Back in 2002, our Physics teacher introduced me to a student who wanted to build an ionic thruster. I had never heard of one, but I was able to tell the young man where to obtain a high voltage power supply (and give him a long lecture about safety). A few days later he popped by to show me a device constructed of balsa wood, aluminum foil and stainless steel wire that would levitate (it was anchored by its power supply wires) when connected to about 15,000 volts. I was kind of blown away to say the least. That young man is an engineer now and ionic thrusters have continued to be developed by NASA. Here is a further demonstration…

Great series.