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Science

Scientists Make Breakthrough In Warping Time At Smallest Scale Ever (vice.com) 64

An anonymous reader quotes a report from Motherboard: [S]cientists at JILA, a joint operation between the National Institute of Standards and Technology and the University of Colorado Boulder, have measured time dilation at the smallest scale ever using the most accurate clocks in the world. The team showed that clocks located just a millimeter apart -- about the width of a pencil tip -- showed slightly different times due to the influence of Earth's gravity. The new experiment paves the way toward clocks with 50 times the precision of those available today, which could be used for a host of practical applications, while also shedding light on fundamental mysteries about our universe, including the long-sought "union of general relativity and quantum mechanics," according to a study published on Wednesday in Nature.

In 2010, JILA scientists used these clocks to measure time dilation at two points with a difference in elevation of 33 centimeters (roughly a foot), which was a big advance at that point. After a decade of fine-tuning their clocks, [Jun Ye, a JILA physicist who co-authored the study] and his colleagues have managed to track frequency shifts within a sample of 100,000 extremely cold strontium atoms, enabling them to snag the unprecedented millimeter-scale effects of dilation. What's more, the team managed to keep these atoms dancing in perfect unison for 37 seconds, setting a new record for the duration of "quantum coherence," or the state in which the behavior of these atoms can be predicted.

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Scientists Make Breakthrough In Warping Time At Smallest Scale Ever

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  • by Tablizer ( 95088 ) on Wednesday February 16, 2022 @05:05PM (#62274511) Journal

    ...it's a start.

    • by shanen ( 462549 )

      Pretty good opening joke. Congratulations on winning the FP race?

      It got me to thinking about how to craft a funny joke on the topic, but I just think too slowly to be a real comedian. Too bad today's Slashdot attracts so few of the actual comedians? Maybe that could be a solution to the ongoing FP problem if most discussions opened with some seriously Funny jokes? What incentives could Slashdot offer?

      On the story itself, it means too little to me, though it reminded me of a still unanswered and somewhat rel

      • by quonset ( 4839537 ) on Wednesday February 16, 2022 @06:38PM (#62274851)

        It got me to thinking about how to craft a funny joke on the topic

        Based on the wording, there is a clear winner:

        You mean a time warp?

        It's just a jump to the left

        And then a step to the right

        With your hands on your hips

        You bring your knees in tight

        But it's the pelvic thrust that really drives you insane,

        Let's do the Time Warp again!

    • How are you going to get enough plutonium though now that the Libyans are out of the market?

    • by Brain-Fu ( 1274756 ) on Wednesday February 16, 2022 @09:33PM (#62275281) Homepage Journal

      If you wanted to work on a car that small, you would need a quantum mechanic!

      I'll see myself out.

  • by Anonymous Coward on Wednesday February 16, 2022 @05:09PM (#62274527)

    The team showed that clocks located just a millimeter apart -- about the width of a pencil tip -- showed slightly different times due to the influence of Earth's gravity.

    First of all, a pencil tip is a sharpened cone so that's not a good comparison for one millimetre.

    Secondly of all, if you still need a comparison with a physical object to know what a millimetre is, you have a serious problem about lack of knowledge of basic measurement units.

    • Maybe a 0.9 mechanical pencil lead. Joke aside, I agree with you.
    • The team showed that clocks located just a millimeter apart -- about the width of a pencil tip -- showed slightly different times due to the influence of Earth's gravity.

      First of all, a pencil tip is a sharpened cone so that's not a good comparison for one millimetre.

      Secondly of all, if you still need a comparison with a physical object to know what a millimetre is, you have a serious problem about lack of knowledge of basic measurement units.

      Or lack of access to, you know, a ruler.

      (I have five in my home office, plus two slide-rules ...)

    • Secondly of all, if you still need a comparison with a physical object to know what a millimetre is, you have a serious problem about lack of knowledge of basic measurement units.

      It's likely in the stylebook [wikipedia.org] that an example needs to be given any time a unit of measure is used. This is how we get "Olympic sized swimming pools", and "Library of Congress" examples. It's a requirement to get a story published.

    • by kwerle ( 39371 )

      Since when is 1mm not "about the thickness of one dime."? That's how they learned it to us!
      Oh. I see upon looking it up that it's substantially thicker. 1.35mm. Good to know.

      • Since when is 1mm not "about the thickness of one dime."? That's how they learned it to us! Oh. I see upon looking it up that it's substantially thicker. 1.35mm. Good to know.

        Probably the same rational that, from TFA, can make this statement:

        But it's incredible to think of 37 seconds, almost a minute ...

        That's *way* closer to 1/2 minute than 1 minute...

    • First of all, a pencil tip is a sharpened cone so that's not a good comparison for one millimetre.

      Agreed! Now somebody please tell me how many grains of sand wide this is or at least how many hairs thick it would be. I'm dying here, so if you need to tell me how many extended carpenter ant legs long it is then please do! If only we had some or standardized unit. Hmm... I got it! INCHES! ;)

    • by Brain-Fu ( 1274756 ) on Wednesday February 16, 2022 @09:31PM (#62275279) Homepage Journal

      ...we are inching our way towards the metric system.

    • by AmiMoJo ( 196126 )

      Do rulers and tape measures in the US not have metric on them? In the UK they are usually metric on one side and Imperial on the other. In Japan and Europe they are metric on both sides.

      I only really became familiar with Imperial units because they were there on every ruler, so I at least have an idea of what an inch is. Since I always used metric for weight and temperature I don't know those Imperial scales, except that 1 Pound is about 500g so when an American says a weight you just halve it to get the me

  • The new experiment paves the way toward clocks with 50 times the precision of those available today, which could be used for a host of practical applications ...

    Domino's will now rue their delivery within 30 minutes or it's free policy ...

  • by cstacy ( 534252 ) on Wednesday February 16, 2022 @05:22PM (#62274581)

    "MEANWHILE, back at the Hall Of The Justice League..."

  • Having clocks this accurate is going to open up a wealth of really interesting experiments and applications although I keep hoping that they'll make some slightly less accurate but easily portable/usable ones since this would enable some really fun time dilation lecture demos.

    That being said it is by no means the smallest scale test of time dilation (which is not a claim the paper makes itself). We have observed time dilation in the lifetime of fundamental, point-like particles for many decades and that
    • We have observed time dilation in the lifetime of fundamental, point-like particles for many decades and that scale is definitely much less than a millimetre.

      Gravitational potentials' influences on the metric have virtually nothing to do with special relativistic effects.

  • The title is wrong (Score:5, Informative)

    by wakeboarder ( 2695839 ) on Wednesday February 16, 2022 @05:31PM (#62274627)

    They didn't warp time, the earths gravitational field did that, they just measured the warping.

    • ... they just measured the warping.

      They've been doing that since they put atomic clocks into space: They tick faster and must be reset to Earth time. So, the news is, they measured the warping over milimetres separation instead of 10,000s of kilometres separation.

    • Yeah. Clickbait headlines suck.
    • They didn't warp time, the earths gravitational field did that

      Oh good, when the Sun gets old we don't even have to build warp engines to move!

    • Well, as human beings they have bodies that are made of physical matter, and therefore have a gravitational pull of their own. So the scientists did warp time, just a little bit, but that isn't what they measured. And anyway we all do that much time-warping with our own bodies.

      Some of us a bit more than others....

      • by cstacy ( 534252 )

        Well, as human beings they have bodies that are made of physical matter, and therefore have a gravitational pull of their own. So the scientists did warp time, just a little bit, but that isn't what they measured. And anyway we all do that much time-warping with our own bodies.

        Some of us a bit more than others....

        It's astounding!

  • That's impressive. (Score:4, Informative)

    by jd ( 1658 ) <imipakNO@SPAMyahoo.com> on Wednesday February 16, 2022 @05:38PM (#62274655) Homepage Journal

    It was a year or two ago that they could measure the difference in time over a scale of three or so metres. To have improved to one or two millimetres in such a short time is nothing short of amazing.

    • Do you think they've already invented time travel and are using it to progress time measuring technology faster?
    • To detect vehicles, people, the moon, asteroids? What does the small detection range imply about the actual amount of gravity difference that can be sensed and over what time scale? Could it detect changes in gravity due to storm fronts moving through?
      • by jd ( 1658 )

        Mass alters time, as per General Relativity. So any change in mass alters the rate at which time passes. A sensitivity this great would allow you to form an incredibly accurate gravitational map of a planet, although it's not altogether obvious if that would be sufficient information to actually form any kind of useful interpretation. Although if you scanned Mars this way, you'd certainly be able to pick up a cave network.

        Now, for your other question. Could you detect vehicles or people? Over any significan

  • by jvkjvk ( 102057 ) on Wednesday February 16, 2022 @05:44PM (#62274687)

    None of us have the same timeline because time runs differently for all of us. Never thought of it that way before.

    Weird.

    • Re: (Score:1, Insightful)

      by Anonymous Coward

      weirder than knowing your feet are going through time at a different rate than your head, at least while standing up

    • One day scientists will discover that there is really only one person, living in billions of distinct time warps.

    • Comment removed based on user account deletion
    • None of us have the same timeline because time runs differently for all of us. Never thought of it that way before.

      Weird.

      That's why the idea of Cartesian Time (one single measurement, shared by everyone) becomes meaningless after Einstein's demonstration of relativity.

      There is only Change, and each subatomic chunk of energy undergoes change at its own pace, spreading it to its neighbors and being affected by them, in a network of cause-effect reactions that cannot be described as a single static centralized model.

  • "The team showed that clocks located just a millimeter apart -- about the width of a pencil tip"

    I don't understand. Can someone convert that to football fields for me.

  • So I have to stand on my head to reverse this perverse time dilation? I'm feeling woozy all ready.
    • What you feel as "the force of gravity" is mostly due to difference in passage of time between your head and your feet. That puts you on spacetime geodesic towards the Earth

  • Coherence (Score:5, Interesting)

    by John Guilt ( 464909 ) on Wednesday February 16, 2022 @07:27PM (#62274973)
    Note that this also seems to show that quantum coherence can be maintained across two frames different enough to each other to have measurably different times.
    • Thats what I was thinking too. It then made me think, what would happen if you had two clocks in coherence, then took one on a ride up to space and back. If they stay in coherence, which time do both clocks now show? the time staying on the ground, or the time from moving around?
  • by mark-t ( 151149 ) <markt AT nerdflat DOT com> on Wednesday February 16, 2022 @11:37PM (#62275467) Journal
    If they were only an mm apart, how do they know that the time difference is solely due to that difference, considering that the scale of the equipment that they ultimately used to read whatever times the clock had are orders of magnitude greater.
  • It's astounding
    Time is fleeting
    Madness takes it's toll
    But listen closely
    Not for very much longer
    I've got to keep control
    I remember doing the Time Warp
    Drinking those moments when
    The blackness would hit me
    And a void would be calling
    Let's do the Time Warp again
  • Clearly this tech is a new way to observe gravitational waves.
    Say good bye to large observatories
    Bench top stuff?
  • The 2-cent version is that gravity isn't even a force, it's a consequence of (space)time warping. PBS Spacetime on YouTube has an excellent explainer for people familiar with GR. Just pay attention to the vectors.

  • Time is measured based on electromagnetic waves of some atoms. Why do we say that time is warped when I think the most likely reason is that the waves of the atom are warped.

    But what is time? If all atomic movement would stop, would time stop? If we speed up atoms e.g by boiling them, does time move faster? Either way you can make time move faster or slower, but you can't travel in time with this method (=by standing in different places on Earth).

  • If they can add even a SECOND to the work day, they will . . .

Every nonzero finite dimensional inner product space has an orthonormal basis. It makes sense, when you don't think about it.

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