Published on March 31, 2017
We spin mercury and create a natural paraboloidal shape. Because it costs so much to produce large parabolic glass mirrors, some observatories have opted to use liquid mirrors. The problem is they can only look straight up. These are called “zenith” telescopes.
I used a rather clunky turntable to spin my bowl of mercury. Despite its appearance, it was very stable.
Spinning the Hg causes it to be pushed outwards through centripetal force to form a nearly perfect bowl shape.
Gallium Liquid Mirror video:
Here is a photo of a large, liquid mirror telescope.
 MERCURY Rotating MIRROR){kind=link}