Page:Popular Science Monthly Volume 82.djvu/305

Rh the absorption is a gradual one, the actual duration of luminous propagation may have to be reckoned in thousands of millions of years. Now the radiant energy of the ether represents its temporary mass. If we knew the relation between mass energy and radiant energy, we could give the ratio between the permanent energy of mass of the stars and the luminous energy of the ether. For example, if the mass energy of a star is on the average $$(10)^{12}$$ times its radiant energy, then the total energy of the universe is always equally divided between ether and matter, because the same radiation comes forth from unit volume of matter, and is distributed to $$(10)^{12}$$ units of ether. Or, if mass energy bears a larger ratio to radiant energy than this, energy may remain longer in its material than in its ethereal form, only a small fraction of the total energy residing in the ether.

To conjoin stellar centers and ethereal expanses, an intermediate order of existence is needed: An order which faces both ways, having relations with the ether and with the stars. Viewed from the side of ether, we begin to dimly apprehend an electric substance, not yet matter, although possessing many of its properties, seeming to be both a substance and a force, mobile, energetic, viscid enough to be localized and to take on intricate forms, a world-plasm, waiting to be incorporated.

Meteorites circulating around a galactic center remain for enormous periods in the neighborhood of their apogalacteum, and moving with extreme slowness, they have time to gather to themselves the scattered atoms of space, even though the attracting masses may average only a few grams. A meteoritic mass of 1 gram which, if quiescent, will attract to itself the particles within a radius of 1 meter in about 2 months, may be expected to leave a clean-swept track of considerable width through that part of its revolution which occurs in intergalactic space. Possibly the meteoritic chondri have thus grown by accretion in the depths of space, even if, as some suppose, their nuclei may have originated by condensation from masses of heated mineral vapor. Such a slow growth is not incompatible with various vicissitudes, and an eventual consolidation of many such masses into compound chondritic complexes, after the manner of the formation of large hail stones.

Particles which are thrown off from luminous stars, or from fine cosmic material near the stars, being driven away by the pressure of light, are not necessarily of dimensions much larger than molecular, and although the swiftness and small mass of such light-repelled particles must prevent them from acquiring additions by attracting the atoms near which they pass, some increase of size is to be anticipated by chance collisions with atoms, the particles being slowed down and reabsorbed by massive attracting bodies. But these are the last steps of an intergalactic process. We must go farther back to reach its inception.

If we attribute the absorption of light in space to the ether itself,