Just when I finally get a look at the world's largest telescope of 1948, and make plans to visit its successor (the 200 inch Palomar telescope near San Diego) in late August, I read about the first light celebration for the new GTC (Gran Telescopio Canarias) in the Canary Islands. Compared to the Mount Wilson scope's puny 100 inch (2.54 meter) primary mirror, the GTC has a 10.4 meter primary (that's 409.4 inches). Of course it's not a single piece of glass like the big ones of old. It will be made up of 36 independent hexagonal mirrors. I say will be because at first light, only 12 of the mirrors were installed. The optics are pretty cool - this diagram is from GTC web site.
This thing will be gathering a lot of light, and with frequently excellent seeing conditions at this site, it should produce some amazing images and scientific results over the next few years. It's just incredible the numbers and sizes of optical telescopes that are popping up around the globe (here's a list - Keck in Hawaii is still the biggest fully operational one at 10.0 meters). I think there really is something to this whole optics thing. Makes me proud to call myself an optical engineer, though none of my designs has ever made it out of the simulation software and into glass and metal.