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Science

Scientists Build World's Most Sensitive Scale 68

Posted by samzenpus
from the weighing-air dept.
Adrian Bachtold at the Catalan Institute of Nanotechnology in Barcelona has created the world's most sensitive scale. The new subatomic weight scale can measure masses as tiny as one yoctogram, less than the mass of a proton. From the article: "Bachtold hopes the scales could be used to distinguish different elements in chemical samples, which might differ only by a few protons. They might also diagnose health conditions by identifying proton-scale differences in molecular mass that are markers of disease."
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Scientists Build World's Most Sensitive Scale

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  • by pecosdave (536896) * on Monday April 02, 2012 @05:07AM (#39546917) Homepage Journal

    It's bad enough that model builders have to worry about cops making a big deal about owning precision scales. Now they're worried about coke dealer splitting granules.

    • by xaxa (988988) on Monday April 02, 2012 @06:57AM (#39547235)

      How precision is "precision"? What do model builders need, and what for?

      In Europe most people weigh cooking ingredients (rather than measure volume, as in the US). My pretty average digital kitchen balance cost about £15 and is accurate to 1g (up to 5kg).

      (I've also never bought coke. Is 1g a small enough amount, or do you need to measure 0.1g or whatever?)

      • by pecosdave (536896) *

        I'm not sure, but being a model builder is enough for "probable cause" in many places, so I'm sure the dealers like better. I mean I have to register to buy cold medicine around here, that scale should be something along the lines of shooting up flares.

      • by vlm (69642) on Monday April 02, 2012 @07:35AM (#39547365)

        How precision is "precision"? What do model builders need, and what for?

        Model railroad cars work best when all the cars have a certain specified mass. Too light and the odds of derailing increase, too heavy and the engine can't pull them. Also a "large" differential means that when going around curves you'll derail. If you're just taking premade or pre-designed cars out of a box you probably don't have to bother, but if you're substantially modifying the car, then it gets pretty important. I'm too lazy to look up the "standard mass for a N scale boxcar" but someone motivated could probably google for it. Obviously getting the G scale mass correct requires nothing more than a bathroom scale, but a N scale mass is going to require at least a very good kitchen scale, if not higher precision.

        The R/C planes and model rockets I built had a mass goal, where the designer believes a skilled builder should be able to get the completed airframe down to a certain weight. Theres not a heck of a lot you can do if you are over, other than evaluate your skill level, etc. Maybe enormous glue fillets cause more problems via weight than they gain in strength. I'm old enough to have caught the tail end of tissue and dope covering (monokote was dominant... have been out of the hobby for a 1/4 century, is monokote still dominant? If its such ancient history no one knows what it is, monokote was a mylar film with heat glue on one side that you'd stick to the wood with a special little iron, then a hair dryer made it slightly shink to eat the wrinkles along with of course warping the airframe a little). The relevant part of the tissue-dope covering method is its easy to make a strong covering that is as thick and heavy as a rain tarp, but the goal is to apply the dope thinly enough that it weighs nothing. Besides, that stuff was expensive, at least to a kid, so don't waste it. Most people lied about the weight of their models, "its one ounce below the designers spec" is codeword for "damn thing is a pound overweight and I can't figure out why"

        The R/C car people I hung with always weighed in the cars. Depending on your class of vehicle you had to be a certain mass. Too high or low was pretty strong evidence of modifications to a stock class car, and even the unlimited classes had certain limits, for safety and fairness I suppose. The track I ran at had a maximum weight, probably spec'd by insurance or just made up to fit the safety tires that protected the viewers.

        The RC helicopter guys I knew measured the weight of their blades as accurately as they could before they even attempted to balance on the razor-edge balancing thingy. If one blade weighs a tenth of a gram more than the other, its a waste of time to even begin balancing until they match on the scale.

        I'm old enough that the epoxy resin and hardener for fiberglass had to be weighed because of volumetric variation and temperature coefficient of expansion issues and if I recall the catalyst was shipped bare, without fillers, so the modern technique of "just squirt out equal volumes by size" didn't work. To do a small fiberglass repair, you'd squirt out a glob of epoxy resin that looked "about right" then measure it to be, perhaps, 22.0 grams. OK that means you need to carefully squirt out precisely 1.1 additional grams of catalyst, then mix and apply to the boat fiberglass. Too much catalyst means its weak and sets prematurely. Too little catalyst and maybe it wouldn't set at all, which was always an unholy PITA.

        "need" is not relevant to model building. Completely wrong word, at least for non-working models. You do not need a 1/24 scale model of a PanzerKampfwagon-IIIe or a R/C sailboat. You do not need to paint it the precisely correct color. "want" is the word you should have used. And the value of that "want" is nothing more than how much hobby money is available at the time of purchase. Its actually very much like watching TV... lots of "need need need" words but its really "want want want"

        • How precision is "precision"? What do model builders need, and what for?

          Model railroad cars work best when all the cars have a certain specified mass. Too light and the odds of derailing increase, too heavy and the engine can't pull them. I'm too lazy to look up the "standard mass for a N scale boxcar" but someone motivated could probably google for it.

          The "standard mass", as quoted by the NMRA, is expressed in fractions of an ounce - the smallest amount noted is .15 oz (4.25 grams) per scale foot. I.E. n

          • Re: (Score:3, Insightful)

            by Dishevel (1105119)

            Where ever you fall on the bell curve does not matter. If I want a scale that is accurate to 1/1000th of a gram for measuring flour then I should be able to buy one without government agencies drilling into my life. If I want cold medication I should not have to remember to bring my ID. At a certain point people have to tell their governments to "fuck right off". When we do not we lose our rights and our freedoms.

          • by CastrTroy (595695)
            In university chemistry class we were using some kind of really specific scales for weighing something for an experiment. You could actually watch the weight change as the sample sat on the scale. Something to do with the evaporation of the water from the sample if I remember correctly. I really have to wonder what's the point of such a sensitive scale. But the time you removed the sample from the scale to the experiment, the measurement you had previously made would be invalid.
      • by drerwk (695572)
        Smallish servos for RC are in the 1.5-8 gram range, and measured to the 1/10 gram. http://www.pololu.com/catalog/category/23 [pololu.com]
        There are much smaller actuators - Plantraco MicroACT. Weight is 0.41 grams and it comes with a Nano connector. http://www.bsdmicrorc.com/index.php?productID=601 [bsdmicrorc.com]
        Plantraco HingeACT as used on their Butterfly. Weight 0.22 gms.
        And I suspect that these are on among the heavier components of small planes. http://www.microflight.com/Micro-Butterfly-RTF-Set [microflight.com] : Wingspan 3.5 inches (114m
    • I know, right? I had a feeling my cocaine dealer was shorting me a couple yoctograms every time. Now with this scale, I can ensure square trades every time. It's a shame only drug dealers would ever, ever use such a device and thus it would raise such high suspicions. I mean, what use would a scientist have for it?
  • ...I thought that's what mass spectrometers were for.
    • by Arrepiadd (688829) on Monday April 02, 2012 @05:20AM (#39546957)

      Well, mass spectrometers have the (slight) disadvantage of needing a charged "particle". if it's neutral (and for whatever reason you cannot charge it), this seems like a possible solution.
      Granted, it looks like it has a lot of drawbacks of its own (like the heating part).

    • by paiute (550198) on Monday April 02, 2012 @07:30AM (#39547347)

      ...I thought that's what mass spectrometers were for.

      They are. High resolution mass specs measure down to 0.0001 amu (where 1 amu = the mass of a proton). I think the potential here is not for the resolution but the ability of the nanotube scale to measure the mass using a sample of only a few molecules, where a mass spec experiment will need to have a lot more than that injected into the detector.

      • High resolution mass specs measure down to 0.0001 amu

        My mass spectrometer (a Penning trap) routinely measures 1E-8 amu (10^-32 grams), and the best traps are pushing 1E-12 amu. They're getting to the point where they can see the chemical binding (mass-)energy between atoms in a molecule.

        The method in the article is neat, but they've chosen a peculiar definition of "scale" in order to classify this as the most sensitive one.

  • 01 April ... (Score:1, Interesting)

    by Anonymous Coward

    Oh come on, this has to be a 1 April gag.

  • Have they fixed... (Score:4, Interesting)

    by jtownatpunk.net (245670) on Monday April 02, 2012 @05:34AM (#39547005)

    Have they fixed that whole "kilogram standard losing mass" thing yet?

  • Very interesting. However the article does not mention the maximum weight this scale is able to measure.

    I'd love to know how many protons I am made of. I guess this scale won't help !

  • by Anonymous Coward on Monday April 02, 2012 @06:10AM (#39547111)

    I first read it as massive, so I thought it was about your mom. Then I re read it as smaller and realized they were making a scale for your penis.

  • by Anonymous Coward

    If you put this sensitive scale in front of a chick-flick, will it start crying when the lead character breaks up with her boyfriend or when she nurses a lost kitten back to health?

  • by AbRASiON (589899) * on Monday April 02, 2012 @06:19AM (#39547139) Journal

    Hold the dressing, I've gained three yoctograms this week!

  • by Anonymous Coward on Monday April 02, 2012 @06:26AM (#39547165)

    Had to...

  • by Thanshin (1188877) on Monday April 02, 2012 @08:32AM (#39547585)

    How long until the american edition?

    I want to measure my pressure in hundredths of yoctopounds per square pixie feet.

    And, no, I don't know where I'll find a square pixie.

  • ... must be hell to calibrate.
  • Ok, The Slashdot article was posted today, the 2nd but TFA is from April 1st! Come on now, even if there was such a scale how would one use it? It would have to be in a vacuum, think what air molecules bumping into it would do. Not to mention any stray particles. Dust grains would be like dropping mountains on the thing! I know there are such a thing as clean rooms but that clean?
  • by Anonymous Coward

    This is terrible, incorrect reporting. It's a wonderful feat of science, don't get me wrong, but the portrayal is completely inaccurate.

    Penning traps are the most sensitive "scales" available, and they are much more sensitive than this. I've worked with Penning traps, and we regularly measured masses of 100 keV/c^2, which is 1/10,000 of a proton, or 0.00017 yoctograms in the parlance of this article. There were many Penning traps that were much more precise than ours, too.

    There are several much simpler meth

    • by Anonymous Coward

      Also, isotopic differences don't change the chemical properties of molecules, by definition.

      That is neither by definition nor correct. The effects are just very small usually, depending on the difference in mass involved. The difference between protium and deuterium are quite noticeable, especially in some biological systems (try replacing an organism's water with heavy water). Even carbon-12 and carbon-13 have slight differences sometimes. Plants with c4 carbon fixation fix slightly different ratios

  • Great, so you can compare the weights of two samples to the almost infinitesimal. But how do you ensure the two samples are the same "size" ? I'm afraid your kitchen teaspoon just isn't going to hack it :-( For two finished products (e.g., those rotor blades in one of the other comments), fine. But a sample from nature?

    Think of the wide range in something as simple as "eye of newt"!

  • It's an open question in physics weather antimatter will fall toward earth or move away from it due to gravity. Is there any chance this scale could weigh an atom of anti-hydrogen?
    • This method seems to require direct contact between the nanotubes that make up the scale's mechanism and the analyte, so this device is probably not appropriate for that task.
  • Using this scale, it should be possible to absolutely positively and without question prove telekinesis if any such ability exists in humans. If telekinesis isn't capable of consistently exerting the force required to lift a single lousy proton, it isn't worth worrying about. Even if we are more conservative and insist that TK be capable of consistently exerting a whole femtonewton of force (the weight of a rather large number of protons, to be sure, but certain to be within the resolution of the device w
  • Now if they can only balance my rotational mass in my engine this fine.
  • Being so precise, won't the weight of the air in the room affect the results of the measurement?
    Wouldn't you need to use this in a vacuum for it to be useful? Hell, won't undetectable temperature changes affect the air preasure and alter the results as well?

  • protons are huge mofos. Wake me up when they're using it to measure the mass of a neutrino.

Nothing is more admirable than the fortitude with which millionaires tolerate the disadvantages of their wealth. -- Nero Wolfe

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