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Technology

Peeking At The Future: "Perfect Mirror" Cables 93

Posted by timothy from the unless-this-is-completely-made-up dept.
sonofpan writes: "About 18 months ago I heard about a few guys at MIT who developed a process for creating a (near) perfect mirror that could reflect many different frequencies at any angle with almost no loss of strength (something that was said to be theoretically impossible). Apparently, they have finally gotten their patents and used the technology to create a dielectric coaxial cable that can transmit light across vast distances and around tight turns with virtually no loss of signal. Read about it at: http://web.mit.edu/newsoffice/ nr/2000/waveguide.html and the company they started at: http://www.omni-guide.com. And the original link that described the process and the huge possibilities for its uses is a very interesting read as well: http://web.mit.edu/newsoffi ce/tt/1998/dec09/mirror.html."
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Peeking At The Future: "Perfect Mirror" Cables More

Peeking At The Future: "Perfect Mirror" Cables

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  • No duh - High loss at optical wavelengths (Score:1)

    by Anonymous Coward
    Such structures mimic important properties of traditional, metallic coaxial cables, but without their high absorption losses at optical wavelengths

    I don't know which world you live in, but its kinda hard to pipe light through RG-58.

  • Do the lights go out when you close the mirror? (Score:3)

    by ariehk ( 215517 ) on Wednesday July 26, 2000 @03:05PM (#902930) Homepage
    "This is going to revolutionize the way people think about confining light." Trapping light invites all sorts of intriguing questions, Fink points out. For instance, if you light a candle in a room lined with perfect mirrors, would the room stay illuminated even after the flame is extinguished? You could try putting a cat in a box of perfect mirrors, getting it to blow out the candle, asking it if it's light or not, and working out if it's dead or alive :) Arieh

  • Mirror site :-) (Score:4)

    by Robin Hood ( 1507 ) on Wednesday July 26, 2000 @03:05PM (#902931) Homepage
    What with all the hits their page is getting, do you think they're going to need a mirror site?

    (Sorry, couldn't resist.)
    -----
    The real meaning of the GNU GPL:

  • That's actually a very interesting concept, "perfection is a very strong statement" (to quote sphere, the book). Kind of like the article about flywheels where the design is simple, its just the fact that nothing is lost that is the real key.

  • Hmmm, right. Then you would only be able to see in, and not out, and then only at night when lights are on inside...

    Hmm. Only good for peeping toms, I guess.

    Maybe for the ultimate dash-sun screen for the car!

    Bye!
  • Multiplexing data over a single fiber is already done with DWDM (Dense Wave Dimension Multiplexing). I have heard of up to 32 colors of OC-192 over a fiber pair in the real world, and over 200 in the lab. It sounds like this new material should be able to push that number even higher. Fiber pairs take up a lot less room than coax though, I wonder what this means in terms of bundling a bunch of them. Another thing to wonder about is if this technology will reduce the number of repeaters needed in a WAN. That's especially important when you talk about areas which are hard to get to, like transatlantic cables.
  • I'll admit I don't know much about this. Just some casual interest. Anyway, I wrote a paper a while back about quantum teleportation. It's been successfully done with photons. Anyway, quantum teleportation uses something of a "loophole" to teleport the particle (in most cases photons. And no, it's not really a "loophole"..). Won't go into it much but... you're right, the act of observing something disturbs it. Thus you could not have traditional repeaters, that would work by reading and duplicating the signal. QT, tho, doesn't make a measurement at all, thus leaving the data intact. I dunno. This is probably far from feasible now, (and I'm talking out my butt ;) but it was just a thought.. (and as for "Minds, Machines, and the Multiverse.." haven't read it, but if it has a bunch of hooey about multiple dimensions and physics, I dunno if I wanna read it... ;)
  • Blockquoth the MIT press release:
    This may be a breakthrough in bridging the very different requirements for transmitting infrared and radio frequencies" at opposite ends of the energy spectrum.
    Um, usually, we consider IR and radio to be on the same side of the spectrum, i.e., longer wavelength than visible light. Unless the author sees in the microwave region of the spectrum? :)

  • some additional info... (Score:4)

    by freedman ( 196203 ) on Wednesday July 26, 2000 @03:25PM (#902937)
    Also of interest, might be the following web-page concerning the research group of one of the principal investigators (John Joannopoulos of MIT): ab-initio.mit.edu [mit.edu].

    Actually, when I was at MIT, I took one of Joannopoulos's graduate courses in solid-state physics and can vouch for his teaching abilities in addition to his well-known reputation within the field of electronic structure calculations.

    Also of interest might be the webpage of Prof. Tomas Arias at Cornell (whom I work for now), who was a collaborator of John's at MIT up till last year: www.ccmr.cornell.edu/~muchomas [cornell.edu].

    For a little more background:

    Many of the computational calculations that are used by these investigators, in situations like the one where the perfect mirror was postulated, fall into the category of "ab-initio electronic structure calculations". The "ab-initio" part, latin for "from first principles", denotes that the calculations attempt to simulate actual resultant macroscopic behavior from the much more fundamental precepts of the quantum mechanical interactions between the atoms and electrons in the material under investigation. This has some very interesting advantages, not the least of which is that the resulting calculations do not have to justify higher level assumptions, whose applicability might be less assured. That's not to imply that no assumptions are used in this process (if NO assumptions were used, even most modern supercomputers would be unable to calculate the resultant quantities of interest for any more than 4 or so atoms). As it is, typical experiments generally are able to consider 100-150 atoms, which is usually sufficient to determine many properties of interest. The main approximations that are still necessary are the free electron approximation (which mandates that atomic nuclei and core non-valence electrons are immobile compared to the much lighter valence electrons which are important for conduction) and the independent electron approximation (which stipulate that the potential felt by a valence electron is not specifically dependent on the impact of every other electron [as it would be ideally], but is instead affected by a sort-of mean-field approximation of all the other electrons' potentials). However, this independent electron approximation necessitates that the resulting Hamiltonians (energies of the system) must be found by iterative self-consistent methods, whereby each successive output is computationally fed into the algorithm as input until the result converges within certain error limits. The independent electron approximation is usually implemented in terms of either the Hartree or Hartree-Fock theories (in case you want to search for more info).

    Anyway, that's all I have the energy to write about, but the websites I spoke of above, probably give links to lots more material. They also have some amazing photos of the ab-initio simulations.

    -Daniel
  • Actualy, going by that logic, you wouldn't be able to see through either side, as it reflects ALL visable light, but I'm sure we could adjust the staturation to allow for a percentage of light to pass, which would not only make it energy efficient for homes, but more secure as it would always be hard to see in.

    Tom

  • "So only God has been able to build such a device (the atom with its ever moving cloud of electrons) ..."
    Actually God's following 'his own rules' on this one. Atoms arn't perpetual motion machines. If it wasn't for all those suns doing matter to energy conversions (and the huge energy surplus we started with at the big bang) the whole universe would eventually drop to 0 Kelvin and the motion of those electons would stop.

  • Re:Oh yeah! Bionic soldier, here I come! (Score:1)

    by Anonymous Coward
    Oh yeah, and there's the fact that CO2 lasers are less than 10% efficient so get get 100 watts of laser power you would need more than a 1000 watt power source. I hope you have plenty of room in your midriff.
  • Actually this has not much to do with multiplexing, which is already in place to a large degree. I think (AT&T at least) is using about 6-7 different colors on their main fibers...

    The colors dont interfere anyways, but having a higher reflectivity should make it so you can have longer runs of cables without repeater stations.
  • I believe... (ie, I'm making this up as I go along) that polarisation is preseved by reflection.
  • I found this line in the article interesting:

    "...walls, windows or even car interiors coated with the 'perfect mirror' could very efficiently reflect heat while appearing transparent."

    Sorta sounds like the "General Products Hull" from Larry Niven's Known Space books.
  • HAHAHAHAHAHAHAHAHAHA!!!!!!!!!!!! OMG!!! Dude, that was TRUELY classic! I bow before your superior bastardry.
  • It would have to be a highly reflective cat.
  • This is the only way I could think of it happening:
    The light from a candle (or, actually, probably a laser) would hit a mirror at such at angle that it got reflected back to *almost* the same spot, then *almost* the same spot on the other mirror, and then *between* the first two spots on the first mirror, and eventually it would all be funnelled kindof into one thin line.
    Kindof like when we put the automatic pool cleaner in my pool, and at first it works, but then it just goes straight across and back, and we have one clean strip, and crap across the rest of our pool.

    This way, the light would never actually hit the candle/laser/whatever.

    However, they say it is an *almost* perfect mirror. This means that it's not really perfect, and even if it reflects. 99.999999999999999999% of the light, with the speed that light moves it would all be gone in a fraction of a second. (probalby, it's summer, I refuse to do the real math.)

    And, btw, to test if the light was there, you just stick your hand in the box. If there's a blinding flash of light and your hand turns black and charred, it worked.

  • On their site they mention that their technology, among other things, will exhibit very low attenuation. Low-attenuation fiber was the latest and greatest when China and Japan were laying their fiber. Thinking they were ahead of the game, they laid this stuff, only to find later that low-attenuation cable doesn't carry ITU multiplexed data very well. In low-attenuation fiber, adjacent channels tend to interact with each other, causing harmonic interference at other ITU channels.

    Fortunately, most of the fiber laid here in the US is the older, higher attenuation fiber which is great for ITU multiplexed data. As a consequence, the Asian markets have been researching S (short) band multiplexing, because the effects of the low-attenuation fiber are less noticeable at bands outside of the ITU grid.
  • Actually, at 0 Kelvin, quantum tunnelling turns all matter into liquid.. An extremely viscous liquid, but a liquid nonetheless..
  • Now I'm just wondering here...if this is a "perfect" mirror...and it reflects most frequencies...would it not make a very good shielding type material...coupled with Tempest type technologies...if it does in actuallity reflect microwaves...and possiably radio...how much higher or lower does it go...;)...I'd love to have a shielded laptop that doesn't weigh 80lbs...;)
  • Ok, assuming the mirror is "perfect" (yeah, I know its not) and you kept pumping photons into an enclosed box, is there some kind of maximum energy density, a point where the light starts coagulating into matter?

    --Fear the blue screen of innovation
  • You are completely incorrect in your thinking. If the law actually applied as you believe, nobody would be doing research in academia if there was any chance for profit.

    AFAIK, the govt funds the university, the univ funds the department, the dept funds the research. Partial proceeds go to univ, partial to the dept where they were working, and the rest to their company. There are THOUSANDS of govt funded people who have patents. Getting a patent just means that your name is on the patent. If you are funded by someone, usually there is a standard contract or formal agreement of profit sharing or something. Especially at an amazing institution like MIT.

    I don't know the exact details, but believe me, they can and have received patents and started their own company for it. A lot of graduate students at MIT own/run companies while still going to school there.

  • But funny.

  • The real deal (Score:1)

    by Anonymous Coward
    The technology, however compelling to read about in a news report, is completely untested, unverified, and there is no indication that it will actually be a viable product.

    Most likely, they will follow the well established route of hyped MIT startups, which consists of:

    1. MIT obtaining equity in their startup.
    2. MIT issues news releases promoting the technology (or the company indirectly), heralding its promising future and 'revolutionary' technology, while not disclosing their interest.
    3. IPO occurs, making the stock valuable.
    4. MIT dumps their shares.
    5. Insiders get rich.
    6. The company loses millions of dollars, and never becomes profitable, having no viable, market-ready product.
    7. The remaining investors, forever hopeful, are left holding the bag.

    Reminds me of Akamai.
  • Doesn't the concept of the perfect mirror mean that the dialectric constant is different according to each frequency, in such a way that at any angle, at any frequency, it still reflects?

    Another thought; doesn't this mean that we now have plastic mirrors? If you created windows out of this stuff, for example, wouldn't there be much energy savings because the window would reflect IR, visible light, and UV, for example, and insulating a building from the sun?

    Bye!
  • OK how does that work? These guys are academics, right? So their research was funded by the state? And maybe they might have had some industrial sponsors. They would be expected to right papers about their results. And yet they still get the right to make all the money out of it? Funny, I thought the government paid for this sort of thing to get research into the public domain... but this is patented, so although anyone can know about it, no-one can use it. If those were my tax-dollars, I would be pissed.
  • Ooo, or just by polarizing it in one direction, sorry, just thought of that...
  • Doesn't this really mean that we now have a plastic mirror, where before one needed metal like aluminum or silver or stuff to make mirrors?

    So now we can have microwaveable plastic containers that are shiny, if IR is allowed through? That we can create a film to place on windows that reflect all the light without using metals such as copper and gold? That we could build LCD displays with this material to provide brighter, thinner, lighter displays?

    It isn't just fibers and cables; it really is a mirror, isn't it?

    Bye!
  • More to the point is that polarization is preserved. Polarization is the primary quantity which is "quantum entalgled" in most current efforts at quantum cryptography, so preserving it is of the utmost importance in making quantum crypto a reality in the near future.
  • Generally what happens is that MIT's PLTO (Patent/Licensing Transfer Office, or something like that) usually owns the patent, but then gives an exclusive license to the company founded by the researchers working at MIT (relatively typical in academia). Usually works out that of the proceeds from this patent license (and they can be significant), 1/3 goes to university proper, 1/3 to founder's department (physics or mat-sci eng.), 1/3 to founders themselves.

    So, it's not really a case of state-supported research where the investigators are making undue profit.

    -Daniel
  • There was recently an article [slashdot.org] on slashdot that dealt with that topic (photonic switching).

    --
  • Wouldn't you also now be able to use the polarization as a data carrier as well?
  • If you compare the frequencies of IR versus radio frequencies, you're talking the difference between 400GHz v.s. 1MHz (or much lower). Quite few orders of magnitude. If you split the spectrum at visible light, which is not unreasonable, yes, they are on the same side. But if you look at the EM radiation that we use for communication, they are almost as far apart as we can get (have gotten).
  • Now you're talking! I was thinking that if this is a polymer, then it could be laid out, flat, too.

    Can you imagine a sheet of this stuff on your ceiling?

  • How the hell do these guys get a patent on research done using a federal grant? This is all public domain. Hate to burst their for profit bubble but Nortel, Cisco, and Agilent I'm sure will have something to say about this.
  • Tight corners, kinks, bends, and wrapping can all notch or damage the conductors, which can wreak havoc on high-speed signalling.


    Well what exactl;y is a tight angle? Is a 90 degree turn through a 3 inch diameter circle ok? Also kind of sppeds does normal bending become an issue? 10/100 or only gigabit? Obvisiously with cheap wire and extreme bending etc its an issue at any speed. If its only a major issue at gigabit speed then I wouldn't be concerned because if I had that kind of money I would get my self all the tools neccessary to wire my dorm properly. But till them I'll stick with my $12 pci 10/100 NICs.


    My school auctually wired up our dorms pretty well. All cables cut to proper lengths, 3Com 10/100 hubs with fiber uplinks, etc, etc.
  • On their website they claim that they might get even more bandwidth out of a perfect-mirror cable than out of single-mode fiber.

    This is all fine, but how are they going to deal with light bouncing back into the transmitter (lasers break when their light is reflected back into them), and the multi-mode characteristic of their cable?

    The EM-picture in the first article seems to show a multi-mode characteristic, and because of the mirrors used I see it as a step-index fiber, which can not be used for long-range broadband transmission. Light coupled in at an angle has to travel a longer distance than light that is emitted along the axis of the cable, and so it takes longer to propagate that light.

    I'm really not an expert in electro-optics, but could somebody please enlighten me about this?
  • funded by DARPA and the USAF.

    as i recall, one of the major impediments to high power lasers has been energy lost to the amplification mirrors/lenses...major cooling systems to keep them from exploding...plus very heinous alignment issues.

    now the USA might be able to use ground based lasers (ala missile command) to protect herself (and the other western democracies) from nuke-wielding totalitarian/terrorist nations.
  • and it's a 1-way (or is it 2-way?) mirror

    One way. That way it acts as a mirror only one way. Or maybe, taking it a different way, that you can only see through it one way. Either way, two way doesn't make sense in any way.

    Anyway, that's way more than I intended to send your way.

  • See this. [sciam.com] at Scientific American.

  • Implications (Score:4)

    by Chairboy ( 88841 ) on Wednesday July 26, 2000 @02:14PM (#902971) Homepage
    Hey, I just realized what this means. If it's reflective on such a wide range of frequencies, that means that the amount of multiplexing data compression you can do is huge.

    One of these fibers might be able to carry a hundred times more data then any current fiber, for instance, just by having sub-bands that use different light frequencies. Each band would think they had exclusive use of the superfiber, so they could all be running at max datarate.

  • Faster Data Transfer? (Score:4)

    by PHr0D ( 212586 ) on Wednesday July 26, 2000 @02:09PM (#902972) Homepage
    ..I could use that to download that 100k animated gif on the company website [omni-guide.com]..
    --------------------------------------
  • Wouldn't this be ideal for the story a while back about broadband in the city? I.e. light as a signal?

  • Oh yeah! Bionic soldier, here I come! (Score:4)

    by Chairboy ( 88841 ) on Wednesday July 26, 2000 @02:11PM (#902974) Homepage
    This is exactly what I've been waiting for. Now, I can get that 100 watt CO^2 laser and RTG power source implanted in my midriff and run one of these cables through my arm and to my fingers so I can fire laser beams from my hands!

    No need to invest in handguns, spare keys, or window defrosters, I'll just take a finger laser, thank you!

    The reason I haven't done this before, of course, is the heat problem with fiberoptics cooking all the musclemeat between the laser and the aperature.

    Oh, that and I don't have the millions it'd take to buy the hardware and surgeons needed. But that's hardly the important issue here, is it?
  • but 2-way could mean it mirrors one way, and you can see through it the other. I've actually heard it both ways, and was wondering which was correct.

  • The article seems to indicate that this is more usefull in scientific research where polarization is important. For the real world application does this new technology really offer much over current fiber optic technology? And I don't see anything about cost.
  • This could substantially reduce or even eliminate the need for amplifiers in optical networks. Secondly it will offer a bandwidth capacity that could potentially be several orders of magnitude greater than conventional single-mode optical fibers.

    Curious to know what is the dieletric constant of the OmniGuide material.

  • Re:Implications (Score:5)

    by MAXOMENOS ( 9802 ) <mike&mikesmithfororegon,com> on Wednesday July 26, 2000 @02:18PM (#902978) Homepage

    Hey, I just realized what this means. If it's reflective on such a wide range of frequencies, that means that the amount of multiplexing data compression you can do is huge. One of these fibers might be able to carry a hundred times more data then any current fiber, for instance, just by having sub-bands that use different light frequencies. Each band would think they had exclusive use of the superfiber, so they could all be running at max datarate.

    Just what we need. Another 50,000 channels of cable TV.



    The Tyrrany Begins.... [fearbush.com]
  • There have been a dirth of high-bandwidth transmission schemes to come out in the past few years, but each has only met with limited if any applications for two reasons, practicality (cost, installation, etc.) and inertia, after all a great majority of people still connect to the internet on twisted pair. As wonderful as these developments are, i gradually get dissillusioned and thing at this point that we probably won't ever see this on a network for a good long while.

    i.e. whatever happened to IBM's laser computing, and micromagnetic disks that stored over 1G?

  • I always wanted a mirror in which I'd look perfect!
  • Rather than a mirror that can reflect "many different frequencies at any angle with no loss of strength", wouldn't a perfect mirror be one that made you a couple inches taller and dropped 15 lbs?
  • In a related note, Cisco has just announced they have bought a small optical networking start-up in Boston, MA area for $3.1415926M. . . .

    But seriously, is anyone else concerned that Cisco seems to be buying up any company with any relation at all to networking? I think within a very short time the Justice Department is going to have to step in to ensure they don't become the MS of the network hardware world.

  • Cant remember the name right now, but it dealt with some new plastic or glass substance which could trap light, which started being used in all kinds of applications, from using windows of the stuff to slow light 12 hours (in effect giving streets daylight during the night), to spying and government control at the end...

    Anyone know which book Im talking about? Something like "Other days, other eyes"?

  • Re:Screw networking (Score:5)

    by Shoeboy ( 16224 ) on Wednesday July 26, 2000 @04:09PM (#902984) Homepage
    Can you imagine a sheet of this stuff on your ceiling?
    And wake up every morning thinking a naked fat guy was about to land on top of me? No thanks.
    --Shoeboy
  • Well, I expect that even if the mirrors reflected all of the light emitted by the candle, the candle itself would absorb the light it emitted.
    --
  • Only if you can keep the candle somewhere other than inside. That reflected heat is gonna melt(vaporize) that candle real quick if there is any storage at all.
    And...
    If you have a hole to put it[photons] in that hole it is also going to be an exit. See Lasers etal.
  • Will this work with the current generation of optical switches or will optical switches need to be built that utilizes this technology also?

    Does this fiber maintain polarization integrity to allow two data channels of the same color with 90 degree cross polarization's 83 dB attenuation?

  • I've actually thought about something similar to this before, except not in terms of a battery. Say you have a small ball like that, and it's a 1-way (or is it 2-way?) mirror, so that any light that goes in, gets trapped inside, basically charging whenever light is shining into it (of course, this would only be possible if the mirrors were 100% reflective in one direction, and transparent in the other). So, say you make this ball breakable. You could then throw the ball, creating a flash of blinding light, no? Or maybe it would be energy too, depending on how much light was stored (I haven't taken physics yet, so that probably isn't true...I'll get back to you once I have ;-). But anyway, that could have interesting military value (or self-defense). Ah well, I'll stop rambling now I guess...the whole thing is probably completely impossible...but it would be cool.

  • Re:some additional info... (Score:4)

    by MattEvans ( 62089 ) on Wednesday July 26, 2000 @04:30PM (#902989)
    Daniel,

    Actually, although Joannopoulos does do a lot of electronic structure stuff (and is quite good at it), the research which lead to this mirror breakthrough comes from the other half of his group. He also does research on "photonics", which is essentially the study of light propagation through materials with varying dielectric constant. The scale is well beyond that of ab-initio electronic structure; visible light wavelengths are an order of magnitude larger than lattice constants/interatomic spacings, which are of course the relevant length scales for (valence) electrons. Photonics is done more-or-less macroscopically; everything is derived from good old Maxwell's equations.

    That being said, what Joannopoulos' photonics group does is essentially very similar to band structure calculations. Assuming there's a periodicity in the dielectric constant in the material (just like a periodic potential in a crystal!), then Maxwell's equations can be recast in a form which bears a striking resemblance to the Schrodinger equation for an electron in a solid. What they get out of that is a "band structure" for light. Certain frequencies are allowed, some are forbidden. Thus it becomes possible to make a perfectly selective waveguide. Just design a material which has "band gaps" at the frequencies you want to filter, shine the light through, and let nature (Bragg reflections? :) ) take its course. Of course, you can also do other cool stuff, like introducing defects, which create localized states just like in solids. This is a source of little "light boxes". There are a lot more similarities; Joannopoulos et al. have written a really good book on the subject called "Photonic Crystals". It's short and quite easy to read, but a few years out of date . Also, if you know how to make the analogies, it makes an excellent introduction to concepts of electronic band theory.

    The above explanation might be incorrect in its details. I read the book pretty quickly and superficially on the subway when I was visiting MIT this spring (opposite of you: I was a physics undergrad at Cornell, and will be going to MIT this fall). I encourage you (or anyone) to look into photonics more closely. It's really fascinating.

    Matt
  • Actually Nortel is in a dead heat with Cisco to see who can spend the most outrageous sums of money for any kind of optical-networking startups. By-the-by there is also a good deal of research being done on all-optical chips, here's a li nk [thestar.com] to some work being done at the University of Toronto. It would be incredible if this 'perfect mirror' could accelerate the likelihood of this coming to my desktop! PS the link showing as li nk is not my fault! I previewed and tried to correct it four times but Slashbug is at max power and is determined to make me look like a knob!

    ----
  • Don't forget your electricity 101 rules of inductance and capacitance. The twisting of twisted pair is designed to be an almost perfect balance for signaling quality through the wires contained in the shielding. You inhibit that quality when you have lots of cables in a bundle (capacitor) or you make it go through turns (inductor). Sheilding helps, but shielding is only so good, even on the best quality shielded twisted pair you should watch how many cables you bundle together. Really watch if you're using UTP.

    That's one of the reasons a full 56k modem is not allowed, to much signal in your pair goes into the other pairs in the bundle of wires on the pole.
  • Nope, sorry. Assuming a large portion of your trafic already passes over fiber, your ping would bearly change (the light travelling down the fiber will be going the same speed [more or less])

    I'm guessing the ammount of bandwidth (not latency) would be huge tho...

  • Thanks for explaining that, it sounds like a much more reasonable arrangement than it appeared. I wonder if the rationalisation of this is that 'the researchers deserve it' or 'the researchers know best how to exploit this to raise the most funds for this University'.
  • For once and for all people!!!!!

    CAT5 is NOT a type of cable! What you have there is technically termed 'blue cable'. CAT5 is an installation/testing scheme, which, if the cable install passes testing using expensive equipment, it is CERTIFIED cat5...

    There is no such thing as 'cat5 cable'.. There is such a thing as a 'cat5 installation'. Thus, it is impossible to have a cat5 cable at ninety degrees, because the installation scheme has a whole bunch of rules concerning this, including a lack of kinks/crossovers/parallel runs with power-cable etc etc etc

    If you dont follow the rules, hire the equipment, pass the testing and get a certified dude to sign off, it aint cat5.

    End Rant.


    Simon

  • Thermal Insulation? (Score:3)

    by Maq ( 102976 ) on Thursday July 27, 2000 @12:48AM (#902995)
    OK my physics is garbage, but couldn't a thin sheet of plastic tuned to reflect only wavelengths in the IR spectrum be used for "perfect" thermal insulation?

    If so I can't begin to think of the applications this tech could have above and beyond increasing bandwidth.

    Maq
  • The main problem in high-bandwidth fibreoptic communication are NOT losses in the fibre (and has not been since the late 70's). The overhauling problem is dispersion. A pulse subject to dispersion will, when travelling in a fibre, flatten out and become much wider. In optical communication you send data in time bins. To send the digital sequence 10110 you would in the first bin send a light pulse, the next none, and then a new pulse, another and finally none.

    | * | | * | * | |
    | * * | | * * | * * | |
    |** **|*******|** **|** **|*******|

    Dispersion makes the pulses to broaden and makes it troublesome for the reciever to detect if there is a pulse or not in the time bin.

    | ***| | *** | *** | |
    | *** |*** *|** **|** **|* |
    |* | *** | | | *******|

    Sorry about the figures! The "|" sould really align, forming five time bins.

    However there are clever techniques to overcome this problem, for example solitons. A soliton is a pulse that can travel through a fibre without changing shape.

  • But as a previous poster pointed out, mirrors do not reflect photons, they re-emit them. So the original photons (and their spin information) would not survive the journey.

    $ cat < /dev/mouse

  • After a while the light is eventually going to be turned into heat due to the reflection from the glass cable. I wonder how many loops around the earth it can manage before it peters out.
  • From the article:
    Because they are made from relatively common materials, these mirrors could be made at a low cost and used for applications covering large areas.
    This sounds promising. Hopefully it will be cheaper to manufacture this in a fiber optic like form than the current fiber technology we use. This would be good for connections from hub to clients. I'd have to rearrnge my dorm if the angle of my cat-5 cable affected my bandwidth. However, this I could just encircle around my room. Of course custom cutting is another issue. Fortunatly the cat-5 standard is being rewritten to allow for gigabit ethernet over it and there are several other copper solutions for gigabit.

  • double-A photon batteries... (Score:5)

    by Sebastopol ( 189276 ) on Wednesday July 26, 2000 @02:21PM (#903000) Homepage
    This is from one of the links off of the article:

    Trapping light invites all sorts of intriguing questions, Fink points out. For instance, if you light a candle in a room lined with perfect mirrors, would the room stay illuminated even after the flame is extinguished?

    It seems there wouldn't be any way to test to see if the light was trapped inside the room. If you looked inside, some light would escape, and if any energy was exiting the box as a result of the light, then it wouldn't be trapped in the room.

    Maybe I'm confusing light & energy here, but if you burned a candle in a box made of this perfect mirror: 1) all of the heat energy from the chemical reaction during burning the candle is released in photons via radiation; which means 2) all of the chemical energy would be converted to photons bouncing around in the box; therefore 3) the box/room would now be a type of battery storing the energy in photons.

    So could one create little boxes-o'-light that would have pracitcal uses like a common battery?

    I think I'll stop now that I've grossly misused a good number of physics concepts...


    ---
  • Hmmm. I'll take two, and do you have them in blue?

  • Real World Implications (Score:4)

    by rockwall ( 213803 ) on Wednesday July 26, 2000 @02:22PM (#903002)
    If anyone is interested in the real world implications of this breakthrough, I suggest you check out Mother Earth, Mother Board [wired.com]. Written by Neal Stephenson, it is a rather lengthy article about the difficult process of laying undersea fiber. Part of that difficult is because of the imperfections of today's fiber and the need for signal amplification.

    Technology such as this could eliminate the need for periodic repeaters and signal amplifiers, and quite possibly make cable-laying a less complicated proposition.

    Who knows, one day soon, our only worries in accessing a trans-Pacific might be the latency inherent in the speed of light! yours,
    john
  • The practical application of this all is far superior networking between buildings/floors/offices in a college campus or business. Being able to eliminate most of the drawbacks of fiber means better bandwidth throughout enterprises, at lower costs. However, before this can become practical, we will need some powerful optical switches that are actually cheap.

    Damn, just when I was getting excited. Oh well, at least Qwest, ATT, etc. will be able to experience the savings, and pass it on to customers. Yeah, right...

  • This may make Quantum Cryptography a reality (Score:5)

    by Pontiphex ( 146376 ) on Wednesday July 26, 2000 @02:50PM (#903004) Homepage
    One of the biggest things holding back quantum cryptography is the fact that you can't go but 30km before you lose the signal. In traditional communications you can just use a booster/repeater....but when we are talking about measuring the spins of photons we run into the heisenburg wall. (can't measure something without disturbing it)

    Since repeaters would need to measure a photon to recreate it as a stronger signal, this has always been out of the question. But now if we have this cable that can go great distances without repeaters, then we are one giant step closer to quantum crypto.

    If you want more info on the subject, I suggest the book "Minds, Machines, and the Multiverse"

    --b
  • What the hell would be the point of having a window that reflects all light away? :)

  • Re:double-A photon batteries... (Score:4)

    by mindstrm ( 20013 ) on Wednesday July 26, 2000 @02:54PM (#903006)
    Yes, the idea woudl be somewhat correct.

    All 'heat' energy is not released as light. A more proper analysis woudl be that the energy released by the burning candle is released in the form of a) EM radiation (light) and b) chemical changes. Most of the 'heat' detected comes from conduction/convection by the hot gasses given off in the reaction. So.. some of the 'energy' given off of the exothermic reaction that is a burning candle is kinetic, some is EM, and some goes into chemical changes themselves.

    Yes, with a perfectly reflecting surface *and nothing inside to absorb the light*, you would have a 'photonic battery... but it wouldn't work with a candle in the middle.

    I suppose, given the right reflective surface, we would be able to put immense amounts of light into a small enough container and use it as a battery.. however, perfect reflection has it's limits. Enough energy in the form of photons would cause the mirror to stop working.. remember how a mirror works. It doesnt' 'reflect' photons, it 're-emits' them. There is a limit to what it can reflect; a laser with enough juice can still destroy a mirror.
  • Sounds like you might be aware of this already, but the angle of your cat5 *does* have an impact on your bandwidth. Tight corners, kinks, bends, and wrapping can all notch or damage the conductors, which can wreak havoc on high-speed signalling.

    Of course, ths is assuming that the rest of the premises is wired to proper cat5 standards, which in the dorms I lived in was far from true. Lots of people abuse UTP because they think wire is wire, but if you look at the cat5 standard it really isn't.

  • Besides which, if you had a device that could use the light created by the candle for power, why not just carry the candle around? :-)
    --
  • That we can create a film to place on windows that reflect all the light without using metals such as copper and gold?
    If it's a perfect mirror, then it reflects all light...
    That means no light goes through it...
    Um, that makes for a pretty bad window.
  • I plug in my computer with a "UL cable".
  • The hadware required on each end would be... well, it would be interesting to say the least. How do you detect and break out the seperate frequencies easily? The only way I can think of off the top of my head is some sort of high-quality digital ccd-thingy like they use in cameras to catch the light.

    There is also the fact that to really use this technology to it's full and to use all available frequencies you would have to at least start by covering all visible, ultraviolet and infrared. Then you go into microwave? X-ray? Hmmm... interesting. It would certainly make it interesting to be able to lay one piece of cable and not have to think about it again for a few decades - just upgrade the kit at each end to the next generation. You can do that with fibre, but how long is fibre suitable for orders-of-magnitude upshifts in throughput requirements? A decade? Maybe two? In theory, your idea is that as long as there is always some spare ER spectrum left, you can push a bit more down... and we haven't even got into compression algos. on this yet! :-)
    --
  • It also has low-loss properties, reducing the need (and therefore cost) of optical amplifiers.
  • i.e. whatever happened to IBM's laser computing, and micromagnetic disks that stored over 1G

    My guess is there arn't >1G microdrives because there is not a big demand for them. There is a demand (maybe large) for smaller (CF2 rather then CF3) microdrives (and IBM licenced the tech to someone else who is working on it). There is also a demand for cheeper microdrives (and the cheeper the bigger the demand).

    The microdrive costs much less per meg then flash baised CF cards (CF about $2/Meg, microdrive under $1/meg -- according to pricewatch). But you can get a 48M CF Flash card, or smaller. And that holds a lot of photos (about 70 2.1Mpixel modestly jpeg'ed images). You can't get a Microdrive for less then 340M, which is overkill for most people cammeras, so $250 for 340M may be a great deal compaired to $94 for 48M, but it is really like the Price Club "buy a can of beans larger then your torso and get it for 70% off!" deals.

    As for laser computing, I donno. I'm not sure I recall hearing them talk about using lasers for anything other then a clock driver, and I think they (or someone else) uses that allready.

  • If you were to light a candle inside the room that would release particulate matter into the air. This would eventually abosrb the radiation provided the particles are big enough. Of course that doesn't address the problem of actually looking inside.
  • One particularly neat thing about Joanoupolis's group is that they also developed photonic band gap simulation software for linux. Check it out. [mit.edu]
  • In the spirit of the only stupid question being the unasked one,

    Does it have to be a photon? Could a bozon held in a laser containment device (you know, one of those cooling things) (or maybe if it is charged an electromagnetic bottle) be used instead?

    Photons have polarisation that can be measured. Are there any other attributes that can be observed in the same way, but perhaps applicable to non-photons?
  • If it's reflective on such a wide range of frequencies, that means that the amount of multiplexing data compression you can do is huge.
    True, if you can fit more frequencies into a single fibre with less interference there is room for more data and/or faster transfer via multiplexing.

    One of these fibers might be able to carry a hundred times more data then any current fiber, for instance, just by having sub-bands that use different light frequencies.
    Not only that but it also stands to make fibre cheaper (if the cable itself isn't too exxy) due to the reduced need for repeater stations, at the moment the loss of signal strength is a major issue. I really hope that stuff like this takes off, it means cheaper, faster access at home.

  • Question (Score:4)

    by tealover ( 187148 ) on Wednesday July 26, 2000 @02:27PM (#903018)
    If you break the mirrors will you get 7 regular years of bad luck or 7 internet years of bad luck?
  • but could someone mirror the perfect mirror? theoretically?

    Elimination of the need for optical amplifiers will cut the cost of deploying and maintaining optical networks. Combined with the increased bandwidth, it will allow network operators to slash cost-per-bit dramatically In other words, brace for a Time Warner/AOL buyout. Anyone want to bet on how long OmniGuide is it's own corp?
  • Per cost: Until it's massed produced, it's effectively approaching an infinite cost, as it's in the prototyping stage. I don't think anyone can speculate a cost until someone can create a mass-produced version. They don't say how cost effective this material is...

    However, unlike current fiber optic technology, this can take multiple wavelengths and multiple polarizations with negligible loss. So in traditional fiber you can only have a beam of wavelength X; in this cable, you can have a beam of wavelength X in 2 different polarizations without problems. Twice the bandwidth now available!

    Another benefit is that now you are not limited to a specific spectrum spread by the fiber. You now have access to more or less the entire visible spectrum, plus any other pieces of the spectrum that the cable can reflect perfectly. No clue how big the bandwidth increases with this, but potentially huge!

    This technology is an improvement, but it can be used in places where it would be a revolution, not just an evolution. It mentions optical computing, where routing was a problem on a small scale, among other things. It just takes a decent genius to figure out how to use this stuff ^^

    Bye!

  • Screw networking (Score:4)

    by Shoeboy ( 16224 ) on Wednesday July 26, 2000 @02:27PM (#903021) Homepage
    If you've got a perfect mirror, give 2 of em to me so I can glue em to the tops of my shoes.
    --Shoeboy

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