This just popped into my head. I have no idea if it makes any physical sense at all, but what the heck…
It has been hypothesized that whatever is apparently causing the expansion of the universe to accelerate will do so in the future to such a degree that literally everything, down to the sub-atomic particles that make up atoms and nuclei, will be pulled inexorably from every other particle at an exponentially-increasing rate. The result of this “Big Rip” will be a cold (converging on absolute zero), dark universe, with each quanta of matter and energy pulled so far and so fast from any other that they will be causally isolated, literally completely cut off from all else.
For some reason I got to thinking about this: For anything connected to anything else by any other force but the color force holding quarks together, the strength of the interaction decreases with distance. For gravity and electromagnetism, for instance, this relationship is defined by a simple inverse-square law.
Not so the color force: At extremely short distances, the force is weak, then increases to a maximum per unit distance very quickly (so-called “asymptotic freedom”) such that as two quarks are pulled further and further apart, the force needed increases linearly with distance until there is so much energy in this system that an entirely new pair of antiquarks (or quarks, if it’s two bound antiquarks) is created, thus creating a pair of mesons. Because of this, quarks are said to be “confined” such that they can never appear outside of multi-quark particles collectively referred to as hadrons. (of which there are quark-antiquark mesons, triple-quark or triple-antiquark baryons, and maybe some more exotic things).
So, it would seem that if, for instance the space between an electron and a proton increases, they move apart and that’s it. You’re left with nothing but the same proton and electron further away from one another. The forces between them decrease as the square of the distance, approaching zero at infinity. Quite mundane and a little depressing.
But if the space between two quarks increases, it seems the force in the system must, when something like the diameter of a hadron is breached, increase linearly, ultimately creating a meson. And as these two particles are pulled apart, you get another meson. It can’t be helped: No quark can be alone, per confinement.
So, as the big rip really rips into action, shouldn’t there be an exponentially growing number of mesons being created, apace with the expansion of space, such as the rate of expansion approaches infinite, the rate of meson creation would as well? Couldn’t this slow a big rip down? Or does the cosmological constant, quintessence, whatever, trump even the color force in the end?