- Some amazing astrophotography (scroll down after clicking) taken from Bear Mountain near Meadow Lakes (famous for TV and radio transmitters). I thought their description of why and how they picked the site was interesting.
- What happens with all that stuff you leave curbside for the recycling service to haul away? It goes into athrough an eddy current separator, of course.
... a magnet pulls out any ferrous metals, typically tin-plated or steel cans, while the non-ferrous metals, mostly aluminium cans, are ejected by eddy current. Eddy-current separators, in use since the early 1990s, consist of a rapidly revolving magnetic rotor inside a long, cylindrical drum that rotates at a slower speed. As the aluminium cans are carried over this drum by a conveyer belt, the magnetic field from the rotor induces circulating electric currents, called eddy currents, within them. This creates a secondary magnetic field around the cans that is repelled by the magnetic field of the rotor, literally ejecting the aluminium cans from the other waste materials.
Friday, February 08, 2008
It's full of stars
Two quick things:
