How do you know all those things about the physical world? For example- you say that "all of the physical laws of the universe are defined by computable maths". Do you really know what all the physical laws of the univese are?

We don't know. We just think it likely. We are unaware of counterexamples, or reasons to suspect the existence of counterexamples.

Again I have to ask- who is this "we"?

Apologies if my question sounds too contrarian, but I think you are making some very big assumptions about the computability of the laws of physics that are not really based on anything concrete, like a strong knowledge of the mathematics of modern physics.

We is humanity, as far as I know and as far as brief Googling is able to determine. I am not a physicist, so I have good knowledge of physics up to the high school level, and a dabbler's knowledge of what lies beyond. I am open to correction, so feel free to offer some contradictory evidence if you have any.

What exactly did you google for?

Are we really communicating here? I'm saying that there is a lot that physicists don't know about physics and that therefore it's impossible to make the assumption that you make, that every law of physics is computable. Because nobody knows all of them, and nobody knows what nobody knows, or how much of it there is.

And you're saying that, given high-school physics and "dabbling", we know all of it and it's all computable.

Is that a good summary of our discussion so far?

> Is that a good summary of our discussion so far?

Hrm, I wouldn't say so, and I don't think if that is your impression that it's going to be very productive to continue it.

FWIW: "Please respond to the strongest plausible interpretation of what someone says, not a weaker one that's easier to criticize. Assume good faith."

Yes, I'm aware of the guidelines, thank you. They are not a tool to passive-aggressively end conversations by accusing other commenters of bad faith.

But I agree this is not a productive conversation. I don't see that you have a very clear idea of what you are trying to say.

Even if real infinities existed, it would be impossible to tell. What do you measure it against?

Infinite computations are not the only computations that are impossible to perform. For example, if I asked you to enumerate (not calculate) the number of X time units in all the time from the start to the end of the universe, setting X to the closest time unit to the time an operation took on your chosen hardware (past, present or future) you would not be able to complete this computation.

For instance, if the fastest hardware available to you performed about one operation each femtosecond, it would not have the time to enumerate all femtoseconds from the birth of the universe to its death. And that number is a finite quantity.