[antonvs]

> First, the "inverse square law" isn't a law in the colloquial sense (like a maximum speed limit law) where the universe is forced to obey it. Instead, "law" is just a conventional phrase indicating what the consensus among scientists is regarding certain observations.

That's incorrect in this case. It's a hard requirement that can easily be mathematically derived, so easily that I'll do it here:

1. The surface area of a 3D sphere, 4πr^2, is proportional to the square of the radius.

2. Radiation from a point source that is evenly radiating outward is therefore spread out over an area that increases in proportion to the square of the distance from the source.

3. Therefore, such radiation must obey an inverse square law, in any universe in which the preconditions -even radiation from a point source through 3D space - are true.

> Future observations of radiation propagation might run completely contrary to those we've had up to now

That's provably not the case, and I've just proved it beyond doubt. From this proof, we know what kind of situations are subject to this law, and can even determine what kinds of situations might not be subject to it.

A similar point applies to conservation laws, such as conservation of energy and conservation of momentum. Noether's theorem shows us that such conservation laws must hold, again in any universe where the preconditions around differentiable symmetries hold.

With that in mind, I don't think the rest of your comment makes much sense. Not only does science answer "why" questions in many cases, it can answer them so definitively that we can apply that knowledge to other universes.

[chopin]

You just shifted the question from "Why do we have an inverse square law for radiation" to "Why do we live in a 3d universe".

Same goes for the Noether theorem. It shifts the question from "why do we have certain conservation laws" to "why do we have certain symmetries".

[antonvs]

> You just shifted the question from "Why do we have an inverse square law for radiation" to "Why do we live in a 3d universe".

That's not "shifting the question", that's a different question.

The point is that there is a meaningful sense, discovered by scientific study, in which we understand why there is an inverse square law for radiation.

If the examples I've given are not answers to "why" questions, how would you characterize them?

In any case, the idea that we can never know the answer to any "why" question because there's a causal chain that goes back to the creation of the universe is silly. We can understand the connection between parts of a chain without knowing where the chain came from, and that's exactly what science has done, so successfully that some people are now complaining that we don't know how the universe began.

Besides, the question of why we live in a 3D universe has a similar answer - see Max Tegmark's "On the dimensionality of spacetime": https://space.mit.edu/home/tegmark/dimensions.pdf

Given that, where do you think "I've shifted the question" now? At some point, do you not recognize that the question being asked really has no meaningful relevance to the original question?

In fact, examples like these go beyond just answering "why" questions - they tell us that this universe, and even other universes with similar properties, couldn't be any other way!