You know those
invisibility cloaks scientists have been struggling to master for decades? This here is said cloak's perfect opposite, and it's bending our minds in ways you can hardly fathom. Ulf Leonhardt, a professor at the University of St. Andrews, has worked with a brilliant team of scientists in order to construct what he calls a universal mirror, or if we're being proper, an omnidirectional retroreflector. Unlike conventional mirrors which simply reflect objects at 90 degrees, this concoction reflects objects back at
any angle. In other words, a device such as this would make aircraft, boats and satellites entirely easier to track with radar, but it'll have to mature quite a bit before it's ready for that kind of action. The current build is just a single centimeter high and ten centimeters in diameter, and as with invisibility cloaks, the main ingredient here is metamaterials that we won't pretend to fully understand. Just one word of caution, boffins -- don't let
Geek Squad get ahold of this stuff.
[Image courtesy of
Barbara Rich, thanks JR]
posted Jul 20th 2009 6:33AM
Ehh, sorry this unintelligent comment but can someone clarify what this is about? It seems pretty cool but I don't really understand...
This technology makes it possible to reflect light right back to the source, no matter the angle it hits the mirror with. When you look at a regular mirror, you only see your own reflection when you're in front of it, but if you look at it at any other angle, you see what's at that same angle to the opposite side of the mirror. This wouldn't happen with this technology. For example, if they used it for a car rearview mirror, you wouldn't be able to see other cars, just yourself, no matter at what angle you tilt the mirror.
"A universal mirror would serve a variety of purposes. Installed on aircraft, boats or satellites, a universal mirror would makes these objects easier to track with radar. When radio waves ordinarily hit these objects, they scatter in many different directions, and only a few radio waves bounce back to the original source of the radar.With a radio universal mirror, all the radio waves would bounce back to their original source, making them much easier to detect and giving the object a much larger radio profile"
@eGGnext
Thanks a lot!
I believe that this is just another retroreflector. These things have been around for decades.
See Wikipedia: http://en.wikipedia.org/wiki/Retroreflector
Mirrors are more fun than television.
Better looking too.
What are some potential uses for this in the world of technology other than aircraft tracking? TVs perhaps, i dont know.
I think the images on these sites are misleading, if you were to actually look into a mirror that only reflects light back from the direction it came, you'd just see your eyes, because the only light rays that are reaching your eye have to have come from the same path before it bounced off the mirror.
Yes, and that would be really, really odd, unless of course what they mean is that the light rays come back, along with a bunch of other rays, as if the mirror were perfectly oriented towards you.
Which seems to beg the question of why can't a field-array of tiny corner mirrors be made and what would the effect of that be?
That's what I thought.
Moreover, you can buy devices with similar function. It's called Retroreflector, check it out in wikipedia.
Actually, if this works the way it was explained here, you wouldn't see anything. It would just be black. There's got to be more to it than what was written here, which I must say was a pretty poorly executed article.
If you're going o talk about something like this, at least give us a basic understanding of WHAT IT IS!
"Unlike conventional mirrors which simply reflect objects at 90 degrees...."
?
That doesn't sound right. What about, "Angle of incidence equals angle of reflection?" Perhaps I don't understand what the author means.
Honestly, engadget, please fix the comment system. That was supposed to go to Mike's comment directly above.
If a mirror reflected at 90 degree angles, wouldn't that mean you would never be able to see yourself in it?
Yes. Thought the same thing when I read that.
"Unlike conventional mirrors which simply reflect objects at 90 degrees, this concoction reflects objects back at any angle."
I thought mirrors reflected light, not objects.
"If a mirror reflected at 90 degree angles, wouldn't that mean you would never be able to see yourself in it?"
It's 90 degrees from the angle of origin, which doesn't apply when you're directly in front of the mirror.
Get a flashlight, go to mirror. Point it at an angle towards the mirror. The light is reflected off by 90 degrees from the angle of the original light beam.
The above 2 comments, in addition to the article, are completely wrong. Mirrors do not reflect light at 90 degrees to any "angle of origin." If you point a flashlight at 20 degrees relative to the normal (perpendicular line to the mirror), the reflected beam will be 20 degrees relative to the normal on the opposite side of the incident beam. There will be 40 degrees between the incident and reflected beams, and this varies with the incident angle.
pics or it didn't happen
I think its "Screenshot or it didn't happen"
Slightly off topic, but the office I'm currently sitting in is a couple of hundred yards from the skymirror shown in the photograph.
....I didn't expect to see a photo of Nottingham on engadeget! :)
Yeah - I had to take a second look. It's outside the Nottingham Playhouse - Robin Hood land, actually a stone's throw away from Nottingham Castle. Look - there goes Kevin Costner! ;-)
"In other words, a device such as this would make aircraft, boats and satellites entirely easier to track with radar."
Which is why nobody will ever attach one to their aircraft, boat, or satellite.
For anyone interested, I was able to find the real paper here: http://www.physics.nus.edu.sg/corporate/research/res_paper/nmat2489.pdf
So in other words, if I'm shooting a scene in a movie of a girl in front of a mirror, it doesn't matter where I put my camera because I'll see it in the shot?
Great.
/s
Not really. No matter where you put the camera, the camera will see itself in the mirror.
@Jake
That's what I said.
@Michael
Not quite, what Jakes mean is that the camera would ONLY see itself. Every pixel in the photo would seeing itself. Really, this is blowing my mind. Can we see a picture of what this would actually look like?
Looks like someone has told author about conventional retroreflectors, (mirrors arranged so that they are 90 degrees from each other). He pretended to understand and memorized: "90 degrees".
P.S. It's also the boiling point of water at standard pressure.
The lead picture on the engadget front page is an art installation outside of the the "Play House" theatre in Nottingham City Centre (UK). Quite weird to see on the front page of an international tech site!!
Stuart
Nottingham!
Maybe I'm confused, but if it only reflected where the light came from, wouldn't you only see the light source when you looked in the mirror? Since my eyes don't tend to create light, I wouldn't see myself.
Well, your eyes still reflect light, like most objects.
Although the only light you can see is that which enters your pupils, so therefore only the light that reflects from your pupils is what you'd be able to see in the mirror. Of course people's pupils are dark (because the pupil is the hole into which light enters your eyeball), so the only light that reflects is either that reflecting off the cornea or the light reflecting off the retina.
Yeah, the mirror would look pretty black, for the most part.
I thought corner cubes already did this... maybe this does it in some new more interesting way.