The End of a Solar Telescope
Snotnose writes:
Problem: You have a 250 ton telescope that needs to turn smoothly all day. Solution? Set it on a pool of mercury. It worked very well for over 50 years. But time marches on.
A solar telescope in New Mexico is being torn down, and the reason is a pool of liquid mercury hidden inside it. The mercury was the clever trick that made the telescope work. It is now the thing that dooms it.
The telescope's optical system weighs 250 tons, and it had to turn smoothly all day. You can't spin something that heavy on ordinary wheels. So instead the whole thing floated on a sealed pool of liquid mercury. Mercury is dense and flows easily, so the load rode on the fluid and turned with almost no friction. That is how the 250-ton optical system of the Richard B. Dunn Solar Telescope was designed to move.
However, on January 5, crews found some of that mercury where it wasn't supposed to be.
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