LIGO diary--report #7

by Wm. Robert Johnston
last updated 1 August 2001

Wednesday, 25 July 2001: Currently I am assisting in some data entry of the daily system status reports. Besides constituting a daily record, this information goes into a database so that trends in the behavior of any of about 150 different components or readings can be identified.

Otherwise I have done some more reading, some practice on some computer skills, and some efforts at calculations involving some special cases of relativity. (Did you know that because of relativistic space-time curvature, the Earth's diameter is 4 millimeters longer than it should be? If you did, you didn't tell me.)

An interesting tidbit from this week for all you skeptics: general relativity has practical applications in the GPS system. The Global Positioning System satellites must make corrections for the effects of relativity. If this were not done, the system would not provide the accurate location information that soldiers, pilots, and other GPS users rely on.

So far we have had two presentations this week:

Last Saturday I went with several others students from LIGO to an alligator farm in Hammond. This farm is among the largest in the United States with thousands of alligators and turtles at any given time. The pond with large alligators was said to hold 250. Some we saw were over 3 meters long.

We have had late afternoon-evening thunderstorms on several days, including one right now.

Image credits: Wm. Robert Johnston, © 2001 (top); LIGO-Livingston, 2001 (bottom).

© 2001 by Wm. Robert Johnston.
Last modified 1 August 2001.
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