3D printing industries

Source, February 7, 2013: 3dprinting industry

From the article:
Archimedes, the ancient Greek mathematician famous for creating numerous
inventions, laying the foundations for calculus and for determining the
areas and volumes of just about everything, has been resurrected with
the help of to two Harvard mathematicians and a 3D printer. In order to
pay homage to the great thinker, Elizabeth Slavkovsky and Oliver Knill
took some of his most notable mathematical proofs and ideas and printed
them in 3D.
Of these proofs is Archimedes personal favorite, which illustrates
that the volume of a sphere is # the volume of a cylinder with the same
height and diameter and that the same is true for the surface areas of
both shapes.  This insight was so important to the philosopher that
he had his tomb marked with a sphere circumscribed by a cylinder.
Slavkovsky and Knill, thus, found it appropriate to replicate the
relationship in 3D, printing a model with a half-sphere placed on the
top of a cylinder, creating an object they call "The Drinkable Proof".
As water is poured through the top of the sculpture, it fills exactly 
of the cylinder (the volume of a sphere).