Episode 132 - Letter to Pythocles 06 - More on The Weather
Date: 07/30/22
Link: https://www.epicureanfriends.com/thread/2606-episode-one-hundred-thirty-two-letter-to-pythocles-06-more-on-the-weather/
Summary
Section titled “Summary”Martin reads sections on earthquakes, wind, hail, snow, dew, frost, ice, the rainbow, and the halo around the moon; Martin draws on his experience of earthquakes in Japan to illustrate how two distinct seismic wave types can signal a distant strong quake, while Epicurus’s explanation via subterranean air and collapsing caves, though mechanically wrong, follows the right method of proposing natural causes. Joshua describes the Tower of the Winds (Horologion of Andronicus of Cyrrhus, Athens, ~50 BC) — a twelve-meter octagonal marble structure with eight wind-deity reliefs, eight sundials, a triton weather vane, and a clepsydra water clock — as an early attempt to subject meteorological phenomena to systematic measurement. The episode features a spirited discussion of John Keats’s “Lamia” and its complaint that “philosophy will clip an angel’s wings” by reducing wonders like the rainbow to mere natural explanation, with Cassius and Joshua jointly rejecting Keats’s view: natural understanding enhances rather than diminishes the experience of nature, and the Epicurean study of nature is meant to deepen emotional engagement with the world, not suppress it. Joshua recounts a vivid personal anecdote about English storm-chasers who traveled from Texas to Sioux City, Iowa specifically to observe Midwestern thunderstorms, illustrating the genuine wonder that meteorological phenomena inspire even for those who understand them naturally. Cassius closes with the Lake Peigneur disaster — a Louisiana salt mine punctured by an oil rig that caused an entire lake to drain into the earth and refill with Gulf saltwater — as a modern example of how catastrophic natural events can seem so uncanny as to invite supernatural explanation, and notes the irony that Mount Vesuvius, often invoked as a sign of divine wrath, preserved the Herculaneum library of Epicurean texts.
Transcript
Section titled “Transcript”Cassius: Welcome to Episode 132 of Lucretius Today. I’m your host Cassius, and today we continue with Epicurus’s Letter to Pythocles looking at more weather phenomena. Let’s join Martin reading today’s text.
Martin: Earthquakes may be brought about both because wind is caught up in the earth so that the earth is dislocated in small masses and is continually shaken, and this wind either takes into itself from outside or else because masses of ground fall into cavernous places in the earth and fan into wind the air imprisoned there. And again earthquakes may be brought about by the actual spreading of movement which results from the fall of many such masses of ground. There are also many other ways in which these motions of the earth may be caused. Hail is produced both by a powerful congelation when certain windy bodies form together from all sides and split up, also by a moderate congelation of watery bodies and their simultaneous division. Their circular shape may possibly arise because the corners melt off all round or because at their conformation, bodies whether watery or windy come together evenly from all directions. Snow may be produced when fine particles of rain are poured out of the clouds owing to the existence of suitable shape and the strong and constant compression by winds of clouds of the right kind, and then the water is congealed in its descent owing to some conformation of excessive coldness in the clouds in the lower region, or else owing to a congelation in clouds of uniform thinness. Dew may be produced both when such particles as are productive of this kind of moisture issue from the atmosphere and meet one another, and also when particles rise from moist regions or regions containing water and then meet together and cause moisture, and afterwards fall back on the ground below. Frost is produced by a change in the dew particles when such particles undergo a definite kind of congelation owing to the neighborhood of a cold atmosphere. Ice is caused both by the squeezing out from the water of particles of round formation and the driving together of the triangular and acute-angled particles which exist already in the water, and again by the addition from without of particles of this kind. The rainbow is caused by light shining from the sun onto watery atmosphere, or else by a peculiar union of light and air which can produce the special qualities of these colors. A halo around the moon is caused either when air is carried towards the moon from outside or when the air checks the effluences carried from the moon so equitably that it forms them into this cloudy ring all around without any gaps, or else when it checks the air around the moon uniformly on all sides so as to make that which encircles it round and thickened.
Cassius: Thank you, Martin. We have earthquakes, wind, hail, snow, dew, ice, rainbow, and the halo around the moon — quite a range. Let’s start with earthquakes. Martin, I believe you have actually experienced earthquakes.
Martin: Yes, almost monthly during my time in Japan. I was never close to a strong one, but I was there during two strong distant ones. What made them different from local weak ones is that there were two distinct parts — different types of seismic waves arrive at different speeds. When I noticed these two groups of waves coming with a time gap between them, I could guess there must have been a very strong earthquake far away. If you think of a truck rumbling past versus a railway vibration — the earthquake vibrations have lower frequency, slower but with higher amplitude. People who are accustomed to them can find them almost calming, as if the earth is alive.
Cassius: What strikes me about his explanation is the role he assigns to air. Rock is normally static. Air and water move. So he reaches for air as the movable force inside the earth — which is of course mechanically wrong, since it is tectonic plate movement. But his method is right: he proposes natural causes and explicitly says “there are also many other ways in which these motions of the earth may be caused,” leaving the explanation open.
Martin: The one element he gets right is the collapse of caves — that can genuinely cause local tremors. There is also the connection between seafloor earthquakes and tsunamis, which Japan certainly knows about. Poseidon was god of both the sea and earthquakes in Greek mythology, and that association turns out to have a natural basis.
Joshua: There is a cave in South Dakota called Wind Cave National Park that illustrates his reasoning beautifully. The cave is so enormous it has only one known entrance. When atmospheric pressure rises outside, air is forced into the cave; when pressure drops, all that pressurized air rushes back out. The man who discovered the cave brought friends to show them the wind blowing out of the entrance — but the pressure had reversed, and when he threw his hat toward the opening it was sucked in. So the connection between caves and wind in Epicurus is not absurd at all.
Cassius: I wanted to talk about the Tower of the Winds that you visited in Athens, Joshua.
Joshua: Yes — in the area of the Roman Agora there is a remarkable building called the Horologion of Andronicus of Cyrrhus, built around 50 BC though possibly earlier. It is twelve meters tall, eight meters in diameter, octagonal marble. Along the frieze just below the roof are eight wind deities in relief — Boreas the north wind, Caecias the northeast, Apeliotes the east, Euros the southeast, Notus the south, Livas the southwest, Zephyrus the west, and Skiron the northwest. In antiquity a triton weather vane at the top indicated wind direction. It had eight sundials on its faces, and inside a clepsydra — a water clock — for keeping time when the sundials were useless at night or under cloud cover. So here is an ancient structure trying to do systematic meteorology: measure the winds, track time by reproducible natural phenomena. It is in excellent condition. If you go to Athens, go see it.
Cassius: That is a perfect illustration of what Epicurus recommends — not just observing phenomena but applying a measuring standard to them. Even though the figures are called wind gods, the building itself embodies something different from supernatural religion.
Martin: I looked it up while you were talking. It was built around 50 BC, so it post-dates Epicurus — it is roughly contemporary with Cicero and Caesar. But it represents the same impulse.
Cassius: Hail next. Martin, you’ve experienced dramatic hailstorms.
Martin: Yes, in Japan and in Germany. My son grew up in Thailand and had never seen hail. When we were walking in Cologne and it started, he ran around trying to catch the pieces. His mother was worried about injury, but the pieces were small. Large hail does cause real damage — cars, roofs, crops. I have seen cars with dozens of small craters across the roof from hail.
Joshua: I remember exactly what road I was on when a freak hailstorm came from nowhere and my friend texted me asking if the world was ending. It is such an uncanny experience when you’re not expecting it. Hail is listed among the ten plagues of Egypt — water turned to blood, frogs, lice, flies, pestilence, boils, hail, locusts, darkness, killing of the firstborn. That hail is on the same list as pestilence and the killing of firstborn children tells you what weight it carried.
Martin: For an agrarian society that cannot compensate for local crop loss through trade the way we can today, hail was existential. It would mean famine.
Cassius: On ice and cryogenic freezing — Martin, what is your opinion on the practice of having yourself frozen after death and expecting to be revived?
Martin: That is nonsense. Even setting aside whether you could restart the brain, the physical problem is this: when you freeze tissue, the water in the cells forms ice crystals. Different tissues freeze at different temperatures. As the body warms back up, the tissues that are still frozen have these sharp triangular crystals — exactly the acute-angled particles he mentions here — still cutting through the already-thawed soft tissue. The organs that have thawed are already mushy; the ice crystals are shredding them. Once you start pumping there would be internal bleeding everywhere.
Cassius: And there is no case in the medical literature of a human being returning from brain death. Death in the Epicurean sense is real and final, which is both sobering and liberating.
Joshua: I saw something the other day that was apparently a genuine business offering post-rapture dog-walking services: pay a subscription, and when the rapture happens we’ll come get your dog. So there are markets for everything.
Cassius: Now the rainbow — you quoted a poem, Joshua?
Joshua: John Keats, “Lamia.” He complains that natural philosophy will clip an angel’s wings, conquer all mysteries by rule and line, empty the haunted air, and unweave a rainbow — taking out all the romance and fantasy. Richard Dawkins wrote a book called Unweaving the Rainbow in direct response. Keats’s view is that when you explain the rainbow scientifically you take value away from it.
Cassius: Which is the opposite of the Epicurean view. The rainbow doesn’t need a divine pedigree to be beautiful. And understanding it — knowing that it involves refraction of sunlight through water droplets — doesn’t diminish the wonder; it adds another layer to it. Epicurus loved to study nature precisely because he found it so full of significance.
Joshua: There is Thomas Jefferson’s head-versus-heart letter, where he explicitly sides with the heart in spite of himself. The emotional response to nature is not in conflict with the rational investigation of it. They can reinforce each other.
Martin: Yes. The question of how emotions relate to reason is not a conflict in the Epicurean view. The deep emotional response to nature is part of why you study it.
Cassius: Now the halo around the moon — I was imagining the general fuzziness around the moon on a cloudy night. But it sounds like Epicurus is describing something more dramatic.
Martin: Yes, it requires ice crystals in the air. If you search “22-degree halo moon” you see a dramatic wide circle around the moon with a clear gap between the halo and the disk.
Joshua: We have these in the northern United States. What we call sun dogs — on the sun you see two false suns at a fixed angular distance on either side, sometimes without the full circle. I have seen sun dogs many times growing up in Iowa but only when it is very cold.
Cassius: We should put pictures in the show notes.
Joshua: Something else I wanted to mention: I used to work at a deli in Sioux City, Iowa. One day three or four vans pulled in and a whole group of people from the United Kingdom tumbled out and came in. They had started in Texas and were chasing storms north up I-29. That is how they ended up at my deli. People travel from Europe specifically to experience Midwestern thunderstorms. Things that were so ordinary to me that I would not even mention them — huge towering cumulonimbus, hail coming sideways, the sky going green before a tornado — were worth an Atlantic crossing to these people. That says something about the genuine interest weather inspires even when you understand it naturally.
Cassius: And yet those same phenomena, when they hit someone directly — a tornado destroying a house, a hurricane, an earthquake — immediately raise the question of why. Why me? What did I do to deserve this? The Epicurean answer, that it was not done to you by anyone, is essential peace of mind.
Martin: And before we close, Mount Vesuvius is the ultimate example. People invoke it as divine punishment. But its eruption in 79 AD preserved the largest collection of papyrus scrolls from antiquity — all Epicurean texts from Herculaneum, written by a philosophy that explicitly denies any intervention of the gods in natural or human affairs. The irony is complete.
Cassius: Very well. Let’s close there and come back next week to complete the Letter to Pythocles. Thanks everybody.
Joshua: Goodbye.
Martin: Bye.