“One thing is certain, that the Sun will finally lose its heat; it is condensing and contracting, and its fluidity is decreasing. The time will come when the circulation, which now supplies the photosphere, and makes the central mass a reservoir of radiant energy, will be obstructed and will slacken. The radiation of heat and light will then diminish, and vegetable and animal life will be more and more restricted to the Earth’s equatorial regions. When this circulation shall have ceased, the brilliant photosphere will be replaced by a dark opaque crust which will prevent all luminous radiation. The Sun will become a dark red ball, then a black one, and night will be perpetual. The Moon, which shines only by reflection, will no longer illumine the lonely nights. Our planet will receive no light but that of the stars. The solar heat having vanished, the atmosphere will remain undisturbed, and an absolute calm, unbroken by any breath of air, will reign.
“If the oceans still exist they will be frozen ones, no evaporation will form clouds, no rain will fall, no stream will flow. Perhaps, as has been observed in the case of stars on the eve of extinction, some last flare of the expiring torch, some accidental development of heat, due to the falling in of the Sun’s crust, will give us back for a while the old-time sun, but this will only be the precursor of the end; and the Earth, a dark ball, a frozen tomb, will continue to revolve about the black sun, travelling through an endless night and hurrying away with all the solar system into the abyss of space. It is to the extinction of the Sun that the Earth will owe its death, twenty, perhaps forty million years hence.”
The speaker ceased, and was about to leave the platform, when the director of the academy of fine arts begged to be heard:
“Gentlemen,” he said, from his chair, “if I have understood rightly, the end of the world will in any case result from cold, and only several million years hence. If, then, a painter should endeavor to represent the last day, he ought to shroud the Earth in ice, and cover it with skeletons.”
“Not exactly,” replied the Columbian chancellor. “It is not cold which produces glaciers—it is heat.
“If the Sun did not evaporate the sea water there would be no clouds, and but for the Sun there would be no wind. For the formation of glaciers a sun is necessary, to vaporize the water and to transport it in clouds and then to condense it. Every kilogram of vapor formed represents a quantity of solar heat sufficient to raise five kilograms of cast-iron to its fusing point (110°). By lessening the intensity of the Sun’s action we exhaust the glacier supply.
“So that it is not the snow, nor the glaciers which will cover the Earth, but the frozen remnant of the sea. For a long time previously streams and rivers will have ceased to exist and every atmospheric current will have disappeared, unless indeed, before giving up the ghost, the Sun shall have passed through one of those spasms to which we referred a moment ago, shall have released the ice from sleep and have produced new clouds and aerial currents, reawakened the springs, the brooks and the rivers, and after this momentary but deceitful awakening, shall have fallen back again into lethargy. That day will have no morrow.”
Another voice, that of a celebrated electrician, was heard from the center of the hemicycle.
“All these theories of death by cold,” he observed, “are plausible. But the end of the world by fire? This has been referred to only in connection with the comet. It may happen otherwise.
“Setting aside a possible sinking of the continents into the central fire, brought about by an earthquake on a large scale, or some widespread dislocation of the Earth’s crust, it seems to me that, without any collision, a superior will might arrest our planet midway in its course and transform its motion into heat.”
“A will?” interrupted another voice. “But positive science does not admit the possibility of miracles in nature.”
“Nor I, either,” replied the electrician. “When I say ‘will,’ I mean an ideal, invisible force. Let me explain.
“The Earth is flying through space with a velocity of 106,000 kilometers per hour, or 29,460 meters per second. If some star, active or extinct, should emerge from space, so as to form with the Sun a sort of electro-dynamic couple with our planet on its axis, acting upon it like a brake—if, in a word, for any reason, the Earth should be suddenly arrested in its orbit, its mechanical energy would be changed into molecular motion, and its temperature would be suddenly raised to such a degree as to reduce it entirely to a gaseous state.”
“Gentlemen,” said the director of the Mont Blanc observatory, from his chair, “the Earth might perish by fire in still another manner. We have lately seen in the sky a temporary star which, in a few weeks, passed from the sixteenth to the fourth magnitude. This distant sun had suddenly become 50,000 times hotter and more luminous. If such a fate should overtake our sun, nothing living would be left upon our planet. It is probable, from the study of the spectrum of the light emitted by this burning star, that the cause of this sudden conflagration was the entrance of this sun and its system into some kind of nebula. Our own sun is travelling with a frightful velocity in the direction of the constellation of Hercules, and may very well some day encounter an obstacle of this nature.”
“To resume,” continued the director of the Paris observatory, “after all we have just now heard,
