flying silently (electrostatics)

Interesting article over on ars about some experimenters who have made a (small) silent aircraft. (I used to live near the big airport, my bedroom window about directly even with the flight path, so quiet sounds really, really good to me.)

The propulsion uses a wire that ionizes the air, combined with a small foil that is negatively charged, to attract the air ions, thus creating enough wind to push the craft forward, using no moving parts. This seems to be the first instance of the theoretical idea finding tech that is good enough to sustain it (principally, a lightweight lithium battery power source).

This was a short flight, but so was the first one by Wilbur and Orville, and look where that led. Perhaps you Jetsons flying car is only a few decades away.

Very interesting. The science fiction reader in me is thinking of several possibilities. Spying/surveillance, for example. Not aircars though. The difficulty with those is other than that flying vehicles are noisy.

Could this be adapted to vertical takeoff vehicles? Someone’s going try, I’m sure.

I wonder how long the ions it creates last. If there are lots of drones in a small area, could they be some kind of hazard? Or if you have a large plane, could they be a hazard to the ground crew? Or damaging to the craft itself over a long period?

At first blush, I wanted to call BS, but after reading and watching the video, it it clear they did achieve proof of concept. Congrats to all involved.

A far as what use this could be, someone asked that at one of the earlier balloon ascents in Paris, in the late 1700s. Ben Franklin (was U.S. ambassador to France ) responded "what good is a newborn babby?

Where is my fucking Jetpack? :mad:

I wonder if electrostatic propulsion will ever scale up enough to be practical. (Of course they said that about airplanes to begin with).

P.S. room-temperature superconductors would help with everything electrical. And I just read about a breakthrough in physics where someone demonstrated something that had been originally thought to be impossible: a “one-way” magnetic field, or the magnetic equivalent of a diode: https://phys.org/news/2018-11-defy-19th-century-law-physics.html

That’s extremely cool. I opened the thread thinking this would be about takeoff from an electrostatic conveyor belt.

Working experimental jet packs have been around since the 1960s, and now you can pay someone to fly one of theirs:

https://www.jetpackaviation.com

Since fight times are in the range of several dozen seconds, you better be more then a minute man if you want a fucking jet pack.

How does this differ from an ionocraft?

Bad AskNott, bad!

Not different, except up until now ionocraft were demonstration devices that only worked above an electrically charged plate, and the flying part had to be hooked to an external power source (could not lift its own battery.)

This plane is (apparently) self contained, carrying its own power, as well as the complete ionizer, cathode & anode.

Also, you have been able to buy non-flying systems like this for a while:

“Bladeless” fans aren’t bladeless, they just have hidden blades. Uh, I mean hidden blades.

I don’t have access to journal subscriptions any more. Can someone follow the link chain in Lumpy’s post to the part where they actually say what they heck they’re talking about? All of the meanings I can think of to attach to the words they’re using are either crackpot crazy impossible, or mundane, well-known, and boring, neither of which would have gotten them a publication in PhysRev.

Is this helpful?
*After several unsuccessful attempts to break magnetic reciprocity, the team decided to try using an electrical conductor in movement. By solving Maxwell’s equations analytically, the researchers very quickly demonstrated that not only could reciprocity be broken down but that, the coupling could be made maximally asymmetric, whereby the coupling from A to B would be different from zero but from B to A it would be exactly zero. Having shown that total unidirectional coupling was possible theoretically, the team designed and built a proof-of-concept experiment which confirmed their findings.

(Romero-isart/Kirchmair): “If the coupling between coils is symmetric, some part of the energy can also flow in the opposite direction which can greatly reduce the efficiency of the transfer. By using a magnetic diode to prevent this backwards flow, the efficiency of the transfer could be greatly enhanced.”*