Planetary Nebulae.--The planetary nebulae represent a number of minute objects visible in the heavens. They look like globes of a bluish-coloured gas and are sometimes mistaken for small stars. Sir J. Herschel writes about them as follows: “Planetary nebulae are very extraordinary objects. They have, as their name implies, a resemblance to planets, presenting discs, round or slightly oval, some being quite sharply defined, terminating in others a little hazy or softened at the border. They are comparatively rare objects, not more than 25 having been observed, and of these nearly three-quarters are in the southern hemisphere. Their disc is circular or slightly elliptic, with sharp, clear, and well-defined outline, having exactly the appearance of a planet with the exception only of its colour, which is full blue, varying somewhat upon green. M. Arago has surmised that they may possibly be envelopes shining by reflected light from a solar body placed in their centre, invisible to us because of its excessive distance.”
The suggestion which arises to our mind in view of the atomic and gravitating Aether is, that the planetary nebulae are exactly what their names imply, that is, nebulous matter around planets. We have already learned that each satellite and planet possesses an electro-magnetic field, which field takes more or less the shape of a spherical form, so that if there are planets existing in the far-off systems in space, as we are compelled to believe that there are, then they too would possess an electro-magnetic field, which would be composed of spherical envelopes surrounding the several planets. These planets would shine by reflected light, as suggested by M. Arago.
The possession by the planet of the nebulous matter, which we have already suggested is composed of the denser parts of the Aether around the planet, would give to the planet a nebulous appearance which would satisfactorily account for the term already given. They would indeed be what Sir John Herschel suggested they were, viz, planetary nebulae.
Spiral Nebulae.--The Spiral, or Whirlpool Nebulae, are remarkable objects, and were first discovered by Lord Rosse with his six-foot telescope. One of the best examples of the spiral nebulae is that known as 51M. Small telescopes show this as two clusters, one of them being surrounded by a ring, at a distance, which is divided into two parts. Lord Rosse, however, found it to be really a spiral nebula, the ring running into a series of spiral coils of nebulous matter, the outlying parts being connected with the main part by curved bands.
Huggins has found that the spectrum of this nebula is not gaseous. Other examples of this class are 99M and 33M. What these spiral or whirlpool nebulae are, is unknown, but, on the hypothesis of a condensing and gravitating Aether which is in a state of rotation, the spiral nebulae can be easily pictured. For, as the condensation goes on, rotation will set in, and if we can picture such a phenomenon taking place in a plane which is at right angles to the line of vision, then we should have a full view of a nebula which would present a spiral form. Indeed, there is no phenomenon in connection with nebulae that cannot be physically explained by a condensing, gravitating and rotatory Aether; and as Aether is universal, the same properties will apply to it in distant space as they do in the solar system; and apart from a gravitating and rotatory electro-magnetic Aether, the phenomena of our own solar system cannot be physically conceived or explained.
Therefore, if such an Aether can explain the phenomena associated with our own system, it ought also to explain, and that to the fullest extent, all phenomena incidental to and associated with the innumerable systems that flood the universe at large.
[43] Outlines of Astronomy.