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Newsgroups: sci.physics.relativity
Subject: Re: E = 3/4 mc? or E = mc?? The forgotten Hassenohrl 1905 work.
From: nospam@de-ster.demon.nl (J. J. Lodder)
Reply-To: jjlxa31@xs4all.nl (J. J. Lodder)
Date: Sat, 7 Dec 2024 12:03:24 +0100
References: <309fb33a3a66f01873fdc890e899a968@www.novabbs.com> <674BCF8E.822@ix.netcom.com> <674CCA90.3DD9@ix.netcom.com> <a89d71ab22cb1e3e279a59fe50ab5ebb@www.novabbs.com> <9f1cd556912a273a8946c77614611242@www.novabbs.com> <8a0014e4135992c8ec7bd3f2f1983164@www.novabbs.com> <d906fde3148d43d339b1663f1127216a@www.novabbs.com> <13877dcc9c6a6f2dd8056d8c05f0c661@www.novabbs.com> <a7d26012926823b22e139af8670cbbe7@www.novabbs.com> <df76d88c3e9729de443afca2c0cf99fa@www.novabbs.com> <2c831e6c7e0103c00fcebe8074fec8db@www.novabbs.com> <7d37d6e841cd1936217b21a5847fc507@www.novabbs.com> <7511bb1b9b748c76df265f91eaaa468a@www.novabbs.com> <67503f94$0$12915$426a74cc@news.free.fr> <3c8abe81804e4c5b6ced7aefae766c7d@www.novabbs.com> <6750b8d4$0$29710$426a74cc@news.free.fr> <2Ji4P.2$4s%.1@fx15.ams4> <6751f410$0$518$426a74cc@news.free.fr> <geD4P.802$qW31.662@fx07.ams4> <675357ca$0$28494$426a74cc@news.free.fr> <7dde1f4c26d5621d09432295bd146ac7@www.novabbs.com>
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ProkaryoticCaspaseHomolog <tomyee3@gmail.com> wrote:

> On Fri, 6 Dec 2024 20:00:10 +0000, J. J. Lodder wrote:
> 
> > Finaly, you really need to get yourself out of the conceptual knot
> > that you have tied yourself in.
> > Something is either defined, or it can be measured.
> > It can't possibly be both,
> 
> Sure it can, provided that you use a different measurement standard
> than the one used in the definition.

Sure, you can be inconsistent, if you choose to be.
Don't expect meaningful results.

> It would not make sense to quantify hypothetical variations in the
> speed of light in terms of the post-1983 meter. But they would make
> sense in terms pre-1983 meters. Or (assuming some incredible ramp-up
> in technology, perhaps introduced by Larry Niven-ish Outsiders) in
> terms of a meter defined as the distance massless gluons travel in
> 1/299,792,458 of a second. Or gravitons... :-)

Completely irrelevant,
and it does not get you out of your conceptual error as stated above.

Summmary: There must be:
1) a length standard, 2) a frequency standard [1], and 3) c

Two of the three must be defined, the third must be measured.
Pre-1983  1) and 2) were defined, and 3), c was measured.
Post-1983 2) and c are defined, 1) must be measured.
So in 1983 we have collectively decided that any future refinement
in measurement techniques will result in more accurate meter standards,
not in a 'better' value for c.  [2]

Finally, an excercise for you personally.
You quoted a pre-2018 experiment that verified that E=mc^2
to some high accuracy. (using the measured value of Planck's constant)
Post-2018, Planck's constant has a defined value,
and  E=mc^2 is true by definition. (of the Joule and the kilogram)

So E=mc^2 can no longer be verified by any possible experiment.
Now:
Ex1) Does this make the experiment you quoted worthless?
Ex2) If not, what does that experiment demonstrate?

Jan


[1] Or a time standard, which amounts to the same in other words.
But defining it as a frequency standard is more 'natural'.

[2] Note that all this has nothing whatsoever to do with physics.
 (like c being 'really' constant in some sense or something like that)
 It is all about metrology, so about the ways -we agree upon-
 to have standards in the most stable, accurate, and reproducible way.