101Melting all that glass to the con-
sistency of cold honey takes six to
10 hours, but preheating the fur-
nace to 2,129 degrees Fahrenheit
takes about a week. It also requires
enough electricity to power 1,500
homes. The two-story machine is
the diameter of a fairground car-
ousel and spins a bit faster than
one to give the mirrors their con-
cave shape. (That curvature is
refined during polishing.) The giant
machine continues turning for
more than three months as the
glass anneals. So far, the lab has
cast five mirrors for the new scope.
COOK TIME