Mathematicians Of The Day

26th September

On this day in 1679, a fire destroyed the home and observatory of Johannes and Koopman Hevelius in Danzig (now Gdańsk).

Click on for a poster.

Quotation of the day

From Hans Reichenbach
Let us assume that the three dimensions of space are visualized in the customary fashion, and let us substitute a color for the fourth dimension. Every physical object is liable to changes in color as well as in position. An object might, for example, be capable of going through all shades from red through violet to blue. A physical reaction between any two bodies is possible only if they are close to each other in space as well as in color. Bodies of different colors would penetrate each other witout interference ... If we lock a number of flies into a red glass globe, they may yet escape: they may change their color from red to blue and are then able to penetrate the red globe.
The Philosophy of Space and Time