[pinkmuffinere]

As a naïve fool with no understanding of quantum physics, I want to take a stab at this! Here’s my hypothesis:

Consider a world in which everything is “very quantum”, and there are no easy approximations which can generally be relied on. In such a world, our human pattern-matching behavior would be really useless, and “human intelligence” in the form we’re familiar with will have no evolutionary advantage. So the only setting in which we evolve to be confused by this phenomena is one where simple approximations do work for the scales we occupy.

Sincerely, I don’t think this argument is super good. But it’s fun to propose, and maybe slightly valid.

[perlgeek]

The main objection is: if there wasn't a classical limit, our brains would have evolved differently.

So yes, we can use the antrophic argument as evidence for the existence of the classical limit, but it doesn't have explanatory power for why there is a classical limit.

[movpasd]

This is called the anthropic principle. I personally have objections to it, specifically that due to emergence it is hard to make definitive statements about what complex phenomena may emerge in alternate universes. However, it's taken seriously by many philosophers of physics and certainly has merit.

[GoblinSlayer]

Isn't that argument from ignorance? You can consider a class of physics similar enough to our physics, it should give enough space for research.

[movpasd]

My point is that it isn't possible to determine the emergent behaviour of a complex system from first principles. So arguments of the type "these physics don't result in atoms being produced, so life can't emerge" doesn't imply that other complex structures _like_ life don't emerge.

[GoblinSlayer]

Then how do we make technology if we don't know the result?

[Qwertious]

Technology is made iteratively by repeated trial and then observed error in the physical structures we've created (i.e. we build machines and then watch them fail to work properly in a particular way).

Technology that works in a different universe without atoms, would require us to be able to experiment within that universe if we wanted to produce technology that works there with our current innovation techniques.

[Gibbon1]

I'm a fool too but two things I remember. One was a paper discussing the thermodynamics of groups of particles. When they have strong interactions with nearby particles classic behavior emerges very quickly as the number of particles increases. And not n equals 1 million, or 1000, but more like two dozen.

And then there was Feynman asked to explain in layman's terms how magnets work. And he said I can't. Because if I taught you enough to understand you wouldn't be a layman. But he said it's just stuff you're familiar with but at a larger than usual scale. And he hinted even then one level down and you run out of why's again.

[groestl]

> have no understanding of quantum physics

But you know about the Anthropic Principle :)