Slashdot Mirror

← Back to Stories (view on slashdot.org)

New Most Precise Clock Based On Aluminum Ion

Posted by ScuttleMonkey on from the many-stitches-in-time dept.

eldavojohn writes "The National Institute for Standards and Technology has unveiled a new clock that will 'neither gain nor lose one second in about 3.7 billion years,' making it an atomic clock twice as precise as the previous pacesetter, which was based on mercury atoms. Experts call it a 'milestone for atomic clocks.' The press release describes the workings: 'The logic clock is based on a single aluminum ion (electrically charged atom) trapped by electric fields and vibrating at ultraviolet light frequencies, which are 100,000 times higher than microwave frequencies used in NIST-F1 and other similar time standards around the world.' This makes the aluminum ion clock a contender to replace the standard cesium fountain clock (within 1 second in about 100 million years) as NIST's standard. For those of you asking 'So what?' the article describes the important applications such a device holds: 'The extreme precision offered by optical clocks is already providing record measurements of possible changes in the fundamental "constants" of nature, a line of inquiry that has important implications for cosmology and tests of the laws of physics, such as Einstein's theories of special and general relativity. Next-generation clocks might lead to new types of gravity sensors for exploring underground natural resources and fundamental studies of the Earth. Other possible applications may include ultra-precise autonomous navigation, such as landing planes by GPS.'"

147 of 193 comments (clear)

  1. So I guess this means by twidarkling · · Score: 1

    that I've got very little hope of the clock at work running fast, anymore, eh?

    --
    Canada: The US's more awesome sibling.
    1. Re:So I guess this means by Hijacked+Public · · Score: 1

      eh?

      You Canadians keep your hands off our clock.

      --
      "Sacrifice for the good of The State" - The State
    2. Re:So I guess this means by alexj33 · · Score: 2, Interesting

      will 'neither gain nor lose one second in about 3.7 billion years,'

      What clock are they going to check it against to verify its accuracy?

      And if there is such a clock, why isn't that clock being tested instead?

    3. Re:So I guess this means by wooferhound · · Score: 1

      >> What clock are they going to check it against to verify its accuracy? Stonehenge

      --
      We are Dead Stars looking back Up at the Sky
    4. Re:So I guess this means by ultranova · · Score: 1

      What clock are they going to check it against to verify its accuracy?

      Another aliminum clock, I'd imagine. Fire up a bunch of them and see how much their readings deviate after some time (measured as the median of their readings).

      --

      Forget magic. Any technology distinguishable from divine power is insufficiently advanced.

  2. Ah, I unplugged the atomic clock... by tjstork · · Score: 2, Funny

    I unplugged the atomic clock by mistake. I was just brooming around and I knocked out this here plug. Anyone know what time it is?

    --
    This is my sig.
    1. Re:Ah, I unplugged the atomic clock... by sconeu · · Score: 4, Funny

      Does anybody really know what time it is?
      Does anybody really care?

      --
      General Relativity: Space-time tells matter where to go; Matter tells space-time what shape to be.
    2. Re:Ah, I unplugged the atomic clock... by castironpigeon · · Score: 1

      It's taco time!

      --
      mmmm...forbidden donut
    3. Re:Ah, I unplugged the atomic clock... by Lumpy · · Score: 1

      Nooo...

      IT'S Peanut butter and Jelly Time!

      --
      Do not look at laser with remaining good eye.
    4. Re:Ah, I unplugged the atomic clock... by HoboCop · · Score: 1

      Wrong again. It's clearly Hammer Time.

    5. Re:Ah, I unplugged the atomic clock... by BigDXLT · · Score: 1

      Peanut butter jelly time!
      Peanut butter jelly time!
      Peanut butter jelly time!

    6. Re:Ah, I unplugged the atomic clock... by Kozar_The_Malignant · · Score: 3, Funny

      Sorry, but it's Friday, and it's five o'clock somewhere.

      --
      Some mornings it's hardly worth chewing through the restraints to get out of bed.
    7. Re:Ah, I unplugged the atomic clock... by PatHMV · · Score: 2, Funny

      Does anybody really know what time it is? Does anybody really care?

      25 or 6 to 4...

    8. Re:Ah, I unplugged the atomic clock... by sabt-pestnu · · Score: 1

      Been there, done that. The critical element of the device fell out. The only question is, "How long until the planet disappears"?

    9. Re:Ah, I unplugged the atomic clock... by Sponge+Bath · · Score: 1

      After traveling 88mph in a Delorean, it's once again hammer time!

    10. Re:Ah, I unplugged the atomic clock... by deglr6328 · · Score: 5, Interesting

      The long list of lame jokes that would inevitably accompany this article are obvious and unsurprising. But these "oooh now I can get to my next meeting within one yoctosecond of it starting" jokes may be more apt than you realize. There is a real issue of how to even use a clock this accurate at all. This new Al ion clock is supposedly accurate to one part in 10^17, yes? An article I read in SciAm ~8 years ago predicted this milestone would be reached within the decade, and it seems they were right. The problem is, you will introduce a relativistic time dilation to a clock with an accuracy on the order of 1 in 10^17 merely by walking down the street with it. Similarly, you will experience a comparable magnitude of time dilation by reducing the earth's gravity you experience by raising your elevation off the ground by only 10 centimeters. Aside from pure physics experiments like measuring a potential variation in the fine structure constant since the beginning of the universe and such, I don't know how practical application of a clock this accurate could be achieved. For instance, even if you manage to get a time standard of this level accuracy aboard a GPS satellite, you need to know the satellite's location in orbit, it's "ephemeris data", to an equal degree of accuracy in order to make use of such a time standard. Is that even possible? How do you transfer a time standard of such extreme precision between two clocks while preserving its integrity? If that can't be done, what is the practical use of an absolutely stationary clock that can never be moved? Even for the measurement of the fine structure constant at something like 1/10^18, you will have to take into consideration the movement of the continent due to plate tectonics and the movement of magma bubbles in the planet's mantle in order to have confidence in the accuracy of your answer.

      --
      - "Hear that?! The percolations are imminent! Cease your ingress!"
    11. Re:Ah, I unplugged the atomic clock... by Bluesman · · Score: 1

      When I hear that I know it's time to change the radio station.

      --
      If moderation could change anything, it would be illegal.
    12. Re:Ah, I unplugged the atomic clock... by bluie- · · Score: 1

      1.21 jigga watts!

      --
      life is a tragedy to those who feel, and a comedy to those who think
    13. Re:Ah, I unplugged the atomic clock... by Hurricane78 · · Score: 1

      The positioning thing should be solvable by the satellites pointing lasers at each other. Or something comparable.

      The rest is math, and then earth’s and your relative position to that grid is the only inexact factor.

      --
      Any sufficiently advanced intelligence is indistinguishable from stupidity.
    14. Re:Ah, I unplugged the atomic clock... by jmizrahi · · Score: 5, Interesting

      You are absolutely correct, the time measured by such a clock is going to be dependent on general relativistic effects, most prominently by distance from the mean geoid. However, I fail to understand how you jump from that to concluding that it's useless. For example, you could use such a clock to make precision measurements of general relativity and test possible extensions. Moreover, a clock that sensitive should be able to "feel" changes in gravity caused by density fluctuations in the Earth. This could help find oil deposits, for example. The summary says as much. Generally speaking, you NEVER lose by increased precision. It is true that if your specific application is limited by low precision in some other component, you won't gain by increasing precision somewhere else. However, that's not the case here. I'll admit that I don't know enough about GPS and satellites to answer your specific question, but my impression is that they currently ARE limited by time standards.

    15. Re:Ah, I unplugged the atomic clock... by SleazyRidr · · Score: 1

      I'm pretty sure it's Miller time.

      --
      Is 1563649 a prime number?
    16. Re:Ah, I unplugged the atomic clock... by IICV · · Score: 5, Interesting

      Allright then - you take twelve of these clocks, grouped into clusters of three, arranged in the shape of 3D right angle with each cluster as far away from the other as possible. You isolate them as well as you can, so that they are not disturbed by local vibration and other such things. Probably the best thing to do would be to launch them into space.

      Then you measure their time differences.

      If there's any differences, assuming you've isolated them well enough and are filtering out the expected noise, those differences must be due to external gravity waves.

      Tadaa, we've got a gravity wave antenna. Maybe someone's talking in that spectrum.

    17. Re:Ah, I unplugged the atomic clock... by tsotha · · Score: 1

      That's what I was wondering. With those kinds of relativistic influences emerging as considerations, it seems like they're past the point where additional accuracy provides any sort of real benefit.

    18. Re:Ah, I unplugged the atomic clock... by spire3661 · · Score: 1

      Space and time are one. The more accurately we can measure time, the more accurately we can measure space.

      --
      Good-bye
    19. Re:Ah, I unplugged the atomic clock... by wonglijie · · Score: 1

      We may not have all the answers.. yet. But one day we may. It might be noteworthy that the pace of RnD is progressing exponentially too.

    20. Re:Ah, I unplugged the atomic clock... by arminw · · Score: 1

      ....Does anybody really know what time it is?....

      The deeper question might be: Does anybody know what time is? Supposedly, we can now measure time even more accurately than before, but I still have not heard anybody tell me what the nature of time is. We experience it every day, but what is it really? Einstein pondered this and came up with a theory trying to explain time, space and gravity. We experience all three of these every day, but does anybody actually know what they are? Is the time as clocked by the motion of the earth the same as clock by a vibrating atom?

      --
      All theory is gray
    21. Re:Ah, I unplugged the atomic clock... by Anonymous Coward · · Score: 1, Informative

      I think you miss the point of accurate clocks. Everything you have said is exactly why we need such accurate clocks. The accuracy of GPS is not due to the accuracy of a single clock. It comes about by comparing clocks on different satellites. It is those relative differences that allow you to measure distance or changes in the fine structure constant, or whatever else you want to measure. Let's say we can get one of these clocks on a GPS satellite. How will we know the exact orbit? By comparing it to a stationary clock. That will tell us its altitude. Then we use the clock on the satellite to compare against other clocks on other satellites. The worse every clock in that chain is, the worse our overall results are. The better every clock in that chain is, the better. Yeah, the whole point of accurate clocks is so that you can compare them so that you can measure all of the things you are worried about.

    22. Re:Ah, I unplugged the atomic clock... by maestroX · · Score: 1

      There is a real issue of how to even use a clock this accurate at all.

      How do you prove the clock is more accurate than the reference clock?

    23. Re:Ah, I unplugged the atomic clock... by Bengie · · Score: 1

      that's the idea. time dilation is very useful in lots of math. Like the other guy said, link two satellites together via a laser and measure the difference in dilation as they pass over different parts of the earth. lots of other useful things to.

    24. Re:Ah, I unplugged the atomic clock... by IICV · · Score: 3, Funny

      I'm smoking 100% pure grade-A science, son.

    25. Re:Ah, I unplugged the atomic clock... by ozbird · · Score: 1

      NTP FTW!

    26. Re:Ah, I unplugged the atomic clock... by TeethWhitener · · Score: 1

      Aside from pure physics experiments like measuring a potential variation in the fine structure constant since the beginning of the universe and such, I don't know how practical application of a clock this accurate could be achieved.

      I was thinking maybe for a near-term application you could look for prospecting or seismographic uses of this. You know, place a widely-spaced array of clocks on a large section of land and use the extreme precision to measure gravitational anomalies. May tell you something about density changes of material in the Earth. I dunno; the most obvious application is probably to shoot a few of these into space and look for gravity waves, but if by 'practical application' you mean actually practical, prospecting was the best I could come up with off the top of my head.

    27. Re:Ah, I unplugged the atomic clock... by jasoncar · · Score: 1

      I'm pretty sure it's Miller time.

      Seconded

    28. Re:Ah, I unplugged the atomic clock... by MeepMeep · · Score: 1

      If so I can't imagine why
      We've all got time enough to cry

    29. Re:Ah, I unplugged the atomic clock... by jd · · Score: 1

      The world's most accurate clock means the world's most accurate frames-per-second measure. How can anyone not want to measure the FPS on their games to a thousand decimal places?

      --
      It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
    30. Re:Ah, I unplugged the atomic clock... by jd · · Score: 1

      For that matter, you could exploit relativistic effects. With a geophysical map of the area, you should be able to determine your position from the nature of the drift in the clock (so long as you have a second clock source of equal accuracy that is fixed relative to the geography you can measure the drift with).

      Likewise, two aircraft could measure their relative velocity with incredible accuracy.

      In terms of physics experiments, gravitational wave detectors need extremely accurate measurements. Any experiment that will (once and for all) determine if Relativistic or QM gravity is the correct model will also require this kind of accuracy to tell the difference.

      Same for superstrings. You aren't going to be able to find them if you rely on a self-winding wristwatch for timings.

      --
      It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
    31. Re:Ah, I unplugged the atomic clock... by jd · · Score: 1

      I'd go for a tetrahedral organization myself. You'd need more of these clocks, sure, but you've a better chance of filtering out the noise that is still going to be present.

      Noise source 1: Space expands, but it doesn't do so uniformly on a scale that would be practical for your experiment. If it was uniform, you could eliminate the relativistic effect easily.

      Noise source 2: Space isn't of uniform density. The biggest problem will be localized variations in the solar wind, but the gas streaming off planets, space dust, and other such irritants, will give you gravitational fluctuations. For that matter, so will the orbits of planets. If you can plot these, you can computationally eliminate them.

      Noise source 3: Chaos Theory. Can't avoid this one. James Gleik's book "Chaos" demonstrates the problem when he talks about a billiard ball bouncing off the cushions on the table. If the only perturbations to the trajectory are the bounces and gravitational fields, if a ball travels far enough to bounce seven times then the orbits of asteroids around Alpha Centuri would need to be considered to determine the final resting point.

      The idea of collecting far more data than you strictly need is that you can apply error-correction methods to reduce or eliminate the errors that have been introduced by the noise.

      --
      It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
    32. Re:Ah, I unplugged the atomic clock... by poopdeville · · Score: 1

      Time is the monad that keeps us from changing what we have already done.

      --
      After all, I am strangely colored.
    33. Re:Ah, I unplugged the atomic clock... by calidoscope · · Score: 1

      Not too surprising as that song was hitting the airwaves circa 1971. Bet there are some slashdotters whose parents weren't even born when that song first aired.

      --
      A Shadeless room is a brighter room.
    34. Re:Ah, I unplugged the atomic clock... by calidoscope · · Score: 1
      As others have mentioned, sounds like a neat way of making a new gravity meter or gravity gradiometer. The gradiometer would probably be more interesting as gravity meters good for sensing a 1 centimeter change in elevation already exist.

      FWIW, I worked with some of the people who were involved with the gravity gradiometer work at the Univ of West Oz.

      --
      A Shadeless room is a brighter room.
    35. Re:Ah, I unplugged the atomic clock... by holmstar · · Score: 1

      Is the time as clocked by the motion of the earth the same as clock by a vibrating atom?

      I would say no, because time varies depending on how deep in the gravity well you happen to be. The earth itself is experiencing different rates to time depending on altitude/depth, and the density of nearby rock, etc. So the only time that the earth clocks would be an average time.

      Makes me wonder how much of the current of the liquid portion of the earths core is due to the difference of the passage of time between the crust and the core. I know the difference is pretty minor, but it must contribute something.

    36. Re:Ah, I unplugged the atomic clock... by Bengie · · Score: 1

      doesn't matter since no card can handle Crysis(High settings) at a decent FPS yet.

    37. Re:Ah, I unplugged the atomic clock... by arminw · · Score: 1

      ....I would say no, because time varies....
      I would agree with you, but the difference could be more substantial than we imagined. The motion of the earth around the sun is governed by gravity, which depends on mass and distance as governed by the constant G. The motion of atoms is governed by the electric force and the Planck's constant h, which itself is distance and time-based, inversely proportional to the speed of light, 300,000,000 meters per second. The speed of light c, is governed by the virtual particles in space, as evidenced by the zero point energy. It is therefore possible, of which there are indications, that the nature of space itself determines time. As the universe expanded, space itself changed, as did the so-called constants upon which atomic frequencies depend.

      The red shift, rather than representing time and distance, represents stretched light vibrations, because the speed of light was incredibly faster when the universe was small and hot. Therefore the atomic clock is only accurate now, short-term, but is useless for measuring long ages of time into the past, unless we can determine exactly how it changed since then.

      --
      All theory is gray
  3. Extraordinary claims by Locke2005 · · Score: 3, Funny

    The National Institute for Standards and Technology has unveiled a new clock that will 'neither gain nor lose one second in about 3.7 billion years' Sure, they say that now, but just TRY tracking them down to get your money back 3.7 billion years from now when you find out they were lying!

    --
    I've abandoned my search for truth; now I'm just looking for some useful delusions.
    1. Re:Extraordinary claims by pnewhook · · Score: 2, Insightful

      Or if they move it. Once they do general relativity takes over and the time is now 'wrong' according to a stationary observer.

      --
      Tesla was a genius. Edison however was a overrated hack who liked to torture puppies.
    2. Re:Extraordinary claims by DoofusOfDeath · · Score: 1

      but just TRY tracking them down to get your money back 3.7 billion years from now when you find out they were lying!

      If they were lying, then presumably you'd be aware of it before the 3.7 billion years had passed.

    3. Re:Extraordinary claims by mhajicek · · Score: 1

      But what are you going to compare it to in order to find out?

  4. I'm no genius, but... by N1tr0u5 · · Score: 1

    I imagine that being able to measure one of the basic elements of reality, time, in a more precise manner is a great boon. Wouldn't this be akin to finding out how to measure much smaller spaces? Great!

    1. Re:I'm no genius, but... by sakdoctor · · Score: 1

      I don't know.
      I'll get back to you in SQRT(h bar x G / c^5) seconds.

    2. Re:I'm no genius, but... by spun · · Score: 1

      Is time a basic measure of reality, or only an illusion? I mean, time only looks basic from inside. The actual moments that make up a timeline may form backwards, all at once, or randomly, yet from the inside we would still perceive them as happening in a linear fashion, because there are references to the past in each present moment.

      --
      - None can love freedom heartily, but good men; the rest love not freedom, but license. -- John Milton
    3. Re:I'm no genius, but... by causality · · Score: 1

      Is time a basic measure of reality, or only an illusion? I mean, time only looks basic from inside. The actual moments that make up a timeline may form backwards, all at once, or randomly, yet from the inside we would still perceive them as happening in a linear fashion, because there are references to the past in each present moment.

      You can really drive yourself nuts trying to figure this out. Personally, I tend toward the viewpoint of some non-theistic Eastern philosophies which state that there is only really the Eternal Present or the Here and Now. Memory or "past" is like a track record of how this Now has changed. Furthermore, much human stress and misery and worry is caused by living in your head's notion of the future or the past rather than the Now.

      In an attempt to deter the more naive and shortsighted interpretations of this, it is not a rejection of preparedness or planning. If you are building a house, you have to draw up plans (i.e. blueprints), so in the Here and Now you are planning a house. But while you do so, you're fully present to experience planning a house. You're not caught up in past regrets or future worries so you can actually enjoy what you're doing.

      Another interesting idea I have heard is that this is like a roll of film. The entire movie is contained there, all at once, in a single package. But it's not very useful in this form. You need the element of time, of one frame of the film after another, in order to watch the movie. The movie has a beginning and an end and it has events in-between, yet the entire movie has already been decided and is present in its whole form. Our consciousness could be something like the projector that animates the movie by introducing a framerate or time element.

      --
      It is a miracle that curiosity survives formal education. - Einstein
    4. Re:I'm no genius, but... by spun · · Score: 1

      Your film analogy falls down because, in this way of looking at things, we are in the film, not watching it. Our consciousness is part of the film, another track on the film, like a sound track. As far as I can tell, there isn't anyone watching the film. But in each frame, the consciousness track has all kinds of echoes and reflections of previous frames. Those echoes and reflections are the things that make time appear to move.

      --
      - None can love freedom heartily, but good men; the rest love not freedom, but license. -- John Milton
    5. Re:I'm no genius, but... by PRMan · · Score: 1

      It's interesting that it's kind of like what the Bible always said about God.

      --
      Peter predicted that you would "deliberately forget" creation 2000 years ago...
    6. Re:I'm no genius, but... by causality · · Score: 1

      Your film analogy falls down because, in this way of looking at things, we are in the film, not watching it. Our consciousness is part of the film, another track on the film, like a sound track. As far as I can tell, there isn't anyone watching the film. But in each frame, the consciousness track has all kinds of echoes and reflections of previous frames. Those echoes and reflections are the things that make time appear to move.

      That depends on your notion of consciousness and separateness. The way Bill Hicks put it, "we are all one consciousness experiencing itself subjectively." There is only one united Universe, so we are both the observer and the observed. We're not in the film, we are the film, along with every star and planet and being and every thing that exists or ever existed. In this framework, the concept of ignorance is the perception of ourselves being split into "self" and "other", like a misunderstanding of the meaning of self-awareness (i.e. ego).

      It mainly comes from the lack of appreciation for the fact that you could not exist as you are if not for a million other things that also exist as they are, that everything depends on everything else (cause-and-effect, i.e. my username "causality"). It's the interrelatedness of all things. So we have time in order to experience ourselves, not to observe some "thing" that we could be inside of or outside of.

      An analogy I've heard involves holograms. It's similar to the notion of a fractal, self-similar Universe. Let's say you take a glass photographic plate and take a regular photograph with it. You then hit that plate with a mallet and break it into ten pieces. What you have is like a jigsaw puzzle of the original photograph, with each piece containing 1/10th of the information of the photo. Then you take another glass photographic plate and this time you take a hologram. You then hit that plate with a mallet and break that into ten pieces as well. What you get is completely different. You would get 10 complete holograms, with the only difference being that each is 1/10th the size. Each one has the full information and full 3D representation of the original unbroken hologram, because each part contains the whole. Our relationship with the Universe is like this though we often view the rest of the Universe as something outside ourselves.

      --
      It is a miracle that curiosity survives formal education. - Einstein
    7. Re:I'm no genius, but... by spun · · Score: 1

      In my theory, the universe at it's most basic level is awareness. The brain forms human consciousness by limiting awareness down to only that which matters for survival. It doesn't build up consciousness from nothing, but rather, limits it down to what's useful.

      Subjectively, though, we aren't one consciousness. In fact, the defining characteristic of my consciousness is that only I have privileged access to its informational content.

      You've got a very Buddhist outlook on life, one that's very similar to my own. I'd say you are right, it's more correct to say we are the film, rather than we are in it or watching it. That view expresses the unitary nature of reality better than the way I put it.

      When you break a hologram, each piece does not contain all the information of the original. It contains the whole image, but blurrier and less detailed. Just saying...

      Like you, I believe the rest of the universe is not something 'outside' me. I am not a separate and self creating entity, nothing is. Everything exists because the conditions to support it existing, exist.

      But this is all just interesting theory, some words on a screen. As the Tao Teh Ching says, the Tao we can talk about is not the true Tao.

      --
      - None can love freedom heartily, but good men; the rest love not freedom, but license. -- John Milton
    8. Re:I'm no genius, but... by causality · · Score: 1

      But this is all just interesting theory, some words on a screen. As the Tao Teh Ching says, the Tao we can talk about is not the true Tao.

      Lao Tzu had that one right, but I think that's a failure of language, not expression. The language just reflects the average person's ability to use symbolic reference. Another way of saying the same thing is that there must be some consensus about the meaning of a word for it to have a definition. When you are talking about (it's horrible, but for lack of a better term I'll use it) "mystical" experiences that the average person neither seeks nor experiences, of course language will fall short because no such consensus has been built.

      What you can do is have some understand of these things yourself. Then someone else who also has some understanding can refer to it, knowing very well that the words are inadequate. This won't be an obstacle for those who have seen it for themselves. It will, however, be useless for the purpose of instructing those who have not. The best you can do for them is to challenge them to find out for themselves what you mean.

      So we're not really talking about the Tao, yet we can acknowledge a shared experience of it.

      --
      It is a miracle that curiosity survives formal education. - Einstein
    9. Re:I'm no genius, but... by spun · · Score: 1

      Well, in my opinion, Lao was simply saying the map is not the territory. Anything we say about reality is just that: a map. We map reality to concepts, and that is the first flaw. The second flaw happens as we map concepts to language for transmission to another consciousness.

      The third flaw, which is the one you talk about, happens when the other person maps language back to concepts. But even if they get it right, they are still left with concepts, not direct experience of the present moment, which is the only truth, and the reality those concepts seek to map.

      Damn. Wait a second...

      Teach me to start replying before finishing reading, why don't you? You sum it up perfectly in your final paragraphs.

      You can say something like 'reality is non-dualistic' to someone who hasn't seen this, and they will most likely completely misinterpret it, "Ah, So reality is unitary! I get it! It's all one thing!" Well, yes and no...

      It's like describing color to a blind man.

      "Well, red is warm-"

      "You mean I can burn myself on red things?"

      "Well, some red things, but that's not the point, sigh..."

      --
      - None can love freedom heartily, but good men; the rest love not freedom, but license. -- John Milton
    10. Re:I'm no genius, but... by causality · · Score: 1

      When you break a hologram, each piece does not contain all the information of the original. It contains the whole image, but blurrier and less detailed. Just saying...

      To me that doesn't contradict it at all. It really only deepens the analogy. To me, that's like the way people generally feel incomplete and unfulfilled unless they feel deeply connected with something far greater than themselves. Those fragments of the hologram are blurrier and less detailed because they no longer experience themselves as the whole original.

      I think this is about your fundamental connection with the Universe, with All That Is or however you care to say it. I believe this is a good and pure longing that often becomes perverted. Instead of that more natural connection, people lose sight of that but the "question" of it must have some kind of answer, as things like separateness and aloneness and pointlessness can be very painful. So they satisfy that pure longing in an impure way, by placing undue emphasis on institutions, corporations, governments, sports teams, trends, conformity, etc. It's all an attempt to feel like part of something bigger than yourself. What we get for dealing with it incorrectly, in that impure way, is mindlessness, groupthink, helpless dependency, and the struggle to determine who is in charge.

      --
      It is a miracle that curiosity survives formal education. - Einstein
    11. Re:I'm no genius, but... by spun · · Score: 1

      I would say, genetically speaking, the desire to be part of something larger is advantageous. Being in a tight knit social group, one is much more likely to survive and breed than an isolated individual. I don't think there is anything metaphysical about this desire, necessarily. Even someone who felt naturally at one with the universe would still feel the common human desire to be a respected member of a group, to be part of something meaningful.

      Rather, the feeling of being separate from the universe leads to the problem of evil. A single, unitary thing can't be out of balance, it can't be evil or good. Only when we see the universe and ourselves as a disconnected collection of individual pieces do we suffer from the problem of evil. We see things as being out of balance, and we invent a byzantine system of ideas to compensate for the idea that we are separate.

      Karma. God. The Soul. Reincarnation. An Afterlife. All these concepts are an attempt by the human mind to restore the balance that has been lost by seeing things in pieces.

      Of course, it is all well and good to remember this while conversing with a like minded individual. It is much harder to remember when some asshole cuts you off in traffic.

      --
      - None can love freedom heartily, but good men; the rest love not freedom, but license. -- John Milton
    12. Re:I'm no genius, but... by arminw · · Score: 1

      ...Our relationship with the Universe is like this though....
      which however assumes that the universe is eternally self existent i.e. God. We know from science and observation that this is not so. The universe had a beginning where all things started, including time.

      Rather than the film analogy, I like the parade analogy. We humans are like the observers on the street corner. We see the parade units coming toward us down the block, round the corner and disappeared from sight. However God, in a higher dimension, is like the news crew in the Goodyear blimp. God sees a parade of time, all of it, before the units even form and after they disband.

      If humans truly understood time, we would be accurately able to predict the future. By this I mean not just in vague terms, but specific things, such as predicting next 10 lottery numbers or exactly what would be printed on next week's Wall Street Journal stock pages. Apparently, we are not allowed to know the nature of time, even though we can measure time more accurately than any of the physical quantity.

      In this context, the disciples of Jesus are asking him for the time of his return.

      Acs 1:7 And He said to them, It is not for you to know the times or the seasons, which the Father has put in His own authority.

      --
      All theory is gray
    13. Re:I'm no genius, but... by causality · · Score: 1

      I would say, genetically speaking, the desire to be part of something larger is advantageous. Being in a tight knit social group, one is much more likely to survive and breed than an isolated individual. I don't think there is anything metaphysical about this desire, necessarily. Even someone who felt naturally at one with the universe would still feel the common human desire to be a respected member of a group, to be part of something meaningful.

      Most things like this have higher and lower forms of expression. The need for physical and biological survival and the realization that this comes much more easily when you work together with others who have similar interests (the family, clan, nation) is the lower form. The sense of union, the bliss of oneness with All That Is, and the beauty and vitality that come from this is the higher form. I view these as two sides of one coin.

      Of course, it is all well and good to remember this while conversing with a like minded individual. It is much harder to remember when some asshole cuts you off in traffic.

      That's when you get to put your beliefs into practice, which is a privilege. It's where you find out if this is an area in which you have more work to do. You can get annoyed at that asshole in traffic, which allows his negativity to get into you and tempt you to express it like he has done. You can also see that he is so inconsiderate of others because he suffers, because he has to bear the terrible burden of ignorance, because he is unable to unconditionally love.

      When you realize how terrible that truly is, that it represents a waste of his mortal time on Earth and the beautiful gift of life, and see that you would not wish this on an enemy, you no longer want him to suffer. Then you have the power to feel compassion instead of anger, which is really just a minor form of hatred.

      --
      It is a miracle that curiosity survives formal education. - Einstein
  5. Marketing angle by sakdoctor · · Score: 4, Funny

    For the domestic market they can use the marketing angle that aluminium is safer than mercury, and that it will case less pollution when you come to trade it in.

    In fact, I think I'll order one now.

    1. Re:Marketing angle by RealErmine · · Score: 3, Funny

      For the domestic market they can use the marketing angle that aluminium is safer than mercury, and that it will case less pollution when you come to trade it in.

      In fact, I think I'll order one now.

      Everyone knows that aluminum is an intermediate material in terms of durability and weight reduction. Wake me up when it is replaced with carbon fiber.

      --
      Dewey, you fool! Your decimal system has played right into my hands!
    2. Re:Marketing angle by damien_kane · · Score: 1

      Add the fact that only 1 single atom of aluminium is needed per clock ...

      +/- a few electrons...

    3. Re:Marketing angle by Hurricane78 · · Score: 1

      But carbon fiber breaks without showing any deformations before it happens.
      So when such a clock would be off, it would be off by millions of years. ;)

      --
      Any sufficiently advanced intelligence is indistinguishable from stupidity.
  6. It's about time by Switchback · · Score: 3, Funny

    Well this is money well spent. I mean, having to correct my clock every 100 million years was becoming just too laborious.

  7. Plane landings? by Dynedain · · Score: 4, Insightful

    If you need a clock that's accurate to 8.6 x 10^-19 seconds in order to land a plane, you're probably doing it wrong.

    --
    I'm out of my mind right now, but feel free to leave a message.....
    1. Re:Plane landings? by jpedlow · · Score: 1

      Or Doing it incredibly right. ;)

    2. Re:Plane landings? by ircmaxell · · Score: 5, Informative

      You need that kind of precision to do it from several hundred miles away (As is what happens with GPS). The Satellites all have clocks on board that are synchronized and constantly transmit the time. A GPS receiver simply needs to listen to a few of the satellites, and compute the difference between their times to determine the location. The kicker of it is that since the satellites are moving at fast speeds (relative to us), the time of their clocks are different from "our" time. So special relativity is used to counter those relativistic effects. So basically, GPS is only as accurate as the clocks that form its backbone. That's one of the reasons why unaugmented GPS is limited in accuracy to a few meters. Improving the accuracy of the clocks (by orders of magnitude) has the potential to cut down a few meters to potentially tens of centimeters... You'd need that level of accuracy to land a plane... Planes "flare" during landing (slowing the rate of decent to nearly 0 just as the wheels touch down). Plus or minus even one meter in any direction (up, down, forward, back, side to side) could be catastrophic. So current "autoland" autopilots use radar altitude and ground based ILS (radio based navigation) to gain the necessary precision. If GPS accuracy gets good enough to where you don't need those aux systems (or need them as primary at least), complexity of autopilots would drop significantly...

      --
      If a man isn't willing to take some risk for his opinions, either his opinions are no good or he's no good
    3. Re:Plane landings? by spleen_blender · · Score: 1

      Mod up. The relationship between space and time is very interesting and parent has a good explanation. GP is doing it wrong.

    4. Re:Plane landings? by Lumpy · · Score: 1, Redundant

      Um no. You can do guidance without a GPS reference that is pretty darn accurate. In fact, using the various marker transmitters around an airport you can easily detect if you are lined up and on the glide path.

      I remember my IFR training, there is a whole lot of other info for landing an airplane that you have outside a GPS.

      --
      Do not look at laser with remaining good eye.
    5. Re:Plane landings? by Burdell · · Score: 2, Informative

      The relativistic speed means their clocks run slower than clocks sitting still on Earth, according to special relativity. Another source of GPS time difference is that they are farther away from the center of Earth's gravity than we are, so according to general relativity, their clocks run faster than clocks on Earth. Both factors have to be taken into account.

    6. Re:Plane landings? by ircmaxell · · Score: 5, Informative

      Correct, which is why I said in my post that ILS and radar altitude are needed at the present time. Radar altitude systems are prohibitively expensive and big (pretty much only usable on commercial airliners and in military applications). ILS is good for approach, but you can't land off it. It'll get you down to 50 feet AGL (or less in certain areas), but it won't get you though the flare. That's because the glideslope portion of the ILS signal is set a 3 degrees. So it can only tell you your relation to the 3* slope, not distance above the ground (which is what's really needed when you're over the threashold). ILS gets you aligned with the runway, and onto the proper approach path. It's an approach system, not a landing system (and was never designed as such)... For an ILS system without a radar altimiter, the pilot always must handle the actual landing. (hence the classes of autopilot, and existence of a decision height -- The height which you need to either be able to proceed visually, or abort the approach)... That's why autoland based on GPS is such an interesting thing. It would enable cheaper autoland systems which are a lot smaller than present systems (Basically business jets and light aircraft could potentially be equipped) and don't depend on airport infrastructure. So you could theoretically autoland on a small General Aviation airport...

      I do have my Private Pilots license with Instrument rating, but I also love physics...

      --
      If a man isn't willing to take some risk for his opinions, either his opinions are no good or he's no good
    7. Re:Plane landings? by Eternauta3k · · Score: 1

      I, for one, want my planes landed to a quarter of a nanometer

      --
      Yeah. Would you choose a neurosurgeon who pokes around people's brains in his spare time? I wouldn't.
    8. Re:Plane landings? by show+me+altoids · · Score: 1

      But then you would have to have the height above sea level (or some other reference) of a lot of spots on the runway for every runway that you may try to land on with the same accuracy. Could be done, but seems like a lot of trouble for something that can be accomplished easier by other means.

      --
      I feel sorry for people that don't drink, because when they get up in the morning, that's as good as they're gonna feel
    9. Re:Plane landings? by Dynedain · · Score: 1

      Funny, this car is already accurate to 2cm using GPS.

      1m in plane landings may be catastrophic, but 2cm certainly is not. And GPS can pinpoint your location, but gives you no information on up-to-date ground conditions. For this, local sensing ability (like radar) will always be necessary.

      --
      I'm out of my mind right now, but feel free to leave a message.....
    10. Re:Plane landings? by ircmaxell · · Score: 1, Informative

      There's a simple answer. The speed of light (in a vacuum) is the absolute speed limit. The red and blue shifts you are talking about are when an object with mass goes faster through a specific medium than light can. But the key point there is that it's through a specific medium. Even if you were inside of a space ship that was going through a dense cloud faster than light could go through it, you'd still be going far less than C. Plus, the light that's measured here is presumably passing through a vacuum inside of the clock... That's without taking relativity into account. Once you add special relativity, the effect that time slows as you approach C causes everything to work itself out. Note that there's no absolute clock. There is no such thing as absolute time. There's only time relative to a reference frame. So while the clock on a space ship going 0.5*C relative to earth will go significantly slower than one on earth, it'll still be just as accurate within that reference frame (So two ships with the exact same velocity (vector) which have these clocks will be as accurate as they would be if sitting on earth).

      Even if time did stand still or go backwards, you wouldn't be able to tell since our perception is dependent on time going forwards. Since time must be constant in any non-accelerated reference frame (gravity asside), if a clock was stopped by the slowing of time, so would your heart, and cells, and brain, and electrical impulses, etc...

      I would recommend a pair of books for you written by Richard Feynman. Six easy pieces and Six Not so easy pieces... They provide a good "foundation" if you've never had a college level calculus based physics series before...

      --
      If a man isn't willing to take some risk for his opinions, either his opinions are no good or he's no good
    11. Re:Plane landings? by plover · · Score: 3, Informative

      But his assumption that clock error is responsible for all of the current lack of precision is wrong. Clock error is responsible for probably less than a third of the current error. Atmospherics, multipath reflections, and ephemeris errors account for the bulk of the error.

      Sure, every improvement is an improvement. But these clocks are not a magic bullet that will magically grant centimeter precision.

      --
      John
    12. Re:Plane landings? by ElSupreme · · Score: 1

      Yeah but you get lots of error in transmission losses, and reflections. The clocks are accurate enough, the actual positions of the satelites, and the reflections, and absortions of the signals are what gives you error.

      --
      My addiction: Arguing with idiots. AKA Slashdot!
    13. Re:Plane landings? by Fnkmaster · · Score: 1

      I would think the primary issue with using civilian GPS for an application like this is that it is a degradable, government-controlled signal. A warning of a terrorist attack could suddenly lead to the signal turning to degraded mode, and then a plane in process of landing might think it's several meters away from where it actually is. That could lead to something bad happening I imagine.

    14. Re:Plane landings? by ircmaxell · · Score: 1
      That's why I said:

      So basically, GPS is only as accurate as the clocks that form its backbone. That's one of the reasons why unaugmented GPS is limited in accuracy to a few meters. Improving the accuracy of the clocks (by orders of magnitude) has the potential to cut down a few meters to potentially tens of centimeters...

      I did acknowledge that it's not the only part of the accuracy equation. However, since it (as you say) accounts for somewhere "less than" 33% of the error, it's indeed blocking the progression to sub-meter resolution. Currently, GPS is limited to around 3 meters or so (IIRC). So 33% of that 3 meter "error" would be 1 meter... So that implies, that unless we improve the accuracy of the clocks, sub-meter accuracy would be impossible (using unaugmented systems). Installing these clocks on the GPS satellites won't in itself increase the accuracy to 10cm, but it would make it technically possible (which it would not be without them)...

      --
      If a man isn't willing to take some risk for his opinions, either his opinions are no good or he's no good
    15. Re:Plane landings? by TooMuchToDo · · Score: 1

      Correct. Until aluminum ion clocks can compensate for issues in the ionosphere, radar altimeters, WAAS/LAAS, and ILS are still going to be in style.

    16. Re:Plane landings? by TooMuchToDo · · Score: 1

      The US can selectively degrade GPS by geographic region. If they degrade it intentionally over US soil because of an attack, I'm far more concerned over other issues than GPS being degraded.

    17. Re:Plane landings? by mseidl · · Score: 1

      rtkgps http://en.wikipedia.org/wiki/Real_Time_Kinematic is accurate to 1cm. So that would help.

    18. Re:Plane landings? by StuartHankins · · Score: 1

      ...and continuing this line of thought, the "flying cars" we hear about from time to time could use such an auto-land feature. Making the technology cheaper is part of what has to happen for that technology to "take off".

    19. Re:Plane landings? by blueg3 · · Score: 3, Informative

      Red and blue shift are not caused by moving faster than the speed of light in the local medium (though Cherenkov radiation is), but rather by motion of the emitting object relative to the observer. (Not to mention cosmological and gravitational shifts.)

    20. Re:Plane landings? by KingOfTheMoon · · Score: 1

      Special Relativity was the most facinating suject I studied in college. It's extremely useful too, for example if I ever find myself in a limousine travelling at .8*c, I can calculate how much shorter it's gotten.

    21. Re:Plane landings? by mpe · · Score: 4, Informative

      Improving the accuracy of the clocks (by orders of magnitude) has the potential to cut down a few meters to potentially tens of centimeters... You'd need that level of accuracy to land a plane... Planes "flare" during landing (slowing the rate of decent to nearly 0 just as the wheels touch down). Plus or minus even one meter in any direction (up, down, forward, back, side to side) could be catastrophic. So current "autoland" autopilots use radar altitude and ground based ILS (radio based navigation) to gain the necessary precision.

      "Full blind autoland" systems have been around since the 1960's An unexpected problem with the first systems is that they were "too accurate", runways wear out quickly if touchdown always happens in the same place.

      If GPS accuracy gets good enough to where you don't need those aux systems (or need them as primary at least), complexity of autopilots would drop significantly...

      Most landings are performed by pilots. Even in an autoland situation the pilots go through similar procedures to if they were flying the plane. Otherwise things are likely to end up like TK1951.

    22. Re:Plane landings? by harlows_monkeys · · Score: 1

      The difference between current atomic clocks and a perfect atomic clock would only result in a fraction of a millimeter in positioning difference, tops.

    23. Re:Plane landings? by GooberToo · · Score: 1

      1m in plane landings may be catastrophic,

      Actually that's not likely. If the runway tolerances are so tight, you wouldn't be trying to land there, let alone autoland there. You're talking about a runway which has +- 1m for the airplane to safely remain within. Someone would be looking for a different runway. Generally speaking, on small planes land on such runways.

    24. Re:Plane landings? by ircmaxell · · Score: 1

      The three most valuable things to a pilot are 10 gallons more fuel, 1000 feet more altitude and 5 minutes ago...

      --
      If a man isn't willing to take some risk for his opinions, either his opinions are no good or he's no good
    25. Re:Plane landings? by initialE · · Score: 1

      So what you're saying is, instead of dying from something in a Bruce Willis movie changing my altitude, I could be dying from something in a James Bond movie changing my altitude?

      --
      Starbucks, Harbuckle of Breath.
    26. Re:Plane landings? by sr180 · · Score: 1

      Radar altitude systems are prohibitively expensive and big (pretty much only usable on commercial airliners and in military applications).

      Not true at all. Radar Altimeters are not big and expensive (well not in aviation terms), and many civilian airplanes carry them. They are generally stock equipment on small civilian helicopters and light planes, even down to the 152/172 size.

      --
      In Soviet Russia the insensitive clod is YOU!
    27. Re:Plane landings? by Bengie · · Score: 1

      My wife's "Magic Bullet" vibrates at a much lower frequency, but it feels much better for her.

  8. Re:Assuming We're still around by Locke2005 · · Score: 2, Insightful

    Uh, I think what they really mean is that it is accurate to about one four-billionith of a second per year, which beats the heck out a Timex. I don't think anyone seriously believes the device itself will last long enough to lose or gain even a microsecond.

    --
    I've abandoned my search for truth; now I'm just looking for some useful delusions.
  9. Sensitivity by seven+of+five · · Score: 1

    Forget the 3.7 billion year thing. What's important is this thing's accurate to one part in 10^17. Correct me if I'm wrong, but it'll probably run faster or slower depending on how close you stand to the thing.

    On toppa that, it never needs winding.

    1. Re:Sensitivity by Lisandro · · Score: 1

      I was thinking the same. Housing the device so it would be unnafected by gravitational anomalies would be quite challenging...

    2. Re:Sensitivity by orient · · Score: 1

      The more accurate we measure the time, the more accurate we measure the speed. According to Heisenberg, this leads to less accurate info on position. So a perfect clock would create a meltdown around it, wouldn't it?

      --
      Laudele lor desigur m-ar mahni peste masura.
    3. Re:Sensitivity by ZERO1ZERO · · Score: 1

      I don't get this. How will it run faster or slower? doesn't it run at a constant rate.?

    4. Re:Sensitivity by holmstar · · Score: 1

      Yes, the clock is constant within it's own frame of reference. However, like everything else, that frame of reference is affected by time dilation.

      Since your body has mass, it's presence near the clock will cause the clock to slow slightly in comparison to an identical clock placed farther away from you.

  10. Don't we already have this? by TubeSteak · · Score: 1

    Other possible applications may include ultra-precise autonomous navigation, such as landing planes by GPS.'

    IIRC, not only do we already have this capability, but they had to design in some wiggle room because the precision touchdowns were hammering runways on the same spot until they started to break.

    --
    [Fuck Beta]
    o0t!
  11. feedback loop? by antimatt · · Score: 1

    The extreme precision offered by optical clocks is already providing record measurements of possible changes in the fundamental "constants" of nature ...

    Hang on. Those bits of matter we're using to determine potential changes to physical constants are governed by physical constants. If every 1-meter rod in the world suddenly became a 1.0001-meter rod while we weren't looking, how would we know?

    1. Re:feedback loop? by blueg3 · · Score: 1

      It shouldn't shock you to learn that the fundamental constants that influence the behavior that drives the clock are different from the fundamental constants whose change they're interested in measuring.

  12. Real atomic wristwatch by line-bundle · · Score: 1

    If you just wanted an atomic wristwatch here is the first real atomic wristwatch. Not those fakes which use radio reception

    http://www.leapsecond.com/pages/atomic-bill/

  13. Useful for deep-space navigation? by jpedlow · · Score: 1
    Would this be useful for things like XNAV? http://en.wikipedia.org/wiki/XNAV

    I could forsee it being handy for things like deep-space navigation. And THAT would be extremely interesting!

    For making ultra precise time and distance calculations? I guess when you're talking several thousand AU or even lightyears, if we can get a clock to such precision, then we would be able to hopefully narrow down accuracy of such systems to say....a few meters in a lightyear? (just as an example, probably more like a few meters in an AU, but I havent done the math)

    Ofcourse, I'm not well versed in such things, I'm sure someone with more knowledge than me about this could readily correct me. :)

    1. Re:Useful for deep-space navigation? by TooMuchToDo · · Score: 1

      It's be pretty cool if this was our first step (and we didn't know it) towards deep-space navigational systems for interstellar travel.

  14. Re:Single ion? by thijsh · · Score: 1

    Now this is finally a bet worthy of http://www.longbets.org/

  15. 3.7 billion years from now ... by Korbeau · · Score: 4, Funny

    neither gain nor lose one second in about 3.7 billion years

    Location: 3.7 billion years from now, early December, Planet Earth

    Doomsayer: "The ancient "Scientific Community" civilization was so certain a great cataclysm would come in the following months based on their long-lost primitive yet poweful and mythical calculations that they even deemed unnecessary to keep track of time correctly starting this age! The end is near my friends! A new age will come!"

    1. Re:3.7 billion years from now ... by SnarfQuest · · Score: 1

      And, wouldn't you know it, the clock was off by 1.00037 seconds. What a crappy clock!

      --
      Who would win this election: Andrew Weiner vs Andrew Weiner's weiner.
    2. Re:3.7 billion years from now ... by bobdotorg · · Score: 1

      The end is near my friends! A new age will come!"

      Well, when the atomic _alarm_ clock goes off, hitting the snooze button will not be an option.

      --
      __ Someday, but not this morning, I'll finally learn to use the preview button.
  16. I predict by Nonillion · · Score: 1

    I predict another flood of reference standards to hit e-Bay soon. I've been waiting to find a good (affordable) cesium / rubidium standard for a while now. :P

    --
    "I bow to no man" - Riddick
  17. Setting it? by OfficialReverendStev · · Score: 1

    Ok really curious here: If this new clock is twice as precise as the previous clock... how do they know they've set its time right?

    --
    A casual stroll through the lunatic asylum shows that faith does not prove anything. - Neitzsche
    1. Re:Setting it? by stevelinton · · Score: 1

      There is no real interest in measuring absolute time here. What these clocks really are is ultra-stable oscillators and by (carefully) counting their oscillations, they can be used to measure intervals.

    2. Re:Setting it? by John+Hasler · · Score: 1

      > ...they can be used to measure intervals...

      Which is all that can be measured anyway.

      --
      Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
  18. Nothing could go wrong, right? by jack2000 · · Score: 1

    A single atom they say? Que random decay in 4 3 2 1 ...

    1. Re:Nothing could go wrong, right? by gyrogeerloose · · Score: 1

      A single atom they say? Que random decay in 4 3 2 1 ...

      But just think--that will give us a new excuse:

      "Sorry I'm late for work, boss--the aluminum atom in my alarm clock decayed..."

      --
      This ain't rocket surgery.
    2. Re:Nothing could go wrong, right? by jack2000 · · Score: 1

      A single atom, that seems like a terrible idea, they'd have to have at least 4 clocks like that running simultaneously so they can replace the atoms in them if any one fails...

  19. Well... by Phizzle · · Score: 1

    ... its about time!

    --
    I will not be pushed, filed, stamped, indexed, briefed, debriefed or numbered. My life is my own.
  20. You're late by spun · · Score: 3, Funny

    You should have been here to welcome us .0000000001 seconds ago. Your membership in the Committee to Welcome Our New Overlords has been revoked.

    --
    - None can love freedom heartily, but good men; the rest love not freedom, but license. -- John Milton
  21. Drop some science on me by oldhack · · Score: 1

    How do you measure how precise a clock is? How do you go about defining the reference for time?

    --
    Fuck systemd. Fuck Redhat. Fuck Soylent, too. Wait, scratch the last one.
    1. Re:Drop some science on me by RobVB · · Score: 1

      Compare it to a sundial.

      --
      I'd rather you rationally disagree than irrationally agree.
  22. Re:Assuming We're still around by LarrySDonald · · Score: 1

    'Sok. My timex syncs to Colorado. Now I just need to either get people to care or cure my OCD to the point where 1s/week isn't unacceptable.

  23. Can someone explain how... by Low+Ranked+Craig · · Score: 1

    accuracy to 1 second in 100 million years is not adequate for landing a plane via GPS?

    --
    I still cannot find the droids I am looking for...
    1. Re:Can someone explain how... by bughunter · · Score: 1

      GPS works by triangulating the phase delays of radio signals transmitted from GPS satellites. The accuracy of your position is proportional to the square root of the phase delay of a signal whose frequency is in the Megahertz, so you're losing a factor of 1 to 100 million right there. Add on top of that the scaling factors due to the orbital velocity of the satellites, the rotational velocity of the earth's surface, and the velocity of the airplane, and (for things like landing planes) a seven- to nine-nines reliability requirement, and even the best non-differential GPS systems only get an accuracy on the order of 10 meters.

      This is a lot when you're trying to land the nose gear of a plane full of living humans going 100 MPH on a stripe about half a meter wide.

      According to TFA, the Aluminum Ion clock offers about a 3000x factor of improvement on precision, which gets us down to the kind of accuracy we need for landing commercial airliners without the kinds of mishaps that will cause disproportional media feeding frenzies over the use of automated landing systems.

      --
      I can see the fnords!
    2. Re:Can someone explain how... by mcgrew · · Score: 1

      Someone did explain how. Read the comments!

      --
      Free Martian Whores!
  24. Even Better by causality · · Score: 4, Insightful

    For those of you asking 'So what?' [ ... ]

    Do you have any idea how many Slashdot articles could benefit from such an explanation?

    --
    It is a miracle that curiosity survives formal education. - Einstein
  25. Not my fault! by Hartree · · Score: 1

    It was YOUR aeon to watch the aluminum atom. I did it LAST aeon. It was there safe and sound when I finished!

  26. Good Science and All, but... by Kozar_The_Malignant · · Score: 1

    Saying you're keeping precise time with an aluminum clock just doesn't sound as cool as saying you're using a cesium fountain clock. The proper Mad Science(tm) approach should involve things like ytterbium lasers and liquid helium, not just aluminum.

    --
    Some mornings it's hardly worth chewing through the restraints to get out of bed.
    1. Re:Good Science and All, but... by MrFlibbs · · Score: 1

      This is just a first step. In the next phase they hope to reclaim their Mad Science(tm) credentials by switching to transparent aluminum. Cesium is so 1960s.

      Hard to compete with ytterbium lasers, though. Maybe sharks with frickin' yterbium lasers mounted on their heads?

  27. Thank goodness... by aardwolf64 · · Score: 1

    I can sleep better knowing that my atomic clock will only lose 1 second in 3.7 billion years instead of 2. My life has been forever changed.

  28. Re:Assuming We're still around by Anonymous Coward · · Score: 1, Informative

    Long-distance low-frequency radio syncing is actually quite inaccurate, at least as far as atomic timekeeping goes. There's the simple propagation delay based on your distance from the radio source, plus the possibility of getting waves that were reflected from the ionosphere, possibly more than once, likely varying from sync to sync, and no good way to know how much additional delay that adds even if it were consistent. Not to mention the issues with synchronization itself -- once you get the correct time code you wait for the next "beat" to start counting, but there's some delay between when the beat is received and when counting starts, or there's anticipation of the beat and possible imprecision due to that anticipation.

    And there's the issue of non-continous correction. While your watch indicates approximately the correct time after a sync, there's likely some jump in the notion of local time after each sync, and between syncs there's no guarantee that timekeeping is accurate at all -- if you design a clock to sync every 12 hours it can be off by almost 2 seconds/day without displaying the wrong second-accurate time, and that doesn't lead to very consistent timekeeping on intervals shorter than the sync period.

    All in all, it's plenty accurate for a wrist watch, but it's not really a high-precision time or frequency source.

  29. Ultra precise autonomous navigation by 140Mandak262Jamuna · · Score: 1

    Other possible applications may include ultra-precise autonomous navigation, such as landing planes by GPS.'

    As soon as they fix the unintended acceleration and unresponsive braking in earth bound vehicles, they will take the next step, is landing the plane by GPS.

    --
    sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
  30. Planes can already land with GPS ... by tkjtkj · · Score: 1

    the author needs a lil update on the capabilities of military-grade GPS :
    "Other possible applications may include ultra-precise autonomous navigation, such as landing planes by GPS." omits one fact: the present accuracy of mil GPS is +/- 1cm
    easily within the range to accomodate landing on a deck ..

    --
    "There are 11 kinds of people: those who know binary, those who don't, and those who could not care less!"
  31. Too bad it will only be used for another 461 days by maddogmiller · · Score: 1

    When Christ comes back, time will cease. Oh well, it was fun while it lasted.

  32. Re:Single ion? by Sulphur · · Score: 1

    Who wants to bet that they lose the aluminum ion before the cesium clock accumulates an error of a millionth second?

    The Al ion was formerly part of Schrodinger's cat.

  33. Re:Single ion? by Jeng · · Score: 1

    I'm really not up on this field of science, but it looks like aluminum is a very stable element so I guess it won't just decay away in a few million years.

    http://www.chemicalelements.com/elements/al.html

    Isotope Half Life
    Al-26 730000.0 years
    Al-27 Stable
    Al-28 2.3 minutes

    --
    Don't know something? Look it up. Still don't know? Then ask.
  34. No, I can't imagine why by tjstork · · Score: 1

    Does anybody really know what time it is?
    Does anybody really care?

    I was just walking down the street one day...

    and to think all these young ones don't know about Chicago...

    --
    This is my sig.
  35. Head Scratching Time by Ancient_Hacker · · Score: 1

    I have a serious problem with trying to even imagine how you validate the world's best clock.

    Would you not have to have a better clock to compare it with?

    And how do you know THAT clock is keeping good time?

    And who guarantees that the aluminum ion will always vibrate to that precision?

    Sounds a bit like the old 3-card monte game.

  36. Re:Assuming We're still around by Shadow+of+Eternity · · Score: 1

    And all of this is why I usually just get a cheap digital watch from wal-mart that can survive being driven over a few times and periodically reset it to be about ~2-3 minutes ahead of the average of whatever I care about (professor's clock, usually).

    --
    A bullet may have your name on it but splash damage is addressed "To whom it may concern."
  37. One... by kclittle · · Score: 1

    One al-U-men-ee-um, two al-U-men-ee-um, three al-U-men-ee-um...
    Yep, pretty accurate, I'd say!

    --
    Generally, bash is superior to python in those environments where python is not installed.
  38. It doesn't matter ... by woody.jesus · · Score: 1

    ... how accurate they get the clocks, the Amtrak train will still be late.

    --
    "You never pushed a noun against a verb except to blow up something" (Spencer Tracey, 'Inherit the Wind')
    1. Re:It doesn't matter ... by holmstar · · Score: 1

      The trains are late mostly because they have to share the same tracks as freight trains, which don't really care if the Amtrak trains are late. Note that Amtrak leases access to the tracks, which are actually owned by the freight companies from the most part.

  39. The Star Trek Fanatic version by sacrilicious · · Score: 2

    "My god... transparent... ALUMINUM?"
    "No no, this is *timekeeping* aluminum. You see, it consists of an incredibly preci-"
    "Traaaaaansparent aluminum... amazing."

    --
    - First they ignore you, then they laugh at you, then ???, then profit.
  40. Vibrating? by IceFoot · · Score: 1

    The logic clock is based on a single aluminum ion ... vibrating at ultraviolet light frequencies....

    Vibrating? Heh. Aluminum ions don't vibrate. Silly science reporters.

  41. But... by tjstork · · Score: 1

    We may not have all the answers.. yet. But one day we may. It might be noteworthy that the pace of RnD is progressing exponentially too.

    But, so is the price of R&D... when Einstein was around, it was pretty cheap. A few decades ago, it was hundreds of millions for a nuclear pile. Now, its what, tens of billions of dollars for space telescopes and super colliders. At the rate we're going, we're going to hit a wall because the cost will simply be too high.

    --
    This is my sig.
  42. Re:Assuming We're still around by poopdeville · · Score: 1

    Whatever, just get a netbook with an NTP client and sync up to the US Navy, like any fullblooded American scientist already does.

    --
    After all, I am strangely colored.
  43. Much simpler to operate laser interferometers... by John+Hasler · · Score: 1

    ...between each pair of your satellites. Which is, in fact, the plan.

    --
    Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.