The hidden structure of the periodic system

The periodic table of elements that most chemistry books depict is only one special case. This tabular overview of the chemical elements, which goes back to Dmitri Mendeleev and Lothar Meyer and the approaches of other chemists ...

The universal beauty of the mountains can be seen in graphs

Mountains have character. The continuous gentle, wavy hills and wide valleys of the Carpathians, Appalachians or lower parts of the Alps contrast strongly with the soaring peaks, ragged ridges and deep ravines of the high ...