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

On 2024-12-07 16:03:31 +0000, ProkaryoticCaspaseHomolog said:
[missing article on my server, sorry about mixed up quote levels]

On Sat, 7 Dec 2024 11:03:24 +0000, J. J. Lodder wrote:
 
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]
 
You don't "get" the point that I was trying to make. Let us review

I do get it, and it is wrong.

| Resolution 1 of the 17th CGPM (1983)

[snip boilerplate material]

Gamma ray burst observations have constrained the arrival times
between the visible light and gamma ray components of the burst to
be equal to within 10^-15 of the total travel time of the burst.

[snip more irrelevancies]

This is irrelevant for the issue of E=mc^2.
Differential travel times are a test for a non-zero photon mass, if any.

Definitions are BASED ON state-of-the-art known physics. They do not
DETERMINE physical law.

Are you really incapabable of understanding
that all this is about metrology, not physical law?
No definition of units can ever determine or change any physical law.

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?
 
Not at all.

Correct.

Ex2) If not, what does that experiment demonstrate?
 
It would demonstrate an inadequacy in the definitions that must be
addressed in some future conference when the discrepancies have been
better characterized.

I'm sorry, but this is not the right answer,

Jan