Right, I've always thought that if we're likely to see anything approaching a "cloak of invisibility" that a chameleon approach is a lot more feasible. Of course one could use a partially transparent/lightbending region or pinhole cameras to let someone inside such a metamaterial shell to see outside, but my point was more that there have been so many articles of this sort recently. The summaries and titles are almost always misleading and then people go on to hypothesize about future developments in the field without having ever done more than read the title of the summary.
The chameleon or mimicry approach does seem a lot more practical a direction to work in, especially for vehicle-mounted systems. Of course, there are other problems with that approach. Generating that much light, unless done more efficiently than we are capable of doing now, will also generate heat and possibly noise in other portions of the spectrum. Even assuming a much tighter system, which is fair enough because we're already assuming great advances in optics and computing with such a suit, where do you get the power?
Then there are lighting problems. You have to account for not only normal lighting and brighter but also the possibility that some genius will come up with the idea of defeating your stealth suit with a bit of high-intensity coherent light. Unless the suit can also detect and respond to a sudden and very localized increase in intensity and generate a matching pattern and intensity at the appropriate exit point, you might have the situation where a super-operative with a stealth suit could be humbled by a laser-pointer. Much like stealth bombers and cell phones. It wouldn't even necessarily be that hard to add a bit of optics to a laser sight on an assault rifle, say a small mirror capable of allowing your laser to cover a spotlight-sized area by continuously varying the angle of emergence by some small amount. Couple this with a bit of cheap range-finding and it should be possible to notice the extra latency as the laser is emulated by the suit systems even if it were capable of doing so.
So, win some, lose some. It'd make more sense to try for highly-advanced camouflage than invisibility. Say something that will change pigments to match the environment closely and calculatedly. This seems to me even more feasible. Projectors could allow you to be even more precise, but they have other hurdles to overcome. Thanks for the thoughtful reply!
This innovation and others like it have seen far too much press already. I know, I know, it's slashdot and no one RTFA anyway, but if you did you'd quickly realize that there really is nothing to see here. Let me explain at least for those of you who will read a comment if not any of the articles appearing in popular science sources for the last several months:
Imagine for the moment placing an object behind a mirror. Better yet, inside a mirror. Amazing! You cloaked it from observation from visible wavelengths! Understood, this is much more meta and complex than all that. It bends the light around instead of sending it away. But that's all. In the same way that you can't see anything on the other side of the mirror, nothing on the other side of the mirror can see you. We're not going to see invisibility cloaks or special forces in lightbending armor out of this, because even if the technology were practical and cheap the special forces would still be blind. Any light you let in is light that's not making you invisible by being elsewhere.
These results are undeniably groundbreaking, but they are received as something entirely different from what they really are.
Slashdot Mirror
Right, I've always thought that if we're likely to see anything approaching a "cloak of invisibility" that a chameleon approach is a lot more feasible. Of course one could use a partially transparent/lightbending region or pinhole cameras to let someone inside such a metamaterial shell to see outside, but my point was more that there have been so many articles of this sort recently. The summaries and titles are almost always misleading and then people go on to hypothesize about future developments in the field without having ever done more than read the title of the summary.
The chameleon or mimicry approach does seem a lot more practical a direction to work in, especially for vehicle-mounted systems. Of course, there are other problems with that approach. Generating that much light, unless done more efficiently than we are capable of doing now, will also generate heat and possibly noise in other portions of the spectrum. Even assuming a much tighter system, which is fair enough because we're already assuming great advances in optics and computing with such a suit, where do you get the power?
Then there are lighting problems. You have to account for not only normal lighting and brighter but also the possibility that some genius will come up with the idea of defeating your stealth suit with a bit of high-intensity coherent light. Unless the suit can also detect and respond to a sudden and very localized increase in intensity and generate a matching pattern and intensity at the appropriate exit point, you might have the situation where a super-operative with a stealth suit could be humbled by a laser-pointer. Much like stealth bombers and cell phones. It wouldn't even necessarily be that hard to add a bit of optics to a laser sight on an assault rifle, say a small mirror capable of allowing your laser to cover a spotlight-sized area by continuously varying the angle of emergence by some small amount. Couple this with a bit of cheap range-finding and it should be possible to notice the extra latency as the laser is emulated by the suit systems even if it were capable of doing so.
So, win some, lose some. It'd make more sense to try for highly-advanced camouflage than invisibility. Say something that will change pigments to match the environment closely and calculatedly. This seems to me even more feasible. Projectors could allow you to be even more precise, but they have other hurdles to overcome. Thanks for the thoughtful reply!
This innovation and others like it have seen far too much press already. I know, I know, it's slashdot and no one RTFA anyway, but if you did you'd quickly realize that there really is nothing to see here. Let me explain at least for those of you who will read a comment if not any of the articles appearing in popular science sources for the last several months:
Imagine for the moment placing an object behind a mirror. Better yet, inside a mirror. Amazing! You cloaked it from observation from visible wavelengths! Understood, this is much more meta and complex than all that. It bends the light around instead of sending it away. But that's all. In the same way that you can't see anything on the other side of the mirror, nothing on the other side of the mirror can see you. We're not going to see invisibility cloaks or special forces in lightbending armor out of this, because even if the technology were practical and cheap the special forces would still be blind. Any light you let in is light that's not making you invisible by being elsewhere.
These results are undeniably groundbreaking, but they are received as something entirely different from what they really are.