Attraction acts in all operations of nature

Attraction is the cause of the hardness of bodies.

You see that all the phenomena of nature, experiments, and geometry converge from all sides to establish the reality of attraction. You see that this principle acts from one end of our planetary world to the other—on Saturn and the smallest atom of Saturn, on the Sun and the faintest ray of the Sun.

Doesn’t this active and universal power seem to dominate all of nature? Is it not the sole cause of many effects? Does it not intermingle with all the other mechanisms through which nature operates?

For example, it is highly plausible that it alone causes the continuity and adhesion of bodies. Attraction acts in direct proportion to mass; it acts on every corpuscle of matter. Therefore, each corpuscle gravitates in this way, just as Saturn gravitates toward Jupiter.

Let us observe what happens to bodies on the surface of the Earth:

If I place two ivory balls A B and C D against each other (figure 73), they attract one another; but their mutual tendency is overwhelmed by their gravitation toward the Earth.

Suppose each ball has a diameter of two lines (a unit of measure), that’s 120 seconds of line per diameter, and there is a one-second gap between them. Point D is 120 seconds away from point C. Bodies at the point of contact attract in inverse proportion to the cube of the distance—and even more strongly. If we take only the cube, then point D attracts and is attracted 1,728,000 times less than point C. And since points A and D are four lines apart, they attract each other 10,944,000 times less than points B and C. Now, the mass of the Earth compared to each of these balls is like the cube of 1,500 French leagues (equal to 3,325,000,000 leagues) to the cube of two lines (equal to eight lines). Thus, the gravitational pull of each ball toward Earth is incomparably greater than their mutual attraction.

But if the two balls are extremely small, their diameter becomes infinitesimal; their entire substance nearly touches at the point of contact. The force of attraction can then become immense compared to opposing forces. The two tiny bodies, joined together, form a solid and continuous body.

The smallest bodies have the most surface area, and therefore the most points of contact. Solid masses are thus composed of smaller molecules attracted to one another.

Attraction acts in fluids just as in solids. Two drops of water or two globules of mercury merge instantly into one. Air cannot be the cause, since the same effect occurs in a vacuum. No ether or subtle matter pressing the drops can cause this union—such matter would press between them and prevent contact, scattering them rather than joining them.

Thus, it is by mutual attraction that they join, forming a single round body.

Every solid and fluid, being subject to attraction, owes its hardness to the attraction between its parts. The more matter a metal contains in a small volume, the harder it is. The more matter it contains, the more each part is in immediate contact with its neighbor—this is where attraction is greatest. Let us reflect on this: in our enlightened age, no philosopher has found a satisfying explanation for the continuity, adhesion, cohesion, or hardness of bodies. I am not surprised—they have found none and never will, because there is none other than this. Whatever fluid or mechanism one imagines, the question remains: why are the parts of that fluid contiguous? There must be a force given by God to matter that binds its parts together—and this force is what I call attraction. As I’ve said before, no philosophy places man more directly under the hand of God.

If you place two bodies—steel, tin, or crystal—as smoothly as possible against each other, you will find it difficult to separate them. If you add a substance like pitch to fill the surface irregularities, you cannot separate them at all. Why? Because the pitch’s particles touch the glass particles directly, which they did not do before. Then, attraction increases in proportion to the completeness of the contact.

Why do capillary tubes draw liquids into their narrow spaces when immersed? Again, it is not air that causes this:

Air pressure, which raises mercury to 28 inches in a barometer, cannot do so in a capillary tube.

This effect occurs in a vacuum as well as in air.

Ether or subtle matter would press the cavity and prevent water from rising.

Thus, it is attraction from the top of the glass that causes this phenomenon. The proof is clear:

Water rises higher in capillary tubes the longer they are. Air, by contrast, never raises mercury beyond the height determined by its weight, regardless of barometer length.

Changes in air pressure or elasticity affect mercury height in a barometer, but never the height of water in a capillary tube—because attraction remains constant.

Now, if this force governs all bodies, it must play a major role in countless physical and chemical experiments that have never been properly explained.

The actions of acids on alkalis may well be philosophical illusions—like vortices. No one has ever defined what an acid or alkali truly is. When one assigns properties to one, experiments often show those properties belong to the other. So all we know is that some bodies ferment with others—and nothing more. But if we consider that there is a real force in nature causing all bodies to gravitate toward one another, we may believe this force is the cause of all dissolutions and major effervescences.

Let’s examine the simplest dissolution: salt in water.

Drop a piece of salt into a basin of water. The water at the edges remains unsalted for a while—it can only become salty through motion. Motion arises from central forces. Water particles closest to the salt must gravitate toward it. The more they gravitate, the more they divide the salt—this happens in proportion to the square of their speed and their mass. The divided particles move, and their motion spreads throughout the basin. This explanation is not only simple—it is based on all the laws of nature.

Conclusion: summarizing the substance of this work:

There is an active power that causes all bodies to tend toward one another.

Regarding celestial bodies, this power acts in inverse proportion to the square of the distance from the center of motion, and in direct proportion to mass. This power is called attraction in relation to the center, and gravitation in relation to the bodies gravitating toward it.

This same power causes bodies to fall to Earth, in the progressions we’ve observed.

A similar power causes adhesion, continuity, and hardness, though in a very different proportion than celestial attraction.

This same power acts between light and bodies, as we’ve seen—though the exact proportion remains unknown.

As for the cause of this power, so vainly sought by Newton and his followers, what better can we do than quote Newton himself from the final page of his Principia?

Here is how he speaks—as a physicist as sublime as he is a profound geometer:

“I have thus far shown the force of gravitation through celestial phenomena and those of the sea; but I have nowhere assigned its cause. This force comes from a power that penetrates to the center of the sun and planets without losing any of its activity, and which acts not according to the quantity of surface of matter particles, as mechanical causes do, but according to the quantity of solid matter; and its action extends over immense distances, always decreasing exactly according to the square of the distance, etc.”

It clearly and explicitly states that attraction is a principle that is not mechanical.

And a few lines later, he says:

“I make no hypotheses, hypotheses non fingo. For whatever is not deduced from phenomena is to be called a hypothesis; and hypotheses—whether metaphysical or physical, whether of occult qualities or mechanical assumptions—have no place in experimental philosophy.”

I do not claim that the principle of gravitation is the only mechanism in physics; there are likely many other secrets we have yet to wrest from nature, which work in concert with gravitation to maintain the order of the universe.

Gravitation, for example, does not explain:

The rotation of planets on their own axes,

The direction of their orbits—why they move one way rather than another,

Nor the astonishing effects of elasticity, electricity, or magnetism.

A time may come, perhaps, when we will have gathered enough experiments to uncover other hidden principles. Everything suggests that matter possesses far more properties than we currently know. We are still only standing at the edge of a vast ocean—how many things remain to be discovered! But also, how many things are forever beyond the reach of our understanding.