Philosophy 167: Class 9 - Part 2 - Descartes' Vortex Theory: Three Kinds of Matter, Vortices, and the Creation and Capture of Planets.

Smith, George E. (George Edwin), 1938-

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Synopsis: Outlines Descartes' model of planetary motions as a vortex centered on the Sun, with three kinds of matter for stars, planets, and the space between them.

Philosophy and science.
Celestial mechanics.
Vortex theory (Astrophysics)
Descartes, Rene, 1596-1650. Principia philosophiae.
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ID: tufts:gc.phil167.89
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It's worth reading the whole thing. This is the lead in as you see it's way up at article number 30 and part 3. But it's the lead in to the vortex theory. Now that we have, by this reasoning, removed any possible doubt about the motion of the Earth, we'll come back to that.
Let us assume that the matter of the heaven in which the planets are situated unceasingly revolves like a vortex having the sun as its center. And that those of it's parts which are close to the sun move more quickly than those further away. So we've got the sun turning.
The view's going to be it drives the vortex around it, but the further out you go the more you slow down. So if the sun turns in something like 24 days, all the planets take longer to complete their circuit and then progressively longer the further out you go.
And that all the planets, among which we shall now from now on include the Earth. So here we have just flat out the Earth is among the planets. There's not even an argument. You'll see the argument for it a little earlier, but the main argument comes after this.
Always remain suspended among the same parts of this heavenly matter. Suspended, meaning they're being carried along by the vortex. They're not moving relative to the vortex. For by that alone, and without any other devices, all their phenomenon are very easily understood. Understood is, I haven't locked it up but it's almost certainly gonna be the Latin word that corresponds to our word, intelligible.
Thus, if some straws or other light bodies are floating in the eddy of a river. Where the water doubles back on itself and forms a vortex as it swirls. We can see that it carries them along and makes them move in circles with it. Further we can often see that some of these straws rotate about their own centers.
And that those which are closer to the center of the vortex which contains them. Complete their circle more rapidly than those which are further away from it. Finally, we see that although these whirlpools always attempt a circular motion they practically never describe perfect circles. But sometimes become too great in width or in length.
So that all the parts of the circumference which they describe are not equidistant from the center. Thus we can easily imagine that all the same things happen to planets, and this is all we need to explain, again, explicare is the infinitive of the verb. All their remaining phenomenon.
So it's the analogy with whirlpools on earth, with objects in them turning around, that's the basis for the whole theory. That, of course, coupled to the fact that if the planets are moving curvilinearly. Their natural tendency is to recede from the center. Something has to be holding them in.
That something has to be in contact with them even though we can't see it. Therefore, there's something out there touching it. That's a crucial part of the reasoning. And you'll see that in the last, the final step of the defense of Descartes in the second half tonight, near the end of the class.
yYou'll see him saying that very thing. So, here's his picture. Vortices inside of vortices inside of vortices. And the one in the middle is us. With the sun in the middle, etc. I'm not gonna do full justice to this cuz I don't wanna spend the time and I'm not sure.
The real time is the time I'd have to spend in preparation to get all the details of the vortex theory at my fingertips. Not the time I would spend, I'd have to spend time in class too. I'll use that as my rationalization for not being really, for trying to work on his theory.
But the idea goes like this. There are three kinds of matter. Two kinds are etherial, celestial, we can't see them. The smallest kind of matter which is very irregular in shape and very very small and hence can move very fast. Cuz remember, the larger an object is the more resists changes of motion.
That kind of matter is what forms the sun and the stars. And it's moving at a very high rate. Surrounding it is celestial matter that may contain terrestrial matter. That's the third kind of matter. Including air, objects, etc. The celestial matter is made of colobials they're usually called.
I again don't recall what the Latin is. But he always portrays him as if they were spheres of different size too small for us to see. And he likes them packed into one another for things like refraction. His theory of refraction is the packing of the spheres deflects the pressure.
Which is what light is, it's the pressure, deflects it. And these things are very small, they move very fast, but they're a lot larger than the stuff forming the stars. And they surround the stars and they move the sun and stars in their circular motion, drive these globules into a vortex.
That gets, the motion gets slower and slower as you go out. The globules get smaller, the actual translational velocity increases. It's a very complex distribution of size and speed among the globules going from the surface all the way out to the end of the vortex. And what prevents the vortex from coming apart is it's surrounded by other vortices that are not aligned with it.
If they were aligned with it, they would collapse into one. So by being opposed, they in effect, maintain one another in reasonable position. Now they're interacting, so obviously this is gonna be very, very messy. Light itself, the reason the sun gives off light, is light itself is a pressure, and that's why it's instantaneous.
It's a pressure exerted on the globules that go right to our retina as a form of pressure. Remember, it has to be pressure. What else could it be? Everything has to be by contact, but the fact that it propagates instantaneously is a further thing. But the pressure's given a rise to by the sun, by the extraordinarily rapid motion of the particles of the first type within the sun.
They're generating pressure on the globules and everything else further out. Okay. And when we see a star, because it's in a different vortex there's absolutely no reason to think that the position we're seeing it in is it's true position. There's every reason to think that refraction has displaced it and we would have to know a lot more to infer where that star really is.
Okay. Now it's an interesting question. The stars remain relatively fixed compared to one another. He doesn't discuss that much other than he thinks these vortices last for eons. Some collapse but most of them last for eons. Remember the instantaneous propagation of light, because that's gonna be significant. So, I've already said the speed and size variation among the globules going out.
And he tries to show this to some extent by the lines, as they're of course his drawings or at least, initially his drawings that turned into wood cuts. Since the matter of the first type is so small and it fills all of space between globules. It's obviously escaping constantly from the sun.
What's counteracting that? Flow of that matter in the poles of the vertices come in and feed the motion of the sun rotating. And that then keeps the whole process going and that's passing from one to another. There's more detail on this but let me go on to the next stage of it to kind of just outlining the theory.
So in the principle problem and John Schuster emphasizes this in the paper I put on, except one of the papers of his I put on supplementary material. The problem he thought most interesting was why there our planets out to Saturn and not beyond that. And why they're stationed in the way they are.
Namely, having a regular pattern of speed relative to one another. He doesn't site the three-halves power rule but there's every reason to believe he was aware of it. In that there's some kind of regularity. And the answer's gonna be that the globules forming the vortex, because of their variation in size and speed.
Also have a variable capacity to resist the centrifugal, the tendency out of any terrestrial manner. And therefore, of any planet. So planets end up being in exactly the spot where their quantity of solid matter, permits the action of the globules on them, like gravity. To exactly hold them at that position, on a regular basis.
And there's an equally meant to like. It's a buoyancy like model, but it's not buoyancy, it's a much more complicated model of a pressure differential resulting from the speed and size of the globules and their variation. So, there's an analogies. This is all of using 20th century analogies.
The analogy would be there's a pressure field and that pressure field within it is creating an effective buoyancy. It's creating a density field, and that density field is like a buoyancy, balancing each planet in its proper location. And what makes it the proper location is the amount of solid material in the planet.
The planets, themselves, used to be stars. What happens is, well we'll start with sun spots. What's a sun spot? The matter of the first type happens to just fit together in such a way that it aglutenates and forms terrestrial light matter on the surface of the sun. And if you get enough of that, what happens?
The whole surface is surrounded by matter of the third type formed out of matter of the first type. At that juncture, you cease giving off light. So the star becomes disappears, and you cease being able to drive the globules. So what happens, the vortex, that vortex collapses, because it's not getting the push it needs from the matter of the first type inside the star or sun.
When that happens, the body in the middle, now surrounded by all these, in effect sunspots that have completely covered the surface. It starts moving off. And it moves off from one vortex to another and becomes a comet. That's what comets are, and this is the path of a comet from one vortex to another as drawn by Descartes.
But if this comet moving through the vortices moves close enough into the region where it can be captured by equilibrium, it becomes a planet. So planets are present out of a capture mechanism, not out of a formation mechanism within each vortex. What else do I wanna say? No, I'll come right back.
Nova's where suddenly a new star comes into being, is a star sitting there completely covered up. And something happens that breaks the barrier on the surface. Once that happens there's enough activity in the matter in the first sort and it then tears the whole thing apart and you've got a nova or super nova.
So he's able to account for that. Hey, I trust everybody realizes that this is not how vortex motion works. But I repeat, nobody had anything remotely akin to a theory of vortex motion until very much the 20th century. And I said before we started, you can't imagine how much vortices dominate your lives.
I'll give you a couple of examples. What causes heart attacks from arteriosclerosis? Vortex motion forming in the bloodstream. That then forces coagulation. It's just all over the place that vortices dominate in our lives. And the reason that I find that so beautiful is that we didn't understand until very modern terms.
Yet they were absolutely everywhere. We're still struggling to understand them. We can't predict tornadoes yet. We can say the circumstances are rife for one, but what triggers that severe of a vortex suddenly is not at all straightforward. Think of how much energy is in those things.