Mathematicians Of The Day

8th June

On this day in 1637, the printing of René Descartes' Discours de la Méthode was completed, including its important appendix on Geometry in which he introduced the Cartesian coordinate system.

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Quotation of the day

From Giovanni Cassini
Light takes some time to come from the satellite to us; and it takes approximately ten or eleven minutes to traverse a distance equal to the semi-diameter of the Earth's orbit.