Path: ...!news.mixmin.net!feeder1-2.proxad.net!proxad.net!feeder1-1.proxad.net!cleanfeed2-b.proxad.net!nnrp3-1.free.fr!not-for-mail Newsgroups: sci.physics.relativity Subject: Re: Energy? From: nospam@de-ster.demon.nl (J. J. Lodder) Reply-To: jjlxa31@xs4all.nl (J. J. Lodder) Date: Sat, 3 Aug 2024 12:43:25 +0200 References: <66A8307B.8B6@ix.netcom.com> <9U6dneBCi4_A_DX7nZ2dnZfqn_qdnZ2d@giganews.com> <66A9CBC9.2213@ix.netcom.com> <66AD00A3.3BC9@ix.netcom.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Organization: De Ster Mail-Copies-To: nobody User-Agent: MacSOUP/2.8.5 (ea919cf118) (Mac OS 10.12.6) Lines: 108 Message-ID: <66ae09cc$0$3667$426a74cc@news.free.fr> NNTP-Posting-Date: 03 Aug 2024 12:43:24 CEST NNTP-Posting-Host: 213.10.137.58 X-Trace: 1722681804 news-3.free.fr 3667 213.10.137.58:59536 X-Complaints-To: abuse@proxad.net Bytes: 5083 The Starmaker wrote: > Ross Finlayson wrote: > > > > On 07/30/2024 10:29 PM, The Starmaker wrote: > > > Ross Finlayson wrote: > > >> > > >> 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. > > >>> > > >>> > > >>> > > >>> Stefan Ram wrote: > > >>>> > > >>>> In a chapter of a book, the author gives this relation for a > > >>>> system with mass m = 0: > > >>>> > > >>>> E^2/c^2 = p^"3-vector" * p^"3-vector" > > >>>> > > >>>> . 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.". > > >>>> > > >>>> So, his intention is to kind of prove that a particle without mass > > >>>> must have momentum. > > >>>> > > >>>> But I wonder: Does "E = 0" really mean, "there is no particle."? > > >>>> > > >>>> 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. > > >>>> > > >>>> Can we be confident that "E = 0" means "no particle", or could > > >>>> there be a particle with "E = 0"? > > >>>> > > >>>> Here's the Unicode: > > >>>> > > >>>> EÂ"/cÂ" = pâ∞˜ · pâ∞˜ > > >>>> > > >>>> and > > >>>> > > >>>> |This implies that either there is no particle at all, E = 0, or we > > >>>> |have a particle, E â≈ 0, and therefore pâ∞˜ â≈ 0. > > >>> > > >> > > >> Entropy has two definitions, sort of opposite each other, > > >> "Aristotle's and Leibniz'". > > >> > > >> 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. > > >> > > >> So, energy is defined by other definitions, the least. > > > > > > What is Einstein's definition of...Energy? > > > > > > > > > > > > > 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. > > > Okay, let me put it this way...it seems you are trying to make an 'attempt' to > define the word "energy". > > You got 5 or 6 paragraphs that seems you are scrounging the Internet in > seach for meanings. > > It sounds like 6 different people wrote it! Indeed, you may call things 'energy' in any way you want. But back to basics: something that you call 'energy' isn't really an energy in a physical sense unless you can show how it can be converted (partly, and at least in principle) to 1/2 mv^2. With conservation of energy of course, Jan