〈 Berger | Dillon 〉

What do you mean by "hard to swallow"? Hard to accept that our definition of infinity is a good one?

Oh I don’t have problem with the definition. I don’t think it’s good or bad. It’s just that, I’ve been use to thinking about finite things for so long that I’m more likely to ask the question, “where does this end?”. I just have to get use to it and I’ll be fine. No biggie.

I like to think that about infinity as a useful approximation to the physical world, and you don't ever run into trouble with it until you get to QFT

Physically, can something be infinite ?

I don't think so, no.

Alright, can a thing with existence (physical or not) be infinite? I’m currently thinking of the universe, or whatever the “necessary entity(not talking about anything conscious)” is. Not trying to talk about religion, I’m just wondering what cosmology tells us.

Our observable universe is not infinite, and nothing in it is infinite. The universe *could* be "infinity old", but that's a senseless notion, since at any given moment it will be some finite # of seconds old. As for the unobservable universe, your guess is as good as mine

If we have t=0, doesn’t that make the universe finite (or is that just the “observable universe)?