I didn't post anything last week, because I had to stay late at work. And what was I doing? Helping make this interesting object
So, what is it? We're making (remaking, actually) an insulated flask capable of holding liquid helium. To get insulation good enough to hold a liquid at 4 degrees above absolute zero, you need a couple of things. First, you need a very good vacuum layer between the flask and the outside world. A pair of nested steel cylinders with a good set of seals takes care of that. But secondly, there's the problem of black-body heating. If you've ever felt heat coming off of a piece of glowing metal, it's the same idea. And room temperature objects emit black-body radiation, which can transfer enough heat to boil the liquid helium. So, we wrap the vacuum jacket in something called superinsulation, which is aluminized mylar, the sort of thing used to wrap marathon runners after they reach the finish line. Except that we need about 100 layers of the stuff, which is why we're unrolling it off the storage roll and onto the actual jacket, ending up with something that looks for all the world like a very very shiny Torah scroll.
-dms