Flourescent strips, pulsing lights and a chiller cabinet.

May 28, 2004 5:43 AM

A random question involving fluorescent strips, pulsing lights and possibly a chiller cabinet. [MI]

Last night I spent some time watching a chilled cola vending machine. It had a glass front and a pair of strip lights inside the case.

Every now and then I was aware of the noise of a fan running with a pulsing speed at about 2 - 3 Hz. Whenever it happened I was aware of a strange pulsing of light down the tubes. 'Dark' spots of light were being created on each audible pulse and then flowed down the tube to be sucked back in at the other end in perfect syncronisation with the creation.

The pulses of 'light' and 'dark' were apparently the same size and travelled quite slowly. There were probably about 30 bands down a four foot tube. I'd guess that the air inside the vender was in the 2-6 celcius area.

To make things worse, I'm not 100% convinced that the sounds wasn't coming from a coffee vending machine on the opposite side of the room.

What the hell was going on?

posted by twine42 to Home & Garden (9 answers total)

You were tripping on acid.
posted by fletchmuy at 7:53 AM on May 28, 2004

yeah I'm going to have to say acid as well
posted by trbrts at 8:23 AM on May 28, 2004

Yeah, I'm with fletch and trbrts.

A friend of mine once had that happen, except he was looking at the ceiling for half an hour.
posted by bshort at 8:38 AM on May 28, 2004

Response by poster: nope... definitely no drugs involved (I wish) and several other people saw it too...

All together now... "#If you've never seen an elephant ski, then you've never been on acid..."
posted by twine42 at 8:51 AM on May 28, 2004

florescent lights flicker off and on at high speed; they are high frequency pulses, yet your eyes cant' see it. The ballast may be going out. If the coke machine changed to pepsi then your on acid:P
posted by thomcatspike at 10:17 AM on May 28, 2004

There are weird little plasma instabilities that can occur in neon tubes and so I assume they also happen in other kinds of gas-discharge tubes. Maybe the fan (or chiller compressor motor?) was drawing enough current to make the power sag a little and produce some visible effect in the tube? Or maybe it was just the cosmic consciousness making contact with you through the vending machine.
posted by hattifattener at 1:58 PM on May 28, 2004

i'd guess that you're seeing some kind of standing wave that's not quite steady. perhaps the contacts aren't so good in the fan, and it's dumping noise into the supply when it runs (at whatever frequency the fan contacts are making/breaking contact). fluorescent lamps are unstable - the plasma would grow and grow til it goes pop, if they didn't have a ballast that damps the growth. it's possible that somehow the ballast is affected slightly by the noise from the fan motor, which is one way to get some kind of variation with time. but i don't have a full explanation, so this is just bullshit, really.

i don't think you're on drugs - i'm pretty sure i've seen the same thing myself, several times (i never really thought it that odd, perhaps because i've always been surprised these things work so steadily).
posted by andrew cooke at 2:57 PM on May 28, 2004

I'm in favor of the cosmic consciousness hypothesis. You should go and read VALIS immediately.
posted by kaibutsu at 3:44 PM on May 28, 2004

Besides the electrically or RF induced plasma instabilities, sound is also not an unlikely culprit at all, despite all the easily accesible LSD jokes.

See: cymatics.

So, yeah. You're *probably* not actually hallucinating when you think you see a candle flame dancing to the beat of that godforsaken longhaired hippy crap you're listening to while undoubtably having an opium orgy.
posted by loquacious at 4:03 PM on May 28, 2004