Get ready for your horoscope to change it’s scope. For centuries, human beings have searched the stars to help them navigate the earth and understand themselves. Ancient Babylonians were among the ...

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 ...

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

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 ...

IN the Paris Observatory a number of clocks provided with two dials showing sidereal and mean time were installed last year as part of the permanent equipment of the Observatory. This suggested to me ...

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, ...

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 ...