Neon is lighter than air but rarely used due to its scarcity. Nonetheless a transparent elastic bladder inflated with neon could be made to glow if it also contained two small drones, one with a cathode, the other with an anode, producing an electrical discharge between them. They could carefully adjust their positions so as to be approximately in the vertical axis, one about a third from the top and the other about a third from the bottom, and gradually recharge themselves from sunlight and movement, which probably wouldn't work but the result is you have a neon light source which could be steered by remote control around the room, for a while anyway. You get them in there in the first place like ships in a bottle - they fold up, you insert them, inflate the balloon and they then unfold themselves and start arcing.
-- nineteenthly, Mar 11 2017

Periodic Video on Geissler tubes https://www.youtube...watch?v=NYvEnAvouVA
[bungston, Mar 12 2017]

Or you could always just put an LED light in them like they have at the dollar store.
-- RayfordSteele, Mar 11 2017


// producing an electrical discharge between them //

They would need to be connected electrically for that to work.

// could be steered by remote control around the room //

Errr, how ? The drones are inside; you would need an additional propulsion system outside.
-- 8th of 7, Mar 11 2017


OK, since I can't decide whether to start on the fact that the neon's buoyancy is defeated by a couple of 10^5 zettaDalton molecules in each balloon, or the fact that the propellers will make short work of the required electrical tether (not to mention the balloon itself), or the goldfish-in-a-ball steering, or the perpetual charging system... I've decided you're trolling and will allow the science officer to virtually assault you around the head and neck with a copy of CRC's "Handbook" of Chemistry & Physics, 62nd edition.

(bad science, but avoids [m-f-d] via multiple passes through the "fails in interesting ways" loophole)
-- lurch, Mar 11 2017


[+] huge inflatable light bulb.

Ignoring the by-one's-bootstraps bit.
-- FlyingToaster, Mar 11 2017


What is needed is a house truss system in the scale, and to replace, the elastic balloon material. Maybe self assembling material research will give us the LTA grail.
-- wjt, Mar 11 2017


I may evoke antigravity at this point, which changes my Halfbakery Geek Code to ep++s++g--B+A+ .
-- nineteenthly, Mar 12 2017


/They would need to be connected electrically/. Is that so? I thought the gas itself served as the electrical conduit. Periodic videos has a fine one on a turn of the century toy made of blown glass with various gases inside; I am pretty sure there are no wires. Neither have I seen wires on my inspection of neon beer signs.

/density/. I understood that to make gases glow with electricity the gas inside the tube must be at less than atmospheric pressure. A balloon will be at atmospheric pressure or a little over. Will it still glow?
-- bungston, Mar 12 2017


The issue there would seem to be a sufficiently strong envelope to withstand the pressure differential. That is doable, or there wouldn't be such things as neon lighting. However, whether it would still be lighter than air is a different matter.

I'm not sure if it would glow. I have some vague idea that colliding atoms/ions would cancel out the excited electrons, but I don't know. However, I will find out.
-- nineteenthly, Mar 12 2017


// /They would need to be connected electrically/. Is that so? //

To complete the circuit.
-- notexactly, Mar 12 2017


There might be a way around the near vacuum to get the neon glow. Think of two balloons one inside the other. make the outer balloon corrugated and rigid, so it frequently stands about a millimneter above the diameter of the inner balloon. The outer balloon is sucked down to near vacuum, with various squiggle lines of near vacuum with glowing neon inside them. That way you could get a neon looking floaty object.

witiricity is a thing that lights up a 60W lamp at 300 feet or 300 meters (do not remember), so if it can do that, a narrow beam of witricity on the double layer baloon should keep it glowing brightly.
-- beanangel, Mar 13 2017


That corrugated balloon scheme is slick, bean.
-- bungston, Mar 13 2017


Yes, that's really neat.

If one of the drones is earthed by coming into contact with the balloon or there's simply a discharge from a single drone onto the surface, that would then neutralise the balloon. In fact, would it be possible to dispense with the drones entirely and simply charge it by rubbing?
-- nineteenthly, Mar 14 2017


/rubbing?/ There has to be current to excite the gas I think. A static charge on a balloon has nowhere to go.
-- bungston, Mar 14 2017


So how about something which generates static electricity within the balloon, such as internal friction? Or, is there a practical way of slowing light in those circumstances which will lead to momentary flashes getting dimmed and extended? Would it be possible to cool the neon to form a Bose-Einstein condensate in a layer near the surface? Then when momentary flashes of light hit that layer, they would slow and leave the balloon gradually.
-- nineteenthly, Mar 14 2017



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