Follow Slashdot stories on Twitter

 



Forgot your password?
typodupeerror
×
Shark Science

Scientists Using Lasers To Cool Molecules 169

An anonymous reader writes "Ever since audiences heard Goldfinger utter the famous line, 'No, Mr. Bond; I expect you to die,' as a laser beam inched its way toward James Bond and threatened to cut him in half, lasers have been thought of as white-hot beams of intensely focused energy capable of burning through anything in their path. Now a team of Yale physicists has used lasers for a completely different purpose, employing them to cool molecules down to temperatures near absolute zero, about -460 degrees Fahrenheit. Their new method for laser cooling, described in the online edition of the journal Nature, is a significant step toward the ultimate goal of using individual molecules as information bits in quantum computing."
This discussion has been archived. No new comments can be posted.

Scientists Using Lasers To Cool Molecules

Comments Filter:
  • OMG Sharks (Score:2, Funny)

    by Anonymous Coward

    .. with friggin' freeze rays on their heads .... *groan*

  • Farenheit? (Score:3, Insightful)

    by muyla ( 1429487 ) on Wednesday September 22, 2010 @11:15AM (#33664066)

    What about human readable units for once? maybe 1 Kelvin or -272C would be OK

    • Re: (Score:3, Insightful)

      by Lifyre ( 960576 )

      Or if you're going to use worthless units at least use Rankine...

      • There are a lot of science nerds who don't know offhand what a Rankine is. Asked without context, I know for sure that I wouldn't be able to come up with the definition. At least -470 degrees -460 degrees Fahrenheit gets across the idea of 'really, unbelievably, unimaginably cold' to most everyone, and 'most everyone' is the target audience of most news sites.

        • by necro81 ( 917438 )
          Rankine is simple: it's the absolute-zero referenced version of Fahrenheit. One degree Rankine is one degree Fahrenheit, by definition. Zero Rankine is absolute zero, or 459.67 F.

          Or, put more compactly in word analogy form:
          Rankine : Fahrenheit = Kelvin : Celcius
    • Re:Farenheit? (Score:4, Insightful)

      by rossdee ( 243626 ) on Wednesday September 22, 2010 @11:47AM (#33664628)

      I agree - I can understand Fahrenheit for weather and human body temps, but for cryogenics you should be using kelvin.

      • Re: (Score:3, Informative)

        As someone who isn't American I can't even do that. My entire knowledge of Farenheit is that 0 C is around 32 F. and 451 F is where paper burns. Also the conversion rate is like TempInCelcius * (9/5) -32 or something. It's really a terrible system to use for a scienctific article.

        • 0 - 100 on the Farenheit scale does a pretty good job of approximating the temperature extremes in temperate climates.

          What you need to know is this:

          0 degrees is too cold.
          100 degrees is too hot.

          • yeah, and for casual conversation and meteorology in the states I'm sure it does a bang up job. But my point is that for an article posted on a site with an international audience or any article dealing with scientific experiments and studies it's somewhat anachronistic. Like describing the content of a graduated cylinder in pints.

        • Quite agreed. I'm very fond of the metric system, and honestly can't understand why half a continent (and a bit of island on our side) clings to archaic and complex scales; but the one thing I'd change is to not only get rid of Farenheit but also of Celcius. It may be defined in human measurements (freezing and boiling water), but Kelvin is an absolute scale, and the rest is just two other numbers to remember (0 and 100 vs 273 and 373).
          • well one reason is plumbing. Even in Canada our plumbing is done in imperial for legacy reasons. Same with carpentry. All old pipes and beams and joints (so the entire sewer system) is imperial.

    • by JordanL ( 886154 )
      Also of note: this experiment setup was designed over 30 years ago (and tested) by a Professor at the University of Colorado. Yale didn't do anything new here.
      • by JordanL ( 886154 )
        Pardon me, I mean about 20 years ago. :) (I am of course referring to Cornell and Wieman who won the Nobel prize for producing the first ever Bose-Einstein condensate.)
      • ...designed over 30 years ago (and tested) by a Professor at the University of Colorado. Yale didn't do anything new here.

        Well, not quite true. While laser cooling [wikipedia.org] isn't new as either a concept or an application, there is a novel twist here. This is (apparently) the first time laser cooling has been successfully applied to molecules, rather than just monatomic gases.

        So yes, the "gee whiz!" Slashdot summary is a tad misleading, but there really is new technology being reported. Of course, you knew that already, since you read the linked article before posting...right?

    • Because that would just force me to do calculations to convert Kelvin or Celsius into Fahrenheit.
    • Given the wording "what's known as absolute zero", it seems assumed that the reader doesn't have much understanding of cryogenics, so given that target audience, -460F is the best way to communicate how cold this is (-272C assumedly wouldn't make sense to them). Ironically, you call for human readable units despite that being exactly what they were going for.
  • Energy, not heat. (Score:5, Informative)

    by captaindomon ( 870655 ) on Wednesday September 22, 2010 @11:16AM (#33664070)
    Laser beams are focused energy in the form of electromagnetic radiation, not energy in the form of thermal entropy of molecules in matter. There is a difference. Laser beams can transmit their heat to matter (they normally do), but laser beams are not "Hot".
  • by John Hasler ( 414242 ) on Wednesday September 22, 2010 @11:18AM (#33664124) Homepage
    Wrong. Laser beams are very cold. The photons are highly ordered and there is very little random motion among them.
    • Re: (Score:3, Insightful)

      by nacturation ( 646836 ) *

      Wrong. Laser beams are very cold. The photons are highly ordered and there is very little random motion among them.

      Wrong? It's not true that the general Bond-watching audience thinks of lasers as being white hot?

      • It's not true that the general Bond-watching audience thinks of lasers as being white hot?

        The general Bond-watching audience cannot reasonably be said to think at all.

      • by Jahava ( 946858 ) on Wednesday September 22, 2010 @12:13PM (#33665056)

        Wrong? It's not true that the general Bond-watching audience thinks of lasers as being white hot?

        It's pretty obvious: The atoms are stirred, not shaken.

      • Wrong. Laser beams are very cold. The photons are highly ordered and there is very little random motion among them.

        Wrong? It's not true that the general Bond-watching audience thinks of lasers as being white hot?

        Clearly we think of them as red-hot.
        Actually I haven't seen Goldfinger in ages, but weren't the lasers red? Wouldn't it then be logical to think that the lasers are red-hot rather than white-hot?

        This comment isn't quite pointless enough yet, so I'll throw in a, "wah! they should have used real units like celsius! wah!"

    • You are also wrong. Laser beams are neither hot nor cold. Those terms qualitatively describe temperature. Temperature, at least when used scientifically, refers to the average kinetic energy of mass particles within a given volume (as they bounce around). Electromagnetic radiation does not have a temperature.

      • by kmac06 ( 608921 )
        You are also wrong! Blackbody radiation, for example, certainly has a temperature associated with it. I'm actually not sure how to think of the temperature of a laser (and I have put some thought towards it, and am studying in quantum optics in grad school). Even a weak laser can heat up a physical object, so it is quite hot. It comes from a lasing material that is at a negative temperature [wikipedia.org], so it could also have negative temperature. But as another poster pointed out, it has very low entropy. This leads me
        • While you can infer the temperature of a blackbody from the radiation, the radiation itself does not have a temperature. And just because radiation can heat an object, does not mean the radiation itself has "heat". The radiation has energy... which when transfered to an object with mass results in that object heating up.

          Temperature is a property that only applies to particles with mass. And really only applies to groups of particles. Hence heat (which is a more qualitative description of temperature or a ch

          • by kmac06 ( 608921 )
            I don't think I agree with that. Let's say we have one system that is held at a fixed temperature, and another system that is isolated, other than a radiative connection to the first. Looking only at this second system, the only interaction it has is through this radiation field. It eventually assumes the same temperature as the first system. However, it's only "seeing" the radiation field. Therefore it's the radiation field that has that temperature.
            • Let's say we have one system that is held at a fixed temperature, and another system that is isolated, other than a radiative connection to the first. Looking only at this second system, the only interaction it has is through this radiation field. It eventually assumes the same temperature as the first system. However, it's only "seeing" the radiation field. Therefore it's the radiation field that has that temperature.

              Isn't that a bit like saying that a conveyor belt of negligible weight transporting 10000 tons of rocks from one location to another, one ton at a time, has significant weight itself? Kinetic energy in atoms is different from the energy of photons. As I understand it photons don't have temperature, they carry potential energy (momentum) which can be manifested in kinetic energy in matter it hits, but before it hits any matter this momentum is not temperature. When it hits the photon is converted to kinetic

              • I'm not sure physicists refer to photons as having potential or kinetic energy. Better to say they carry electromagnetic force.

                But otherwise you are right, temperature is a measure of the kinetic energy of particles with mass. That energy can be converted to photons, which then radiate away until they are absorbed by other particles, which then heat up. None of that implies that photons have a temperature.

                As far as your question goes, you can't stop a system from radiating, so at some level the outgoing rad

      • by jpapon ( 1877296 )

        You are also wrong.

        Indeed, they were. The following statement made me scratch my head a bit:

        The photons are highly ordered and there is very little random motion among them.

        By that logic, light traveling through a perfect vacuum would also have a "temperature". Which is... well... puzzling.

  • We now know that almost 40 years ago, UFO Space Aliens were shining beams of light into nuclear weapons storage areas to make them inoperable [aolnews.com]. Former USAF officers will be having a press conference on Friday, to prove it. So, big deal on the whole lasers-cooling-molecules thing.
  • Who the hell... (Score:5, Insightful)

    by ameline ( 771895 ) <ian.amelineNO@SPAMgmail.com> on Wednesday September 22, 2010 @11:21AM (#33664172) Homepage Journal
    Who the hell uses Fahrenheit for anything remotely connected to science? I can understand translating 0K to -273.15C, then 1K is -272.15C -- but how meaningful to anyone is -459.67F?
    • It's in Medical Daily, not a scientific journal. To them, -459.67 is more meaningful as it is a larger (negative) number than -273.15. The following C, K or F is just confusing fluff. The article started with a James Bond reference; you can't expect a high degree of scientific accuracy or detail in such an article. It's likely the original researchers used K.

      • Re: (Score:3, Insightful)

        by rubycodez ( 864176 )

        yes, and moreover, the fact that Bond was going to get cut in half and die was not the greatest source of anxiety in that scene, it was that the laser was headed for Bond's *junk* first

      • by EdIII ( 1114411 )

        It's in Medical Daily, not a scientific journal........The following C, K or F is just confusing fluff.

        So in this particular instance would it be accurate to say that the Medical Daily was fluffing Slashdot?

    • Re: (Score:2, Informative)

      by Thelasko ( 1196535 )

      Who the hell uses Fahrenheit for anything remotely connected to science?

      I know, they should have totally used Rankine. [wikipedia.org]

    • Who the hell uses Fahrenheit for anything remotely connected to science? I can understand translating 0K to -273.15C, then 1K is -272.15C -- but how meaningful to anyone is -459.67F?

      I think the intended audience for this article is Farmer Bill in Idaho. "Uh-huh, feels like a nippy -459.67F... guess I'd best cover up them there puhtaters."

    • by jmv ( 93421 )

      You mean I should stop telling people that the Plank constant is 6.28*10^-37 Btu*second?

    • Re: (Score:3, Informative)

      by Guppy06 ( 410832 )

      "Who the hell uses Fahrenheit for anything remotely connected to science?"

      First and foremost, you write for your audience. If your intended audience typically uses degrees Fahrenheit, you use degrees Fahrenheit. That, or you triple the size of your article, with the bulk of it devoted to phrases like "triple point of water" that will make your audience's eyes glaze over.

      Second, you're not going to do very well in a thermodynamics course in the United States (let alone get meaningful work afterward) if you

    • Re: (Score:3, Insightful)

      by demonbug ( 309515 )

      Who the hell uses Fahrenheit for anything remotely connected to science? I can understand translating 0K to -273.15C, then 1K is -272.15C -- but how meaningful to anyone is -459.67F?

      Yes, because -273.15C provides so much more information than -459.67F.
      It really, really doesn't matter. Why do people even complain about things like this? Is it so hard to plug the number into a calculator to get it in units you are capable of comprehending?

      If you are going to complain that Fahrenheit was used, then at least have the decency to request Kelvin (the proper SI unit) rather than Celsius.

      • by geekoid ( 135745 )

        It's frustration from not keeping to a global standard.

        The US should really be metric by now. We can wank about superiority all day, but the bottom line is both do well for the trained person. Not having a standard cause issues, wastes money and so on.

        We would be Metric by now if it wasn't for the bone head president, Reagan.

        • We would be Metric by now if it wasn't for the bone head president, Reagan.

          Don't forget about the 300 million or so people who don't really want to convert to the metric system.

        • by lgw ( 121541 )

          I hate the metric system. The units are awkward, and multiples of 10 make it hard in field conditions. Making everything powers of 10 was great before there were mechanical calculators, when important scientific calculations were done pencil-and-paper. Now the measurment system makes no difference in getting the right answer in a scientific context (heck, calculate and convert anything right in the Google search box), so the units should be chosen to be friendly to an "estimate in the field and do the ma

          • by jpapon ( 1877296 )
            I mean, I see your point that it would be nice if units were designed to make estimates and field calculations easy, but that's not really the point of units. The whole point is to make everything standardized.

            If you start making each unit particular to field applications, then it gets REALLY complicated when you need to start solving something which uses two different types of units.

            Say, for instance, that you needed to estimate how much water was in a pool. Your measure of distance is in base 10, but y

            • by jpapon ( 1877296 )
              And by base, I meant powers, but you get the point.
            • by lgw ( 121541 )

              You mean you don't know every reasonable power of 2 off the top of your head? Is that what /. is coming to? :)

              Yeah, it is slightly awkward when changing between distance and fluid measure, though a cubic yard is close enough to 200 gallons and 0.8 tons for field work. Most of the historic fluid measures were the size of the industry standard shipping containers, which all evolved differently, creating a bit of a mess.

              (Of course, in the One True Measuement System, the important thing to remember is that a

      • by ceoyoyo ( 59147 )

        Most people who want more information beyond "almost absolute zero" probably at least remember something from high school chemistry: that absolute zero is -273 C. Most of the world also knows that water freezes at 0 C and room temperature is somewhere around 20-25 C. That gives a fair amount of information.

        Most of the world has very little idea what meaningful points on the Fahrenheit scale are and I've never heard anyone refer to cryogenic temperatures in Fahrenheit before.

      • I propose that any time anyone suggests that a given temperature scale is more "natural" or "arbitrary" than another temperature scale, they automatically lose the argument. And get perma-banned from Slashdot. These "my temperature scale can beat up your temperature scale" arguments are beyond tiresome.
  • by MiniMike ( 234881 ) on Wednesday September 22, 2010 @11:21AM (#33664174)

    They may have a new method, but laser cooling [wikipedia.org] itself is not new. There was even a Nobel prize [nobelprize.org] awarded in 1997. It seems the advancement here is that they are using laser cooling on molecules (strontium monofluoride) instead of single atoms.

    • by BeardedChimp ( 1416531 ) on Wednesday September 22, 2010 @12:11PM (#33665010)
      I actually attended a guest lecture by him in 2002 at Queens University where pretty much the entire talk was about cooling things with lasers.

      Amazing lecture actually, he shoved about 20 balloons into a small liquid nitrogen flask throughout slowly arousing curiosity. Then whipped them out, frisbying them over the heads of students. The balloons were flat but began to expand even in mid air. Damn that was cool.

      Anyway, at the time he explained that the current limit on their approach was being on earth. Essentially they trap the atoms inside a magnetic field and slowly uses momentum transfer from the photons to the atoms to cool them. Then once they have reached the limit of that approach they would expand the magnetic field so that the atoms now filled a larger space and tada you have traditional cooling.

      The limit at this point was that they were unable to expand the magnetic field any further without losing its stability. To get round this he said the future aim was to do it in space and expand the field massively.
      That was 2002, no idea where they have gotten with that technology now.
    • by HuguesT ( 84078 )

      I heard Claude Cohen-Tanoudji (one of the recipients of the 1997 Nobel) describe their method in 1992 at MIT. It was one of the coolest lecture ever, no pun intended.

  • by Angst Badger ( 8636 ) on Wednesday September 22, 2010 @11:21AM (#33664178)

    lasers have been thought of as white-hot beams of intensely focused energy

    If there is anything that lasers are not, it's white.

  • Come on. Just say 0 K.

    Acknowledging the appropriate SI units only stings for a little while.
  • What's wrong with just plain "absolute zero"? What's the point in adding "What's known as"? Why do science writers use this silly phrase?

    • by geekoid ( 135745 )

      Because in science, any fact can be overturned by evidence. Granted, in this case it would take over whelimg evidence.

      Science just shows us a bunch of stuff we can't find a way to falsify. That was a pretty extreme example, so please don't use that sentence to 'prove' some bonehead idea.

    • It should be noted that, contrary to popular belief, adding useless phrases like "what's known as" can, believe it or not, keep readers engaged in a post-9/11 world.
  • If memory serves, the heat of a group of atoms is based both on their kinetic energy and vibrational energy. In gasses and, to a lesser extent, liquids, the average velocities of atoms is one factor determining factor of how much heat is in the gas or liquid, but so is the vibrational energy of the atom (otherwise solids wouldn't be capable of getting hot, which they clearly can).

    So while these scientists have demonstrated being able to reduce the kinetic energy of an atom to zero, the article says nothing

    • by sjames ( 1099 )

      "Vibrational energy" is just an oscillation between kinetic energy and potential energy in an elastically bound object. A single atom in a vacuum cannot have vibrational energy at all since there is no force acting on it.

      When you damp the vibration of a string, you are actually operating on it's kinetic energy. Each time it strikes your finger it loses a bit more kinetic energy and so the next cycle is weaker than the last.

  • I want a laser cooled PC, water cooling can leak, air cooling is inefficient, I can't wait till this gets used in similar products
  • Duh (Score:2, Insightful)

    by space_jake ( 687452 )
    I always thought lasers were cool.
  • by roman_mir ( 125474 ) on Wednesday September 22, 2010 @11:46AM (#33664606) Homepage Journal

    No, Mr. Bond; I expect you to yell like a little girl while I am freezing your balls!

  • Can an atom be split using extereme cold? If you stop all the motion of an atom due to absolute zero does it fall apart? Is absolute zero a cessation of motion on a molecular level or an atomic level?
    • by u17 ( 1730558 )
      INAP, but there's no reason why the strong force should stop working just because the atom isn't moving. I don't understand your second question; since atoms in molecules have fixed positions relative to each other, surely atomic immobility implies molecular immobility and molecular immobility implies atomic immobility?
      • by jpapon ( 1877296 )
        I'm not sure, but I think they were asking if the electrons stop in their orbits. And I have no frickin' clue, but I'd guess no.

        In any case as far as I know, temperature is vibration. I don't see why stopping its vibration would cause an atom to split.

  • It wants its Nobel Prize back.

    Seriously, laser cooling has been around for decades. Want a more interesting article? How about something about a laser which really is a beam of intensely-focused energy capable of burning through anything in its path? Especially if it runs on house current

  • ridiculous summary (Score:4, Informative)

    by jmizrahi ( 1409493 ) on Wednesday September 22, 2010 @12:22PM (#33665246)

    This is a particularly bad science article. First of all, this research is interesting because they are laser cooling molecules. The article makes it sound like the new thing here is using lasers to cool. Laser cooling of atoms has been around for decades, but laser cooling of molecules is considerably more difficult because molecules have far more resonant transitions than do atoms (this is due to the additional rotational and vibrational degrees of freedom.) Traditional Doppler laser cooling relies on cycling transitions, in which the atoms go back and forth between two levels, losing momentum as they cycle. If the particles can "escape" to other levels, the cycle breaks and cooling stops. Traditionally, in atoms this problem is solved by having other lasers on the table which "plug up" these holes by repumping the atoms back into the cooling cycle. With molecules, there has historically been far too many holes to simply plug them with other lasers.

    Second, Fahrenheit? Seriously? Nano/Micro/MilliKelvin is the appropriate unit.

  • and to think that all this time I thought the Jedi were using heat to cut body parts off. Now we might find out they were freezing them and the limbs were fracturing and dropping off. Who'd a thunk?

    LoB
  • Freezing a smuggler who's too quick to jettison his cargo at the first sign of Imperials.

  • You know, I have one simple request. And that is to have sharks with frickin' laser beams attached to their heads!
  • For decades now the microwave has been a common kitchen appliance. But what good is a microwave when your beer is warm? It's about time someone came up with a rapid chilling system for beer. When can I expect to see one of these at Best Buy?
  • This is news for nerds. We all know what absolute zero is.

  • ...and five missiles, we can finally kill a Metroid.

You know you've landed gear-up when it takes full power to taxi.

Working...