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Yoctonewton Detector Smashes Force Sensing Record

Posted by CmdrTaco on from the stop-being-so-sensitive dept.

KentuckyFC writes "A team of physicists has measured the smallest force ever recorded, at 174 yoctonewtons (yocto=10^-24), beating the previous best by three orders of magnitude. Their measurement device consists of a few dozen beryllium ions trapped in magnetic and electric fields using a device called a Penning trap. These ions vibrate at between a few mega and kilohertz, frequencies that can be accurately measured by bouncing laser light off the ions and measuring any Doppler shift they cause. Being charged, the ions are highly susceptible to the tiny forces associated with stray magnetic and electric fields, which change the frequency at which the ions vibrate. Hence the super-sensitive measurements. They team says that straightforward modifications should allow them to measure single yoctonewtons in the near future. This sudden leap in sensitivity could cause a problem for the system of SI prefixes, which don't yet come any smaller than yocto."

8 of 214 comments (clear)

  1. Huh? by Rallias+Ubernerd · · Score: 1, Interesting

    Your comming up with miniscule amounts of movement, and your worrying about finding the proper prefix? Who hasn't hearsd of Scientific Notation?

    1. Re:Huh? by cc1984_ · · Score: 2, Interesting

      Your comming up with miniscule amounts of movement, and your worrying about finding the proper prefix? Who hasn't hearsd of Scientific Notation?

      Scientific notation may be good in science, bad for general press.

      Can you imagine someone selling a 1x10^12B HardDrive?

    2. Re:Huh? by Anonymous Coward · · Score: 1, Interesting

      "... bytes, which is powers of two ..."

      The "B" in "1x10^12B" does refer to Bytes. Had he used a small "b" it would have been bits (which are binary and can be measure in powers of 2).

      The example represents 1 PB (PetaByte)

      That reminds me of an introductory CompSci class that I took in community college. A student asked the teacher:

      Student: "What's the difference between a byte and a bit?"

      Teacher: "Seven."

      I laughed out loud, noone else in the class got it.

    3. Re:Huh? by cc1984_ · · Score: 1, Interesting

      How many people knew what a terabyte was 10 years ago?

      How many people know what a petabyte is now?

      In any case, your reply shouldn't be directed at me. I have no intention of using YoctoNewton more than three times in a sentence. What I was getting at is that scientific notation is not mainstream.

      I was addressing this point:

      Who hasn't hearsd of Scientific Notation?

  2. Uncertianty Principle by Psychotic_Wrath · · Score: 1, Interesting

    At that small of values the uncertianty principle probably plays a big role in error. I wonder if they considered that.

    --

    Doctors do Massage in Longview WA now, who knew?
  3. Low mass gravity measurements by forand · · Score: 5, Interesting

    Haven't had time to read the article but it would amazing if force measurements at these levels could be conducted between well characterized masses to validate general relativity at low mass short distance scales.

    1. Re:Low mass gravity measurements by Steve+Max · · Score: 2, Interesting

      GR (or actually, the Newtonian approximation) has been tested down to distances of ~1mm; for two ~1kg masses, that would be a force of ~10^-4 N. We don't want to get "G" to a better precision (well, we do, but that's not the point of those experiments); we want to see if at small distances the force deviates from the expected (1/r) behaviour. Such a deviation would mean that there are more than 4 spacetime dimensions (with the extra dimensions being compactified, meaning they have a size of only a small fraction of a meter). If we could reliably measure gravity down to some yN, we could test it at REALLY small distances. That would be a real test for extra dimensions, and indirectly a real test for string theory*.

      * = of course, string theorists will always get the size of their extra dimensions to something orders of magnitude smaller than whatever can be tested; after all, they can't have a falsifiable theory, can they?

  4. Sensitivity verses practicality by hAckz0r · · Score: 3, Interesting

    I have to wonder what exactly they expect to measure with such a device. The premise of the Penning trap device is to use a static magnetic field (magnets) and an electric field (electric circuits) to cap the ends of the device to contain the super cooled, in this case beryllium ions. In order to "measure" external electric fields one has to let in external electromagnetic radiation, which will not come without having some overall effects on the containment vessel and circuitry as well. With external electromagnetic radiation power propagating at r^2 the vessel will get more of a dose than the beryllium ions and the electric field will have some level of modulation which will in turn make the ions vibrate in the axial direction based on the reactance of the containment circuitry, not the primary waveform desired to be measured. Yes, you will measure vibrations at the quantum level, but are you really measuring what you think you are? The device is likely so sensitive that due to the uncertainty principal it may defy us the ability to prove what is actually being measured.