I understand that objection, but I disagree. We do have at least two pieces of relevant evidence:
The universe we find ourselves in seems to be a rather simple mathematical object. The final verdict on this, of course, is still out; but if the bottom were something extremely complicated, it would seem to be an unbelievable coincidence that the approximations we’ve found (QM and GR) are so tidy and so very very accurate.
We can usually think of good reasons that simpler mathematical objects wouldn’t contain a great proportion of observers. The particular cosmology of our universe appears to be one of the simplest ways to make evolution of sentient life plausible— for example, QM without gravity results in a dispersive wavefunction, and remotely brain-sized interacting configurations become vanishingly unlikely.
I mean, you could build a conscious agent in Conway’s Game of Life, but it seems unlikely that any not-too-complicated starting configuration would result in one (well, a chaotic one would result in very occasional Boltzmann brains, but those would be much rarer than conscious life is in our universe, more than enough of a difference to outweigh a reasonable complexity penalty on universes).
From these facts, if we expect to be “typical” elements of our reference class (i.e. conscious agents, perhaps with some additional conditions), something like the Level IV Multiverse is strongly supported, and predicts that 1 and 2 will continue to be more strongly validated. (2, in particular, is a pretty decent prediction; it says that we can’t come up with a simpler cosmology-leading-to-sustained-evolution than the one we live in).
Well my comment wasn’t an objection to Tegmark’s mutliverse hypothesis but rather an explanation as to why its the only explanation you’ve ever heard.
But if may object to your objection, I disagree that QM is so very tidy. The standard model has what − 18 free parameters with values assigned as necessary to fit the experimental data? I don’t know that anyone considers this tidy, or that many people think particle physics is “done”. What we have for particle physics is a useful mathematical model but it isn’t an elegant one.
The expectation that we should find an elegant model is not unreasonable but it is not yet accomplished.
I understand that objection, but I disagree. We do have at least two pieces of relevant evidence:
The universe we find ourselves in seems to be a rather simple mathematical object. The final verdict on this, of course, is still out; but if the bottom were something extremely complicated, it would seem to be an unbelievable coincidence that the approximations we’ve found (QM and GR) are so tidy and so very very accurate.
We can usually think of good reasons that simpler mathematical objects wouldn’t contain a great proportion of observers. The particular cosmology of our universe appears to be one of the simplest ways to make evolution of sentient life plausible— for example, QM without gravity results in a dispersive wavefunction, and remotely brain-sized interacting configurations become vanishingly unlikely.
I mean, you could build a conscious agent in Conway’s Game of Life, but it seems unlikely that any not-too-complicated starting configuration would result in one (well, a chaotic one would result in very occasional Boltzmann brains, but those would be much rarer than conscious life is in our universe, more than enough of a difference to outweigh a reasonable complexity penalty on universes).
From these facts, if we expect to be “typical” elements of our reference class (i.e. conscious agents, perhaps with some additional conditions), something like the Level IV Multiverse is strongly supported, and predicts that 1 and 2 will continue to be more strongly validated. (2, in particular, is a pretty decent prediction; it says that we can’t come up with a simpler cosmology-leading-to-sustained-evolution than the one we live in).
Well my comment wasn’t an objection to Tegmark’s mutliverse hypothesis but rather an explanation as to why its the only explanation you’ve ever heard.
But if may object to your objection, I disagree that QM is so very tidy. The standard model has what − 18 free parameters with values assigned as necessary to fit the experimental data? I don’t know that anyone considers this tidy, or that many people think particle physics is “done”. What we have for particle physics is a useful mathematical model but it isn’t an elegant one.
The expectation that we should find an elegant model is not unreasonable but it is not yet accomplished.
Yes, but compare that to the number of free parameters implicit in chemistry before QM and QED came along.
Well there is a difference between saying x is more tidy than y and saying x is very very tidy.