Plasma-Based Midair Displays
June 28, 2015 3:38 AM Subscribe
Plasma can be any temperature, more or less. HID lamp arcs are really hot, neon tubes are warm, and aurora borealis are cold.
But yeah, at normal atmospheric conditions, plasma is very hot. But I think in this application there isn't much of it. Static discharge can make a bright spark on your finger, but you don't get burned by it.
posted by ryanrs at 4:16 AM on June 28, 2015
But yeah, at normal atmospheric conditions, plasma is very hot. But I think in this application there isn't much of it. Static discharge can make a bright spark on your finger, but you don't get burned by it.
posted by ryanrs at 4:16 AM on June 28, 2015
Femto- vs nano- means the amount of energy the laser dumps into your finger is ~3 orders of magnitude less. Damn, this is awesome. Actual holographic displays! They just need to get a couple of hundred times bigger.
posted by topynate at 4:48 AM on June 28, 2015 [1 favorite]
posted by topynate at 4:48 AM on June 28, 2015 [1 favorite]
A giant holographic rabbit is, of course, priority one once the scaling problem is solved.
posted by rongorongo at 5:14 AM on June 28, 2015 [14 favorites]
posted by rongorongo at 5:14 AM on June 28, 2015 [14 favorites]
Does making things bigger entail making things hotter?
posted by eustatic at 5:14 AM on June 28, 2015
posted by eustatic at 5:14 AM on June 28, 2015
Logging in after an extended absence to mention that there are multiple links in this slyt.
posted by _aa_ at 5:42 AM on June 28, 2015
posted by _aa_ at 5:42 AM on June 28, 2015
It'll be a whole lot better once they solve the problem of it sounding like an endlessly playing loop of overly-tasteful piano.
But yeah, this is definitely something that we need while we're waiting for our jetpacks. Colour's going to be difficult, though.
posted by Devonian at 5:46 AM on June 28, 2015 [3 favorites]
But yeah, this is definitely something that we need while we're waiting for our jetpacks. Colour's going to be difficult, though.
posted by Devonian at 5:46 AM on June 28, 2015 [3 favorites]
So, uh, hypothetically, if they scale it up you could make it display like a person? Like someone from the movies, maybe Carrie Fisher in a white robe? Except instead of Obi Wan she'd be saying something like "Joe in Australia, you are my only hope"? That would be doable, wouldn't it? Because I could definitely see a market for that sort of thing.
posted by Joe in Australia at 5:59 AM on June 28, 2015 [14 favorites]
posted by Joe in Australia at 5:59 AM on June 28, 2015 [14 favorites]
Oh good; Though everything else was straightforwardly plausible, the free-floating holograms in Jurassic World were in danger of trying my willing suspension of disbelief.
posted by Captain l'escalier at 6:05 AM on June 28, 2015 [2 favorites]
posted by Captain l'escalier at 6:05 AM on June 28, 2015 [2 favorites]
I'm a little disappointed that with all of Japan's sprites, imps, gods, spirits, they chose to embody (so to speak) Disney's Tinkerbell fairy. But, as Tom says, we live in a flat world (except for these touchy-feely holographs, of course). Plus, I totally understand the science, so when I build my laser machine, I'm not going to burn my finger with that ouchy pink light they warned me about in the video.
posted by kozad at 6:09 AM on June 28, 2015
posted by kozad at 6:09 AM on June 28, 2015
But yeah, at normal atmospheric conditions, plasma is very hot. But I think in this application there isn't much of it. Static discharge can make a bright spark on your finger, but you don't get burned by it.
Static discharges are in fact incredibly hot, temperaturewise, which is why they're bad when you're, say, filling a gas tank. Air just doesn't have a large heat capacity and a narrow spark doesn't have a lot of volume, so there isn't a ton of thermal energy there.
Now it's true that plasmas can be created at low temperatures. Plasma is a gas where most all of your atoms have been ionized so that you've got electrons and ionized atoms flowing about. Usually this is from heating things enough that collisions are knocking electrons off of atoms faster than they can stick back together. However, someplace like outer space you can have a low temperature plasma. Since the density is so low, high energy photons zooming around can knock electrons off faster than they can run back into ions.
I can't off the top of my head tell whether you can use a laser to photoionize air faster than collisions neutralize things, but my guess is even if the temperature is high in a small region, it's small enough and low density enough that heat doesn't get transferred fast enough to hurt the guy sticking his finger in there.
The real concern tends to be the lasers - any laser hot enough to burn you is more than enough to blind you.
posted by Zalzidrax at 6:35 AM on June 28, 2015 [2 favorites]
Static discharges are in fact incredibly hot, temperaturewise, which is why they're bad when you're, say, filling a gas tank. Air just doesn't have a large heat capacity and a narrow spark doesn't have a lot of volume, so there isn't a ton of thermal energy there.
Now it's true that plasmas can be created at low temperatures. Plasma is a gas where most all of your atoms have been ionized so that you've got electrons and ionized atoms flowing about. Usually this is from heating things enough that collisions are knocking electrons off of atoms faster than they can stick back together. However, someplace like outer space you can have a low temperature plasma. Since the density is so low, high energy photons zooming around can knock electrons off faster than they can run back into ions.
I can't off the top of my head tell whether you can use a laser to photoionize air faster than collisions neutralize things, but my guess is even if the temperature is high in a small region, it's small enough and low density enough that heat doesn't get transferred fast enough to hurt the guy sticking his finger in there.
The real concern tends to be the lasers - any laser hot enough to burn you is more than enough to blind you.
posted by Zalzidrax at 6:35 AM on June 28, 2015 [2 favorites]
Since the light spectrum of the plasma isn't tied to the frequency of the laser, perhaps you could have a laser that operates at a frequency at which the eye's optical system is opaque. Although I suppose that would just lead tot he energy being dumped at the front of the eye, not the back... in any case, wouldn't the volumetric energy of the laser be so low away from the focal point at which ionisation occurs that you'd be safe from specular reflections?
As for Tinkerbell: you have to be a little careful with Japan's menagerie of animism. I was researching that one time while working on an SF story, and asked a question in soc.culture.japan looking for further resources. I got a very long and impassioned reply from a maths professor at a Japanese university saying, in essence, that this sort of thing lay behind those aspects of Japanese culture which enabled the extreme nationalism and militarism that nearly destroyed the nation. He was very clear on the need, as he saw it, to extirpate such ideas and not to play with them in any way.
Obviously, not everyone in Japan feels that way. But there may be reasons these researchers decided to stick to Tinkerbell. Or maybe it's just that Disney is universal, like broken hearts and tick boxes.
posted by Devonian at 6:53 AM on June 28, 2015 [1 favorite]
As for Tinkerbell: you have to be a little careful with Japan's menagerie of animism. I was researching that one time while working on an SF story, and asked a question in soc.culture.japan looking for further resources. I got a very long and impassioned reply from a maths professor at a Japanese university saying, in essence, that this sort of thing lay behind those aspects of Japanese culture which enabled the extreme nationalism and militarism that nearly destroyed the nation. He was very clear on the need, as he saw it, to extirpate such ideas and not to play with them in any way.
Obviously, not everyone in Japan feels that way. But there may be reasons these researchers decided to stick to Tinkerbell. Or maybe it's just that Disney is universal, like broken hearts and tick boxes.
posted by Devonian at 6:53 AM on June 28, 2015 [1 favorite]
It'll be a whole lot better once they solve the problem of it sounding like an endlessly playing loop of overly-tasteful trite piano.
FTFY.
posted by Greg_Ace at 8:01 AM on June 28, 2015 [1 favorite]
FTFY.
posted by Greg_Ace at 8:01 AM on June 28, 2015 [1 favorite]
Confirm your purchase by touching your finger to the tiny hovering flash of light. This will be a thing.
posted by klausman at 8:01 AM on June 28, 2015 [1 favorite]
posted by klausman at 8:01 AM on June 28, 2015 [1 favorite]
I've always dreamed of the day when I could go to the Grateful Dead shows, see shit floating around in the air, and not to have needed a hit of acid.
Sadly, that day won't ever come, but this is still fucking cool.
posted by mikelieman at 8:08 AM on June 28, 2015
Sadly, that day won't ever come, but this is still fucking cool.
posted by mikelieman at 8:08 AM on June 28, 2015
I'm a little disappointed that with all of Japan's sprites, imps, gods, spirits, they chose to embody (so to speak) Disney's Tinkerbell fairy
To be fair, half of those things want to drown you in a rice paddy, or steal your face, or sell you an eboshi of dubious provenance and slightly outdated style.
posted by TheWhiteSkull at 8:18 AM on June 28, 2015 [3 favorites]
To be fair, half of those things want to drown you in a rice paddy, or steal your face, or sell you an eboshi of dubious provenance and slightly outdated style.
posted by TheWhiteSkull at 8:18 AM on June 28, 2015 [3 favorites]
Very cool. I (sort-of) understand how you can focus a femtosecond-pulsed laser to generate a plasma effect wherever you want within a given 3-dimensional field. But I don't understand how they can design the system such that the pattern changes with touch (i.e. unchecked box -> checked box, heart -> broken heart). How does the 'haptic feedback' mechanism work? It looked like you wear a wrist device that detected the touch.
Also, I'm not sure that this is scalable. There is going to be a limited range in which you can focus the photons.
posted by kisch mokusch at 8:43 AM on June 28, 2015 [1 favorite]
Also, I'm not sure that this is scalable. There is going to be a limited range in which you can focus the photons.
posted by kisch mokusch at 8:43 AM on June 28, 2015 [1 favorite]
"Of course Santa Claus is real! He's right there! Go give him a big hug."
*FLOP* *CRASH*
"Ha-ha!"
posted by sexyrobot at 8:45 AM on June 28, 2015
*FLOP* *CRASH*
"Ha-ha!"
posted by sexyrobot at 8:45 AM on June 28, 2015
Can somebody call Science, and talk to them about background music?
posted by TheCoug at 10:13 AM on June 28, 2015
posted by TheCoug at 10:13 AM on June 28, 2015
Colour's going to be difficult, though.
Nintendo Virtual Boii 2.0!
posted by a lungful of dragon at 10:50 AM on June 28, 2015
Nintendo Virtual Boii 2.0!
posted by a lungful of dragon at 10:50 AM on June 28, 2015
I'm a little disappointed that with all of Japan's sprites, imps, gods, spirits, they chose to embody (so to speak) Disney's Tinkerbell fairy.
I don't know, it could just be the strategic courting of a potential investor. I could easily see Disney investing several millions of dollars into a system that allowed actual Tinkerbell to actually fly through the crowds at Disneyland before the fireworks show.
posted by LEGO Damashii at 12:58 PM on June 28, 2015
I don't know, it could just be the strategic courting of a potential investor. I could easily see Disney investing several millions of dollars into a system that allowed actual Tinkerbell to actually fly through the crowds at Disneyland before the fireworks show.
posted by LEGO Damashii at 12:58 PM on June 28, 2015
One of the comments below the video quotes something from an article about how the touch-activation works:
"Our system has the unique characteristic that the plasma is touchable. It was found that the contact between plasma and a finger causes a brighter light. This effect can be used as a cue of the contact. One possible control is touch interaction in which floating images change when touched by a user"
Article from +IEEE Spectrum
posted by OnceUponATime at 1:25 PM on June 28, 2015 [4 favorites]
"Our system has the unique characteristic that the plasma is touchable. It was found that the contact between plasma and a finger causes a brighter light. This effect can be used as a cue of the contact. One possible control is touch interaction in which floating images change when touched by a user"
Article from +IEEE Spectrum
posted by OnceUponATime at 1:25 PM on June 28, 2015 [4 favorites]
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posted by leotrotsky at 3:59 AM on June 28, 2015