The word ‘particle’ means ‘a minute portion of matter’, there is no ambiguity, it is a portion, i.e. a distinct volumetric entity, of matter and matter alone, whose outer limits can take any shape or form. Newton’s ‘corpuscle’ is the same thing, ‘a tiny particle of matter’. The word does not define, and cannot be used, to describe any entity that is non-material.
But this word is often used by theoretical physicists to describe hypothetical entities that are not composed of matter, and it is used extensively by them today to explain what they are doing to the wider public.
Which explanations are of course of absolute necessity if they are to receive taxpayer funding for their work, as they can hardly use their means of inter-disciplinary communication, the ‘language’ of mathematics to, for example, persuade government departments to provide them with taxpayers money for their pet projects. And further to assure those taxpaying voters, via popular science books and magazines, that they are doing hugely important and necessary things.
So, while some will argue (correctly) that this is semantics, physicists cannot be allowed to unilaterally decide that they will attribute meanings to words simply to suit their own purposes.
The word particle (along with the word vacuum) is one of the two words which represent the basic assumptions from which the core theories of modern atomic physics have been developed.
These originate from the atomic theories of ancient Greek philosophers, who postulated a solid, indivisible spherical particle – the atom, separated by a non-material space – the vacuum.
And obviously if such particles were arranged, even in the closest possible alignment as in a box of marbles, a continuous, distinct and separating, non-material space, the vacuum, would have to exist.
And these two words, particle and vacuum, still dominate physicists thinking, examples – the positron, the neutron are sub-atomic particles, inter-planetary regions are today still described as being ‘the vacuum of space’. (Again, the word vacuum is generally used very loosely, if someone means a ‘partial vacuum’ or preferably ‘a condition of very low pressure’, they should describe it as such)
I have questioned one of these core assumptions of modern physicists, the concept of a space that is distinct from matter, but the concept of particles and the wide use of this word in discourse also needs to be examined.
Nompes
But for a moment let us leave real particles and consider the use of this word by physicists to mean the wide variety of speculative, non-material ‘particles’ (NOMPES), for example ‘virtual particles’, that are suggested to occupy inter-atomic ‘spaces’.
The first point is that such entities must ultimately have dimension, because if you take any humanly defined dimension and divide it in two and continue to divide the result, ad infinitum, a dimension of zero will never be achieved. Zero is non-existence, it is a mathematical convenience.
So whatever minuscule dimension you choose for your unique, speculative non-material ‘particles’ or nompes, if it is an entity it must have shape or form, and the most obvious one would be a sphere but, even if it did not have a regular form, if such ‘nompes’ were arranged together in the closest possible alignment, they would necessarily be partly separated by a comparably minuscule inter-nompeal ‘space’.
And then this medium would ultimately require definition, perhaps again by filling it with even smaller nompes, which process could go on, ad infinitum, further downwards to the hypothetical zero dimension, an eternal progression.
However there is one avenue that could avoid this, which is to suggest that your space-filling nompes are all platonic solids of equal dimensions, such as tetrahedra, cubes, dodecahedra. This would eliminate a rather inconvenient separating ‘space’, but would obviously produce other problems.
To return to real particles, quantum physicists say that the photon “ is neither a wave nor a particle, nor should we expect it to be”, and the electron is described by some as consisting “entirely of a structure of spherical waves whose behaviour creates their particle-like appearance” and electrons “can at times appear to us as waves, and at other times as particles. In this sense they are neither particles nor waves, in an absolute sense, but only exhibit wave or particle properties, depending on the experiment being performed.”
Presumably this would also apply to all the numerous and hypothetical ‘particles’ that are said to inhabit the atomic nucleus, so we must conclude that, at least as far as modern theoretical physics is concerned, ‘particles’, in the real meaning of the word, simply do not exist.