When I discovered this unexpected coincidence for 1906, several sceptics were greatly surprised. Yet it is true.
It was the same when I accused the Sun of being the author of the interruption of telephonic and telegraphic communication on September 25, 1909, which took place over the whole of France, in all Europe, and throughout the world. The telephone girls were unjustly blamed and the telegraph engineers were equally innocent. Why had no newspaper thought of it? Perhaps because politics are cultivated more than science in the papers of our unbalanced days. I do not accuse our country more than another, the English, German, American, Australian, and other editors having been equally astray concerning the cause of the perturbation.
On that day the intensity of the earth-currents which produced the breakdown was 50 million amperes, whereas the instruments work regularly with 10 to 12 milliamperes. The whole terrestrial globe had been plunged into a magnetic field of great intensity, into a veritable dynamic ocean originating in a solar torrent. A large group of sunspots surrounded by faculæ had arrived on the eastern limb of the solar globe on September 17, and had gradually advanced towards the central meridian of the solar hemisphere turned towards us by the Sun’s rotation. On the 19th, this group had become much larger. The spectroscope had indicated violent eruptions. The enormous group of sunspots was visible to the naked eye and numerous photographs of it had been taken at the Juvisy Observatory. It passed the central meridian of the Sun on the morning of September 24 and continued its course towards the western limb, disappearing from sight on October 1. The magnetic perturbation which struck our planet arrived 30 hours after the passage of this group of sunspots across the central meridian of the solar hemisphere facing us.
We had already, on October 31, 1903, observed a similar cosmic phenomenon, and previously on November 18, 1882, and August 3, 1872. Even before that date a similar event took place on September 1, 1859. But memory is short, and in any case astronomical ignorance is universal.
The magnetic link, invisible but powerful, joins our Earth to the central body of the solar system. Pœebus Apollo holds us in the hollow of his hand at a distance of 92 million miles, and we feel his pulse as he feels our feeble heart-beats. It is not only gravitation, nor only light, nor yet only heat, which throws a celestial bridge from the Sun to the Earth; it is also electricity; it is also magnetism; it is a force still unknown and unexplained which no doubt maintains communication between all the worlds. For the ethereal wave touches Mercury, Venus, Mars, Jupiter, Saturn, Uranus, and Neptune as it touches us, and if we could utilise it we could communicate with our neighbours in the heavens.
Interstellar magnetism! At each stage in the advance of science new horizons open out, unexpected perspectives reveal themselves, enlarging the field of our conquest over nature, but what we do know already is a mere nothing in comparison with what we are yet to know.
What is the nature of the wave or substance which leaves the Sun and reaches the Earth to produce those agitations of the magnetic needle, those magnetic storms and auroræ boreales?
Contemporary physics has been busy for twenty years about ions, electrons, and electric particles. The great perturbations described above are supposed to be due to the arrival in the upper atmosphere of torrents of electrons projected by the Sun and impinging upon the Earth with a speed of several thousand miles per second. The phenomenon is most intense when these emanations from the day-star hit the Earth directly. When they pass on one side, nothing out of the way happens. It may be that the torrent projected in a certain direction by the Sun on September 24 filled space in the direction of projection, and that our globe, travelling along its orbit at 67,000 miles an hour, only passed through that region on the following day.
Ions and electrons, those convenient goblins of present-day physics, do they exist? Nobody has ever seen them. Perhaps they are only ingenious interpretations. What does certainly exist is electric force. We may also think of the repelling force exerted by the Sun, which blows so strongly upon the nuclei of comets and produces tails several million miles long and always in the direction opposed to the Sun. Electricity plays a great part in the appearance, the illumination, and the dislocation of comets’ tails, as we see nearly every year in the photographs taken at the Juvisy Observatory and which make such picturesque and suggestive revelations (it even plays a part in organic cells and among microbes).
Whatever may be the real nature of the force in action, it is certain that the magnetic link differs from universal gravitation, but it is no less intimate and all-pervading. The twin forces of gravitational and magnetic attraction between worlds can only be likened to the universal force of love, which attracts souls towards each other.