In place of an elastic medium, of density approximating to empty space, we have this definite granular structure of the universe, elastic and of density ten thousand times that of water.
5. The degradation of light.
Up to the present time it has been a moot question whether there is any loss of light in transmission. Herschel held that there was none. But it is now shown that, owing to the angular redistribution or viscosity of the grains, there is degradation, such as would require fifty-six millions of years to reduce the total initial energy of the light to one-eighth; while the rate of the degradation of the normal wave, owing to the linear redistribution of the grains, is such as would be reduced, in the same ratio, in the two hundred and fifty thousandth part of a second; thus accounting for the absence of any evidence of normal waves except such evidence as might be obtained within some thousands of metres from its origin; as in the case of Röntgen rays.
And we thus have an explanation of the blackness of the sky on a clear dark night as a consequence of the dissipation of the mean motion of light to increase the relative motion of the grains.
