Oct 18

Dialing in the correct time

IMG_20101017_174237, originally uploaded by NDeRC2.

I happened to stop by this sundial in front of Jordan Hall at the right time to capture both the shadow and the key to decoding it in this same image. As you can tell from reading the shadow on the face of the clock, the time seems to be ~5:56 or 57 PM. In the middle of the month of October–i visited the site on October 17th shortly before 6 PM–we should subtract somewhere between 14 and 15 minutes, the markings on the sundial instruct us. Doing the subtraction, the sundial is indicating that the time is ~5:42 PM. My cell phone indicated that the time was 5:43 PM when I took this picture. Based on this one data point, the sundial seems to be calibrated pretty well with my cell phone:)

For a better look at the sundial, here’s an image from this summer’s NDeRC ASTRO workshop:

2010 NDeRC ASTRO Workshop at Jordan Hall of Science, University of Notre Dame