A,
B, and
C. Clock A remains on Earth, and clocks B and C are transported
into a
gravitational environment where, if the "gravitational time
dilation
equation" is correct, they will advance half as fast as the clock
on
Earth. Clock C then has a microchip implanted which doubles the
rate at
which it advances, causing it to advance at the same pace as clocks
on
Earth, and twice as fast as clock B.

I say that the speed of light on Earth, measured using clock A, is
186,000 miles/sec. I say that the speed of light at the location of
clocks B and C is 186,000 miles/sec when clock B is used, and
93,000
miles/sec when clock C is used. I say further that, since clock C
has
been calibrated to run at the same rate as standard time on Earth,
it is
correct, and clock B is incorrect. The implication: the speed of
light
at the location of clocks B and C is, in fact, 93,000 miles/sec.

Do you agree or disagree? If you disagree, please insert a detailed
explanation of your reasons after the sentence, above, which you
believe
to be incorrect.

What you say above is ok, here's the problem. Accelerate
an electron in a CRT using a potential of 1000V (checked
with a voltmeter) and measure its speed next to clock A.
You get some value. Now take the same kit and repeat the
experiment next to clock B. You get the same answer. Now
repeat but measuring the electron's speed using clock C.
The speed of the electron is now half the previous value.
Are you going to redefine the volt or the metre or the
kilogram or the charge/mass ratio for an electron or what?

***{Why would we want to redefine anything?

Because you can calculate the speed from the potential
difference and the charge to mass ratio of the electron.
Since neither has changed, the calculated speed must be
the same


Mitchell, I'm going to snip the majority of what you
said, sorry. I'm not interested in your philosophical
rambles, the experimental evidence is what matters to
me though I'll correct a few other points in passing.

...
, but your using clock C means the measured value
differs.

...
Nothing at all, but the kinetic energy of the electron
when it hits the phosphor on your crt is unchanged so
slowing it down isn't a viable explanation.


***{The duration coefficient is D = 2 in our hypothetical situation.
That means clocks will have to be doubled in that situation, to make
them keep standard time. Result: the electron will take twice as long to
travel from the electron gun to the phosphor, and its average velocity
over that interval will, in fact, be half what it would have been if the
same CRT were operating on Earth.


Exactly. However, the kinetic energy is 1/2 m v^2 and when
that is measured, it is unchanged. The only explanation if
you redefine clocks so that the speed is reduced


***{I'm not redefining anything. Calibrating all clocks to advance at
the same rate--i.e., using Newtonian absolute time--is mandatory in the
real world, because it is the only way to get things to work. They even
do it with GPS. The reason is that you cannot coordinate actions if the
people or devices that are supposed to cooperate are using clocks that
run at different rates. Therefore I do not have to "redefine clocks so
that the speed is reduced." The fact is that according to the clocks
that are used whenever things need to actually get done, the speed of
light is not a constant. That is simply a fact. Nobody uses Einstein's
uncalibrated local clocks in the real world George! So please stop
accusing me of redefining clocks. Nobody but a few sheltered nitwits in
the academic world is enamored with Einstein's clocks, and the only
purpose they use them for is to cover up the fact that, when real clocks
are used, relativity falls apart. --MJ}***

would be
that either the mass was increased or the law for kinetic
energy was wrong and that's what I said to start with.


***{The possibility you steadfastly ignore is (a) that the mass
decreased due to the loss of binding energy, (b) that the law for
kinetic energy is correct, and (c) that the calculated answer near the
event horizon of a black hole is not the same as the calculated answer
here on Earth, due to the enormous difference in circumstances. What law
of physics says we always have to come up with the same answers, George?
--MJ}***

This is not an explanation; it is a
statement of the plain results of measurement, when clocks calibrated to
keep standard time are used.


Clocks _are_ calibrated Mitchell, don't waste your time
pretending they aren't.


***{In the workaday world they are, because they have to be. As noted
above, activities cannot be coordinated, if the various factors involved
use clocks that run at different rates. What that means is that people
use clocks that, to extremely high accuracy, run at the rest-frame rate
of T--that's big T, upper-case T-- in GR's "time dilation" equation:

t = T[1 - 2GM/rc^2]^.5

Nobody uses clocks that run at t--i.e., little t, lower-case t--except a
few pointy-headed academics, and even they only use them when they feel
the need to bamboozle some sucker into believing that "all the
experimental evidence supports the constancy of the speed of light in
vacuo," or some similar piece of nonsense from the overflowing sewers of
post-Humian irrationalism.

--Mitchell Jones}***

The question is why, when relativists were
confronted with the fact that the theory of relativity was falsified by
measurement, did they respond by attempting to change the method of
measurement?


Nonsense, SR was published long before gravitational slowing
of clocks was measured.


***{Yup, but Einstein could hardly have failed to notice that the SR
"time dilation" equation only supported the constancy of the velocity of
light when uncalibrated local clocks were used. After all, inside a
space ship at, say .8c, the ratio t/T comes out as follows:

t/T = [1 - (.8c)^2/c^2]^.5 = .6

That means one of Einstein's uncalibrated local clocks will advance .6
sec for every 1 sec advanced by a clock calibrated to keep standard
time, and light in that locality will slow by exactly the same amount.
Result: in .6 sec as measured by the uncalibrated local clock, light
will advance (.6)(186,000) = 111,600 miles, and its speed according to
that clock will be 111600/.6 = 186,000 miles/sec. According to the clock
calibrated to keep standard time, however, the speed of the light will
be 111,000 miles/sec. In other words, the kind of clocks used in the
workaday world say the speed of light is not constant!

You don't think Einstein noticed this? You don't think his awareness of
it had just a teeny-weeny bit to do with his amazing postulate that only
uncalibrated local clocks could be used to evaluate his theory?

--Mitchell Jones}***

(In the world at large, of course, standard time has continued to be
used,


Nope, in the world at large time is measured by atomic
clocks which run the usual way. Leap seconds are used
to keep civil time in step with the slightly variable
rotation of the planet.


***{You say "Nope," but then, oddly, you confirm what I have been
saying--to wit: all clocks in the workaday world are calibrated to keep
pace with standard time. The fact that standard time nowadays is defined
by cesium atomic clocks that are occasionally adjusted to keep them in
sync with Earth's orbital and rotational characteristics does not alter
that key fact in the slightest. The practice of calibrating all clocks
to keep pace with standard time is what is at issue here. That is the
practice which cannot be followed, if the speed of light is to be deemed
constant. I proved that, for the umpteenth time, just above. That's why
Einstein stipulated that only uncalibrated local clocks could be used to
evaluate his theory. --MJ}***

Frankly, that sort of an attitude just leaves me open mouthed with
amazement.

You are amazed that I assume the laws of physics are
universal?


***{That remark was not directed at you in particular, but at the
generalized class of people who behave in that way. (Whether you will
ultimately fall into that category is yet to be determined. :-) What I
intended to say was that I am amazed when I encounter inveterate refusal
to accept the plain results of measurement.


You are the only one doing that. Experiments including
Sagnac's, the MMX, stellar aberration and so on ruled
out all the aether theories other than an extended


***{You didn't do very well when you attempted to defend those claims,
yet you remain unconvinced that they are wrong. Well, I'm not surprised.
What that means is that it's time to agree to disagree, and draw this
discussion to a close. --MJ}***

version of that proposed by Lorentz which preserves
Lorentz invariance, and that means time must be defined
a certain way if the laws of physics are to be universal.


***{Time is already defined by the requirements of the workaday world.
We cannot coordinate our activities unless we calibrate all of our
clocks to advance at the same rate, so that's what we do, and that
procedure means it is T as measured in a rest frame, and not t, which is
the proper measure of the speed of light, in situations where the "time
dilation" equations apply. Result: the speed of light, unarguably, is a
variable, not a constant. That's just the way it is. All measurements
using clocks that have been calibrated to advance at the same rate
support that conclusion. Period. End of story. --MJ}***

I accept the results of the measurements, you are trying
to avoid those that rule out a dragged aether.


***{I am open to any arguments anyone wishes to toss at me in that
regard, just as I was open to yours. It is my opinion that your
arguments were unsound, and I believe I demonstrated that quite
conclusively. In any case, I had my say and you had yours, and others
will evaluate the outcome in accordance with their own concepts and
preconceptions. Therefore it appears to be time to draw this to a close.
--MJ}***

Relativists evidently do not
like the results of measurement when clocks calibrated to standard time
are used, and so they want to use uncalibrated clocks.


Telling lies won't help you, scientific clocks are always
calibrated to the internationally accepted standard.


***{Lies? My, my. What that tells me is that I was correct, above, in
thinking I had conclusively demonstrated my conclusion, and also correct
in thinking that this discussion is approaching the limits of its
usefulness.

Anyway, to repeat: the workaday world uses calibrated clocks of
necessity. When GPS started out, for example, they tried using cesium
clocks on the satellites, without calibrating them to run at the same
rate as clocks on the ground. In effect, they were using Einsteinian
proper time rather than Newtonian absolute time. That means the clocks
on the satellites advanced at rates influenced by their lower
gravitational potential and their higher speeds, while clocks on the
ground kept standard time. Result: the clocks on the satellites got
further and further out of sync with those on the ground, and GPS made
larger and larger errors. Result: they turned on an onboard
microcomputer, which began adjusting the readings of the onboard clocks,
so that they advanced at the same rate as standard time on the ground,
and that solved the problem. In other words, they had to use Newtonian
absolute time to get GPS to work. They tried Einstein's uncalibrated
local clocks, and they failed to get the job done.

My point, therefore, is not that relativists advocate abandoning
standard time in the workaday world. They wouldn't dare. The point,
instead, is that relativists insist on using uncalibrated local clocks
WHEN ATTEMPTING TO DEFEND THE SO CALLED LAW OF
CONSTANCY OF THE SPEED OF LIGHT.

Hopefully that distinction is clear enough for you to grasp, because it
is all you are going to get. Once a discussion deteriorates to the point
where one party calls the other a liar, its useful life is pretty much
over.

--Mitchell Jones}***

so that it says the same potential
applied to an identical electron accelerates it to a
lower speed


***{If I fire a bullet through the air, and then fire another one
through water, you are willing to adust the calculation in the latter
case to take the resistance of the water into account. Yet if I fire an
electron through low-pressure aether here on Earth, and then fire one
through high-pressure aether just above the event horizon of a black
hole, you insist that the speeds ought to be the same. Frankly, that
makes no sense to me at all. --MJ}***


Of course not, but then I don't accept that your aether
exists so our assumptions differ, and what I am pointing
out is that if an aether did exist and it slowed the
electron down then the elctron would hit the screen with
lower energy. That doesn't happen. An electron accelerated
through 1V at ground level has trhe same kinetic energy as
one accelerated through the same potential at the top of a
hill.


***{There are no significant differences between the bottom and the top
of a hill, but there are differences. Potential energy, for example is
greater at the top of the hill, and it has mass; and, other things
equal, speed will be slightly greater at the top of the hill than at the
bottom. The differences, of course, are negligible for practical
purposes. They are not negligible, however, when values at the surface
of the Earth are compared to those just above the event horizon of a
black hole. --MJ}***

George


************************************************** ***************
If I seem to be ignoring you, consider the possibility
that you are in my killfile. --MJ
  #582  
Old March 25th 07, 07:48 PM posted to sci.physics,sci.astro,sci.physics.relativity
George Dishman[_1_]
external usenet poster
 
Posts: 2,509
Default Some troubling assumptions of SR


"Mitchell Jones" wrote in message
...
In article ,
"George Dishman" wrote:
"Mitchell Jones" wrote in message
...
In article .com,
"George Dishman" wrote:
On 20 Mar, 21:21, Mitchell Jones wrote:
In article ,
"George Dishman" wrote:
"Mitchell Jones" wrote in message
...

...
***{Let's get concrete. Suppose we start with three identical
digital
clocks, all set to keep standard time here on Earth. Call them
A, B, and
C. Clock A remains on Earth, and clocks B and C are transported
into a
gravitational environment where, if the "gravitational time
dilation
equation" is correct, they will advance half as fast as the
clock on
Earth. Clock C then has a microchip implanted which doubles the
rate at
which it advances, causing it to advance at the same pace as
clocks on
Earth, and twice as fast as clock B.

I say that the speed of light on Earth, measured using clock A,
is
186,000 miles/sec. I say that the speed of light at the location
of
clocks B and C is 186,000 miles/sec when clock B is used, and
93,000
miles/sec when clock C is used. I say further that, since clock
C has
been calibrated to run at the same rate as standard time on
Earth, it is
correct, and clock B is incorrect. The implication: the speed of
light
at the location of clocks B and C is, in fact, 93,000 miles/sec.

Do you agree or disagree? If you disagree, please insert a
detailed
explanation of your reasons after the sentence, above, which you
believe
to be incorrect.

What you say above is ok, here's the problem. Accelerate
an electron in a CRT using a potential of 1000V (checked
with a voltmeter) and measure its speed next to clock A.
You get some value. Now take the same kit and repeat the
experiment next to clock B. You get the same answer. Now
repeat but measuring the electron's speed using clock C.
The speed of the electron is now half the previous value.
Are you going to redefine the volt or the metre or the
kilogram or the charge/mass ratio for an electron or what?

***{Why would we want to redefine anything?

Because you can calculate the speed from the potential
difference and the charge to mass ratio of the electron.
Since neither has changed, the calculated speed must be
the same


Mitchell, I'm going to snip the majority of what you
said, sorry. I'm not interested in your philosophical
rambles, the experimental evidence is what matters to
me though I'll correct a few other points in passing.

...
, but your using clock C means the measured value
differs.

...
Nothing at all, but the kinetic energy of the electron
when it hits the phosphor on your crt is unchanged so
slowing it down isn't a viable explanation.

***{The duration coefficient is D = 2 in our hypothetical situation.
That means clocks will have to be doubled in that situation, to make
them keep standard time. Result: the electron will take twice as long
to
travel from the electron gun to the phosphor, and its average velocity
over that interval will, in fact, be half what it would have been if
the
same CRT were operating on Earth.


Exactly. However, the kinetic energy is 1/2 m v^2 and when
that is measured, it is unchanged. The only explanation if
you redefine clocks so that the speed is reduced


***{I'm not redefining anything. Calibrating all clocks to advance at
the same rate--i.e., using Newtonian absolute time..


That's a redefinition. The SI second is defined and
scientific clocks use that definition. Civil time
such as UTC is defined in a particular frame and
measurements are converted where necessary.

--is mandatory in the
real world, because it is the only way to get things to work. They even
do it with GPS. The reason is that you cannot coordinate actions if the
people or devices that are supposed to cooperate are using clocks that
run at different rates.


Sure, but the laws of physics don't use civil time. Atoms
don't care about UTC.

Therefore I do not have to "redefine clocks so
that the speed is reduced." The fact is that according to the clocks
that are used whenever things need to actually get done, the speed of
light is not a constant. That is simply a fact. Nobody uses Einstein's
uncalibrated local clocks in the real world George!


In the civil world, no but in science where accuracy
matters they do.

would be
that either the mass was increased or the law for kinetic
energy was wrong and that's what I said to start with.


***{The possibility you steadfastly ignore is (a) that the mass
decreased due to the loss of binding energy,


That would further _decrease_ the energy, and since an
electron is a fundamental particle it doesn't have
anything to be bound. You could suggest the mass of the
electron is _increased_ so that you get the same energy
for the lower speed.

(b) that the law for
kinetic energy is correct, and (c) that the calculated answer near the
event horizon of a black hole is not the same as the calculated answer
here on Earth,


As far as I know, there is no "black hole" in my monitor
where electrons are accelerated through several kV.

due to the enormous difference in circumstances. What law
of physics says we always have to come up with the same answers, George?


The rule that the laws must reflect reality and accelerating
an electron through 1V gives it an energy of 1eV regardless
of where you do the experiment. I have only given a crude
example but you asked above for me to "insert a detailed
explanation of your reasons" if I disagreed. You should now
understand why, it means that basic laws that work universally
using the current scientific definition of time would not
work. That's the problem 19th century physicists were facing
and Einstein's correction of Newton's incorrect assumption
that time in nature was absolute solved it. If you think
you can make an aether theory work and thus regain absolute
time, feel free to try but nobody has done it so far and
dragged aether doesn't achieve it.

George


 




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