Re: E = 3/4 mc? or E = mc?? The forgotten Hassenohrl 1905 work.

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.