So, I've come up with what I think is a pretty darn neat idea for my Burningman project, but the technical implementation thereof is what I'm getting hung up on. The reason? ...It involves things I conceptually understand, but have never implemented on an applied basis- like thermodynamics, isolating nitrogen through fractional distillation of supercooled air, precision machining, the compression/expansion of gases, a variety of mathematical formulas, and so on. The idea? Well, I can't go into too much detail here (shhh- its top secret!!), but basically I'm trying to build something like a lightweight Adiabatic Carnot engine to power sub-atmospheric flight from my backyard. No, really. Trust me. I'm actually serious. ...Its completely steampunk; the plan is so elegant and simple, I can't see why its been this overlooked for this long. In fact, the technology has been around since the late 1700's, its just that nobody seems to have bothered to put it all together in this particular way- which is what makes it both elegant art and great science. Plus, it also looks like you can't order what I want off the Internet- (um, anybody got a spare minature turboexpander??) we're going to have to make make it all ourselves. But- the good news is, I think you can get *most* of the required parts at Home Depot. Oh- it might also help if you had access to a machine shop, and lived in or near Los Angeles. Hell- even if you just have a machine shop and aren't a scientist, we should probably chat. And yes- unfortunately, I don't have a grip of cash to implement it- but that's also kind of the point. ...Much in the same spirit that the UNIX operating system was developed, we'd be doing this just for the fun of doing it- to see if it actually can be done. So- if you're interested and have a few weekends to spare, why not drop me (Steve) a line??