PDF Slides - UMBC

Additional Slide [not shown in class]
..obviously Physics neither ‘knows’ or ‘cares’ about human convenience!
… eg. there is no reason why the Earth
has to spin an integer (eg exactly 365 “days”) number of times
every complete orbit of the Sun (ie 1 “year”)
… this and other effects make keeping
practical “wall-clock time” (UTC)
in agreement with ‘celestial time’ a challenge
… and numerous time systems can be defined
all of which are based upon practical need
Dennis Hopper: Apocalypse Now:
You can't travel in space, you can't go out into space, you
know, without, like, you know, uh, with fractions, okay?
…Disagree – there are a lot of fractions in space
Ian M. George PHYS 304 (2011 Fall) Meeting 04