M aker

P.O.K.E.R. Night

Or, Let’s Build a Vortex Tube Party! By Mister Jalopy

IN 1867, SCOTTISH PHYSICIST ROBERT Clerk Maxwell proposed a “thought experiment,” suggesting that it may be possible to break the second law of thermodynamics, if you could find a molecularly minded demon that was willing to cooperate.

Start with two hypothetical containers of equal temperature with a connecting trap door controlled by a gatekeeper to sort hot from cold molecules. When the demon sees a fast/hot molecule racing toward the door, he opens the trap to let the hotter molecule speed into container A. Similarly, if a slow-moving molecule is headed toward container B, the demon would allow it to pass until the two containers are at different temperatures. Assuming that

the demon would have modest demands for his efforts, you would break the cornerstone of physics laws — something for nothing.

The Hilsch Vortex Tube

After an impressive 72-year run, the “Amateur Scientist” column fell victim to a 2001 Scientific American modernization effort. A terrible loss, the “Amateur Scientist” was an inspirational resource that dedicated considerable effort to explaining the hard science behind the projects.

Whether working on “Cloud Chambers to Detect Nuclear Events” (see page 156 for MAKE’s version of the cloud chamber ) or “An Inexpensive X-Ray Machine,” you really felt like you were in the midst

Photography by Mark Frauenfelder and Mister Jalopy

34 Make: Volume 09