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This question was closed on physics exchange. Can anyone help me with this question here? As I understand it, everything evolves, which means that everything changes based on causes and conditions. So to the contrary, are fundamental particals and the "quantum" of Quantum mechanics constant, unchanging and have always existed?

Thomas Schwarz
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  • Why was it closed on physics exchange, what part was away from physics? – Ioannis Paizis Nov 16 '23 at 17:49
  • Quantum particles move around, their wave functions evolve and some of their internal parameters can change (spin direction). They can even be created or annihilated in collisions. They also have internal parameters that never change (mass and charges). – Conifold Nov 16 '23 at 20:49
  • Particles are understood to be quanta of quantum field theories. But quantum field theories, especially those of electrons, are thought to be so-called "effective theories," i.e. they make good predictions away from singularities due to high/low energy, but may have little to do with what actually is. The principled physicist can usually only speak to what mathematical formalism makes good predictions and must remain agnostic about (or at least aloof about) the metaphysics of his formalism. – Charles Hudgins Nov 17 '23 at 01:46
  • @Charles Hudgins, sure but here in philosophy se we are interested in the ontological part too. – Ioannis Paizis Nov 17 '23 at 08:43
  • @IoannisPaizis As you should be. My point was just that one shouldn't make the mistake of thinking that the standard model speaks to ontology. The consensus, I'm fairly sure, is that the standard model is an effective theory. To be clear, this is not always the consensus in physics. For example, the theory that electricity is the flow of electrons was not, in its time, considered an effective theory. It was thought that there really were these discrete entities called electrons that transported something called electric charge. – Charles Hudgins Nov 19 '23 at 15:02
  • Field theory is a correction to that theory, but it turns out that it is (as in evidence points to this fact) only an effective theory. Maybe it's clearer to say that there are theories we know to be only effective, theories we suspect are only effective, and theories that we think actually speak to ontology. The standard model is somewhere in the middle of this spectrum. If it would be helpful, I could give examples of physical theories that lie on different points of this spectrum. – Charles Hudgins Nov 19 '23 at 15:04

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I suppose someone will write an explanatory answer in the context of quantum mechanics. Just a quote from Heisenberg.

The atoms or elementary particles themselves are not as real; they form a world of potentialities or possibilities rather than one of things or facts.

Heisenberg Physics and Philosophy p186.

Ioannis Paizis
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  • I am onterested to know where Heisenberg makes this statement, in which context? Do you know? – Jo Wehler Nov 16 '23 at 18:05
  • Don't know, I had found it in a book I think of Rupert Sheldrake, and now I googled it. Besides the quote, I think that the link is sufficient : https://en.m.wikipedia.org/wiki/Quantum_fluctuation#:~:text=In%20quantum%20physics%2C%20a%20quantum,Werner%20Heisenberg's%20uncertainty%20principle. – Ioannis Paizis Nov 16 '23 at 18:17
  • The linked article "Quantum fluctuations" speaks about "virtual particles". In general, electrons with their huge lifetime are not virtual particles. - It would be helpful to know the context of Heisenberg's original statement. – Jo Wehler Nov 16 '23 at 18:31
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    @Jo Wehler, not exactly that, but I found this ITS AWESOME, LISTEN ALL : https://youtu.be/xbpOMkBMtYU?si=mRu_b7DLrTeUpbCL – Ioannis Paizis Nov 16 '23 at 18:55
  • Thanks for this great historical document. Do you understand acustically Heisenberg's expression at 6:13? - But the clip does not relate to the quoted statement above. – Jo Wehler Nov 16 '23 at 19:17
  • @Jo Wehler, NO I think it's German. Anyway if I find I will notify. – Ioannis Paizis Nov 16 '23 at 19:24
  • Sorry, the problematic word in Heisenberg's clip is at 6:31. – Jo Wehler Nov 16 '23 at 19:31
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    @Jo Wehler, I don't get the word either, but I think that he emphasizes what he said before that language is not enough to describe the ontological implications of QM, so it's left to philosophers to complete the job. – Ioannis Paizis Nov 16 '23 at 19:48
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    @Jo Wehler, I found it. Heisenberg Physics and Philosophy (his own book) p186. (archive.org) pdf. – Ioannis Paizis Nov 16 '23 at 21:37
  • Thank you. Yes the quote refers to the end of his chapter 10 on "Language and Reality in Modern Physics". - Indeed, Heisenberg discriminates between, on one hand, the reality of the phenomena observed in experiments with elementary particles. And on the other hand, the world of tendencies and possibilities which characterizes the ontology of elementary particles. – Jo Wehler Nov 16 '23 at 23:25
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They are fundamental and their inherent properties are unchanging as far as we know. Current estimates suggest the lifetime of an electron is vastly longer than the age of the Universe. Of course, they also have variable properties such as position, energy, etc, which change according to circumstances, and they can be created or annihilated.

Marco Ocram
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  • aren't elementary particles quantum fluctuation in vacuum? – Ioannis Paizis Nov 16 '23 at 17:42
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    and, how can something be eternal if it's properties change? sounds like a theological perspective to me. – Ioannis Paizis Nov 16 '23 at 17:46
  • Is this is the explanatory gap between QM and physics? that is bridged by Platonism? – Ioannis Paizis Nov 16 '23 at 17:57
  • @IoannisPaizis Stable particles like electrons are not quantum fluctuations. - The old substance-attribute theory of Aristotle attempts to explain why the substance remains the same, but the attributes change. - As a first guess one may compare an electron to a substance. But a closer look from the viewpoint of quantum field theory refutes that assumption that electrons have an identity as individual particles, i.e. that they exemplify the concept of a substance. Quite unusal and takes some getting used to! – Jo Wehler Nov 16 '23 at 18:15
  • @Jo Wehler, so you say that what physics considers a stable particle, in QM has no identity, is not an individual particle: that's what I am saying. – Ioannis Paizis Nov 16 '23 at 18:25
  • @Jo Wehler, my comment about Platonism is that physics uses Platonism in the sense that they define a particle as stable ie as existing always, although it's not, it's a process. – Ioannis Paizis Nov 16 '23 at 18:26
  • @Ioannis Paizis What about converting your two last comments into a separate question? Then there would be more space to discuss how quantum mechanics (QM) and quantum field theory (QFT) as its extension are questioning our usual concepts and also the applicability of technical terms from Plato or Aristotle or any other philosophy. - Like you I consider the switch from a substance view to a process view to be helpful, possibly even necessary. – Jo Wehler Nov 16 '23 at 18:40
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    @Jo Wehler, Just for reference, in Greek most words include the concept of process, for example: entelechy = "εντελέχεια" = ἐν + τέλος + ἔχω = inside + final + has, and is also female which denotes a "becoming of", so the Greek translation (shortened and quick) = the physical process by which unmorphed matter is transformed from the field of potentiality to the field of physical reality by completing its teleological self realization : https://el.m.wiktionary.org/wiki/%CE%B5%CE%BD%CF%84%CE%B5%CE%BB%CE%AD%CF%87%CE%B5%CE%B9%CE%B1 – Ioannis Paizis Nov 16 '23 at 19:12