Predicting Ancient Meteors
Have you ever wondered what the ancient Greeks thought about meteorites? It is a bit of a niche question I suppose, but it came to mind recently as we published an article on Bad Ancient all about the use of meteorite iron to make a dagger for the Pharaoh Tutankhamun. Interestingly, the Boy King did have a dagger made from a meteorite, but it was not made in Egypt! Take a read of the article if you are interested by clicking the link.
Anyway, as we were fact-checking the response - brilliantly written by Kyle Lewis Jordan - I stumbled across an interesting reference to a large meteorite found near Aegospotami, which sat on the Asian side of the Dardanelles (the Hellespont). Its appearance caused quite the debate.
Anaxagoras’ Prediction
The story pertains to the pre-Socratic philosopher Anaxagoras, who lived in the early 5th century BCE. Born in Asia Minor, he later moved to Athens and became one of the renowned thinkers of his day. It is said that a young Socrates read every book Anaxagoras wrote!
One the most famous stories about his work comes to us from an array of sources, in which he predicted that a large rock would fall from the sky. His theorising of what amounts to meteorites is in itself interesting, but according the Roman writer Pliny he went one step further by predicting when such a rock would fall (Natural History 2.149):
The Greeks tell the story that Anaxagoras of Clazomenae in the 2nd year [467 BC] of the 78th Olympiad was enabled by his knowledge of astronomical literature to prophecy that in a certain number of days a rock would fall from the sun
The impact this had on the people of Aegospotami was, understandably, profound. The stone was very large, the size of a horse-drawn cart according to Pliny, and it became something of a tourist attraction.
The Greco-Roman writer Plutarch tells us that (Lysander 12.1-2):
according to the common belief, a stone of vast size had fallen from heaven at Aegospotami, and it is shown to this day by the dwellers in the Chersonese, who hold it in reverence.
What made Anaxagoras’ work so ground breaking was that he was working off the idea that the heavenly bodies were not static. He theorised that the stars could and were moving, therefore they were capable of falling. He also reckoned that the Sun was a hot rock, like the other stars, and so predicted that it would shake and a small piece break off (Diogenes Laertius 2.10)
It was not just this one meteorite he correctly predicted. Pliny tells us of at least one other sites which had their own (Anaxagoras-divined) heavenly rock:
A stone is worshiped for this reason even at the present day in the gymnasium at Abydos — one of moderate size, it is true, but which the same Anaxagoras is said to have prophesied as going to fall in the middle of the country.
Pliny found these rocks of such interest that he went to visit one in the south east of France, but gives us no more information than a matter of fact statement that he had seen one himself. Infuriating!
Controversy and debate
Needless to say, Anaxagoras’ prediction and explanation caused much debate in the ancient world; a debate that was still raging 500 years after his death.
The 4th century BCE natural philosopher Aristotle was not one to accept another’s explanation for natural phenomena. When discussing meteorites, he specifically references the one at Aegospotami (Meteorology 344b):
For instance when the stone at Aegospotami fell out of the air-it had been carried up by a wind and fell down in the daytime-then too a comet happened to have appeared in the west. And at the time of the great comet the winter was dry and north winds prevailed, and the wave was due to an opposition of winds
What Aristotle was arguing was that the the sight of a comet occurring at the same time as this large rock appearing was a case of correlation not causation. He did not believe that the sky, or anything within it, was capable of falling to the ground but he did believe that comets in the sky were a sign of heavy winds. This heavy wind explained the movement of such a large rock - apparently.
It can be difficult to really appreciate the stakes in these ancient scientific debates. Understanding the nature of the cosmos could have very serious repercussions. Pliny highlights just what was on the line if Anaxagoras was right (Natural History 2.149):
If anyone believes in the fact of this prophecy, that involves his allowing that the divining powers of Anaxagoras covered a greater marvel, and that our understanding of the physical universe is annihilated and everything thrown into confusion if it is believed either that the sun is itself a stone or ever had a stone inside it. But it will not be doubted that stones do frequently fall.
It is interesting that even with this word of warning, Pliny is also honest enough to accept that meteorites proove that stones do fall from the sky.
Anaxagoras’ ideas were ultimately considered problemtic, even in his own time. He was actually driven out of Athens after he was charged with impiety. His crime: declaring that the sun was made from a mass of red-hot metal. During the trial he was defended by the great Athenian orator and statesman Pericles, one of his former students. The defence failed and he went abroad, seein out his days in Lampsacus in Asia Minor.
On his death, the locals erected an inscription in his honour (Diogenes Laertius 2.15):
Here Anaxagoras, who in his quest
Of truth scaled heaven itself, is laid to rest.
I also have written an epigram upon him:
The sun's a molten mass,
Quoth Anaxagoras;
This is his crime, his life must pay the price.
Pericles from that fate
Rescued his friend too late;
His spirit crushed, by his own hand he dies.