Around 500 B.C., the PythagoÂreans were among the first to imagine a geo–decentric world system.
Their Universe was focused on a central fire, and Earth was balanced by its ideal, perfect counterÂpart: Antichthon.
Although rendered superÂfluous by the insights of Copernicus and Kepler, it might exist thanks to the principle of Lagrange.
Yet, we do not know.
PART 1: EQUILIBRIUM
THE PYTHAGORAEAN WORLD SYSTEM BY PHILOLAUS
According to the Pythagoreans, the universe consists of ten heavenly bodies, nine of which circle around a tenth (the Central Fire). The stars were believed to be static points of light dwelling outside the moving heavenly bodies.
THE PHILOSOPHERS
Pythagoras and his students were the first to take up mathematics around 500 B.C. They developed a cosmology which was the first to argue that the Earth was not the center of the universe. To keep the Earth’s movement in balance, they needed a Counter–Earth, and therefore proposed the existence of «Antichthon» (Greek for «Counter–Earth»).
ANTICHTHON
ET IN ARCADIA EGO (MEMENTO MORI)
This sketch by Nicolas Poussin from 1667 depicts the birth of art. An Arcadian shepherd recognizes his fellow’s shadow being cast onto a tombstone and circumscribes the silhouette with his finger. Art is discovered at the moment when the ideal (Arcadia), a foreshadowing of death (the shepherd’s shadow), and death itself (the grave) coincide. The balancing of life and death that leads to the discovery of art is analogous to Antichthon’s balancing of the Earth in a dichotomous universe. Only art can unify the two.
Counter-Earth was not just a device invented to balance and explain the universe. It also became an imaginative receptacle for things that were impossible on Earth. In this sense, it was similar to Arcadia or Mount Olympus.
Antichthon was imagined as beautiful, fertile, and immeasurably large, as an ancient, eternal, and ethereal place, a place of endless opportunity, diversion, and vice, and as a cradle of the arts, sport, and sciences. This notion was carried over into medieval culture.
GOD
Antichthon was also present in Christian theology, though not in any verbalized, concrete form. God, which we do not know, was posited as counterweight, an omnipresent, omnipotent, and impartial companion. God is the ensign for the absent, the invisible, the «other».
THE SEVENTH DAY
And on the seventh day God rested from his work and looked down upon the Earth—as on this engraving by Julius Schnorr von Carolsfeld. The three primary celestial bodies (Earth, Sun, and Moon) represent the Holy Trinity. But only by adding God can the two-dimensional triangle of the Trinity be modified to represent spatiality, taking the shape of the simplest of the Platonic solids: the tetrahedron.
And He dwells in heaven—on Antichthon.
COPERNICUS, KEPLER, AND LAGRANGE
By the Renaissance, both philosophers and scientists had abandoned Antichthon as there was no need for a Counter-Earth in the Copernican world model.
Galileo Galilei was condemned for arguing that the Earth itself was in motion, and Antichthon retained its theological role as an outdated, pre-Christian cipher for both heaven and hell.
In 1609, Johannes Kepler rendered the system dynamic by describing the rules governing the movement of the spheres. In 1772, Joseph-Louis Lagrange elaborated the theory by pinpointing five locations in the Sun–Earth system at which all gravitational forces cancel each other out. Lagrange point L3 is not visible from the Earth, but was assumed to be the exact location of Antichthon.
And so, in the 18th century, Antichthon’s orbit became calculable and its existence would have once again fitted in with the cosmology of the age. All that was lacking was the philosophical need.
A GLIMPSE BEHIND THE SUN
It took another 300 years until in 2006, NASA launched two probes which, traveling in opposite directions, veered away from the Earth, passing both in front of and behind its orbit around the Sun.
THE STEREO PROBES
In 2006, NASA launched two probes (STEREO Ahead and STEREO Behind) which roughly follow the Earth’s orbit, circling the Sun both counterclockwise and clockwise. In the first half of 2007, shortly after they had reached their final orbits, their cameras were able to penetrate the region of Lagrange L3, although their sensitive COR1 coronagraph did not capture any signs of an object lurking there.
Intended for the stereographic study of the Sun, the two dichotomous probes are equipped with synchronized cameras. When they left Earth, they had a brief glimpse behind the Sun, at last affording us a chance to look out for Antichthon.
But nothing was found there, at least nothing larger than a few hundred kilometers across.
HI CORONAGRAPH TAKEN BY STEREO BEHIND
The two bright objects in this picture taken by the HI instrument on board STEREO Ahead are Venus and Mercury. Antichthon, if it existed, would manifest itself in similar fashion on the far right of the image.
ALL FIELDS PANORAMA
This panoramic image covers 360°, it shows the complete sky as if seen from between Earth and the Sun. The perimeters for Earth and Antichthon are symmetrically arranged. Inset: no Antichthon is visible.
PART 2: EXPEDITION
ANTICHTHON EXISTS AGAIN
Today, Counter-Earth is real once again. A receptacle for our wishes and perceptions of the ideal, it is waiting to stimulate our imagination. But this time, we are not fantasizing. We are imagining Antichthon based on what we know about objects in the solar system.
Antichthon is the size of a small moon or asteroid, and therefore has little gravity and no atmosphere. It is made of rock and sand, and might even contain water. It might harbor a plant species believed to exist in the vacuum of space.
Most probably it is an uninhabited, barren place—not at all what the Greeks imagined it to be.
THE MARTIAN MOON PHOBOS
Phobos measures about 10 km across and is well documented. It is therefore an ideal proxy for Antichthon. We substituted Phobos for the Antichthon that has not been disproved, and imagined going on an expedition to Phobos in order to see what Antichthon might look like.
WE CHOOSE TO GO TO ANTICHTHON.
Under the Full Moon on Mount Etna, and on the southern flank of the Furka Pass we found landscapes and lighting conditions that might resemble Phobos and mimic Antichthon.
PART 3: EPILOGUE
LAST OR FIRST APPROACH
Around 2012, the STEREO probes will arrive behind the Sun. By then, their mission will have been accomplished, but they will remain operational, since their power source is the Sun.
We have asked NASA to point STEREO’s cameras so that the question of Antichthon can be resolved once and for all.
The answers are pending.
