About time keeping, the definition of “sidereal” is “of or with respect to the distant stars (i.e. the constellations or the fixed stars, not the sun or planets)”, as defined after a google search.

Pop quiz! How long is the average year? If you said “365 days”, then congratulations! You’re wrong. If you said “365.25 days” ...

Sidereal time literally means “time by the stars.” A sidereal day is a measurement of one rotation of Earth referenced to distant background stars — think of this as the amount of time it takes a ...

Did you know there’s more than one type of astrology in the world, or that these different types of astrology use completely different time-keeping systems? Western astrology is the “mainstream” type ...

OBSERVATORY practice in the past has always been to use separate clocks for indicating solar and sidereal time. In the case of quartz crystal clocks, this practice could be continued by using two ...

Katie has a PhD in maths, specializing in the intersection of dynamical systems and number theory. She reports on topics from maths and history to society and animals. Katie has a PhD in maths, ...