PDF Slides - UMBC
PDF Slides - UMBC
PDF Slides - UMBC
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ut Solar Time is actually a bit tricky …<br />
- Earth’s orbit is an ellipse<br />
so speed is not constant throughout orbit<br />
- Sun moves on ecliptic, not celestial equator<br />
so dα/dt ≠ constant<br />
Solution: introduce an hypothetical “Mean Sun”<br />
which moves around the around the celestial<br />
equator at a constant angular velocity<br />
…hence 24x60x60 = 86,400 s<br />
in a Mean Solar Day throughout the year<br />
[even this actually changes slowly with time!]<br />
Ian M. George PHYS 304 (2011 Fall) Meeting 04
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