http://en.wikipedia.org/wiki/Negative_refractive_index
It doesn't occur naturally, and admittedly, doesn't really have any practical application in ophthalmic optics, but it's pretty cool anyway.
And, more inportantly, one of the Universities doing research into the subject is about 20 minutes from where I live :) (University of Rochester)
Last edited by WFruit; 07-23-2010 at 10:41 AM. Reason: learning to type....
There are rules. Knowing those are easy. There are exceptions to the rules. Knowing those are easy. Knowing when to use them is slightly less easy. There are exceptions to the exceptions. Knowing those is a little more tricky, and know when to use those is even more so. Our industry is FULL of all of the above.
No time to read the entire article as I'm at work presently. But in short - is it saying it actually speeds up light in a medium?
Not exactly. It's hard to describe simply (at least for me), but there is a nice video on the page showing what happens. Essentially it bends backwards in the medium....
Here's a good quote from the article: "In essence these negative index metamaterials were noted for having the ability to reverse many of the physical properties that govern the behavior of ordinary optical materials. One of those unusual properties is the capability to reverse, for the first time, the Snell's law of refraction"
There are rules. Knowing those are easy. There are exceptions to the rules. Knowing those are easy. Knowing when to use them is slightly less easy. There are exceptions to the exceptions. Knowing those is a little more tricky, and know when to use those is even more so. Our industry is FULL of all of the above.
If you read the article in detail still waiting on a metamaterial that works in the visible spectrum and through out the entire visible spectrum or broadband. Interesting article although it is wikipedia so take it with a grain of salt.
I take Wikipedia with at least two grains of coarse sea salt.... However, since one of the Universities doing research on the subject is University of Rochester, where my wife is both an employee and student, I managed to find out who's doing the research there and snagged some time to speak with them about the subject :)Originally Posted by HarryChiling
There are rules. Knowing those are easy. There are exceptions to the rules. Knowing those are easy. Knowing when to use them is slightly less easy. There are exceptions to the exceptions. Knowing those is a little more tricky, and know when to use those is even more so. Our industry is FULL of all of the above.
And it can do all of this in the blue part of the visible spectrum, making it "the first negative index metamaterial to operate at visible frequencies,"
http://www.physorg.com/news191168001.html
Science is a way of trying not to fool yourself. - Richard P. Feynman
Experience is the hardest teacher. She gives the test before the lesson.
Awesome, I used to do that at Towson University, you'd be amazed at how easy the porofessors are to approach when you are discussing subjects they are passionate about.
Yup, still not broadband. I could see this technology having potential applications in our industry on the equipment side of things.
As some of the others have noted, a negative refractive index would just flip the angle of refraction (imagine substituting a -n in Snell's Law of refraction). A refractive index of less than 1 would represent light traveling faster than the speed of light, assuming the numerator was the speed of light in air or a vacuum.But in short - is it saying it actually speeds up light in a medium?
Of course, light can still speed up when entering a different medium, which occurs when the refractive index of the first medium is higher than the refractive index of the second medium, such as light leaving a lens material into air, for instance.
Of course, achieving a velocity that is faster than light in a vacuum, at 300,000 km/s, is probably one of the Holy Grails of physics. Scientists recently claimed to achieve faster-than-light travel with electronic signals in Cesium vapor, although this really wasn't strictly the case.
Best regards,
Darryl
Darryl J. Meister, ABOM
I understand the difficulties in super-luminal velocities - and I blame the Lortab for my silly post earlier this morning. Love this stuff even so. Thanks for punching back softly guys! hehehe
Not broadband, no. And even if it was, it wouldn't be all that useful in ophthalmics. (Although with the example in Robert's post, I foresee a whole new generation of Blue Blockers.....)
What's interesting to think about, is that if you did have a metamaterial with a negative index that could affect the visible spectrum, you wouldn't be able to see it.... it would refract (not reflect) light back out of itself.... it would,essentially, look like a black hole.
There are rules. Knowing those are easy. There are exceptions to the rules. Knowing those are easy. Knowing when to use them is slightly less easy. There are exceptions to the exceptions. Knowing those is a little more tricky, and know when to use those is even more so. Our industry is FULL of all of the above.
Although I've never bothered to look into it, I suspect that it would simply cause light to diverge, instead of converge, or vice versa. There are probably some clever applications of this technology though.What's interesting to think about, is that if you did have a metamaterial with a negative index that could affect the visible spectrum, you wouldn't be able to see it.... it would refract (not reflect) light back out of itself.... it would,essentially, look like a black hole.
Best regards,
Darryl
Darryl J. Meister, ABOM
Next anisekonic thru the door is getting one of these babies fit unilaterally.
HAHA! LOVE it! ;)
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