Aether and Gravitation

by William George Hooper

As the reappearance of the comet was calculated by the application of the Newtonian Law of Gravitation, such a result only gave added confirmation to the application of that law to cometary bodies.

Of the Long Period Comets there are several known. That of 1858 has a period, it is thought, of 2000 years. The 1811 comet has a period of 3000 years, while that of 1844 has a period of over 10,000 years. All these comets move in orbits of such great size that their return is improbable. One of the characteristic features about Long Period Comets is their great brilliancy and size.

The 1858 comet, known as Donati's Comet, was first seen by that astronomer at Florence in June. It was invisible, however, to the naked eye, as it only appeared through the telescope like a faint cloud of light, gradually getting brighter and brighter. Toward the end of August it began to show signs of developing a tail, and became visible to the eye on August 29th. During September and October it greatly increased in size and brilliancy, and was plainly visible in the western heavens. After October 10th it was only visible in the southern hemisphere, gradually decreasing in brightness. It was seen till March 1859, when it disappeared, and will probably not return till the year 3858, as its period of revolution is about 2000 years.

Donati's Comet passed between the earth and many stars, which could be seen very distinctly through its tail. One of the stars was Arcturus, and, though some of the densest parts of the comet passed over it, yet the star could be seen all the time, thus conclusively proving that the head and tail of a comet are only composed of gaseous matter, probably condensed Aether, as suggested in [Art. 111].

Art. 114. Parts of a Comet.--A comet may be divided into three parts: 1st, Nucleus; 2nd, Head or Coma; and 3rd, Tail.

The nucleus is the central part of the head or coma, and is generally the brightest part of the whole comet. On the theory that a comet is due to the condensation of Aether, the nucleus would represent the first act in the process of condensation, as there would have to be some centre of condensation, and that centre would be represented by the nucleus. Further, the process of condensation would assume a spherical form, as the conception of our aetherial atom is that of a sphere or an oblate spheroid. As the process of condensation went on, the layers that would be produced would form a kind of envelope around the point of condensation, with the result that the nucleus would ultimately consist of a large mass of gaseous matter, made up of layer upon layer of condensed Aether around some central point, which formed the nucleus.

This hypothesis agrees with observed phenomena, because, when we deal with the tails of comets, we shall see that the tail is simply formed by the reverse process to that of condensation, as in the case of cometary tails the gaseous envelopes so formed will be thrown off (either through heat generated by friction, or by the increased heat as the comet nears the sun), which are then repelled away from the sun by the centrifugal force. Herschel,[40] referring to the nucleus, states, paragraph 559: “An atmosphere free to expand in all directions would envelop the nucleus spherically,” while in his Reflection on Halley's Comet, he states, Art. 570, “1st, That the matter of the nucleus of a comet is powerfully excited and dilated into a vaporous state by the action of the sun's rays, escaping in streams and jets at those points of its surface which oppose the least resistance. 2nd, That the process chiefly takes place in that portion of the nucleus which is turned towards the sun, the vapour escaping in that direction. 3rd, That when so emitted, it is prevented from proceeding in the direction originally impressed upon it, by some force directed from the sun, drifting it back and carrying it out to vast distances behind the nucleus forming the tail.”

When we come to deal with the question of the formation of the tail, we shall find that every reflection made by Herschel is satisfactorily fulfilled by the conception of a gravitating and condensing Aether. Before considering the tail, however, we will deal with the head or coma.

The head or coma is that part of the comet which exists round the nucleus. It is less bright than the nucleus, and oftentimes appears as a shadowy mass of light. Herschel, in his 4th Reflection, states that “a considerable part of the vapour actually produced remains in the neighbourhood of the nucleus forming the head or coma.” So that the head of a comet is simply the vaporised part of the nucleus which is produced by the increased heat of the sun, in the same way that water would be vaporised by the addition of heat, the vapour in that case being thrown off in the form of steam.

This formation of the head is but a continuation of the reversal of the process of condensation, which originally gave existence to the mass of matter termed the comet. The diameter of this head or coma often extends to thousands of miles. The head of the 1811 comet was 540,000 miles in diameter, while that of the 1843 was 112,000 miles. As the nucleus is formed of a series of envelopes, so the head also consists of a series of envelopes.