When it rains, it’s time to do some touristy indoor things, or in this case, underground tours. The Tower-Soudan underground mine is now a state park and you go down the original mineshaft about a half-mile underground.
Here Martin plays with a toy model of the elevator shafts that show how the two shafts counterbalance each other.
Here’s an OSHA-approved open pulley and belt in the crushing room (not operational since the 1960’s)!
Donning hard hats, we’re ready to go down the shaft. Instead of the historical mining tour, we took the science/physics tour this time. The mine is an ideal place for some types of experiments since the half-mile of overhead rock shields out many particles.
Here is one of the main rooms in the physics lab. The large hexagonal thing near the center is the The MINOS (Main Injector Neutrino Oscillation Search) Far Detector is a 6,000 ton particle tracking device that is observing neutrinos sent from Fermilab, which is near Chicago. MINOS tries to precisely determine mass differences among neutrinos, 3 of the 12 fundamental building blocks of matter.
Another experiment is The CDMS 2 (Cryogenic Dark Matter Search) Detector that seeks traces of Weakly Interacting Massive Particles (WIMPs) that might comprise a significant fraction of Dark Matter. This baby is cold – at 0.02 degrees kelvin, about -460. We all knew it could get cold in northern Minnesota, but -460?
One of the most fascinating objects is the mural on the right that depicts humanity’s search for the building blocks of matter. It is so bizarre to see a large mural a half-mile underground.