The Creation

[11]

11. In the beginning, from the surging and fusion of fluid through light or heat, innumerable bubbles (bullae) were born, varying in magnitude and thickness. For whenever subtle things attempt to break through dense things, and there is something that resists, they are formed into certain hollow bubbles, and gain an internal motion of parts, and consequently a consistency or cohesion (through our Theory of Motion).

It is easy to deduce this specifically from those first abstract principles. The same is evident from glass-making workshops, where from circular motion and the straight spirit of fire, glasses—the simplest kind of artificial things—are prepared; similarly, from the circular motion of the earth and the straight [action] of light, bubbles were born.

12. These bubbles are now the “seeds of things,” the filaments of species, the receptacles of aether, the basis of bodies, the cause of consistency, and the foundation of such great variety as we see in things, and of such great impetus as we admire in motions.

If these were absent, all things would be like sand without lime, and by the gyration of dense things, the aether would fly away and be expelled, leaving our earth dead and condemned. On the contrary, by the bubbles—strengthened by gyration around their own center—all things are solidified and held together. This is also the reason why arched things, which we admire, prevail in strength, and why round glasses subsist in elastic experiments, while those of another figure are shattered.

13. All water is a heap of innumerable bubbles. Air is nothing but subtle water.

I distinguish air in this way from aether: air is heavy (gravis), while aether, through its circulation, is the cause of gravity.

Hence, the air and whatever floats in it—such as clouds and projectiles—are rotated with the earth just as water is with a vessel; even the sea, with its shores not closed off, includes the earth rather than being included by it along with the bottom. Although, as I said, some retardation or motion in the contrary direction is not lacking, from which, with the strongest commotion of the Ocean occurring under the tropics—through rarefaction, attraction, and solar light—the water follows the motion against the earth more easily than the earth itself because it is lighter.

The same is repeated several times daily (for water once scattered by a clash needs space to collect itself back into a heap). There is the dash of the Ocean upon the shore of America nearest to us and other particular dashes and absorptions. Then, the Moon, when it shines with full light, makes the air beneath it lighter and less pressing through rarefaction; the water, therefore, swells beneath it.

Conversely, when the Moon is new, the air beneath its darkness is denser and more pressing; therefore, it causes the water to swell toward the shores. Finally, in the equinoxes, the direct opposition of the motion of light or aether to the motion of the earth (for then the source of light or the solar optical motion is at the equator) sharpens all things depending on the motion of the aether.

…with current causes, daily tides, at the new and full moons (by the same effect of contrary causes), but especially at the equinoxes, are increased by universal and particular currents. Finally, the phenomena of fixed winds and other ordinary motions of water and air are not difficult to deduce.

I do not number Fire here, for flame is only an ignited exhalation, a spark is ignited soot; fire itself is nothing but a collection of aether and air breaking out and exploding.

14. But what of the Earth? There is no doubt that it consists entirely of bubbles (bullis), for the basis of the earth is Glass (Vitrum), and Glass is a dense bubble. It is established by fluxion—that is, collected from the aether by a surging, or by fire stirring itself by insinuating into things—and lastly by its exit, its end and nature being vitrification.

What wonder is it, then, if the terrestrial globe—transformed and made flowing by the action of light—has passed from dense or terrestrial things into glass, and water and air into thinner bubbles? Nor was there then, as in a homogeneous state when things were not yet firm, a need for that force in changing which is now required in a system constituted against the torrent. Since in a free or natural state, things are moved easily by however small a force, whereas in the present systematic and, so to speak, civil state, they are not moved unless by things proportioned to the sense.

15. Furthermore, it is easily imagined that these bubbles, these glasses, are variously inserted, figured, and massed together to produce such a great apparatus of things, of which we shall soon speak in the origin of species.

…let us now preoccupy ourselves with the affection of the whole system, that is, gravity: and rightly so, since gravity is the cause of most extraordinary motions in our globe, or certainly the key to them, even those exerted privately in species; and physical work must be given so that all things are reduced, as much as possible, to mechanical reasons, as they are the simplest.

16. Gravity arises from the circulation of the aether around the earth, in the earth, and through the earth, the cause of which was discussed above in sections 9 and 10.

This aether, furthermore, penetrates water and air most greatly, since they are more porous. Hence, the earth descends in water (unless it contains more superficial aether than the water itself), and water descends in air.

17. Whatever has been separated from the Homogeneous (for things joined together do not sensibly gravitate because of an insensible gravity mutually lifting itself in all parts) and is placed in a location having more aether and less earth, now impedes the circulation of the aether and disturbs it. The more it is elevated, the more it disturbs it, because the entire circum-terrestrial aether is homogeneous in itself, like an ocean or air, running through various rivers, borders, lakes, straits, and channels.

Every heterogeneous thing disturbs the circulation of a homogeneous liquid, because even if one part attempts to follow a part carrying the liquid away, the other part cannot follow due to a different reason of consistency or divisibility.

This is also why things dissolved in liquids are gradually cast down and shine forth into crystals; and why things enclosed and digested gradually ferment.

18. This is now the reason why air, water, and earth gravitate in the aether: for they are cast down by its circulation. Since they disturb the circulation, they are expelled—not upwards, for they would disturb it more there (because spherical surfaces increase in the duplicate ratio of diameters, not in the same ratio as the diameters; and thus a greater inequality happens in sections acting on the same body)—therefore downwards, that is, descending. Hence, furthermore, comes the increment of impetus due to a new impression everywhere during the descent in any free or freer aether, as the ratio of that thing allows.

From here, other mechanical and static phenomena are deduced in a common manner and mode.

19. For there are two Mechanical Potencies: impetus from falling, and distance from the line of direction. The third is physical, which I am accustomed to call Nisus [striving/effort], such as comes from the motion of muscles, of which we speak below in section 50. Distance from the line of direction increases potency… Every power in bodies depends on velocity, since things, however continuous, can be moved by any motion of theirs, however small.

…axis in the wheel and axle (peritrochio), the screw, and the pulley; it has been discovered that in balancing things, a weight always ascends as much more quickly as the load descends, and conversely, as much as the load is greater than the weight; and that this is the ratio of linear [paths] completed in the same time, which is the ratio of distances from the line of direction.

20. However, there remain some things even in common motions and phenomena that, at first glance, appear contemptible but are difficult to solve if you look into them more sharply. For example:

• Why do hard things struck against hard things spring back?
• Why do certain things, when bent, restore themselves with such great force?
• Why, according to the most ingenious experiments of men like Huygens and Wren (which are universal), does a body striking a resting one—as if a permutation were made—remain in its place, while transferring its own motion to the other?
• A similar ratio exists for two [bodies] running together.

Such things and many others of this kind are not consistent with the abstract reasons of motions unless the “economy” of our globe is added.

21. A sufficiently illustrious specimen of this matter can be found in Reflection and Refraction. It is in the mouths of all that the angle of incidence and the angle of reflection are equal, and experiments—both phoronomic (kinematic) and optical—favor this. The very concise and beautiful appearance of the theorem charms one, which has imposed upon even the greatest men, persuading them that the proposition could be demonstrated universally from the abstract nature of motion.

…to be demonstrated. I too believed this, until, having applied a holiday and severe inquiry, I noticed that all that work was a game. I examined the demonstrations of Digby, Descartes, and Hobbes (but of how great men?), and I found that the sweetness of the opinion had more value [to them] than the rigor of the demonstration.

Meanwhile, it cannot be denied that [the theory] is sufficiently confirmed by the senses, and therefore should be referred to observations rather than to theorems. The reason for this constancy, if not from the abstract theory of motion, must at least be rendered from the Hypothesis of Concrete Motion, or the Economy of Present Things.

It was in the interest of the world that the matter be so established: for without this law of reflection, sight and hearing could not exist. It is sometimes credible that this equality of angles arises from the fact that, although it appears so, the motion of those impinging is not straight; they continue into a circle or an ellipse in the other part, and consequently, it happens that the Angle of Reflection and Incidence are equal, because each is an angle of contact of one and the same arc on both sides. See the abstract theory of motion, th. 8.9.

Furthermore, if the impact is perpendicular to the sense, the two arcs of impact and repercussion are joined so acutely to each other that the line appears to the sense to be the same. This cannot be refuted by any experiments, because most motions that appear straight are in reality curved, but so insensibly that all phenomena occur just as if they were truly straight.

[18] …But there is yet another more frequent reason, and one more congruent with the economy of things, for explaining the equality of the angle of incidence and reflection universally. To be sure, that which is commonly assumed absolutely of all bodies—that one impinging upon another is struck back or refracted—is only true of Elastic bodies, or those that restore themselves after compression or dilation.

But by the admirable craftsmanship of the Creator, or for a benefit necessary to life, all sensible bodies, due to the circulation of the aether according to our hypothesis, are Elastic; therefore all sensible bodies reflect or refract. No body considered by itself, unless it were animated by the perpetual ventilation of the aether, would reflect or refract, at least according to these laws commonly reported.

For if a body in motion strikes one at rest, it will penetrate it entirely without any refraction, even if the impinging body were the size of a grain of sand and the receiving body were a thousand leagues in thickness; if both the receiver and the impinging body move, and the blow is directed into the center of motion, and in that same line, the stronger will overcome the slower, or if they are equal, rest will follow. If the impact is eccentric, a new motion around its own center will be added to the prior motion. If they concur in different lines, or make an angle with equally swift motion, both will move along the line bisecting the angle, or, if it is not bisectable, they will rest; all of which pertains to demonstrating according to the abstract theory of motion. But the face of sensible bodies is plainly another thing.

Page [19] …for all hard things are so by a certain internal motion returning into themselves; all things are discontinuous, whence other things being equal, mass effects more; all things are Elastic, or compressed, and soon being left to themselves, they are restored to their prior state by the gyration of the aether.

He who confuses these laws of apparent motion with the rules of the true [abstract] motion is similar to one who believes it makes no difference between mechanical and geometrical demonstrations as far as proof is concerned. And yet, thus far, by none of those who have philosophized about motion has a matter of such great moment for obtaining solid demonstrations concerning God and the mind been obtained. (Lest anyone think that a laborious inquiry into these first and abstract laws of motion lacks fruit.)

It remains to demonstrate how, once the Elasticity (Elatere) of sensible things is assumed, the laws of reflection and refraction follow. As far as reflection is concerned: if a hard body, or one restoring itself, strikes another hard body which it cannot penetrate, it will nevertheless compress it according to the line in which it falls, continued into the receiving body itself. The receiving body, however, will immediately react along that line in which it best can: in a perpendicular impact, it can do so no other way than that in which the impact was made, and consequently the impinging body will return by the way it came. But in an oblique impact, it will react from that region in which the thing is still whole, or in which compression has not yet been made, into which therefore the other compressed parts attempt to recover themselves—that is, the line opposite to the line of impact…

[20] …making a divarication; therefore with the same angle to the surface, but into the other region[cite: 1, 2]. This reaction is so much stronger as the impact was swifter, all other things being equal (for the speed of the restoring part is as great as that of the compressing part); likewise, it is stronger as the impinging and receiving bodies are harder (because the vibration is so much more violent, like bows suddenly released)[cite: 1, 2].

And if both are hard, not only is the impinging body repelled by the receiver, but also from itself; just as we, by repelling the earth with our feet, make a leap[cite: 1, 2]. Therefore, with the concurrence of both being so strong, and with a vibration reciprocated several times like that of strings, the air between both—being intercepted no less than the internal air of any body—is compressed and then scattered again, producing a sound so strong and varied[cite: 1, 2].

Finally, with all things being restored as much as possible to their prior state by the gyration of the aether, it is no wonder that such a vehement reflection follows[cite: 1, 2]. I hope that such a physical reason for reflection has now finally been rendered[cite: 1, 2]. The matter deserves a delineation, but it is foreign to this [brief] sketch, though it will not be lacking in its own time[cite: 1, 2].

Refraction is a certain mixed penetration of reflection: whence it is partly transmission and partly deflection; and it approaches or departs from obliquity only as much as the resistance or density of the medium allows[cite: 1, 2]. The reason for this is that, among sensible bodies, almost only the aether truly moves by itself, and it is the “first mover” (primum dektikon), while other things move through it[cite: 1, 2].

Hence it happens that no impediment can be objectified to motion without it being propagated, for all pores are pervasive to the aether, and it is always animated by weary new supplements[cite: 1, 2]. Hence it also happens that even if, through the abstract theory of motion, every reaction detracts from speed, nevertheless, on the contrary, in sensible bodies, speed is preserved (unless insofar as it usually becomes more insensible by dispersing into many parts)[cite: 1, 2]. It detracts from the region or determination, which is the Law of Refraction[cite: 1, 2].

I will depart from here when I have added one more thing: it is also clear to the sense that an inflated bladder struck against the floor leaps up so high by a certain elasticity (Elatere) of the compressed air, which attempts to restore itself[cite: 1, 2]. What, then, forbids us from believing that other hard things, when struck against hard things—since they are everywhere full of thick, enclosed air, and full of air compressed by impact—effect a repercussion by a very swift and strong reciprocation, like sounding strings? (This even lasts for some time, which is why the duration of sounds and vibrations in struck bells is quite long)[cite: 1, 2]. This can be transferred to other phenomena of motions and concurrences, and applied to things with much light[cite: 1, 2].