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Science

NIST Unveils Chip-scale Atomic Clock 172

Posted by CmdrTaco from the and-it-fits-in-the-oh-never-mind dept.
grumling writes "The heart of a minuscule atomic clock, believed to be 100 times smaller than any other atomic clock has been demonstrated by scientists at the Commerce Department's National Institute of Standards and Technology (NIST), opening the door to atomically precise timekeeping in portable, battery-powered devices for secure wireless communications, more precise navigation and other applications. "
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NIST Unveils Chip-scale Atomic Clock More

NIST Unveils Chip-scale Atomic Clock

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  • timing is extremely important (Score:4, Funny)

    by Anonymous Coward on Sunday August 29, 2004 @10:21AM (#10102374)
    especially when you're trying to get first psot

  • Useful (Score:3, Funny)

    by AKAImBatman ( 238306 ) <akaimbatman@ g m a i l . com> on Sunday August 29, 2004 @10:21AM (#10102376) Homepage Journal
    opening the door to atomically precise timekeeping in portable, battery-powered devices for secure wireless communications, more precise navigation and...

    Video games!

  • Yeah... (Score:5, Funny)

    by dmayle ( 200765 ) * on Sunday August 29, 2004 @10:22AM (#10102380) Homepage Journal
    Yeah, so I can keep time 5 minutes early more precisely than ever before...
  • Today CmdrTaco will post any story he gets, just to make the iMac-fake-picture-hoax-debacle go as far down the page it can get :)

    And that doesn't mean that I don't find this atomic clock thingie absolutely fascinating ...

    [Looking at strange spot on the wall]

    What was I talking about?

  • OK, so when do I get one in my PC... (Score:4, Interesting)

    by Atrax ( 249401 ) on Sunday August 29, 2004 @10:24AM (#10102392) Homepage Journal
    ... so my clock doesn't drift by like five minutes a day, necessitating a daily ping to the USNO time servers? anyone?

    • ... so my clock doesn't drift by like five minutes a day, necessitating a daily ping to the USNO time servers? anyone?

      My MythTV [mythtv.org] box has a rather old clock that drifts a lot. This could create problems with program scheduling, so I've set up a cron job to run rdate every couple of hours, and keep the clock synchronized with one of the NIST NTP servers.

      If you're on a Windows box, I'm sure that a similar automated functionality can be set up.

      • So why don't you just use NTPd [ntp.org] or OpenNTPd [openntpd.org]? And why aren't you using pool.ntp.org [ntp.org] instead of picking on the poor, overloaded NIST servers?

      • Re:OK, so when do I get one in my PC... (Score:4, Informative)

        by Artifakt ( 700173 ) on Sunday August 29, 2004 @11:51AM (#10102834)
        There are about a jillion clock programs for windows that call the NIST clocks on a regular schedule of your choice and adjust the PC. Most of them are freeware. Some of them work with a clock display on desktop, some with the existing clock in the systray. I recomend Beatnik, at http://www.somedec.com/ [somedec.com] free, skinnable, and stable, and no I don't have any connection to the author except using it and some of his other freeware. However, the OP apparently doesn't want to do something like that. I confess, I'm not sure why. If he has a box whose clock drifts by 5 min a day and that once daily ping is eating up substantial time on his connection, the answer is to get a new box or a faster connection. If my clock naturally drifted by 5 minutes a day, I'd want to correct about every 4 hours or so, or maybe I'd just immediatly try replacing the Mobo battery in case that was a sign it was going stale. Maybe I'm missing something there, and he just doesn't want to go through the process manually, but it sounds like he's more wanting to not do it at all.
        • OK, maybe I'm getting way too existential here, but let's say you set this program to check the NIST clock every five minutes. If the time is being kept incorrectly by the local machine, how does it know when five minutes have elapsed so that it can go and get the new time?
        • Any NT based Windows already has the ability to get the time using NTP without resorting to 3rd party apps, some of which are spyware. All you have to do is set a timeserver at the command prompt (I'm out of state, so I don't have my little sheet with how to do it. Sorry.) Then you start the network time service. I think XP even lets you do it in the date and time control panel.
          • net time /setsntp:ntp server list

            Of course, having done that, users still go to the system clock properties to check a date instead of the nice calendar Outlook provides.

            They occasionally lock themselves out when they click on a new date and set themselves orders of magnitude outside Kerberos's 5-minute window.
        • I prefer NetTime [sourceforge.net], even though it's out of active development. Small, light, open source, and supports up to five servers for cross-checks.
      • It's a tickbox in the time settings in XP, you can choose to synch to NIST or time.microsoft.time or you can enter in some other address if you so desire.

    • NTP (Score:4, Insightful)

      by Detritus ( 11846 ) on Sunday August 29, 2004 @11:06AM (#10102588) Homepage
      If you run a full NTP client on your PC, it will compensate for the drift caused by the el cheapo crystal oscillator. By characterizing the drift, it can correct for it, even if you don't have a permanent or reliable Internet connection. It's like a software version of the trimmer capacitor that is used to adjust the frequency of a crystal oscillator.

      • Re:NTP (Score:3, Interesting)

        by AnotherBlackHat ( 265897 )

        the drift caused by the el cheapo crystal oscillator.


        Even the "el cheapo" crystal oscillators are guaranteed accurate to better than 1 cycle per 100,000.
        PC clocks drift by more than 1 second a day because of poor software, not poor hardware

        -- less is better.
        • Frequency errors of 50-100 ppm or greater are common on the PCs that I have installed NTP on, and those are servers and workstations with non-braindead clock handling code in the operating system (Linux, FreeBSD). Just checking the PCs at hand, one has an error of -56 ppm and the other has an error of +141 ppm. Both are from first-tier vendors.

          • Frequency errors of 50-100 ppm or greater are common on the PCs that I have installed NTP on, and those are servers and workstations with non-braindead clock handling code in the operating system (Linux, FreeBSD). Just checking the PCs at hand, one has an error of -56 ppm and the other has an error of +141 ppm. Both are from first-tier vendors.


            Did you check that by running the software, or by measuring the hardware?

            -- less is better.
      • Discount Mumia!

        You, sir, have the funniest sig I've seen in a long time!

  • At last... (Score:4, Informative)

    by Aardpig ( 622459 ) on Sunday August 29, 2004 @10:26AM (#10102405)

    ...Netgear can start manufacturing routers that don't totally fuck [theinquirer.net] the NTP server at University of Wisconsin, Madison.

    • Netgear's problem wasn't lack of technological tools - it was lack of thought when they were designing those routers.
      Extra hardware tools can't fix that, I'm afraid. There was one hardware tool that would have _helped_, which would have been flash memory for storing the firmware, so that the attacking routers could have been upgraded. But when you're trying to design a device for $50 retail, you don't have much headroom for buying more flash or atomic clocks or whatever. DNS would have been a much mo
    • Hmmm. So, why is it that there isn't a rule that says:

      'all routers must run ntp and any machine requesting time services should communicate with it's nearest routers'.

      • The suggested rule assumes that the routers are operated by someone who knows how to configure NTP and how to monitor it for errors and problems. It requires that someone be on the staff that is knowledgable about NTP, has the time to maintain it, and cares about the quality of the time that is distributed. In too many cases, this isn't true.

    • Re:At last... (Score:3, Insightful)

      by haruchai ( 17472 )
      How did this get modded up so highly? Yes, it was a boneheaded decision by Netgear engineers to hardcode an NTP server address but they did work with the University and release a firmware fix in a respectable timeframe.
      Unfortunately, without a way to force an upgrade, the NTP flooding may continue for years. The real lesson here, which in this day and age should be second nature, is that HARDCODING is BAD!!
      Especially, hardcoding ONE source that will be used by hundreds of thousands of clients.
      The engineer(s

      • India: Where discrimination against Dalits has been acceptable for 3000 years

        Indeed. I deplore all forms of racism, including that against Indians and by Indians. Neither excuses the other.

  • Great for GPS (Score:5, Interesting)

    by DustMagnet ( 453493 ) on Sunday August 29, 2004 @10:28AM (#10102414) Journal
    With a atomic clock in a GPS you no longer need to solve for time, so you can get the same quality position with one less satellite. There are times where this could make a huge difference.
    • Right, which makes the first practical application for it military. Submarines, detroyers, etc. A time desync of .00001 can put you miles off course.

      -Electrawn

      • Re:Great for GPS (Score:4, Interesting)

        by Detritus ( 11846 ) on Sunday August 29, 2004 @10:54AM (#10102543) Homepage
        The Navy has been using atomic clocks for decades. Much of the technology in GPS can be traced back to early Navy programs for satellite assisted navigation. When you launch an ICBM from a submarine, you need a very accurate fix on the position of the submarine. Atomic clocks are also as timing references for secure communications links.

        • Re:Great for GPS (Score:4, Informative)

          by Anonymous Coward on Sunday August 29, 2004 @01:04PM (#10103339)
          The Navy has been using atomic clocks for decades. Much of the technology in GPS can be traced back to early Navy programs for satellite assisted navigation. When you launch an ICBM from a submarine, you need a very accurate fix on the position of the submarine. Atomic clocks are also as timing references for secure communications links.

          In fact, the entire history of accurate time can be attributed to naval navigation.

    • Re:Great for GPS... and other things (Score:2, Interesting)

      by Anonymous Coward
      It matters not just for navigation although that is the first time I really noticed how accurate time was getting easier and easier.

      Back in the seventies, our boss showed a video about him sailing across the Atlantic on a small sailboat. There was a shot in the cabin showing his digital watch (a new thing then) swinging back and forth. He pointed that out and said, "That's our chronometer." So at that point you could have the equivalent of a ship's chronometer (worth thousands) for less than a hundred b

    • Re:Great for GPS (Score:5, Insightful)

      by LiquidCoooled ( 634315 ) on Sunday August 29, 2004 @11:15AM (#10102640) Homepage Journal
      There will ALWAYS be a need for an outside reference time source.

      Whilst the device will keep track of time with an accuracy of 1 second in 300 years, what it can't do is keep time without power.

      The effect means a video recorder still shows 00:00, just a lot more accurately than before.

      • Not always. Remember, not all aplications involving time need to know the actual time with respect to the world. In fact, where this development will come in really handy will be ones where only the CHANGE IN (delta) time will be relevant.

        The first that comes to mind is GPS. With an atomic clock onboard, GPS systems will be able to drastically decrease the range of error and, as the grandparent stated, require one less satallite, for functionality.

        -Grym

      • If this thing is accurate enough to be an "atomic clock" then the need for outside reference goes way down. Specifically you could synchronize any time you had enough satellites for an accurate signal. Then when you entered (for example) a canyon and the available number of satellites was reduced, you would still have coverage.

    • Re:Great for GPS (Score:3, Interesting)

      by UnknowingFool ( 672806 )
      With a atomic clock in a GPS you no longer need to solve for time, so you can get the same quality position with one less satellite. There are times where this could make a huge difference.

      Say what? GPS satellites have always had atomic clocks but receivers have had to rely on quartz.

      Multiple signals are always needed by GPS for positioning regardless of timing accuracy. It's called triangulation. The more signals you have the better the accuracy due to timing differentials. Most GPS receivers use

      • Multiple signals are always needed by GPS for positioning regardless of timing accuracy. It's called triangulation.

        But if you had 100% accurate time, locally, you could get perfectly accurate location reading, using the signal from just 2 satellites.
        • Actually, if your precision increases too much, you'd hit the barrier of the Heisenberg Uncertainty Principle :-)
        • But if you had 100% accurate time, locally, you could get perfectly accurate location reading, using the signal from just 2 satellites.

          No, the problem with using just two signals is not accuracy. With only two signals, the problem is that you could be in one of two places. If you were to draw two intersecting circles, they connect at two points. You need another intersecting circle to truly place your location.

          • I think you mean two intersecting spheres, where the intersection is a circle (there will be an arc along this circle, near the surface of the earth, that are all valid solutions. The third intersecting sphere reduces the choice of locations to 2, one of which will not be sane (very distant from the surface of the earth and moving very quickly). The GPS receiver, under the assumption that it is operating on earth, can eliminate the unreasonable answer.

    • Re:Great for GPS (Score:2, Informative)

      by 6800 ( 643075 )
      The quality of clock in the GPS receiver makes a big difference in accuracy of the results. This is true both for navigation and timekeeping types. In any case, the time of the gps receiver must first be set to the time from the sat's but with corrections both for the delay to the receivers position and for the true gps time offset (around 13 seconds, if my memory is correct). Then based on the time held by the receiver, the position can be determined by the delay measurments of and position information in
    • The real application for small accurate clocks is that they can be flown on the GPS satellites. This reduces (or ideally eliminates) the need for a ground control segment (the network of earth stations which transmit time/position correction data to the GPS satellites). In turn, this means the GPS system remains accurate for longer when unattended. That is, even when a hostile power has knocked out all the GPS ground stations the US still has the capability to fly a missile through that hostile power's w
    • With a atomic clock in a GPS you no longer need to solve for time, so you can get the same quality position with one less satellite.

      Is the difference in time-rates between sealevel and orbit (due to gravity well position) enough to cause problems with this, or not? For the current system, all of the GPSes are at about the same depth in the well.

  • The untapped potential for customer products... (Score:4, Funny)

    by Anonymous Coward on Sunday August 29, 2004 @10:30AM (#10102422)
    ...has finally been unleashed! Home users will be able to measure the relativistic effects of using table saws and ice makers.

  • This had to come (Score:4, Insightful)

    by say ( 191220 ) <.sigve. .at. .wolfraidah.no.> on Sunday August 29, 2004 @10:36AM (#10102450) Homepage
    After all, an atomic timekeeper is just that: atomic. It only needs to measure the radiation of a cesium atom. So the core of the clock is simple to make. All the measuring equipment, OTOH, has been huge.

    But it's only natural that this becomes smaller. Give the rich part of the world ten years, and we're all spending our time wearing atomic _and_ digital watches.

    Interestingly, this could affect our lifestyle. The more synchronized timepieces become, doing stuff in sync and on time gets more feasible. But that also lowers the acceptance for being late and inaccurate. And I know that I always come a few minutes late to every appointment.

    Will people start yelling at me for coming only seconds late? Will the unspoken five-minute courtesy time ("the meeting starts at 2pm" really means "2:05pm") disappear? Will I become more stressful because of all this accuracy?

    So, while this seems to be a step forward for mankind, it does not necessarily create more happiness. Just like an entire host of new inventions.

    What bothers me with this is that it is not really useful in a wristwatch (Yes I know - they aren't making it for wristwatches yet - but just wait!). But because everyone else has one, I'll be forced to get one as well. Just like the cellular phone. And then it starts affecting my life. Scary.

    • ...doom! Doom! DOOM! DOOM!

    • Clarification, Cesium is a stable isotope and deos not emit radiation. It resonates naturally at microwave frequencies which is the oscilation that the atomic clock measures.
    • There's a five minute courtesy time??? And all this time I've been showing up early like a sucker ;)
    • Will people start yelling at me for coming only seconds late? Will the unspoken five-minute courtesy time ("the meeting starts at 2pm" really means "2:05pm") disappear? Will I become more stressful because of all this accuracy?

      I'd vote that this won't change things much. After all, watches (& cell phones) that receive a time signal by radio already exist, and even if they only sync to the signal once per 24 hours, existing quartz clocks lose several orders of magnitude less than one second per day.

    • Our five-minute rule works the other way round: if there's a meeting scheduled for 0900 it's unacceptable to arrive later than 0855.

    • After all, an atomic timekeeper is just that: atomic. It only needs to measure the radiation of a cesium atom. So the core of the clock is simple to make. All the measuring equipment, OTOH, has been huge.

      One Cesium atom? Radiation?

      A Cesium clock operates by exposing the Cesium-133 isotope to microwaves and measuring the frequency of the emitted spectral line. If you were measuring atomic decay and using one atom you'd get one decay. Then it'd most likely no longer be Cesium.

      • Not to be picky, but you're measuring the frequency of the _radiation_ when you get a spectral line.

        Just because it's not very energetic, doesn't make it not EM radiation.
    • The "unspoken five-minute courtesy time" that I've always heard is that you have the courtesy to arrive five minutes EARLIER than the scheduled time.

    • Re:This had to come (Score:2, Interesting)

      by Guppy06 ( 410832 )
      "Give the rich part of the world ten years, and we're all spending our time wearing atomic _and_ digital watches."

      The hard part isn't necessarily keeping an eye on the atom, it's all the math needed to approximate what atomic time should be.

      Over the years since the adoption of the atomic second, all sorts of adjustments and clarifications were made to the definition, that include (among others) accounting for blackbody radiation (it's "supposed" to be at 0 K), special relativity (they're "supposed" to be

    • Will people start yelling at me for coming only seconds late? Will the unspoken five-minute courtesy time ("the meeting starts at 2pm" really means "2:05pm") disappear?

      No. The cause of these, is not an issue of clocks loosing/gaining time. I mean, quartz clocks are only off a second every year, or so, so 5 minutes would mean people haven't re-set the time on their clocks in 300 years.

      In fact, the flexibility in timing is more because of the inaccuracies in how we set the time on our clocks and watches.

  • Does wifi/cellular marginalize this? (Score:4, Insightful)

    by theluckyleper ( 758120 ) on Sunday August 29, 2004 @10:41AM (#10102469) Homepage
    I've always imagined that the proliferation of wireless communications would eventually replace the need for having any sort of portable timing devices... I mean, my computer updates its clock from some atomic NTP [ntp.org] server. A wifi clock could do the same.

    Why carry an atomic clock, when you can talk to an even more accurate atomic clock, through the air? Although I guess the few ms of lag between the request and response might introduce too much error for some applications?
    • Yes, even normal users sometimes need more precise clocks. The most obvious case is GPS [slashdot.org] mentioned earlier in these posts. Quote [nist.gov]:
      • Currently, the GPS system provides time to the general public with uncertainties measured in nanoseconds.

      GPS receivers are required to synchronize very closely to the atomic clocks in the GPS sattelites in order to calculate position... they have to measure how far RF signals (travelling at the speed of light) have gone. GPS receivers (and the article's atomic clock) are mo

    • It would be a better frequency reference, which is important for the accuracy of microwave frequency synthesizers used in transmitters and receivers.

      Less phase noise, which improves overall system performance.

      A more accurate timing reference would make it easier for spread-spectrum systems to acquire and maintain lock on received signals.

    • For some people, WiFi is not now - and never will be - an option. Take for example people working in MRI labs, or farmers driving tractors.

      GPS is computationally intensive, whereas a quartz oscillator draws minute amounts of current. A chip-size atomic clock will be an extra option in the size/weight/power/accuracy tradeoff game. An internal clock will be the only choice where the system is placed in a shielded environment such as in a radiation lab or deep underground.

      Although the DARPA Grand Challenge s

  • Could this be the end of NTP? (Score:3, Interesting)

    by feronti ( 413011 ) <gsymons@gscon s u l t i n g . biz> on Sunday August 29, 2004 @10:41AM (#10102475)
    I mean, if every device has its own atomic clock, the only time you'd have to synchronize them would be when you bring them up, unless you were doing some kind of scientific work that requires ultra-accurate timekeeping. Most other applications (I'm thinking Kerberos, remote logging, etc) would only need to be synchronized to the second (or even less) to be useful.
    • You have to sync atomic clocks every time you move them around a good deal (notebooks/portables); plus if you want a fairly reliable stratum-1 timeserver now, you can use GPS, for which you can buy a reasonable OEM receiver for about $50.
    • i don't know about you. but on my network, 1 second delay in clocks screw things up.

      when trying to track down a problem on multiple busy server, 1 second is at least twice (most likely more) as much data as you would need

      a 1 second delay in synchronisation between your web application and a TV show is a LONG time (it's for interactive tv. we have to synchronise with the ads, the questions asked in the show, pauses, etc..)

      of course the biggest problem is when dealing with multi networks problems. i don't

    • if every device has its own atomic clock, the only time you'd have to synchronize them would be when you bring them up

      Not likely. First of all, this is thousands of times less accurate than a full-sized atomic clock, so your clock will drift out of sync gradually.

      Even with full-sized atomic clocks, you rarely depend on any one of them to be 100% accurate, rather, they check between a pool of them, just in case one is slightly off, so it's not hard to imagine that maybe your atomic clock could loose a sec

  • My Samsung SPH-A460 cell phone [samsung.com] only shows the time when it can get a cellular signal. There's also a host of additional phone book software design flaws that make it less useful than my previous, archaic green-and-black phone. Here's to hoping this makes it easier for developers to easily integrate essential functionality into their products.

  • GPS Devices (Score:2, Interesting)

    by KB1GHC ( 800065 )
    This device will be excellent for Global Positioning Systems.

    GPS works like this:
    every GPS satellite has an atomic clock, your GPS reciver calculates all the difforences in time and position of the GPS satellites, and based on knowing the distance from each satellite, is able to calculate where you are. Currently, GPS recievers have Quartz clocks that are constantly kept snycrenized by the attomic clocks in the satellites.

    now quartz clock accuracy is nowhere near attomic clock accuracy, so this will make
    • I thought one of the remaining large error factors in civilian GPS systems was the variable ionospheric delay. That's why the military version uses two frequencies, so they can measure and compensate for the ionospheric delay. The civilian version just uses a constant.

  • Another interesting home networking gadget (Score:3, Interesting)

    by starbird ( 409793 ) on Sunday August 29, 2004 @10:56AM (#10102552)
    When can I buy a netgear networkable home atomic clock box? Plug it in to your network, and use it to update the times on all your systems, instead of pinging NTP servers.

    Or put it on a pci card, I can just put it in my router box.

  • Checklist (Score:5, Funny)

    by UnknowingFool ( 672806 ) on Sunday August 29, 2004 @11:01AM (#10102574)
    Cell phone with web surfing: $150
    Unlimited web surfing option on cell plan: $10/month
    Cell phone with atomic clock and web surfing (future): $200
    The ability to snipe someone on eBay for that powder blue Elvis jumpsuit: priceless
  • That's the missing component in ones home-built cruise missile..

    "pinpoint accuracy"

    Now everyone can have one in their back yard.

  • Gravity (Score:5, Interesting)

    by Anonymous Writer ( 746272 ) on Sunday August 29, 2004 @11:17AM (#10102653)
    Since atomic clocks can be used to measure effects of gravity [nasa.gov], it would be interesting to see how mass producing atomic clock chips could be used to create maps of gravity, seeing how they can be used to reveal geological information [guardian.co.uk].
  • people will be able to have VCRs that show the correct time...
  • This sounds amazing. IANA astrophysicist but it seems amateurs could do some real very long baseline interferometry with these things like the VLBA does.

    It also puts military-level technology again into public hands, this seems pretty dangerous - high school kids's satellites could enable terrorist missile navigation.. oh well I guess this is inevitable.

    Perhaps someone experienced could provide some input into the kinds of things this would make possible?

    I'm wondering if it would enable:

    - distributed seti, heck distributed lots of things.. monitoring of airspace anyone?
    - precise geolocation similarly for vlba? If you can shoot the sun and have a compass, should be able to solve for own location?
    - distributed measurement of environment for atmospheric simulations i.e. on ships at sea to gather wind vectors?
    - high-efficiency use of wireless spectrum, maybe also data transmission in noisy environments?

    from the faq, "atoms are also excellent sensors". Would this enable:
    - teraherz scanners (well maybe it isn't that fast, only 9 GHz) and doppler analyzers
    - portable detectors of acceleration, gravity, relativistic effects, sonar, ..what?
    - also one manufacturer I remember had a very interesting application of very short radio pulses that could be used to make virtual barriers I think the military was interested in it.. Until there page was taken down..

    Also I'm intrigued by the latest computer graphics research into structured light and recording of light fields with distributed cameras. It would seem that an audience with a lot of handycams and these chips could be producing an extremely interesting record of say a sporting event. A camera with a few of these chips might be quite useful.

    What kind of things would be possible with off the shelf hardware and a couple of these chips?

    Would these enable casual interferometry in day or night?

    On the downside I saw a $10 spam sandwich by Dean and Deluca in their Shibuya Station (Tokyo) store yesterday. So some people can already make enough trouble without advanced technology perhaps. Still, the ultimate geek toy? (not the spam.. the clock)

  • My own nuclear powered watch! (Score:3, Funny)

    by Chemisor ( 97276 ) on Sunday August 29, 2004 @12:03PM (#10102891)
    Her: Hey, that's a cool watch!
    Him: No babe; it's not just cool. It is a nuclear powered watch; the most powerful watch in the business!
    Her: Uhh... So you're a mutant?

  • No resonant cavity? (Score:3, Informative)

    by kgp ( 172015 ) on Sunday August 29, 2004 @03:14PM (#10104141)
    Their main page is:

    All the [published] papers are here in PDF form.

    The one thing I can't figure out is how they make a resonant cavity this small ... they obviously have some way around it.

    Others have been asking what's the use as one of their papers says:

    In particular, there has been much recent interest in highly miniaturized atomic clocks ~volume ,1 cm ) for various military
    and civilian applications, including antijam global positioning, and synchronization of encryption keys and communications networks.

    If you know the time precisely you can lock up to the long frame encoded GPS signal without needing CA (more vulnerable to jamming).

  • Battery operated? Not likely. (Score:4, Insightful)

    by unix_hacker ( 136192 ) on Sunday August 29, 2004 @07:38PM (#10105516)
    The story claims that this device pulls 75 mw and that it can be run on batteries. Assuming a 3V system, that's 25 mA of current. If one if these was in a typical portable device with a 750 mAH battery, it would last for 30 hours. Less, of course, if you actually turned on the device. Basically your battery would go dead in a day or so even with the device turned off.

    For reference, real time clock chips that are used in portable electronic devices today pull about 3 microwatts of current -- almost 10,000 times less than this device.

  • After the Little War we'll all have one... (Score:2, Funny)

    by Anonymous Coward
    ...A lifeclock flower implanted in the palm of our left hand.

  • Maybe like pure timing-based protocols [scphillips.com] for communicating over the net?

    Depending on the variability in routing causing different timing delays, I would imagine you could get a fair bit of information across two points without communicating anything that doesn't look like attempted gibberish over IP.

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