Thursday, May 06, 2010

Chinese astronomy and scientific anti-realism

On the last day of my class on Scientific Revolutions and the law, one of the students in the class, Lijing Jiang, gave a presentation titled "To Consider the Heavens: The Incorporation of Jesuit Astronomy in the Seventeenth Century Chinese Court."

Her presentation was about how Jesuit missionaries in China brought western astronomy with them, and how it was received.  This added a very interesting complement to the course, as much of the early part of the semester was about the Copernican revolution (using Kuhn's book of the same name).  Part of what happened early on in astronomy was a division between cosmology and positional astronomy, with the former being about the actual nature of the heavens, and the latter being about creating mathematical models for prediction, to be used for navigation and calendar-setting that incorporated features not intended to represent reality (like epicycles).  These two types of astronomy didn't really get reconnected (aside from the occasional realist depiction of epicycles in crystalline spheres) until Galileo argued for a realist interpretation of the Copernican model.  And that didn't fully catch on until Newton.

In China, calendar reform was very important as they used a combination of a lunar month (based on phases of the moon) and tropical year that had to be synchronized annually, and an unpredicted eclipse was considered to be a bad omen.  The Chinese had gone through many calendar reforms as a result of these requirements, and they considered that theories needed to be revised about every 300 years (in other realms as well, not just astronomy).

The Jesuits happened to bring Copernican astronomy to China in the late 16th/early 17th century, with a goal of impressing and converting the Emperor.  They got their big chance to make a splash in 1610, when the Chinese court astronomers mispredicted a solar eclipse by one day, which the Jesuits predicted correctly in advance.  But this turned out in a way to be poorly timed, as the Counter-Reformation decided to start cracking down on Copernican heliocentrism after 1610, making it a formal doctrinal issue in 1616.  The Jesuits in China thus switched to the Tychonic system which was geometrically equivalent to the Copernican model but geocentric.

Multiple factors persuaded the Chinese to maintain a relativistic, anti-realist understanding of positional astronomy beyond the Scientific Revolution.  In addition to Taoist and Buddhist views of life involving constant change and their past experience with calendars suggesting revisions every 300 years, the Jesuits presented another example of apparent arbitrariness in cosmological model selection, and they continued to stick with the Tychonic model as the western world switched to heliocentrism.

You can read Lijing Jiang's blogging at Science in a Mirror, where she may post something about her presentation in the future.


Jeff said...

Hello, I am writing about a different topic you posted dealing with Chuck Missler. In fairness to accuracy, the prophecy about the King of Israel riding into Jerusalem on a donkey was not correctly depicted by you. It had to be the unbroken colt of an ass. Unless you know how to ride an unbroken animal immediately, this is a lot harder than to fulfill than you try to debunk.

Jim Lippard said...

Jeff, not sure why you've posted this here.

I didn't misrepresent anything--I quoted the prophecy accurately and commented upon it and the claimed fulfillments in the four gospels.

By your reading, the prophecy went unfulfilled according to Mark, Luke, and John, and still had an excess animal in Matthew.

I'm not sure your interpretation makes any difference to my summary. If there were a prophecy that said the Messiah had to make a three-point basketball goal, and Jesus did that, I'd speculate that the fulfillment was more likely a result of intentional practice rather than supernatural intervention. Same here.