Fall 2014

Callander Drive, Veterans' Day, 2014.

It's a beautiful day, and I'm enjoying sitting out on our new front porch. I published on Facebook this morning a picture of the porch with the American flag, but all day I've been flying the Navy flag.  On most of the rest of the days I fly the stars and stripes, so today I'll announce my status as an officer in the United States Navy.

I've been spending much of my fall preparing to teach a course next semester in system dynamics. Preparing for a course the first time is a labor of love: there is no way this works out to a minimum wage! But, the advantage is that when the course runs the second time, the amount of work involved is about 10%. It's especially true for courses where the textbook is rarely updated. This textbook was last revised in 2000.

Next week I begin to work as a consultant in support of US Marine Corps operational analysis. This will absorb the bulk of my free time (especially if I don't have all these lectures finished). It works out well because, as you can see in the picture, the leaves have nearly left the trees and the winter weather will close in soon enough.

I'll try to link more of the photos of the front porch here.

The Concept of Time in Renaissance Italy

Bologna, Italy (June 23, 2014). In the decade after Galileo was placed under house arrest (in 1632), the church had come to a realization that it made a mistake. Church leaders needed to make predictions that depended on knowing several important astronomical facts. In particular, they needed to know exactly how long the year was, and whether the sun moved across the sky at varying speeds. The latter problem would help answer the question of whether the seasons were exactly equal. In addition, Kepler had already introduced the idea that orbits might be elliptical instead of circular, and this created the need to know exactly how far the sun was from the Earth at various points of the year.

The Meridian Line in San Petronio Basilica, Bologna. At noon the sun
crosses this line. It crosses at different points during the year.

Now, if Galileo and Kepler were heretical -- and their hypotheses incorrect -- then there would be no reason to ask these questions. And, there would be no reason to place solar-observing instruments in churches in Bologna and elsewhere. Yet, they did. The meridian line in San Petronio was installed first in 1648 (but not corrected for accuracy until twenty years later).

Such was the background for a week-long course and sightseeing trip to Emilia Romagna with two of Cornell's most distinguished professors, Martha Haynes and Riccardo Giovanelli. (More to follow...)