Today is the feast of St. Lawrence. Keep a watchful eye over the next few nights for his tears!
Yes, the “Tears of St. Lawrence” is an old name for the Perseid meteor shower. The Perseid shower peaks on the morning of August 12 (more or less). It is named for the constellation of Perseus, the region of the sky where the meteors appear to originate. For a long time—dating back to Aristotle at least—astronomers did not consider meteors to be an astronomical phenomenon. They were thought to be a wholly atmospheric phenomenon, like clouds or rainbows or lightning. Think of the name meteor. Who does the weather forecast on your local TV news? The meteorologist—a scientist who studies the atmosphere.
But on the night of November 12-13 in 1833 there was a meteor storm. Meteors flashed across the sky at a rate of over 1000 per minute. That is tens of meteors each second. Multiple meteors would be visible in the sky at any given moment. This event captured the interest of a lot of people, including astronomers. This interest in meteors led several people to independently figure out that there was a recurring meteor shower in August—including the Americans Edward Claudius Herrick and John Locke (of New Haven, Connecticut, and Cincinnati, Ohio, respectively); and Adolphe Quetelet, founder and director of the Brussels Observatory in Belgium.
But in some sense neither Herrick, nor Locke, nor Quetelet was the first to figure out that there was a recurring meteor shower in August. In Herrick’s research he discovered that in certain Catholic areas people had long recognized the recurring meteor shower, and associated it with the feast of St. Lawrence, the 3rd-century martyr who was executed by being roasted alive over a fire (and who reportedly had the lip to tell his executioners, while he was being cooked, to roll him over lest they cook him unevenly!). Herrick wrote in an 1839 paper on meteors:
The annual occurrence of a meteoric display about the 10th of August appears to have been recognized for a very great length of time... a superstition has ‘for ages’ existed among the Catholics of some parts of England and Germany that the burning tears of St. Lawrence are seen in the sky on the night of the 10th of August; this day being the anniversary of his martyrdom.
He cited a newspaper in Belgium that reported:
It is not a little singular that the peasants of Franconia and Saxony have believed for ages past, that St. Lawrence weeps tears of fire, which fall from the sky every year on his fête, (the 10th of August). This ancient popular German tradition or superstition has been found, within these few years, to be a fact which engages the attention of astronomers. The inhabitants of Brussels can bear witness that on the night of the 10th, this year, St. Lawrence shed abundance of tears.
Thus average folk, at some unknown time in the past, were the first people to discover that meteors were not just an atmospheric phenomenon like a cloud or rainbow of lightning, but rather that meteors could be a regularly occurring thing. These people knew of the annual feast of St. Lawrence—which has been on the liturgical calendar for quite a long time. They observed the meteors to fall every August. They put the two together. At its heart, science is about observing the natural world and understanding it. These average folk observed the natural world, and they did not have preconceived notions about what category of phenomenon the meteors were, and so they achieved a better understanding of this particular part of it ahead of the astronomers.
We can actually narrow down the time of discovery somewhat. While the quotation above says that the Catholic peasants had known of the Tears of St. Lawrence “for ages”, in fact they could only have known for at most a few centuries. When Pope Gregory introduced his reformed calendar in 1582, the calendar shifted by a week and a half. Therefore, prior to 1582 the Perseids were not starting to fall around August 10 (they would have been falling in July). Thus our peasants discovered this some time after 1582, but enough before 1839 for the discovery to be viewed then as having be made “ages” ago.
Today we understand the August meteors to be particles of debris that are strewn along the orbit of a comet—particles that enter the Earth’s atmosphere and are heated to glowing, by reason of their rapid motion through the air and the resulting air friction. Earth, circling the sun annually, passes through the cometary debris stream every August, and thus the meteor shower. The Perseid meteors are indeed an atmospheric phenomenon, and they are indeed fiery falling things. It is just that they have an astronomical origin.
Look for the Tears of St. Lawrence the next couple of nights. The best time is when the constellation Perseus is up over the horizon—well after midnight is best, or even before dawn, while it is still dark. (Apparently those Catholic peasants could be a late-night-August kind of people.)
For a more in-depth discussion of Herrick’s work, click here for “The Discovery of the Perseid Meteors”, by Mark Littmann, Sky & Telescope, May 17, 2005.