Tuesday, October 11, 2011

Sunset Here and There

Today I got a call from one of my riding buddies in NYC.  I got the call at 630pm and said I had to go, I still had ten minutes to ride.  He said "No way, it's dark."  I said "See ya" and rode for 10 minutes.  I could have ridden longer because it was a brilliant full moon low in the eastern sky.  And to be exact, I had nine more minutes to ride than my buddy in NYC, not ten.

I guessed at ten minutes as I left to ride, but I knew it was close.  New York is about 120 miles east of Lancaster PA.  At 40 degrees of latitude, each degree of longitude equals about 60 miles on the ground.  The two degrees of difference translates into four minutes on the clock--15 degrees is 1/24th of the one-rotation-per-day spin of the earth.  So the sun sets in NYC just over eight minutes earlier than in Lancaster. And, of course, the sun rises earlier in NYC.

I know.  What good is knowing that?  Maybe nothing, but when GPS and every other gadget runs out of juice, I can still do some rudimentary time keeping and navigation.

Or just write about weird stuff I know.