Seeing With Your Skin? 138
Iddo Genuth writes to tell us that a researcher from Tel Aviv University is exploring the possibility that humans may be able to "see" via their skin. Professor Leonid Yaroslavsky hopes to utilize this possible technology to find solutions for the blind in addition to new types of image capture that might be able to work where conventional lenses fail. Unfortunately he has a long uphill battle ahead to convince others that his theories are possible. "The lenses currently used for optics-based imaging have many problems. They only work within a limited range of electromagnetic radiation. Relatively, these are still costly devices greatly limited by weight and field of view. The imaging Professor Yaroslavsky has in mind has no lenses and he believes the devices can be adapted to any kind of radiation and wavelength. They could essentially work with a 360-degree field of view and their imaging capability will only be determined by computer power rather than the laws of light diffraction."
Done before, using different sensory organ (Score:5, Informative)
Dr. Paul Bach-y-Rita who was at UW Madison has done something with vision being projected via electrical stimulation on the tongue. It is called sensory substitution.
I've seen it first hand. It works.
http://en.wikipedia.org/wiki/Sensory_substitution [wikipedia.org]
Re:Done before, using different sensory organ (Score:2, Informative)
Re:My eyebrows are raised (Score:2, Informative)
It's nothing like echolocation. First of all, echolocation is active scanning, vision is passive scanning (nobody can detect you're looking at them, however you can tell if someone's using echolocation). Echolocation is dependant upon 1 or 2 sensors, while vision needs thousands (and prefers millions) of sensors.
The calculations are explained in this link :
arXivBlog [arxivblog.com]
The article makes several good points. After minimal practice you are able to identify the location of the sun blindfolded.
A bit more practice and you can find people in closed rooms. Or behind you. This is trivially easy if the person behind you is really close, but with training you can increase the range quite a bit. It's impossibly to "feel" further than 2 or 3 meters or so, however, so while it beats our eyes in low light conditions at short ranges, it's not useful to see very far (the article explains this : it *is* possible to make skin vision work for very, very long distances, but the computational cost is off the scale).
Not only do we have skin vision, the article claims, but we use it often. To avoid staring into the sun for example, but also to detect hot objects before touching them.
Do an experiment. Heat up your stove. Hold your hand above it. It's quite clearly there isn't it ? Surely this must be the heated air rising, right ? (even though if you calculate how fast the heat transfers into your hand it doesn't quite make sense, and you don't actually feel air rise)
So now try the same with a pot. Try to identify if it's hot or cold, by just holding your hand close to it (don't touch it). You should, again, with a little concentration, be able to do this with 100% accuracy. Nevertheless, with a vertical surface, there is hardly any heated air coming to your hand, yet you're able to identify the heat from about the same distance.
We're not only able to see with our skin, but we see more than we see with our eyes. No amount of visual inspection with your eyes would tell you a cooking pot is hot or cold : the radiation that gives it away is outside of the spectrum of our eyes (this is due to the limitations of the lens "assembly"). Nevertheless clearly we can detect that radiation.
The theory goes that this is how eyes developed. Skin is sensitive at very short range, and can actually form images of very close objects. But even with the huge brain humans have it only works for at best a few meters.
However a dimpled piece of skin will see more, due to it's shape and will be able to focus further. Making that dimple moveable is an obvious next step.
From there it's a short step to what amounts to a pinhole camera.
Fill a pinhole camera that is round with a drop of water and you've got basic optics (that aren't very stable).
Put a transparent layer of skin above the droplet of water and you have reptile eyes, much, much more stable than the pinhole kind and not nearly as prone to infection.
Let the skin immediately above the hole in the skin grow a little bit and you've got mammal eyes. Add a muscle within that loose hanging skin and you've got human eyes.
Re:Done before, using different sensory organ (Score:3, Informative)
...and a project (also from the UW) involving several guys I know, called Visual Taste [uwinnovators.com] does that as well. There are pictures and videos, if the average slashdot reader can be troubled to follow the link...
Re:My eyebrows are raised (Score:3, Informative)
Re:Follow the money. (Score:3, Informative)
WTF? Tel Aviv University is a very decent research institute that has made many important contributions to science. No, I am not and have never been affiliated with them, but the page you are referring to is obviously that of an alumni organization. And yes, they do raise money for the university, that is what alumni organizations do.
As for Yaroslavsky (the prof working on this "seeing skin" project), I know neither him nor this project (at least not more than the press release states), but his publication list shows that he regularly publishes in top journals such as Applied Optics, Optics Express, and Optics Letters. Clearly he knows a thing or two about light.
http://www.eng.tau.ac.il/~yaro/RecentPublications/index.html [tau.ac.il]