In the past few days, several readers have submitted word of a paper published on Arxiv allegedly confirming the efficacy of Andrea Rossi's "E-Cat," a device Rossi says transmutes nickel into copper, producing cheap energy in the process. (Mentioned before on Slashdot.) Ethan Siegel of ScienceBlogs takes a skeptical look at the buzz surrounding this paper, and asks some seemingly obvious questions, pointing out various ways in which the cold-fusion / cheap-energy claims could be either confirmed or debunked. First time accepted submitter CdXiminez writes with a capsule of Siegel's points: "What would it take to convince a reasonable observer that you've got a controlled nuclear reaction going on here? Things not shown in the earlier report: Show that nuclear transmutation has in fact taken place; Start the device operating by whatever means you want, then disconnect all external power to it, and allow it to run; Place a gamma-ray detector around the device; Accurately monitor the power drawn from all sources to the device at all times, while also monitoring the energy output from the device at all times."