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From: Tom Roberts on 7 Aug 2010 11:47
GogoJF wrote:
> On Aug 5, 2:31 pm, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote:
>> Nature uses no observers, so valid models of physics must not use observers, or
>> at least be independent of observer.
>
> So, you say that all our models should be devoid of the
> observer, in order to measure nature correctly- that we should,
> instead, use our devices which are more precise and accurate?

Hmmm. You can read what I said above. That's what I said. This is not about
precision or accuracy, it is about faithfully modeling nature.

Our models must, of course, include measuring devices, and must model the
measurement process.

For instance, in GR to model the length that a ruler measures,
one integrates the metric along the spacelike path of the ruler.
To model the time interval displayed on a clock, one integrates
the metric along the clock's timelike path.


> At the
> same time, this statement disqualifies all observational measure.

No. It merely points out that the observer is not part of the model.
Measurements are included in the model.


> Einstein's description of relativity routinely uses the observer in
> the thought experiment.

Sure. But you must understand what his observers did -- they applied measurement
instruments, nothing more. So modeling those instruments is sufficient. This was
the literary style of his day, and it persists to today, but there is no need
for a human observer, or any other kind of observer; modeling the instruments is
sufficient.

This is not true for the Copenhagen interpretation of quantum
mechanics. That IMHO is a fatal flaw.


Tom Roberts
From: spudnik on 7 Aug 2010 15:47
that's in its own "resting" frame of reference,
as with Galilean relativity. I also appreciate the citation
of Huyghens, whhofrom ____ got the math to make the inverse-
second-power law from Kepler's orbital constraints.

all of these things are "invariant" within the object's frame
of rest, so, you can just say that the relativistic increase
of mass etc., is just a matter of trying to stop it.

of ocurse, Minkowski obfuscated every God-am thing
with his little lectures about phase-space; then, he ...
nevermind!

> It has nothing to do with earth.

thus:
you were around, what -- a FOX news transmitter?... well,
you'd get more radiation, sitting so close to TV!... so,
anyway, check the UNSCEAR 2000 report; if
it had been redacted of the word, Chernobyl, you wouldn't know
that it was the same hyped-over area.

yes, the SU authorities mistakenly tried to cover it up,
such as they could for a while, and thus also failed
to distrbute the iodine tablet prophylactics for the possiblity
of Cesium-137 poisoning, but that is mostly ameliorated
by not drinking milk from grass-fed cows, for a number of months.

> Bullshit. Unlike you, I was around at the time. The west didn't even know
> something was happening until they detected radioactive elements in the wind
> coming over europe. One of the complaints was that the soviets didn't let
> the world know that chernobyl had melted down. The evacuation was because
> people were dying from massive radiation poisoning.

thus: ah, yes; resistanceless!... so, for realism,
what'd be the minimum "boost," as the bobsledder
approacheth the antipode at sealevel, to get back
to the start?
I didn't think, though, that the brachistochrone/tautochrone
was cycloidal, but that roundtrip makes me wonder.
> > just drop it.
> Well, well that's just a trivial case ;-) How about a half-pipe
> brachistochrone going from point A 5000km above the ground to
> ground-zero at the antipodal point and ending at point A again going
> once around the equator?

--les ducs d'oil!
http://tarpley.net

--Light, A History!
http://wlym.com
From: GogoJF on 9 Aug 2010 19:45
On Aug 7, 10:47 am, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote:
> GogoJF wrote:
> > On Aug 5, 2:31 pm, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote:
> >> Nature uses no observers, so valid models of physics must not use observers, or
> >> at least be independent of observer.
>
> > So, you say that all our models should be devoid of the
> > observer, in order to measure nature correctly- that we should,
> > instead, use our devices which are more precise and accurate?
>
> Hmmm. You can read what I said above. That's what I said. This is not about
> precision or accuracy, it is about faithfully modeling nature.
>
> Our models must, of course, include measuring devices, and must model the
> measurement process.
>
>         For instance, in GR to model the length that a ruler measures,
>         one integrates the metric along the spacelike path of the ruler.
>         To model the time interval displayed on a clock, one integrates
>         the metric along the clock's timelike path.
>
> > At the
> > same time, this statement disqualifies all observational measure.
>
> No. It merely points out that the observer is not part of the model.
> Measurements are included in the model.
>
> > Einstein's description of relativity routinely uses the observer in
> > the thought experiment.
>
> Sure. But you must understand what his observers did -- they applied measurement
> instruments, nothing more. So modeling those instruments is sufficient. This was
> the literary style of his day, and it persists to today, but there is no need
> for a human observer, or any other kind of observer; modeling the instruments is
> sufficient.
>
>         This is not true for the Copenhagen interpretation of quantum
>         mechanics. That IMHO is a fatal flaw.
>
> Tom Roberts

In this situation, one must ask oneself, what are we ultimately trying
to accomplish- a great understanding or a great invention of the
situation? Often one comes with the other. But, if I had to pick
one, I think it would be the invention- because understanding takes
years and years- and the invention just makes our lives easier.
From: glird on 10 Aug 2010 17:09
On Aug 4, 4:02 pm, harald <h...(a)swissonline.ch> wrote:
> glird wrote:
>
>> < No symbol dxi/dx for the ratio of size of units of length appears
either! (Nowhere in his entire paper is there a mathematical symbol
for a length contraction; whether physical or only as viewed by
differently moving systems.) >
>
> Beta (nowadays gamma).

Though it is true that in the LTE, though not in general, dxi/dx =
beta = 1/q; but beta = gamma = 1/q is NOT a symbol for a length
contraction; it is a symbol for a quantity. In the LTE, though not in
general, that quantity is the amount by which the ratio of lengths
does change as measured by the viewing system; but that quantity might
or might not apply to anything at all!

snip
> I am just defending Einstein against accusations of wrongdoing
> while basically his only "sin" was to omit some clarifications to
> which we attach a certain importance.

Though not a "sin", he also failed to understand some of his own
equations, and never did accurately derive the LTE.

Wanna bet!! ??

glird
From: GogoJF on 10 Aug 2010 18:23
On Aug 7, 10:47 am, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote:
> GogoJF wrote:
> > On Aug 5, 2:31 pm, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote:
> >> Nature uses no observers, so valid models of physics must not use observers, or
> >> at least be independent of observer.
>
> > So, you say that all our models should be devoid of the
> > observer, in order to measure nature correctly- that we should,
> > instead, use our devices which are more precise and accurate?
>
> Hmmm. You can read what I said above. That's what I said. This is not about
> precision or accuracy, it is about faithfully modeling nature.
>
> Our models must, of course, include measuring devices, and must model the
> measurement process.
>
>         For instance, in GR to model the length that a ruler measures,
>         one integrates the metric along the spacelike path of the ruler.
>         To model the time interval displayed on a clock, one integrates
>         the metric along the clock's timelike path.
>
> > At the
> > same time, this statement disqualifies all observational measure.
>
> No. It merely points out that the observer is not part of the model.
> Measurements are included in the model.
>
> > Einstein's description of relativity routinely uses the observer in
> > the thought experiment.
>
> Sure. But you must understand what his observers did -- they applied measurement
> instruments, nothing more. So modeling those instruments is sufficient. This was
> the literary style of his day, and it persists to today, but there is no need
> for a human observer, or any other kind of observer; modeling the instruments is
> sufficient.
>
>         This is not true for the Copenhagen interpretation of quantum
>         mechanics. That IMHO is a fatal flaw.
>
> Tom Roberts

Does not the observers' apparatus "mimic" the "applied measurement
instrument"? I think there is room for clarity here. You imply that
this "literary style" that we speak of today- this Einstein thought
experiment kind-of-way of thinking is necessary in discussion but not
needed in real matters of "modeling of instruments". Cannot an
observer pick up a stop watch and become some kind of crude measuring
device?
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