According to Ptolemy's (c. 150 CE) account of the motions of planets, planets moved in circular paths ("epicycles") around center points that in turn moved around the center of the earth along a path ...
In a book by Alexander Moszkowski, there is an Einstein quote about a hypothetical size of the universe (100 million Light years). Moszkowski claims that Einstein had deduced that from the ...
Who discovered what set of factors is responsible for visibility of celestial bodies on Earth's daytime sky?
Visibility of a celestial body on the sky during the day depends on a number of factors - if I recall correctly: the body's magnitude, Seeing, Sky brightness, and probably some others I have missed. ...
Kepler wrote 'De Stella nova in pede Serpentarii' describing the supernova of 1604, now known as SN1604. My understanding is that the constellations used by Kepler and the constellations used today ...