UV Reactive fog?

[laser]

We did a trial years ago, with cooled smoke into bubble machine, with non toxic UV liquid.
Worked well under UV spot and of course lasers.
Bubble residue everywhere means it gets slippery..

[djlorenz]

mmm, ok.. so it works only with liquid and not with gas...
my idea is KO

[heroic]

mmm, ok.. so it works only with liquid and not with gas...
my idea is KO

Volume of one mole of gas at STP = 22.4 litres
Volume of one mole of water at STP = 18 millilitres

Unfortunately the density really works against you here.

[Stoney3K]

I can see what you're aiming at: Trying to boost the visibility of 405nm?

When you shoot 405 through a scrim washed with detergent (or onto a sheet of white printing paper), the stuff gets UV-reactive and the scrim lights up when the 405 hits it, going up a bit in wavelength. The result on the screen image is more like 473-488, bright and nearer to the cyan.

I wonder if it's even possible to do that in free air or haze. The amount of fluorescence doesn't need to be much (a scrim is also mostly white, or any other colour) but it could just be enough to give that 'edge' to the almost invisible 405nm from Blurays.

[djlorenz]

you read into my head

this is exactly what i was thinking... i found somewhere this thing of fluorescent, and i was thinking ho use this thing with my RGP chinese projector (and maybe for a new RGBV next)

for graphics this thing is nice... if you have a waterscreen or a white screen you will get 405 more bright (and maybe see something more, 405nm is very dark) but in 99% times i use lasers for lasershow...but there's nothing to do

[heroic]

I wonder if it's even possible to do that in free air or haze. The amount of fluorescence doesn't need to be much

The problem is the three orders of magnitude difference in density. Gases are roughly 1000 times less dense than liquids and solids. If a photon has a mean free path of 1mm in a liquid, it will have a mean free path of a metre in air. That's the distance you need to get the same interaction. So your comparatively "dim" fluorescence becomes imperceptibly dim.

Let's take the Tekno Bubbles example. These are UV fluorescent bubbles. I have measured their film thickness by interferometry (use a crossed polarizer and a fast camera); they are about 50 nanometres thick. Therefore it would take 50 millimetres of Tekno Bubbles vapour to have the same chance of a 405 nm photon interacting and fluorescing. This is assuming that you have, say, a dye cell filled with the vapour to the exclusion of air.

Safety issues preclude more than a few tens of ppm of fluorescent material in air that also contains a human being. Even the non-toxic ones would be coating everything in the room at higher concentrations. This means you end up with an even lower density- five or more orders of magnitude lower than in the bubble film.

Since this also means the fluorescence is spread over a much larger volume, and the bubbles are not exactly bright to begin with, the effect is not noticeable in any habitable room.

[djlorenz]

but... thinking in liquid... if i will add fluorscent (like bubbles) juice into water of a waterscreen... i think it works

[tocket]

I think you'd actually get quite a lot of visibly fluorescent particles if you put say diphenylanthracene in your hazer oil. I doubt it would work well with a water based fogger though...

If you try it, do it in a room that you don't have to clean afterwards, cause everything will start glowing blue under UV.

[aijii]

diphenylanthracene doesn't sound like something i'd want to breathe in.

but then i don't know anything about it. it just doesn't sound "nice". kinda like gonorrhea.

[tocket]

People are generally afraid of things with weird chemical names, and most of the time it's unfounded. For example 4,5-Bis(hydroxymethyl)- 2-methylpyridin- 3-ol, might not sound like something that's good for you, but it's the chemical name for one of the B-vitamins.

9,10-diphenylanthracene is, at least according to the material safety data sheet, harmless. However, it also says toxicology not thoroughly investigated, so one should of course not start spewing it out in a nightclub. That'd probably even be illegal.