They have a lot to learn about gas molecules.

Hmmm, I'm very skeptical. The MIT thing seems to give a good idea on how far the technology really is. Would be strange if a startup suddenly figured out baffling progress.

Rain? I'd guess that even a fog would ground this thing. Also, remember that while quiet propulsion is nice, it doesn't reduce down draft at all. I would love for it to work like they imply, but I'm not buying any stock.

The ions either have to be moving much faster (which means higher voltages and currents) or there have to be a lot more of them, and interacting with a lot more air. I almost wonder whether creating an updraft would be more effective than creating a downdraft.

Even assuming this thing can fly reliably, it almost certainly trades a minor acoustic pollution problem for a major air pollution problem: it's almost certain to generate massive amounts of ozone -- which is great stuff at the top of our atmosphere (as a UV shield), but VERY detrimental to most animals, including humans, at the bottom of the atmosphere.

What in the world does “filming with a potato” mean?

There is one ion propelled aircraft that is independently verified by NPR etc., to carry its power supply without external assistance, it is called the Self Contained Ion Powered (propelled) Aircraft. There are about 2 dozen flight footage videos of it online flying with onboard power. It was patented for carrying its power supply before the MIT ion glider. Everyone is talking online about the MIT glider or Berkeley mini ionocraft. Please spend 1 or 2 minutes googling the much more efficient earlier craft, US Patent 10,119,527.

IBIWISI I'll believe it when I see it.

@DavidB - the term “filming with a potato” is a jab at the low-quality of the video. I'm not sure where it got started though.

If this actually works, then we can create sky cycles and flying cars similar to the Jetsons sky car