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by jerf 1742 days ago
This is a good example of one of the errors that I often see in what is otherwise the best scientific writing, which is either forgetting to specify what a certain model says, or simply straight up forgetting/confusing that a certain model isn't reality.

Maxwell's equations say that light doesn't interact. Maxwell's equations are known to be wrong in that way. They're still a very good simplifying case that you can do very well with using, by all means, just like Newtonian physics in the right conditions, but they aren't the way reality works. Maxwell's equations also have no place to put a gravity term, yet gravity clearly affects light.

The one I probably see the most often is articles about black holes confidently speaking about "what goes on below the event horizon" from an Einstein relativity point of view, which is where you get all the singularities and ring singularities that lead to different universes somehow, etc, again either forgetting to point out or simply forgetting entirely that those are the specific predictions of Einstein relativity, which is known to be inadequate to describe the inside of a black hole. It is certainly fair to discuss that theory's predictions, and whatever really is happening in there, relativity will certain shine some sort of light on it, but it is a mistake to present it simply as "what happens on the inside". The model is known to be broken here.

I am working out how to phrase this in a way that makes sense to the HN crowd because this tends to ruffle feathers when I say it, but this is all what should be well-known stuff. It's not like I'm "denying science" when I say this; quite the contrary! It's "denying science" when you insist the known-by-science-to-be-broken models are in fact not broken where the science is pretty clear that they are.

3 comments

>Maxwell's equations also have no place to put a gravity term, yet gravity clearly affects light.

The place to put the "gravity term" is in the coordinate system that Maxwell's equations take place in, and the definition of the derivative which is implicitly brought in via the curls, divergences, etc. That's general relativity, and Maxwell's equations are already fully compatible with it.

>[this tends to ruffle feathers when I say it] ... It's "denying science" when you insist the known-by-science-to-be-broken models are in fact not broken where the science is pretty clear that they are.

People are probably taking issue with your use of the words "broken" and "wrong," because you're describing a car that says 90mph on the dealership's sticker but can't go 900mph as "broken," or a one pound lump of beef as "wrong," because although the butcher said it weighed a pound, and you were charged for a pound, it'd be nice if it were two.

Yes, if you add relativity to Maxwell's equations, you get relativistic Maxwell's equations. Ultimately not particularly relevant here anyhow since it's QM describing what's going on here, not relativity.

I don't deal in automotive metaphors because they rarely enlighten, so I'll just stick with, yes, they are broken in those places, and are not suitable for unqualified claims about the nature of reality. This isn't about what would be nice if it were true or slight exaggerations, it's about the models being broken by being applied outside of their domain in an unqualified manner. That's exactly not how they are wrong. They are wrong in a much stronger manner.

And what's more, their strong brokenness is scientific consensus, not some sort of whacky theory. Whack theorization is what you're doing when you take these models, apply them in a domain they are known to be broken in, then claim this is the absolute truth about what is going on.

> relativity to Maxwell's equations, you get relativistic Maxwell's equations

Maxwell's equations imply (special) relativity, so there's nothing to be added. Maxwell's equations imply the speed of light is the same in all reference frames, which is all you need to derive special relativity.

That is why people of the time were trying to understand how this can ben so, why the did things like Michaelson-Morely to look for invariance/ether, and why so many of the terms used in relativity predate relativity, since they were invented to handle that Maxwell's Equations had this invariance.

Basically, Maxwell's equations, as written were relativistically invariant, thus compatible.

Special relativity is (partially) predicted by Maxwell's equations, and they are fully compatible. They are instead incompatible with classical mechanics.

GP claimed that Maxwell's equations are missing a term for gravity/mass, which would be the domain of General Relativity. This is more complicated, as it's true that they didn't predict gravitational lensing. But, they are still compatible with GR, as GR modifies the coordinate system, and Maxwell's equation in the GR curved space-time coordinate system do predict gravitational lensing.

GP also pointed out that Maxwell's equations are not compatible at all with QM, as they incorrectly predict that photons can't interact. Here there is no way to save them - Maxwell's equations are just an approximation, and the actual laws governing the behavior of light are substantially different, only reducing to ME in certain approximations (just like classical mechanics is not compatible with either QM or SR/GR, except as an approximation of either of the two others).

> or simply straight up forgetting/confusing > that a certain model isn't reality.

That's partly to do with the way that high school science is taught. If we made the context clear at all times then people would have a better grounding.

I find your comment confusing. What exactly is the "good example" you're referring to? The person you are replying to appears to have done exactly what you are saying to do, by my reading, so I'm wondering what you're referring to.

'The map is not the territory' is the phrasing I've heard: https://en.m.wikipedia.org/wiki/Map%E2%80%93territory_relati...