Not PI day, just almost PI day, but no invisibility cloaks

Welcome to PI approximation day. Today is the 22nd day of the 7th month, so if we write it in day/month format, it looks like 22/7, which is a close approximation to the value π (only off by 0.04%). 

• As an aside, a closer approximation that is easy to remember is 355/113, the first three odd numbers each used twice. It is only off by 0.000008%! 

Back to dates, March 14th, is often celebrated as PI day, with PI minute being one minute until 2:00 in the afternoon. At that moment, the date/time (in month/day format) would be 3/14 1:59. (Yes, it would really be 13:59, but only the most staunch nerds are willing to be up at 2:00 am to celebrate the right time, which they do.)

So what does all this have to do with the Door? Probably not much, but when we spin up the magnetic fields to open the Door, it does make a sphere, which has pi in the calculation of both volume and surface (just like calculating the area and circumference of a circle).

Considering the recent hoopla with the Potter movie, I was hoping to discuss bending light around objects and invisibility cloaks, but there's still more research to do on it. Maybe next time.