Dunno, but I've heard anecdotally (and the anecdotes were supported by a quick Google search) that he's on Caltech's ACM programming team, so he's definitely one smart cookie.
As of 12:35am EDT on 15 April 2003 the site appears to be down--what happened? Was it the bandwidth police, a hard-coded membership limit (500,000?), or something else entirely? In any case, I'm impressed that a single-processor machine in a dorm room was able to withstand as much traffic as it did.
Yeah after about 2 days there'll be a couple hundred thousand registered people playing 6 degrees, and that's when the network guys will come a'knockin.
Make that a couple of hours--just today, the site went from 6,000 members to 200,000+ members!
Yes, but the first kid doesn't arrive any sooner (neglecting premature births). For me, the quote conjures a very funny image of Henry VIII impregnating every woman in sight trying to get an heir...
Concorde never flew supersonic where there were people on the ground to complain about the sonic boom.
True, so Concorde only flew transatlantic routes (NYC-London and NYC-Paris) in order to maximize the supersonic flight path. A Concorde flight from New York to Paris takes only 4 hours, compared to almost 8 hours for a Boeing 747. (Source)
I would argue that a programmer becomes a software engineer at the point where they develop methods for exhaustively testing their program for failure, and where they are willing to accept the responsibility and consequences of software failure. Simply kludging a program together and getting it to compile is not software engineering. On the other hand, writing a typesetting system like TeX, developing an exhaustive test suite for it, and making it virtually bug-free is an impressive feat of software engineering.
Self-focusing is a neat phenomenon, but I think you got some of the details wrong, and I do not think self-focusing is helpful for "Star Wars" type applications. In general, gradient-index optics have a higher refractive index toward the center and a lower refractive index away from the center, so in order to achieve beam confinement the beam must refract toward higher index, not lower. Thus thermal effects alone cannot cause self-focusing, since thermal effects would make the refractive index near the center of the beam lower, not higher. Thus I think there has to be a nonlinear interaction between the beam and the air that induces a photorefractive effect that increases the index of refraction near the center of the beam in order for self-focusing to occur.
The second problem is that self-focusing is a positive feedback loop, such that self-focusing causes more self-focusing, which makes the beam more and more intense toward the center. Eventually the beam intensity will exceed the breakdown voltage of air, and the air will ionize. This actually make the air opaque, and the beam will either be severely attenuated or possibly completely absorbed. Thus self-focusing might be useful if the beam focus lands on the target, but I do not believe it achieves beam confinement in the same manner that fiber optics do.
Inflammatory rhetoric like yours only erodes foreign and domestic support for the war. If you presented your arguments more objectively, I might listen to them--maybe even be convinced--but your piece is pure flamebait, plain and simple. Cut back on the vindictiveness, and you might convince me and even some others.
Fundamentally, I think the worst thing about this war is that the U.S. began it more or less unilaterally, and explicitly without support from the U.N. I think removing Saddam Hussein would be a good thing, provided the human and monetary cost is acceptable, but the notion that the U.S. has the right to arbitrarily interfere with the governments of foreign nations is fundamentally flawed. Even worse, the U.S. is hypocritical by propping up brutal dictators who happen to be friendly to the U.S. but toppling other governments (some democratic!) which do not conform to the U.S.'s will.
Do you remember who taught the course? If I know the prof, I might drop him an email asking about it. There's probably more than a 50% chance that I know the prof and want to drop him an email anyway.
Are you sure that the beam didn't diverge? If so, I'd be curious to know how, because I can't think of any Fourier optics basis for a non-diverging beam. If there were a limiting aperture anywhere in the beam path, diffraction guarantees that the beam would diverge. Furthermore, divergence is built into the equations for a Gaussian beam, and the only reason an ideal plane wave does not diverge is because it has infinite extent (a condition that is physically unrealizable), which leaves me with no idea how to realize an non-diverging beam.
On a marginally-related note, where did you take Fourier Optics? It didn't strike me as a common course to find except at places with a heavy emphasis on optics like the University of Arizona (my alma mater), the University of Michigan (where I'm at now), or the University of Rochester.
I agree with everything that you said. However, the point of the quote and my.sig, which I'm not sure is clear, is that if you have one specific project that needs to be done (i.e. if you just want one kid), assigning more people to a project will not necessarily accelerate its progress and, as Brooks notes, may even hold a project up. It's analogous to that stupid Microsoft.NET commercial where the woman says, "I need a light bulb." The ordering guy asks, "How many crates?" the woman replies, "One," and the ordering guy says, "He can't do one." Parallelism and/or pipelining can help out a lot if you need many things done, but if there is just one thing that needs to be done (or one thing that has to be done before anything else can be done), parallelizing or pipelining might not help.
Anyone, as I explained in my journal, I adopted the quote as my.sig because I read it late one night and found it just too funny. The mental image of some poor guy wanting a child and impregnating every woman in sight trying to get one sooner, while horribly sexist, just cracks me up.
(1 - v^2/c^2)^0.5 = gamma, which is a common scaling factor in the Lorentz transformations used in special relativity. The common definition of refractive index of a medium is n = c / v where c is the speed of light in vacuum and v is the speed of light in the medium. In the context of these materials, however, the negative refractive index means that the direction of electromagnetic power flow is given by E x -H (a left-handed vector cross product of the electric field vector E and the magnetic field vector H), whereas in most materials the direction of power flow is given by E x H (a right-handed vector cross product).
For Slashdotters at universities or other institutions that have an institutional subscription to Applied Physics Letters, here is the original scientific paper that's mentioned in the articles.
Metamaterials are carefully constructed arrangements of regular materials, whose properties combine to produce behaviours that no "pure" material can duplicate, including negative indexes of refraction.
Just out of curiousity, does anyone know if photonic bandgap materials are considered to be a subset of metamaterials? My intuition says yes, but my intuition is often wrong...
I'd imagine that, even though they are transparent, the exploitation of that fact would be a little off. Especially as the devices get really really minute (which they will...what's the use of a computer consisting only of a screen if it cant display graphics?), I'd imagine that photons would be able to muck things up quite readily. Not even just the fact that photons can knock electrons around, but the fact that light could heat these babies up--not a very good thing for small traces. Unpredictable behavior is the last thing a technology that seeks to become ubiquitus needs.
I don't think these devices would be particularly light-sensitive, at least not to visible light. The fact that the material is transparent suggests that the band gap of ZnO is larger than the energy of a visible photon, so the degree of interaction between visible light with this material should be negligible (i.e. no unexpected switching, and no heating due to light absorption). Contrast this to silicon, which has a band gap of 1.1 eV IIRC, which means that it absorbs (and therefore can be heated by and is opaque to) wavelengths shorter than 1.1 microns (which includes the near-infrared and visible regions of the electromagnetic spectrum).
As far as applications for this material go, the most obvious one I can think of is to locally integrate electronics at every pixel of a CCD or CMOS array in a digital camera. You could give each pixel a circuit to reduce the dark current, to boost the sensitivity, or to make the response more linear, and you could deposit these circuits on the surface of an existing array.
Not to pick nits, but old style vacuum tubes were largely transparent.
But if we were going to nitpick, I would use the phrase "sparsely opaque". Yes, the glass housings of vacuum tubes are transparent, but the metal cathodes and anodes inside the vacuum tubes are quite opaque to visible light.
But from what I recall, Si is also transparent, albeit in the IR band, so the only benefit of going to ZnO is that humans can see through them. Maybe there are other processing advantages to ZnO that permit it to work better with III-V systems?
Outside of scientific research, most people are primarily interested in visible light as opposed to the infrared or ultraviolet light (the Sony Night Shot camcorder notwithstanding). Transparent electronics could be used to make smart pixel arrays for digital cameras with local processing electronics for every CCD or CMOS pixel, for example. If I thought about it for a while, I could probably come up with more uses for integrated optoelectronics in the visible spectrum, but I'm lazy.:-p
Seeing as how these "photography as art" purists discard image information all the time with small depth-of-focus shots, I don't think they would object to the additional creative control that postprocessing with an apodized filter could offer. And even if these purists do object, graphic artists and amateur photographers will definitely embrace the ability to make bad photographs look good.
Slashdot Mirror
Dunno, but I've heard anecdotally (and the anecdotes were supported by a quick Google search) that he's on Caltech's ACM programming team, so he's definitely one smart cookie.
Also, he has a Slashdot account: SkyIce
As of 12:35am EDT on 15 April 2003 the site appears to be down--what happened? Was it the bandwidth police, a hard-coded membership limit (500,000?), or something else entirely? In any case, I'm impressed that a single-processor machine in a dorm room was able to withstand as much traffic as it did.
Yes, but the first kid doesn't arrive any sooner (neglecting premature births). For me, the quote conjures a very funny image of Henry VIII impregnating every woman in sight trying to get an heir...
I would argue that a programmer becomes a software engineer at the point where they develop methods for exhaustively testing their program for failure, and where they are willing to accept the responsibility and consequences of software failure. Simply kludging a program together and getting it to compile is not software engineering. On the other hand, writing a typesetting system like TeX, developing an exhaustive test suite for it, and making it virtually bug-free is an impressive feat of software engineering.
Self-focusing is a neat phenomenon, but I think you got some of the details wrong, and I do not think self-focusing is helpful for "Star Wars" type applications. In general, gradient-index optics have a higher refractive index toward the center and a lower refractive index away from the center, so in order to achieve beam confinement the beam must refract toward higher index, not lower. Thus thermal effects alone cannot cause self-focusing, since thermal effects would make the refractive index near the center of the beam lower, not higher. Thus I think there has to be a nonlinear interaction between the beam and the air that induces a photorefractive effect that increases the index of refraction near the center of the beam in order for self-focusing to occur.
The second problem is that self-focusing is a positive feedback loop, such that self-focusing causes more self-focusing, which makes the beam more and more intense toward the center. Eventually the beam intensity will exceed the breakdown voltage of air, and the air will ionize. This actually make the air opaque, and the beam will either be severely attenuated or possibly completely absorbed. Thus self-focusing might be useful if the beam focus lands on the target, but I do not believe it achieves beam confinement in the same manner that fiber optics do.
Inflammatory rhetoric like yours only erodes foreign and domestic support for the war. If you presented your arguments more objectively, I might listen to them--maybe even be convinced--but your piece is pure flamebait, plain and simple. Cut back on the vindictiveness, and you might convince me and even some others.
Fundamentally, I think the worst thing about this war is that the U.S. began it more or less unilaterally, and explicitly without support from the U.N. I think removing Saddam Hussein would be a good thing, provided the human and monetary cost is acceptable, but the notion that the U.S. has the right to arbitrarily interfere with the governments of foreign nations is fundamentally flawed. Even worse, the U.S. is hypocritical by propping up brutal dictators who happen to be friendly to the U.S. but toppling other governments (some democratic!) which do not conform to the U.S.'s will.
Do you remember who taught the course? If I know the prof, I might drop him an email asking about it. There's probably more than a 50% chance that I know the prof and want to drop him an email anyway.
Are you sure that the beam didn't diverge? If so, I'd be curious to know how, because I can't think of any Fourier optics basis for a non-diverging beam. If there were a limiting aperture anywhere in the beam path, diffraction guarantees that the beam would diverge. Furthermore, divergence is built into the equations for a Gaussian beam, and the only reason an ideal plane wave does not diverge is because it has infinite extent (a condition that is physically unrealizable), which leaves me with no idea how to realize an non-diverging beam.
On a marginally-related note, where did you take Fourier Optics? It didn't strike me as a common course to find except at places with a heavy emphasis on optics like the University of Arizona (my alma mater), the University of Michigan (where I'm at now), or the University of Rochester.
I agree with everything that you said. However, the point of the quote and my .sig, which I'm not sure is clear, is that if you have one specific project that needs to be done (i.e. if you just want one kid), assigning more people to a project will not necessarily accelerate its progress and, as Brooks notes, may even hold a project up. It's analogous to that stupid Microsoft .NET commercial where the woman says, "I need a light bulb." The ordering guy asks, "How many crates?" the woman replies, "One," and the ordering guy says, "He can't do one." Parallelism and/or pipelining can help out a lot if you need many things done, but if there is just one thing that needs to be done (or one thing that has to be done before anything else can be done), parallelizing or pipelining might not help.
.sig because I read it late one night and found it just too funny. The mental image of some poor guy wanting a child and impregnating every woman in sight trying to get one sooner, while horribly sexist, just cracks me up.
Anyone, as I explained in my journal, I adopted the quote as my
(1 - v^2/c^2)^0.5 = gamma, which is a common scaling factor in the Lorentz transformations used in special relativity. The common definition of refractive index of a medium is n = c / v where c is the speed of light in vacuum and v is the speed of light in the medium. In the context of these materials, however, the negative refractive index means that the direction of electromagnetic power flow is given by E x -H (a left-handed vector cross product of the electric field vector E and the magnetic field vector H), whereas in most materials the direction of power flow is given by E x H (a right-handed vector cross product).
The Wilt Chamberlain theory of siring? Anyway, the context for my sig is explained here.
For Slashdotters at universities or other institutions that have an institutional subscription to Applied Physics Letters, here is the original scientific paper that's mentioned in the articles.
As far as applications for this material go, the most obvious one I can think of is to locally integrate electronics at every pixel of a CCD or CMOS array in a digital camera. You could give each pixel a circuit to reduce the dark current, to boost the sensitivity, or to make the response more linear, and you could deposit these circuits on the surface of an existing array.
Delusional fiction might be more accurate... ;-)
The NCAA tournament? Oh...you say there's a war going on? When did Congress declare that?!? :-p
If we start dropping spammers instead of bombs on Iraq, they'll be handing over Saddam in no time!
Minority Report much?
Seeing as how these "photography as art" purists discard image information all the time with small depth-of-focus shots, I don't think they would object to the additional creative control that postprocessing with an apodized filter could offer. And even if these purists do object, graphic artists and amateur photographers will definitely embrace the ability to make bad photographs look good.