Re: Energy?

On 07/30/2024 10:29 PM, The Starmaker wrote:

Ross Finlayson wrote:

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On 07/29/2024 05:14 PM, The Starmaker wrote:

There is no one person on earth that can even define correctly the
word...Energy.
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Stefan Ram wrote:

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    In a chapter of a book, the author gives this relation for a
    system with mass m = 0:
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E^2/c^2 = p^"3-vector" * p^"3-vector"
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    . Then he writes, "This implies that either there is no particle
    at all, E = 0, or we have a particle, E <> 0, and therefore
    p^'3-vector' <> 0.".
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    So, his intention is to kind of prove that a particle without mass
    must have momentum.
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    But I wonder: Does "E = 0" really mean, "there is no particle."?
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    300 years ago, folks would have said, "m = 0" means that there is
    no particle! Today, we know that there are particles with no mass.
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    Can we be confident that "E = 0" means "no particle", or could there
    be a particle with "E = 0"?
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    Here's the Unicode:
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E²/c² = p⃗ · p⃗
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    and
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|This implies that either there is no particle at all, E = 0, or we
|have a particle, E ≠ 0, and therefore p⃗ ≠ 0.

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Entropy has two definitions, sort of opposite each other,
"Aristotle's and Leibniz'".
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The energy or energeia then relates to the entelechiae,
content and connectedness, what results to dynamis/dunamis,
which are the same word, one for power the other potential.
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So, energy is defined by other definitions, the least.

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What is Einstein's definition of...Energy?
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It's capacity to do work.
It's usual that "everything's energy, after mass-energy equivalence
and the energy of the wavepackets of what are photons", yet, it is
that quantities are _conserved_ as with regards to changes of state
and the _conservation of quantities_ for matter, charge, photon
velocity, and neutron lifetime.
I.e., there are conservation laws, about Emmy Noether's theorem
and symmetries and invariance, yet they're really continuity laws,
and quasi-invariance and super-symmetry, and about running constants,
and the regimes of extremes, in a usual theory with least action.
These days sometimes it's "information" instead of "energy" which
is "the quantity", with regards to free information and the imaging
of optical visible light and these kinds of things, sort of a
super-classical and quite modern and thoroughly inclusive sort of
theory.
Just like anything else, it's capacity to do work, with regards
to "least action: sum-of-histories sum-of-potentials" as it's
the potential fields what are real and then intelligence is simply
action on information, with, "levers" everywhere.
Moment and Motion, ....
If you want to know Einstein's opinion, his last word on the matter
is "Out of My Later Years", "Relativity", one theory, with GR first.