Rex Kerr
4 min readJan 28, 2023

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Indeed not, because there is no "wind force".

There is only the interactions between molecules. This was the great insight of statistical mechanics: there are only molecules.

If you know about molecules and how they collide as a gas, you can derive bulk approximations like "wind force". We noticed the large-scale pattern first, but then we understood that this pattern was comprised exclusively of the structure of interactions between molecules.

There is no "wind force"! It's all molecules running into things.

But there are too darned many of them. We want an easier way that to keep track of it all, so we say, "Okay, we understand the collective behavior well enough so that we can replace all the individual behavior with the collective behavior and still get close enough to reality."

So, although the behavior of the eye of a hurricane is completely determined by the physics of individual molecules, it's impractical to compute it at that level. Nonetheless, that the eye is comparatively still is a consequence of the collective action of molecules going left and molecules going right canceling out: they bump into each other and go every which way, leaving some region of relative calm. This is true for any kind of swirly wind phenomenon. With hurricanes we have more things going on--rising air in the middle coming down in various places including the middle, increasing the width of the counteracting-collision zone--but all the collective action is the consequence of the individual behaviors: the structure of their behaviors (local, in this case), and also the quantitative detail of their behaviors (mostly ballistic momentum-and-energy conserving collisions).

There is no extra wind force. It's a convenient way to express the action of the collective without having to worry about too many details.

Likewise, when we compute gravitational attraction, unless gravitational fields are extremely strong, we tend to make simplifications. Yes, maybe that star is comprised of 1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 atoms, and it has angular momentum so it's not a perfect sphere, but you know what? For most things we care about, that it is so many separate atoms doesn't matter--we represent it as a single point with the mass of a thousand billion billion billion billion billion billion atoms. How's that for collective action!

We can do it because we understand the individual relationships--everything pulls on everything--and therefore can calculate the collective. But there isn't any separate star-gravity. It's just regular gravity.

We can calculate this for anywhere we like in the universe, so long as we understand the surroundings well enough. And when we do this for the galactic core, it's absolutely nothing like what you describe. Completely different.

And yet, all people are doing all the time is figuring out the result of collective action. They just have very well-tested ideas about how the collective works.

Everything you say about how the gravitational collective works is contrary to how we know that gravitational collective action works. You imagine hurricanes, but you don't investigate: do we see any interactions like those in a hurricane? What is the structure of the interactions? If the structure is the same with galactic-scale gravitation, they we can go on to quantify whether it works numerically--but if the structure isn't the same, it's time to drop the analogy. You imagine elections for mayor, but you don't investigate: do we see any gravitational interactions like those in an election? Again, if the structure is not the same, the analogy has no reason to hold.

The difference with Model B is not in considering collective action or structure where others do not. The difference is in imparting special powers to the "collective" despite no evidence whatsoever that collective action works that way, and despite a whole heap of evidence that a different type of collective action matches observations very well.

If you wanted to try anyway--to proceed from a vague inspiration to an actual model--you would need to start saying things about how your view of collective action differs from everyone else's. Because the standard view--very well-validated, I might add--does not yield anything like what your "collective" is supposed to. That was the point of my calculation. It's so vastly far off that there's no point being careful: even if you don't plan the exact route, you're not going to walk from New York to Los Angeles in a day; you just note that it's totally out of range.

So, you are committed to postulating very very different physics (not just "hey, normal physics, but think about the collective!"). But you haven't. You haven't even displayed much attentiveness to the structure of existing models (or your model!), which is supposed to be your specialty.

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Rex Kerr
Rex Kerr

Written by Rex Kerr

One who rejoices when everything is made as simple as possible, but no simpler. Sayer of things that may be wrong, but not so bad that they're not even wrong.

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