Michel Jullian wrote: > It won't rise but some of the ions will go round or even through the paper so > you'll get some remaining thrust, it's very hard to insulate high voltages.
Well one could also do what Stephen A. Lawrence suggested earlier. Put the lifter inside a box and place the box on a weight scale. > Anyway no one serious in the field still doubts the ion wind hypothesis, for > thousands of reasons, not the least of them being that it has been > experimentally shown that you get no thrust in vacuum. But some people do > entertain the doubt on their websites, deliberately or not. If it is very hard to insulate high voltages as you say above, what makes the vacuum tests so credible? > What convinced me personnally is the fact that experimental thrusts are equal > to what is expected from ion wind theory (the formula I gave earlier on). So > any contribution of other effects is minimal at most. So the math has the last word. > Anyway EHD experiments are great fun and easy to do, so by all means > experiment and form your own opinion. I already have formed an opinion. The outcome of the suggested experiment might change my opinion. > Beware though that high voltages (25kV for a typical computer screen power > supply) at any sizeable current (more than a few mA) can be lethal, and hurt a > lot in the very least (feels a bit like having your arm caught in a meat > chopper I was told). > > Michel I would conduct the test myself, but my current living circumstances make it unfeasible. Harry
