Time at the Planck scale

How would time be exerienced at the Planck scale? If there was a dimension smaller than the Planck scale would it be worth studying?

Planck time.

In Thief of Time Pratchett riffed off of Planck Time with the concept that between each smallest possible unit of time the universe was literally destroyed and recreated. Not his very best book but a good one.

Chronos has schooled me in the past that the Planck limits are merely hard coded limits on what we could conceivably probe to (and we’re not close to probing those scales as is).

He told me it is quite possible to go smaller than the Planck size which would then of course mean shorter than the Planck time and so on.

We just can’t go there.

I read once on a wiki page though (damned if I’ll ever find it again), that there are theoretical models of cosmology which allow for the entire universe to simply spontaneously vanish. What was I reading?

I’m afraid you took home the wrong message from what I was saying, then, Whack-a-Mole. The short answer is that we don’t know. The long answer is that there might (or might not) be some minimum scale of length and time, or some scale below which things get wonky, and if there is such a length scale, it’s as good a guess as we have that it’s probably (but might not be) somewhere in the general vicinity of the Planck scale.

The closest I know of to that is a collapse of a false vacuum state. The idea is that what we think of as the lowest energy state of the vacuum might not actually be the lowest, but just a semi-stable excited state. If somehow the true vacuum (or a lower false vacuum) were ever achieved in some spot, it would induce nearby regions to also fall down to the true vacuum, and so on, expanding out at the speed of light. It wouldn’t actually happen everywhere at once, but since it propagates at c, we’d have no warning of it happening before it actually hit us.

Yes, I’m pretty sure I was reading something about false vacuum. I’ll poke around tonight and see if I can find it again.