Adam Brown

And similarly, the density of water around you, the viscosity, would change.

So it'll be an environmental variable like that.

There probably was spontaneous nuclear fire.

reactors, not nuclear.

They've discovered a seam in Africa where it looks like there was a fission reaction that naturally happened.

It didn't explode, but it did do the same thing that happens in our nuclear power plants.

Yeah, I mean, absolutely.

Almost certainly.

Anything that humans can do can happen without humans.

It's interesting to reflect on what aspects of human behaviour nature has a tough time doing without us and what it just does on its own.

For example, we make colder things in our laboratories than really exist naturally in the universe, but the universe certainly could make anything colder just by chance.

But

Yeah, vacuum decay is something that if it is possible, will in our future definitely happen.

That's just like a feature of the world that eventually in our distant future, if it's possible at all, it will happen due to a quantum fluctuation.

Our descendants may not wish to wait around for a quantum fluctuation to happen.

They may wish to take the fate into their own hands, since a quantum fluctuations can take exponentially long times to happen.

And if they even happened, you'd end up in a unfavorable vacuum, not hospitable for life, rather than trying to steer the cosmological constant in a happy direction.

but they certainly can happen in our future and indeed definitely will happen if they're permitted.

According to our understanding of quantum mechanics, if they're permitted, they must eventually happen.

Furthermore, there are, again, speculative but not wild theories of the early universe in which this happened in our past.