Coma (astronomy)

“ The nucleus is all the comet's solid matter, a mass of meteoric and other material hanging in the hollow at the coma's center. The great coma blows from its own electrical energy, and is driven through space by the release of some of that energy backward, through the vast tail, which is simply released energy from the coma. It is the great coma that makes a comet deadly to approach, since any matter that enters its terrific sea of electrical energy is converted instantly into electrical energy likewise, changed from matter-vibrations to electrical-vibrations, annihilated. ”

“ There was no sky such as we know upon the Earth, and no sunlight. The air ‘was full of a red glow that came from the coma above us. The gravitation was vertical as it is upon the Earth; and I did not notice that I felt a bit stronger or lighter than I had felt in Sansar. This, I learned, afterward, was because of the extreme magnetic pitch of the nucleus. The horizon, where the whirling rim shot up its wreaths, was the blaze of glorious crimson. ”

“ The comet looked to be a few feet away; and yet I knew that it was thousands of miles from the ether ship. It was boiling crimson, cataclysmic. Never was there a thing so terrible, nor a man so fascinated. I intended to wait for the moment and then plunge into its heart.
“ 'At last the coma had passed, and I knew by the chart that I had come to the tail. The intense light grew dimmer, and, though still a bright crimson, semi-transparent. After a bit I caught a glimpse of the nucleus gleaming like a ruby or violent coal directly behind the coma. ”

“ I told him. "We've only a few score hours left to get inside and bring our force-beams to bear on the nucleus."
The Aldebaranian's voice came slowly in answer. "That coma," he said; "it seems impossible that we can ever get inside it——"
There was silence as I gazed ahead toward the great comet, whose coma was now indeed a terrific spectacle. An immense lurid sea of crimson light, it seemed to fill all the universe, shifting slowly downward and beneath us as our thousand cruisers hummed up at a steep slant over it. ”

“ With the words our cruiser began to sink smoothly downward, still holding its forward flight above the comet, the massed ships behind following steadily in our course. Down—down—by thousands of miles a moment we sank, down until the giant coma beneath seemed the only thing in all the universe, glowing from horizon to horizon like an awful aurora of crimson death. An inconceivably colossal sea of lurid electrical energy, a giant deadly sphere of glowing force which it were annihilation for anything to touch, it stretched beneath us, broadening still as we came closer toward it. ”

“ As a comet approaches the Sun its material apparently contracts, while with increasing distance from that luminary it expands. Usually the nucleus is extremely small and bright, and it often looks like a star shining through nebulosity. High powers must therefore be applied in its examination. Jets, aigrettes, luminous sectors, and other appendages are often involved with the nucleus and outlying coma, and they form a complicated structure well deserving further study. A good deal of mystery still surrounds these appearances; their curious forms and vagaries have yet to be explained. ”

“ Onward toward our universe this mighty comet is thundering, and but one chance remains for us to turn it aside. The center of this comet, of any comet, is the nucleus at the heart of its coma, which is the only solid matter in it. If we could penetrate through the coma to the great hollow inside it, could turn upon that nucleus the powerful force-beams used by our Patrol cruisers to sweep up meteor-swarms, we could possibly push it aside enough to change its course, to send it past our galaxy's edge instead of through it. ”

“ Suppose the atomic engines should refuse to function? Would I go falling through space forever? What would be my fate?
“ 'By the thirtieth hour the Earth had dimmed to a large star, and the moon had grown to be her twin sister. On the other hand the whole Universe seemed to be turning to comet. The coma was now as big as a wagon wheel, a vast ball of winding, whirling, crimson. I could feel its motion, and even at this distance I could sense its terror. The whole Universe was seeping red and trailing in omnipotent beauty. There was pulsation to its light, and vibration ”

“ As the comet draws nearer to the sun, it usually grows somewhat long in the direction of the sun; and before long a portion within the part nearest the sun is seen to be brighter than the rest, and to have a more or less defined outline. This is the nucleus—sometimes seen as a dull disc of nearly uniform brightness, at others as a mere bright point not unlike a star. The fainter light around this is the coma, or hair, which resembles a luminous fog round the nucleus, usually brighter on the side toward the sun, and on the other side growing fainter and fainter till it can no longer be seen. ”

“ Comets there are in our galaxy, as you know, comets that revolve in irregular orbits about various of our stars, and which have been familiar to us always. A comet, as you know, consists of the coma or head, the nucleus, and the tail. The coma is simply a great globe of electrical energy, with a hollow space at its center. ”

“ This giant comet of outer space, though, I knew, moved in no orbit whatever through the empty immensities of the outer void, and so would always race through space in a direction opposite to that of its tail, the energy of the mighty coma shot forth in the tail like the powder of a great rocket, propelling it irresistibly forward with terrific momentum and force. ”

“ And so through the eons, as ever the comet's glory, the coma's power, has waned, they have driven it through another universe, destroying that universe to restore it. On through the limitless void of outer space they have driven it, a cosmic vampire looting the life of universes to restore its own! And now, when the comet's glory has again waned, they have turned it toward our own galaxy, to destroy it as they have done countless others. And within less than a scant half-dozen hours now the comet will have thundered so close to our galaxy that no power in existence can turn it aside! ”

“ The chasm outside, the world and worlds about us, lay now in dusk, their only illumination the lurid, dark crimson light of the comet's glowing coma, a red disk that gave to the barren rocky world about us an inconceivably weird appearance. ”

“ The period of excitation is succeeded by the period of relaxation, and then the patient is in a deep sleep. However violent the external excitations, however painful the surgical operation, nothing can arouse the patient out of the comatose state into which he has fallen. His respiration is regular, his pulse slow and full, his pupils are motionless, and his features, paralyzed as it were, no longer wear that convulsive grimace which may be regarded as the last trace of sensibility. Intelligence is now destroyed. The coma of chloroform and that of alcohol appear to be essentially one. ”

“ If we can reach the great oncoming comet, can penetrate through its deadly coma to the solid nucleus at its center, can deflect that nucleus with our force-beams before the twelfth day ends, we will have turned the great comet aside, will have saved the galaxy itself from death. If we can not, the galaxy perishes and we perish with it. For we of the Interstellar Patrol, who have defended and guarded the ways of that galaxy for thousands upon tens of thousands of years, go out to the oncoming comet now not to return unless we can turn that comet aside and save our universe from doom! ”

“ Intra-cranial tumors, embolisms, thrombi, diseases of the cerebral arteries, and degenerations of the brain,—in short, every morbid change of which the liquids and the solids within the cranium are capable—may become the cause of coma. Toxæmic conditions of the circulating fluids of the body may benumb the brain with comatose sleep. Few diseases, therefore, exist without the possibility of coma as one of their consequences—a coma which, however, must not be confounded with the genuine sleep which sometimes occupies the larger part of convalescence from acute illness. ”

“ We knew that the light is intrinsic, that it comes from the comet itself, and not from the sun. We knew that it is composed of three parts, the head, the nucleus, and the tail. The head, or coma, of a comet, is its main visual part, a ball of transparent light; the nucleus is the bright spot of light directly behind it; and the tail is the wonderful luminous cloud that streams from the head out over the heavens. ”

“ For this gigantic comet, greater by far than any of the galaxy's greatest suns, will crash through the galaxy's swarm of stars like a meteor through a swarm of fireflies, annihilating those in its path by absorbing them and their worlds into the terrific electrical energy of its mighty coma; disrupting all the finely balanced celestial mechanism of our universe and sucking its whirling stars into its deadly self as it smashes on ”

“ He lived all his life without doing what he dreamed of doing. All because of me. And you are an astronomer like Zin, my father. Love is sacrifice. I love you. You wish to solve the stars! I want to see them! I hate this old comet! Let us go into the house and do as father said. Let us take the vials!"
"'It was a lurid moment.
"'The nucleus had become a solid wall of crimson. The coma above us was as thick as blood. We were in the center of a thing that had never been in the memory of man. The comet was running mad. We were riding a thing as swift as thought, There was no time to lose. ”

“ What's worse, from what I knew, the horrific brain trau­mas that bring on a coma don't automatically go away when you regain consciousness. If the coma is the result of a head injury, and if it lasts more than a few days, the chances of regaining all your mental functions are up for grabs. Lou once said there's a scale of eight stages to full recovery. Peo­ple who have short comas can sometimes come out of them and go through those stages quickly—from initial eye move­ment to full mental faculties. Others, who've been under for months or longer can require years to come back. ”

“ The victim of coma often presents a countenance suffused with blood; the pulse beats vigorously, and respiration may become stertorous. But in lethargy the abolition of bodily movements is almost total. In the milder forms of this disorder the patient may be partially roused, so as to attempt an answer when addressed, appearing like a person in very profound sleep; but in the majority of cases he remains insensible, unconscious, and utterly irresponsive to ordinary forms of irritation. Respiration and circulation are reduced to a minimum, even becoming for a time imperceptible. ”

“ Even as the bolts had blasted the pyramid's top our cruisers had shot with the velocity of thousands of light-speeds out from the central world and those about it, out across the comet's heart toward the circular opening through the coma, through that passage of crimson death at awful speed and out into space behind the comet as the passage closed behind us, as the tail behind the comet waned swiftly! ”

“ As just stated, I failed to discern any with the double image prism; but that is not a very delicate test, although, owing to the small size of the nucleus, it is almost the only one practicable. Under the magnifying power used the coma filled the field of view with bright light, and yet exhibited not a trace of polarization when tried by that most delicate of all tests, the Savart polariscope: thus apparently confirming the testimony of the spectroscope that the coma is self-luminous. ”

“ Excluding those exceptional cases in which healthy individuals, as a consequence of inordinate physical exertion, have slept for many hours beyond their ordinary limit, every extraordinary manifestation of sleep-like unconsciousness must partake of the nature of coma. Between natural sleep and this condition may be placed the distinction that the one is always the effect of natural physiological processes, while the other is always the result of injury, of disease, or of some form of intoxication. ”

“ The Earth had passed several times through the tail of a comet without being harmed; there were some who held that it would be the same with the coma, or head. The nucleus was the only part that they feared.
“ 'There lay the secret. Through telescopes I had watched the nucleus shoot jets and great concentric rings of light into the coma. If the head of the comet were electrical—the effect of these discharges—what was the nucleus? Whatever the comet might be, there was no one yet who had ever advanced a theory that held the weight of probability. The nucleus was the heart of the comet. ”

“ Some of us exhibit more than one tail. My brother of 1744, for instance, had no less than six, spread out like an immense fan, extending to a distance of nearly 30 degrees in length. I have just now mentioned that my brother of 1811 was not at first provided with an appendage of luminous vapour. This is often the case with us. Thus the great Comet of 1843 showed at its first appearance simply a nucleus, surrounded by a coma ”

“ In the first case, that of depressed fracture of the skull, the raising of the depressed bone is often followed immediately by return of consciousness; the patient seems to wake as from a deep sleep. In medical practice there are many analogous conditions of abnormal pressure causing coma, as in meningitis, cerebral abscess, hemorrhage, embolism of cerebral vessels, etc. Long-continued or fatal coma may be caused by general morbid states, as uræmia, acetonæmia, surgical hemorrhage, intoxication by narcotics, alcohol, ether, etc., and by asphyxia. ”