Particle is a useful abstraction for us humans. We can think of them as quantum field excitations as well. But that doesn't tell us whole a lot. Thinking in terms of particle allows us to further identify their properties like mass, position, interaction, constituent sub-particles & their charges etc.

Part of thinking about particles as particles is historic & empirical. When started breaking down matter to its lowest indivisible unit, we encountered "particles" and not waves. Then came sub-particles, and finally quantum fields. So this progression of discovery also contributes to it.

Matter is low entropy, entangled energy. Particles are an instance of matter.

I've read on good authority is that a particle is now viewed as the local excitation of a field.

So we end up trying to define a point-particle as a non-intuitive thing. Is this a language problem? — Don Wade

This difficulty relates to the question whether the smallest units are ordinary physical objects, whether they exist in the same way as stones or flowers. Here, the development of quantum theory some forty years ago has created a complete change in the situation. The mathematically formulated laws of quantum theory show clearly that our ordinary intuitive concepts cannot be unambiguously applied to the smallest particles. All the words or concepts we use to describe ordinary physical objects, such as position, velocity, color, size, and so on, become indefinite and problematic if we try to use then of elementary particles. I cannot enter here into the details of this problem, which has been discussed so frequently in recent years. But it is important to realize that, while the behavior of the smallest particles cannot be unambiguously described in ordinary language, the language of mathematics is still adequate for a clear-cut account of what is going on. — Werner Heisenberg, the Debate between Plato and Democritus

The problem is trying to describe a "nebulous-point" - and it doesn't seem to exist in our language. So we end up trying to define a point-particle as a non-intuitive thing. Is this a language problem? — Don Wade

I have my own personal solution to the "nebulous" nature of physical particles. And I have developed my own language to express the apparently dualistic nature of Nature. That's because, I think it's actually a WorldView problem.

In the 18th century, physicists thought they have found the long-ago predicted fundamental element of matter. So, thinking they had found the "holy grail" of physics, they named that supposedly smallest unit of matter "The Atom". But, in the early 20th century, their allegedly un-cuttable "atoms" were split into a so-far un-ending list of constituent parts. Hence, the "ultimate particle" was found to have parts of its own. And the dividing continued until there was nothing material left, except a mathematical definition of a hypothetical "point", with no extension in space.

Consequently, the current fundamental element of Matter contains only the potential for physical substance. It's no longer called an indivisible Atom, but instead, a statistical mathematical "Field". That's essentially an empty place in space where a measurable iota (mass) of matter might or might not appear at some point in the near future. So, the physicists were again forced to find a new term to describe a particle-that-is-not-yet-a-real- thing : it's now called a ghostly "Virtual Particle".

At the same time that the substance of matter was found to be insubstantial, the behavior of those "nebulous" bits of matter, was also neither here nor there. So, the physicists again searched for a new way to encapsulate the essential nature of an object that exhibits both discrete point-like "particle" motions, and continuous wave-like "entangled" motion. Such counter-intuitive comportment required a dualistic, or binary, or bipartite, or amphibian, or dyadic term, but "wave-particle" was the best they could come up with. Strangely, 2500 years ago, Aristotle coined an apt term for such a thing that seems to have-it both ways : hylemorph (form + matter) or (soul + body). Or, as I would call it : "In-form-ation" or "EnFormAction".

However, I have what I think is a more definitive name for the fundamental essence of reality : "Information". Unfortunately, few readers of this post will understand how or why that term applies to the foundations of physics. The philosophical worldview that is based on that "all-is-information" concept is Enformationism, as summarized in the BothAnd Blog. :nerd:

Introduction to Enformationism :
". . . it’s based on the emerging evidence that invisible Information, instead of tangible Matter, is the fundamental substance of everything in the universe, including Energy, Matter, and Mind."
http://bothandblog6.enformationism.info/page80.html

it seems the observion must take place over time - not just a point in time — Don Wade

This is completely true and an important part of modern quantum physics: time-energy uncertainty. In order to measure the energy of a particle more accurately, you must measure it for a longer time, and so become less certain of when exactly it was. Conversely the more precisely you measure when exactly a particle was, the less certain you can be of its energy -- which is why the energy of a particle can fluctuate wildly on tiny timescales, as it's only on average over time that it is around some specific energy.

This is exactly analogous to position-momentum uncertainty, where to measure the momentum of a particle you must measure it over a distance and thus cannot know exactly where it was, and conversely the more precisely you measure where a particle was the less you can possibly know about the momentum it had.

Waves of all kinds, not just quantum particle-waves, have this duality: the frequency of a musical note becomes less well-defined the shorter the note is played, for example.

Great short video about it here:

The question is: Is a particle just a wave function, or is it a description of a probability wave, over time? In trying to visualize how we can detect a "particle", it seems the observion must take place over time - not just a point in time. — Don Wade

To quote Carlo Rovelli, "particles are the objects revealed by detectors". We build up a representation of those objects (and the probabilities of measuring specific values) over repeated observations.

Note that familiar, macroscopic things such as cats and the moon are themselves particle systems, and subject to the same quantum/wave function considerations.

The problem is trying to describe a "nebulous-point" - and it doesn't seem to exist in our language. So we end up trying to define a point-particle as a non-intuitive thing. Is this a language problem? — Don Wade

I don't think it's a problem of language. It's more a matter of thinking carefully about our underlying assumptions regarding reality, locality, determinism, etc., which are also at issue with macroscopic objects even if it's not so obvious.

To quote Carlo Rovelli, "particles are the objects revealed by detectors". We build up a representation of those objects (and the probabilities of measuring specific values) over repeated observations. — Andrew M

A position known as ‘instrumentalism’, I believe.

A position known as ‘instrumentalism’, I believe. — Wayfarer

No, one could be either a realist or an instrumentalist about particles. As with Rovelli, I think that if you can detect it then it's real.

,, it seems the observion must take place over time - not just a point in time. — Don Wade

And it does. Born's statistical interpretation is a useful tool to measure probability over time.

Is this a language problem? — Don Wade

In a way. As others pointed out, it's an evolutionary problem in that the Physics evolves to attempt to measure what is happening.

Basically, its not even about saying it behaves according to some probability distribution.
Some theories do postulate that what is happening is, in the end the output of a probability density function (weighted set of probabilities).

This is where the confusion arises. Every interpretation will still ultimately be a theory for something we measure experimentally.

But you can't measure a single photon, due the problem of Heisenberg's uncertainty principle. You let a clump of them go through, one by one (It's not even definitive that it is one by one) and the pattern can be modelled as a probability density function, or over time using Born's statistical interpretation.

Some theories do propose that that the universe itself is behaving probabalistically and these tools measure what's actually happening, but other theories do not postulate that there is anything at all happening in terms of probability.

For any theory , probability distribution functions etc. are just tools to estimate the values they can't truly measure at the quantum level, approximations. It's not at all clear that the universal process itself is actually probabalistic. Radioactive decay is probably a better candidate for the universe behaving in an indeterministic way, but that's questionable too).

This is also part of the problem. Regardless of what theory we are talking about, technology and fundamental limitations on measurement mean that probability is used to approximate the measure.

The only thing any of these theories have in common with each other in terms of probability, is that probability density function or Born statistical interpretation are tools that used to approximate (in the case of superposition for example), how many photons are likely to be detected at some band or range or subset of probabilities. That's it..

For example the Bohmeian mechanics interpretation (sometimes called Pilot wave theory) of Quantum Mechanics proposes there is no indeterministic probability function at play.The wave of light travels with a pilot wave that interferes with the photon itself.

An intuitive ad hoc way to think about the distinction between wave and particle is that in motion, it is generally represented as a wave, and on measurement or absorbtion by an electron- a particle.

It is not wrong to be confused by this. But that is the current model, Einstein called it wave particle duality.

First and foremost, a particle is an idea, the idea that matter is composed of tiny allegedly indivisible units. This idea is ancient and harks back to the laughing philospher Democritus who named them atoms.

The atomic theory was revived sometime in the 18th to 19th century by figures such as John Dalton and then by Neils Bohr et al. The theory fit observation and experiment to a T except, if memory serves, for some discrepancies that scientists seem to have swept under the rug (I'm unsure how far this is true though).

Anyway, what bears mentioning is that up until a certain point, particles or atoms were conceived of in a non-mathematical way. The first thing to cross our minds when we hear "atom" is our solar system - the nucleus (sun) in the center and electrons (planets) in orbit.

What followed next was quantum physics and, I'm only guessing here, it opened up the possibility of a mathematical formulation of particles/atoms and, as you already seem to know, what came out of it was that particles are actually waves. In other words, for/in mathematics of quantum mechanics, particles/atoms are/appear as waves.

It is not wrong to be confused by this. But that is the current model, Einstein called it wave particle duality. — Paul S

Thanks for the reply! The other comments over the past 24 hours are also interesting as well. Hopefully, you and the others will read this response.

One of the items missed by those that have looked at the "wave-particle duality" is how we define either one - that is: the particle, or the wave. The definition is acording to the "properties" (or actually a specific small group of properties. The brain uses electrochemical formation as inputs that define these properties. Each item, of our "focus", has these specific propties that have developed from habit over time.

When we "think" of different objects/items our brain visualizes a new set of properties that defines each new object. However, the brain can only focus on one set of properties at any specific time. We can easily change the focus, but our brain can still only focus on one set at a time. That creates the difficulty of trying to visualize a duality - such as the wave-particle duality. Another famous example is "The Rubin Vase": https://en.wikipedia.org/wiki/Rubin_vase . One can visualize the faces, or the vase, but not both at the same time.

There are certain behaviors of particle that we it's difficult for us to associate them with waves because we don't observe those behaviors in our daily lives in common waves (water etc) - e.g. spin, anti-particle like electron/positron pair, charge, which further causes more concrete structure to be born (atom) with more unique characteristics. So in my view this has more to do with how particle like behavior these excitations in underlying quantum fields manifest that our brain is more easily able to process and make use of that helps to think of them that way.

In reality there is no wave-particle duality. It's just "waves" (which is actually another abstraction because they are not really waves but at the very fundamental level the phenomenon manifests itself as wave and wave properties).

In reality there is no wave-particle duality. It's just "waves" (which is actually another abstraction because they are not really waves but at the very fundamental level the phenomenon manifests itself as wave and wave properties). — hume

Maybe spectral waves is what they should be called to avoid ambiguity with tangible waves.

The brain uses electrochemical formation as inputs that define these properties. Each item, of our "focus", has these specific propties that have developed from habit over time.

When we "think" of different objects/items our brain visualizes a new set of properties that defines each new object. However, the brain can only focus on one set of properties at any specific time. We can easily change the focus, but our brain can still only focus on one set at a time. That creates the difficulty of trying to visualize a duality — Don Wade

I would still argue that it's more an issue of evolution of the Sciences, and that some apparent workings of the universe (the Josephson effect comes to mind) aren't necessarily intuitive in the way we evolved at the macroscopic level, and hence the language won't be. This is why the language of Math is so important, as it removes this ambiguity. But then you have the issue of teaching something that can be all the more daunting because a new language was needed to define it. You can lose sight of the whole by getting lost in the minutiae.

Absolutely. Math is more exact. But, I believe math separates science and philosophy. To me, philosophy is a better tool (than math) in trying to visualize wave-particle duality - (at this time). But, the foundations of philosophy need to change - especially in the light of quantum mechanics. That's what I'm attempting to do. We have a lot more information to work with now - than they did 2,000 years ago. Want to help?

But, I believe math separates science and philosophy. — Don Wade

I think politics does that. Most of our great Math comes from a time of union between between Philosophy and Science.

“Every good mathematician is at least half a philosopher, and every good philosopher is at least half a mathematician.”
― Gottlob Frege

But in these times, we have an abundance of people well versed in one but not the other.