This question might involve too much current for an electronic engineering board, but it involves electricity, so I'll ask it anyway.
YouTube videos of the railgun https://www.youtube.com/watch?v=ZL4kbBIf39s show a curious phenomenon; billowing clouds of what appear to be flame emerging from the barrel. Those are understandable from conventional cannon, because there is combustion continuing after the projectile leaves the tube, but railguns don't use combustion.
What's going on? They're far too fractal to be supersonic shock waves. Are they plasma, glowing atmosphric gases that have been heated by compression in front of the projectile, or something else?
As we unveil EE Times’ 2015 Silicon 60 list, journalist & Silicon 60 researcher Peter Clarke hosts a conversation on startups in the electronics industry. Panelists Dan Armbrust (investment firm Silicon Catalyst), Andrew Kau (venture capital firm Walden International), and Stan Boland (successful serial entrepreneur, former CEO of Neul, Icera) join in the live debate.