14 ms·

Study produces 3D images that float

160 points by snr 9y ago

andars 9y ago
I've seen this in operation and am acquainted with the researchers. I may be able to attempt to answer some questions about it.
- iliis 9y ago
  Awesome achievement! This really looks like a viable way of true floating 3D-images. Can you levitate multiple particles at the same time? How fast are they moving? How sensitivie is it to disturbances in the air?
  - snr 9y ago
    I'm guessing it's very sensitive to air flow since the photon "shells" are literally trapping the particles.
  - andars 9y ago
    > Can you levitate multiple particles at the same time? Yes, but their device currently is only capable of levitating a single particle. With the current approach, the device would need one laser for confining each particle. The lasers used for RGB could potentially be multiplexed between particles, but this is less likely to work for the confinement due to the instability of the trap. > How fast are they moving? Pretty slow. All the "big" images (Leia, grad student, etc) are long-exposure. You can see the particle moving in real-time at about 0:50. In the videos, you can see the device can almost do real-time persistence of vision for volumes substantially smaller than a fingertip. > How sensitive is it to disturbances in the air? As I mentioned above, the confinement is weak and the trap is pretty unstable. Its possible that they have improved the longevity of the trap in the last few months, but when doing long-exposure the device is surrounded by a heavy cloth barrier to block both external light and air movement.
- snr 9y ago
  How does this compare with the plasma dots approach? https://www.popsci.com/secret-interactive-holograms-plasma-and-femtosecond-laser https://www.popsci.com/secret-interactive-holograms-plasma-a... (Thanks @iliis for posting about this research)
  - andars 9y ago
    I'm not very familiar with the plasma dots approach, but from a cursory look it appears that it is not capable of RGB. On the other hand, there is nothing that can fall out of confinement so the display is probably more stable. That page says the femtosecond plasma display is pretty safe. This display was - and I believe still is, though I could be wrong - using a UV laser for confinement, which is sorta scary.
- starpilot 9y ago
  Where does the cellulose come from? Is it just ambient particles or are they emitted from the machine? Where does it go?
  - andars 9y ago
    The cellulose comes from the black liquor on a spoon (see 0:46 in the video). The put the spoon at the focus of the laser and with luck some particles get confined. After the trap is lost, the particle just sort of drifts away in the air, since they are only tens of microns.
- panic 9y ago
  Cool stuff! I'm curious what limitations there are on how fast the particle can move. Is it theoretically possible to move a single particle fast enough to render complex shapes in real time, or will you need many particles for that?
- klintcho 9y ago
  Would it be possible to suspend these kinds of particles using a standing wave of ultrasound ? Perhaps something similar to https://www.researchgate.net/publication/265401333_Cell_and_Particle_Manipulation_in_an_ultrasound_standing_wave_trap https://www.researchgate.net/publication/265401333_Cell_and_... and then project the laser on them.
  - andars 9y ago
    Sorry, I'm not qualified to give a good answer. I would guess that the relatively long wavelength of ultrasound could potentially cause resolution issues.
    - kakarot 9y ago
      Not only resolution issues, but accuracy issues as well. I doubt ultrasound can provide the same fidelity as a highly-tuned laser high-frequency laser beam when it comes to keeping something in one place.
      - klintcho 9y ago
        Thanks for both your answers. Though I was also thinking perhaps you could just suspend the particles in mid-air, and use the movable prism in a laser projector to actually "render" the projection (thus not needing to move them at at a high frame rate or at all). However I guess, you probably do need to move the particles as well to be able to make it a 3D volumetric shape in space (seen from all angles etc).
- marshray 9y ago
  How powerful are the lasers? What kind of safety equipment is required to view it?
didgeoridoo 9y ago
"The future won't be the future without a Princess Leia projector". Love.
rprenger 9y ago
Kind of funny title given that the speaker says several times in video that it's NOT a hologram
- IntronExon 9y ago
  First things, first, Smalley says. The image of Princess Leia is not what people think it is: It’s not a hologram. Oh well.
- andars 9y ago
  Nonetheless, everybody calls the displays in Star Wars "holograms". Smalley notes this, and the title is using the word in this colloquial sense. There is an unfortunate disconnect between the technical and colloquial meanings of "hologram".
iliis 9y ago
Another method is to use a high-powered pulsed laser to create little balls of plasma in mid-air: https://www.popsci.com/secret-interactive-holograms-plasma-and-femtosecond-laser https://www.popsci.com/secret-interactive-holograms-plasma-a...
- snr 9y ago
  Wow, the plasma-balls one's from 2015!
DrScump 9y ago
https://news.ycombinator.com/item?id=16225854 https://news.ycombinator.com/item?id=16225854 47+ points Actual title of this submit was "Better than a hologram: BYU study produces 3D images that float in 'thin air'"
nanistheonlyist 9y ago
It looks like you can only get a cubic centimeter or so of image volume. Might be limited by how fast they can move the dust mote through the air.
debt 9y ago
Great another medium from which failed reality stars can convince an increasingly stupid public to vote for. Edit: This is funny, no one was a sense of humor. Just imagine Donald Trump's holographic head spinning slowly while he gives the state of the union. That's the future.
- icelancer 9y ago
  >This is funny You aren't the arbiter of your own jokes, as evidenced.
  - debt 9y ago
    I guess there's a wider discussion about why need more and better display technology without a noticeable improvement in quality of life, but idk.
    - dragonwriter 9y ago
      Practical volumetric display could improve lots of fields, including medicine. (Admittedly, VR/AR gets you most of the benefits of that, but its also clumsier.)
- dragonwriter 9y ago
  > Edit: This is funny Perhaps (I disagree, but its subjective), but also ungrammatical and substance free. The latter is probably what HN doesn't like. This isn't Slashdot, and +1 Funny isn't, in general, a thing.
- dang 9y ago
  Please don't post unsubstantive comments or add political flamebait into HN threads. https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html Edit: you've posted a ton of unsubstantive comments and we've asked you before to stop, so would you please stop? We're hoping for higher discussion quality here.
  - 9y ago
dragonwriter 9y ago
I feel like I've seen reports of research demonstration with near future commercial possibility in this field every couple years since sometime in the mid-1990s.
- TaylorAlexander 9y ago
  That’s the reporting. Ideally researchers should just say “we did this.” But then they need continued funding so they like to say “we did this and we believe with more research the commercial possibilities are promising.” And then reporters hear this all and say “the Star Wars display is here now, and soon you’ll have Princess Leia in your living room.” Honestly I feel like the best solution is just to train everyone critical thinking skills but I guess in practice that doesn’t seem to happen.
  - stuntkite 9y ago
    There are lots of ways to make star wars holograms that are much more accessible than this. With our new depth sensors and some other really stupid tricks you can achieve that. There's a reason Apple is hiring like crazy for AR designers. We are pretty closer to in that future. If you're looking for the bleeding edge of what's here now, RED[1] the camera company is putting out a hologram cell phone probably like next month I guess with a hologram display from a company literally called leia[2]. [1]https://www.theverge.com/circuitbreaker/2017/9/8/16272838/red-hydrogen-one-holographic-display-leia https://www.theverge.com/circuitbreaker/2017/9/8/16272838/re... [2]http://www.leiadisplay.com/ http://www.leiadisplay.com/
    - thomastjeffery 9y ago
      From the FAQ: > Is LEIA a hologram? > Leia makes it possible to project an image in the air – an image through which you can put your hand or walk but it's not a 3D projection. The image is flat and thus does not meet the criteria of the hologram definition. So what is it?
      - stuntkite 9y ago
icelancer 9y ago
HN title: "Holograms are here" Actual title: "Better than a hologram: BYU study produces 3D images that float in 'thin air'" Article text: "First things, first, Smalley says. The image of Princess Leia is not what people think it is: It’s not a hologram." Can we not editorialize and/or get the titles completely wrong?
- dang 9y ago
  Yes, that title broke the HN guidelines: https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html. We've replaced it with the article title, or rather a less baity substring of it.
- snr 9y ago
  It's actually a hologram - which is by definition a 3D image. I contend that my original title is appropriate. Holograms ARE volumetric displays. I can see why the researcher wouldn't want to call it that - claim you invented something better than science fiction = instant media coverage. hol·o·gram noun A three-dimensional image formed by the interference of light beams from a laser or other coherent light source.
  - maho 9y ago
    As indicated by your definition, the 3d-effect of a hologram arises from interference of a coherent light source. In the display that is shown in the video, the 3d-effect arises from light-emission (scattering) of a point source that moves around. The light from the point source need not be coherent for this display to work! Therefore, the term "hologram" seems inappropriate. I have never seen a hologram that is also a volumetric display. To me, this would be the holy grail of hologramming, since you could use interference for occlusion effects.
  - BackPropagate 9y ago
    No it’s not.
foxfired 9y ago
For now, they created a single pixel by trapping one particle (not sure what it's made of) and beaming different colors on it. Depending on when they managed to trap two particles, we can start applying Moore's law and double it every so often.
- misnamed 9y ago
  That was the most remarkable thing to me - that's just one pixel moving around. Imagine if we had two, or four, or eight? Pretty quickly we get amazing and complex results.
- shawnz 9y ago
  It sounds to me like they move the particle around and use persistence of vision to make an image.
  - valine 9y ago
    Kind of like CTR displays but in 3D.
earenndil 9y ago
> Humans cannot discern images at rates faster than 10 per second If the PCMR folks already hate everyone saying the human eye sees at 25FPS, imagine how they'd react to that!
- gpm 9y ago
  I have to admit my first reaction to that was "and yet 60fps is apparently too slow for VR". But I think they might have been talking about how long the trail would persist for in our vision, making it appear as one object when it goes in circles. Not how quickly you can flash images in front of us before we won't be able to see them. I'm not sure if it's true in that case.
  - Mithaldu 9y ago
    VR is not about image perception, but image reaction. The important part is how long it takes from you providing input to the input reaction being perceived by you. The latency between that. And given a sufficiently huge sample size (interacting with VR is many minutes of nothing but samples) a human can very easily discern this latency.
DoofusOfDeath 9y ago
I find it interesting that people with such a large variety of world views (Mormons, Christians, Muslims, Buddhists, atheists, etc.) can all produce groundbreaking advances in science, math, and engineering. Pick any two of those aforementioned groups, and you'll find plenty of members from one who consider the other's members to have unfathomably bad reasoning and common-sense skills. And yet, somehow, some members of all those groups bear wonderful intellectual fruit.
- pasta 9y ago
  Maybe because most questions about life are 'why?' questions and not 'how?' questions.
  - brownbat 9y ago
    Minus, say, "how did we get here" or "how should we behave?" Or another way to look at it, we could reduce almost all questions, in science or religion, to something like "what is the nature of this stuff around me?" A subpart, "how can I interact with the stuff?" A subpart of that question, in turn, is "what are the consequences of those interactions?" Sometimes the stuff around you is carbon. You can burn it or build things with it. If you breathe enough of it in certain forms, you might suffocate. Sometimes the stuff around you is other people. You can help them or hurt them in a near endless variety of ways. The consequences are complex but it's generally better to not be a dick, for a variety of reasons. Maybe the stuff around you is... all of reality? Which may or may not be controlled by a unimaginably powerful law giver. Maybe not, but if so, that would certainly affect the consequences of a lot of actions, so it would be worth trying to work out how that system worked if that was the deal. To be clear, I'm not arguing for Pascal's wager here, I'm just needling the idea of non overlapping magisteria. Isn't it all just, "How does reality work?"
    - Cogito 9y ago
      I hadn't heard of non overlapping magisteria (NOMA) before. My immediate thought was that if you assume the 'teaching domains' of science and religion do not overlap at all, then the domain of religion is vanishingly small. If you accept that science covers (at least) all observable things, and also hold the idea of NOMA, then religion must never deal with anything observable. The teaching domain of the unobservable seems like it would be near non-existent. Alternately, let's start from the position that a supernatural power exists and cares about what we do. Why would we be interested in that? We would be interested if that supernatural power has the ability to affect our lives/the world we live in, or will affect our lives after we die/some other aspect of some supernatural world beyond this one. If the power can affect this world, we should be able to observe that interaction. If it is literally impossible to measure any effect, it is the same as if the power is not interacting with the world at all. Which is to say, if the power interacts with the world, then those interactions fall under the domain of science. If the power does not interact with the world, then we can only be interested in what effect our actions, choices, and beliefs will have outside this world, on the supernatural or afterlife. The thing is, we have no way of knowing what that would be, because communicating any of that information to us would count as interacting with the world. Thus, anyone claiming that something should or shouldn't be believed or done, for religious reasons, is either making a testable claim or claiming something which has no reason to be believed. If the magesteria of science and religion truly are non overlapping, it seems that religion's must necessarily be very very small.
radarsat1 9y ago
This is really clever, from a design perspective. I mean, projecting onto a moving particle is a really innovative idea. But scientifically, what I find the most surprising, is that a laser trap can move a particle around at sufficient speeds, outside a vacuum, without losing it. Impressive! I had no idea that was possible. Anyone know what speed or frequency of movement it can achieve?
- aw3c2 9y ago
  Judging from my experience with other well-polished PR pieces from universities, I would expect only the "oscillating above the finger tips" parts to be real time. The more advanced examples were only shown statically and thus were probably like long-shutter images.
  - deleted 9y ago
    [deleted]
- GistNoesis 9y ago
  Projecting on a moving particle isn't quite new. A quick search reveal that there have been projections on falling water droplets since at least 2010. There are also plenty of stroboscopic experiments on water drops which make them fall upwards. I think having a controllable particle is a nice-feat but probably is overkill for 3D displays, you only need to know where the particles are so you can use them as a screen. Although the 2010 paper project on layers of waterfalls, it's easy to imagine a 2d water droplet grid where you watch the droplets form and drop with a hi-speed camera and with a video projector you then project the right pixel at the right time so that light ray intersect water droplet. You can even try this today at home with a shower jet and a pico projector, and see beautiful clouds of red green blue rays. It's probably a fun engineering project to get the right combination of liquid properties, size of droplets, frequencies, video bandwidth to obtain stunning results.

160 points by snr 9y ago

I've seen this in operation and am acquainted with the researchers. I may be able to attempt to answer some questions about it.

iliis 9y ago
Awesome achievement! This really looks like a viable way of true floating 3D-images. Can you levitate multiple particles at the same time? How fast are they moving? How sensitivie is it to disturbances in the air?
- snr 9y ago
  I'm guessing it's very sensitive to air flow since the photon "shells" are literally trapping the particles.
- andars 9y ago
  > Can you levitate multiple particles at the same time? Yes, but their device currently is only capable of levitating a single particle. With the current approach, the device would need one laser for confining each particle. The lasers used for RGB could potentially be multiplexed between particles, but this is less likely to work for the confinement due to the instability of the trap. > How fast are they moving? Pretty slow. All the "big" images (Leia, grad student, etc) are long-exposure. You can see the particle moving in real-time at about 0:50. In the videos, you can see the device can almost do real-time persistence of vision for volumes substantially smaller than a fingertip. > How sensitive is it to disturbances in the air? As I mentioned above, the confinement is weak and the trap is pretty unstable. Its possible that they have improved the longevity of the trap in the last few months, but when doing long-exposure the device is surrounded by a heavy cloth barrier to block both external light and air movement.
snr 9y ago
How does this compare with the plasma dots approach? https://www.popsci.com/secret-interactive-holograms-plasma-and-femtosecond-laser https://www.popsci.com/secret-interactive-holograms-plasma-a... (Thanks @iliis for posting about this research)
- andars 9y ago
  I'm not very familiar with the plasma dots approach, but from a cursory look it appears that it is not capable of RGB. On the other hand, there is nothing that can fall out of confinement so the display is probably more stable. That page says the femtosecond plasma display is pretty safe. This display was - and I believe still is, though I could be wrong - using a UV laser for confinement, which is sorta scary.
starpilot 9y ago
Where does the cellulose come from? Is it just ambient particles or are they emitted from the machine? Where does it go?
- andars 9y ago
  The cellulose comes from the black liquor on a spoon (see 0:46 in the video). The put the spoon at the focus of the laser and with luck some particles get confined. After the trap is lost, the particle just sort of drifts away in the air, since they are only tens of microns.
panic 9y ago
Cool stuff! I'm curious what limitations there are on how fast the particle can move. Is it theoretically possible to move a single particle fast enough to render complex shapes in real time, or will you need many particles for that?
klintcho 9y ago
Would it be possible to suspend these kinds of particles using a standing wave of ultrasound ? Perhaps something similar to https://www.researchgate.net/publication/265401333_Cell_and_Particle_Manipulation_in_an_ultrasound_standing_wave_trap https://www.researchgate.net/publication/265401333_Cell_and_... and then project the laser on them.
- andars 9y ago
  Sorry, I'm not qualified to give a good answer. I would guess that the relatively long wavelength of ultrasound could potentially cause resolution issues.
  - kakarot 9y ago
    Not only resolution issues, but accuracy issues as well. I doubt ultrasound can provide the same fidelity as a highly-tuned laser high-frequency laser beam when it comes to keeping something in one place.
    - klintcho 9y ago
      Thanks for both your answers. Though I was also thinking perhaps you could just suspend the particles in mid-air, and use the movable prism in a laser projector to actually "render" the projection (thus not needing to move them at at a high frame rate or at all). However I guess, you probably do need to move the particles as well to be able to make it a 3D volumetric shape in space (seen from all angles etc).
marshray 9y ago
How powerful are the lasers? What kind of safety equipment is required to view it?

didgeoridoo 9y ago

"The future won't be the future without a Princess Leia projector". Love.

rprenger 9y ago

Kind of funny title given that the speaker says several times in video that it's NOT a hologram

IntronExon 9y ago
First things, first, Smalley says. The image of Princess Leia is not what people think it is: It’s not a hologram. Oh well.
andars 9y ago
Nonetheless, everybody calls the displays in Star Wars "holograms". Smalley notes this, and the title is using the word in this colloquial sense. There is an unfortunate disconnect between the technical and colloquial meanings of "hologram".

iliis 9y ago

Another method is to use a high-powered pulsed laser to create little balls of plasma in mid-air: https://www.popsci.com/secret-interactive-holograms-plasma-and-femtosecond-laser https://www.popsci.com/secret-interactive-holograms-plasma-a...

snr 9y ago
Wow, the plasma-balls one's from 2015!

DrScump 9y ago

https://news.ycombinator.com/item?id=16225854 https://news.ycombinator.com/item?id=16225854 47+ points Actual title of this submit was "Better than a hologram: BYU study produces 3D images that float in 'thin air'"

nanistheonlyist 9y ago

It looks like you can only get a cubic centimeter or so of image volume. Might be limited by how fast they can move the dust mote through the air.

debt 9y ago

Great another medium from which failed reality stars can convince an increasingly stupid public to vote for. Edit: This is funny, no one was a sense of humor. Just imagine Donald Trump's holographic head spinning slowly while he gives the state of the union. That's the future.

icelancer 9y ago
>This is funny You aren't the arbiter of your own jokes, as evidenced.
- debt 9y ago
  I guess there's a wider discussion about why need more and better display technology without a noticeable improvement in quality of life, but idk.
  - dragonwriter 9y ago
    Practical volumetric display could improve lots of fields, including medicine. (Admittedly, VR/AR gets you most of the benefits of that, but its also clumsier.)
dragonwriter 9y ago
> Edit: This is funny Perhaps (I disagree, but its subjective), but also ungrammatical and substance free. The latter is probably what HN doesn't like. This isn't Slashdot, and +1 Funny isn't, in general, a thing.
dang 9y ago
Please don't post unsubstantive comments or add political flamebait into HN threads. https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html Edit: you've posted a ton of unsubstantive comments and we've asked you before to stop, so would you please stop? We're hoping for higher discussion quality here.
- 9y ago

dragonwriter 9y ago

I feel like I've seen reports of research demonstration with near future commercial possibility in this field every couple years since sometime in the mid-1990s.

TaylorAlexander 9y ago
That’s the reporting. Ideally researchers should just say “we did this.” But then they need continued funding so they like to say “we did this and we believe with more research the commercial possibilities are promising.” And then reporters hear this all and say “the Star Wars display is here now, and soon you’ll have Princess Leia in your living room.” Honestly I feel like the best solution is just to train everyone critical thinking skills but I guess in practice that doesn’t seem to happen.
- stuntkite 9y ago
  There are lots of ways to make star wars holograms that are much more accessible than this. With our new depth sensors and some other really stupid tricks you can achieve that. There's a reason Apple is hiring like crazy for AR designers. We are pretty closer to in that future. If you're looking for the bleeding edge of what's here now, RED[1] the camera company is putting out a hologram cell phone probably like next month I guess with a hologram display from a company literally called leia[2]. [1]https://www.theverge.com/circuitbreaker/2017/9/8/16272838/red-hydrogen-one-holographic-display-leia https://www.theverge.com/circuitbreaker/2017/9/8/16272838/re... [2]http://www.leiadisplay.com/ http://www.leiadisplay.com/
  - thomastjeffery 9y ago
    From the FAQ: > Is LEIA a hologram? > Leia makes it possible to project an image in the air – an image through which you can put your hand or walk but it's not a 3D projection. The image is flat and thus does not meet the criteria of the hologram definition. So what is it?
    - stuntkite 9y ago

icelancer 9y ago

HN title: "Holograms are here" Actual title: "Better than a hologram: BYU study produces 3D images that float in 'thin air'" Article text: "First things, first, Smalley says. The image of Princess Leia is not what people think it is: It’s not a hologram." Can we not editorialize and/or get the titles completely wrong?

dang 9y ago
Yes, that title broke the HN guidelines: https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html. We've replaced it with the article title, or rather a less baity substring of it.
snr 9y ago
It's actually a hologram - which is by definition a 3D image. I contend that my original title is appropriate. Holograms ARE volumetric displays. I can see why the researcher wouldn't want to call it that - claim you invented something better than science fiction = instant media coverage. hol·o·gram noun A three-dimensional image formed by the interference of light beams from a laser or other coherent light source.
- maho 9y ago
  As indicated by your definition, the 3d-effect of a hologram arises from interference of a coherent light source. In the display that is shown in the video, the 3d-effect arises from light-emission (scattering) of a point source that moves around. The light from the point source need not be coherent for this display to work! Therefore, the term "hologram" seems inappropriate. I have never seen a hologram that is also a volumetric display. To me, this would be the holy grail of hologramming, since you could use interference for occlusion effects.
- BackPropagate 9y ago
  No it’s not.

foxfired 9y ago

For now, they created a single pixel by trapping one particle (not sure what it's made of) and beaming different colors on it. Depending on when they managed to trap two particles, we can start applying Moore's law and double it every so often.

misnamed 9y ago
That was the most remarkable thing to me - that's just one pixel moving around. Imagine if we had two, or four, or eight? Pretty quickly we get amazing and complex results.
shawnz 9y ago
It sounds to me like they move the particle around and use persistence of vision to make an image.
- valine 9y ago
  Kind of like CTR displays but in 3D.

earenndil 9y ago

> Humans cannot discern images at rates faster than 10 per second If the PCMR folks already hate everyone saying the human eye sees at 25FPS, imagine how they'd react to that!

gpm 9y ago
I have to admit my first reaction to that was "and yet 60fps is apparently too slow for VR". But I think they might have been talking about how long the trail would persist for in our vision, making it appear as one object when it goes in circles. Not how quickly you can flash images in front of us before we won't be able to see them. I'm not sure if it's true in that case.
- Mithaldu 9y ago
  VR is not about image perception, but image reaction. The important part is how long it takes from you providing input to the input reaction being perceived by you. The latency between that. And given a sufficiently huge sample size (interacting with VR is many minutes of nothing but samples) a human can very easily discern this latency.

DoofusOfDeath 9y ago

I find it interesting that people with such a large variety of world views (Mormons, Christians, Muslims, Buddhists, atheists, etc.) can all produce groundbreaking advances in science, math, and engineering. Pick any two of those aforementioned groups, and you'll find plenty of members from one who consider the other's members to have unfathomably bad reasoning and common-sense skills. And yet, somehow, some members of all those groups bear wonderful intellectual fruit.

pasta 9y ago
Maybe because most questions about life are 'why?' questions and not 'how?' questions.
- brownbat 9y ago
  Minus, say, "how did we get here" or "how should we behave?" Or another way to look at it, we could reduce almost all questions, in science or religion, to something like "what is the nature of this stuff around me?" A subpart, "how can I interact with the stuff?" A subpart of that question, in turn, is "what are the consequences of those interactions?" Sometimes the stuff around you is carbon. You can burn it or build things with it. If you breathe enough of it in certain forms, you might suffocate. Sometimes the stuff around you is other people. You can help them or hurt them in a near endless variety of ways. The consequences are complex but it's generally better to not be a dick, for a variety of reasons. Maybe the stuff around you is... all of reality? Which may or may not be controlled by a unimaginably powerful law giver. Maybe not, but if so, that would certainly affect the consequences of a lot of actions, so it would be worth trying to work out how that system worked if that was the deal. To be clear, I'm not arguing for Pascal's wager here, I'm just needling the idea of non overlapping magisteria. Isn't it all just, "How does reality work?"
  - Cogito 9y ago
    I hadn't heard of non overlapping magisteria (NOMA) before. My immediate thought was that if you assume the 'teaching domains' of science and religion do not overlap at all, then the domain of religion is vanishingly small. If you accept that science covers (at least) all observable things, and also hold the idea of NOMA, then religion must never deal with anything observable. The teaching domain of the unobservable seems like it would be near non-existent. Alternately, let's start from the position that a supernatural power exists and cares about what we do. Why would we be interested in that? We would be interested if that supernatural power has the ability to affect our lives/the world we live in, or will affect our lives after we die/some other aspect of some supernatural world beyond this one. If the power can affect this world, we should be able to observe that interaction. If it is literally impossible to measure any effect, it is the same as if the power is not interacting with the world at all. Which is to say, if the power interacts with the world, then those interactions fall under the domain of science. If the power does not interact with the world, then we can only be interested in what effect our actions, choices, and beliefs will have outside this world, on the supernatural or afterlife. The thing is, we have no way of knowing what that would be, because communicating any of that information to us would count as interacting with the world. Thus, anyone claiming that something should or shouldn't be believed or done, for religious reasons, is either making a testable claim or claiming something which has no reason to be believed. If the magesteria of science and religion truly are non overlapping, it seems that religion's must necessarily be very very small.

radarsat1 9y ago

This is really clever, from a design perspective. I mean, projecting onto a moving particle is a really innovative idea. But scientifically, what I find the most surprising, is that a laser trap can move a particle around at sufficient speeds, outside a vacuum, without losing it. Impressive! I had no idea that was possible. Anyone know what speed or frequency of movement it can achieve?

aw3c2 9y ago
Judging from my experience with other well-polished PR pieces from universities, I would expect only the "oscillating above the finger tips" parts to be real time. The more advanced examples were only shown statically and thus were probably like long-shutter images.
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GistNoesis 9y ago
Projecting on a moving particle isn't quite new. A quick search reveal that there have been projections on falling water droplets since at least 2010. There are also plenty of stroboscopic experiments on water drops which make them fall upwards. I think having a controllable particle is a nice-feat but probably is overkill for 3D displays, you only need to know where the particles are so you can use them as a screen. Although the 2010 paper project on layers of waterfalls, it's easy to imagine a 2d water droplet grid where you watch the droplets form and drop with a hi-speed camera and with a video projector you then project the right pixel at the right time so that light ray intersect water droplet. You can even try this today at home with a shower jet and a pico projector, and see beautiful clouds of red green blue rays. It's probably a fun engineering project to get the right combination of liquid properties, size of droplets, frequencies, video bandwidth to obtain stunning results.