> The term that corresponds to "stiffness" normally just gets called "mass", since that is how it shows up in experiments.
Then why not just call it "mass"? That's what it is. How is the notion of "stiffness" any better than the notion of "mass"? The author never explains this that I can see.
> I think stiffness is an ok term if your aim is to maintain a field centric mode of thinking.
"Stiffness" to me isn't a field term or a particle term; it's a condensed matter term. In other words, it's a name for a property of substances that is not fundamental; it's emergent from other underlying physics, which for convenience we don't always want to delve into in detail, so we package it all up into an emergent number and call it "stiffness".
On this view, "stiffness" is a worse term than "mass", which does have a fundamental meaning (see below).
> Mass as a term is particle-centric.
Not to a quantum field theorist. :-) "Mass" is a field term in that context; you will see explicit references to "massless fields" and "massive fields" all over the literature.
Do you also object quarks and gluons having "color" charge?
Mass is a bad term because it's loaded with so many meanings and equivalences already. But also in the kindest and most accurate reading here it still doesn't naturally lead to explaining why some forces have limited range the way that term "stiffness" does, which was the whole point of the article.
> Do you also object quarks and gluons having "color" charge?
No, because no physicist tries to argue that "color" is an appropriate term because of some physical interpretation that involves actual physical properties of colored objects.
This author, OTOH, appears to be arguing that "stiffness" is a better term than "mass" because of some physical interpretation that involves actual physical properties of stiff objects. An analogy with quarks would be to argue that "color charge" is an appropriate term because red, green, and blue quarks somehow have actual properties associated with those colors.
> it still doesn't naturally lead to explaining why some forces have limited range the way that term "stiffness" does
I'm not sure the explanation of that in terms of "stiffness" is any better, because in the setting where the term "stiffness" comes from, there is no such thing as what this author calls a "floppy" object. So his explanation only "explains" the behavior of forces associated with massive gauge bosons at the price of throwing away an explanation of the behavior of forces associated with massless gauge bosons.
In the unit analysis it appears as if it's just kinematic viscosity.
Undergrad-only level physics person here:
I think stiffness is an ok term if your aim is to maintain a field centric mode of thinking. Mass as a term is particle-centric.
It seems these minimum-stretching could also be thought of as a “wrinkle”. It’s a permanent deformation of the field itself that we give the name to, and thus “instantiate” the particle.
Eye opening.