MEGAPIXEL
Baking gigantic mirrors, and cancer pens.
In a mould at the University of Arizona, almost 20 t of glass is spinning, as it is heated to a temperature of 1,165 °C. The glass will become one of the seven mirrors of the world’s biggest optical telescope, the Giant Magellan Telescope, in Chile, which is to zoom in on planets in remote solar systems. The melting of the glass takes four hours, and subsequently, three months of cooling begins, as the mould is still spinning. Finally, the 8 m mirror is polished at a degree of accuracy of one thousandth of a human hair.