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Science Technology

Scientists Create Di-positronium Molecules 160

Posted by samzenpus from the super-laser dept.
doxology writes "The BBC reports that scientists have been able to create di-positronium molecules. A di-positronium molecule consists of two positronium atoms, exotic atoms which are made from an electron and a positron (the anti-particle of the electron). A potential use of these molecules is to make extremely powerful gamma-ray lasers, possibly on sharks."
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Scientists Create Di-positronium Molecules More

Scientists Create Di-positronium Molecules

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  • And doxology ruins the whole thread (Score:5, Funny)

    by BadAnalogyGuy ( 945258 ) <BadAnalogyGuy@gmail.com> on Thursday September 13, 2007 @07:05AM (#20585869)
    Hey! You're supposed to let US make the jokes.

    • Re: (Score:3, Funny)

      by smittyoneeach ( 243267 ) *
      doxology [reference.com]: a hymn or form of words containing an ascription of praise to God
      Perhaps you meant:
      d'enouement [reference.com]: The solution of a mystery; issue; outcome.
      Because if we're not about st00p3d jokes, we're about pedantry. ;)

      • Re: (Score:2, Funny)

        by BadAnalogyGuy ( 945258 )
        No, I didn't make any mistake.

      • Re: (Score:3, Informative)

        by johnw ( 3725 )
        The original article was posted by someone called "doxology"!
        • First day, new eyes. ;)
          This pair o' doxology usages recalls the Steven Wright jape:
          "When I was a boy, I had a dog named Stay. I'd say 'Come here, Stay! Come here, Stay! He would just look at me...and keep on typing. He was an East German Shepherd. Very, very disciplined."

  • Not fair! (Score:4, Funny)

    by hcdejong ( 561314 ) <`hobbes' `at' `xmsnet.nl'> on Thursday September 13, 2007 @07:08AM (#20585889)
    If you're going to include all the applicable memes in the blurb, there'll be nothing left for us to post about.

    • Re: (Score:1, Redundant)

      by Arabani ( 1127547 )
      Come on, at least he didn't use the obvious one!

      In Soviet Russia sharks put lasers on you!

    • Re: (Score:3, Funny)

      by jollyreaper ( 513215 )

      If you're going to include all the applicable memes in the blurb, there'll be nothing left for us to post about.
      If they can make an anti-oxygen, that means we can have di-positronic monoxide, anti-water! It's got positronolytes, what anti-plants crave.

      • Re:Not fair! (Score:4, Informative)

        by Chris Mattern ( 191822 ) on Thursday September 13, 2007 @08:02AM (#20586321)
        Dude, I know you don't read the article, but you should at least read the summary. Positronium isn't anti-hydrogen; it's an electron and a positron, not a positron and an anti-proton.

        Chris Mattern

      • Re:Not fair! (Score:5, Funny)

        by Opportunist ( 166417 ) on Thursday September 13, 2007 @08:02AM (#20586329)
        Anti plants? Are you nuts? Anti plants do anti photosynthesis. And while glowing oaks might be cool, their carbon emissions are just way too high.

        • Re:Not fair! (Score:4, Funny)

          by jollyreaper ( 513215 ) on Thursday September 13, 2007 @09:06AM (#20587303)

          Anti plants? Are you nuts? Anti plants do anti photosynthesis. And while glowing oaks might be cool, their carbon emissions are just way too high.
          Carbon footprints don't matter, my pasta/antepasta reactor will generate all the clean energy we need. Of course, the carb footprint will be a little high but such is the price of progress.
          • That's not carb, that's anti-carb. Can't you smell the new hype?

            "Low-carb was yesterday, today is anti-carb! Yes, eat food that actually BURNS your fat, for real and quite literally!"

            Sure, some will always start pestering you, that it's not healthy, that gamma ray bursts in your body can damage your kidneys or liver, but hey, you die slim!

            • Re: (Score:2, Funny)

              by Kynmore ( 861364 )
              "Have you ever seen what happens to a yeti when 12 containers full of unadulterated gamma rays burst in its stomach?"

          • Re: (Score:2)

            by ATMD ( 986401 )
            The FSM isn't going to be happy about this...

        • Anti plants? Are you nuts? Anti plants do anti photosynthesis. And while glowing oaks might be cool, their carbon emissions are just way too high.
          You just don't get it do you? Anti-Carbon emissions would solve global warming forever!
          • And the energy produced when the carbon dioxide in the atmosphere annihilates the anti-carbon dioxide would solve our energy problems for all time!

        • And while glowing oaks might be cool, their carbon emissions are just way too high.

          Anti photosynthesis would obviously lead to CO2 emissions, not carbon emissions.

          Sigh. You know you're a nerd when your comments are even to nerdy for a news for nerds website. Damn.

          • Ok, ok, nitpicker, CO2. But it ain't the O2 part that is concerning, it's that this pesky carbon atom is between those two nice li'l oxygens.

      • Re: (Score:2)

        by McWilde ( 643703 )
        How do you figure positronium is anti-hydrogen? You'd need at least an anti-proton in there...

        • How do you figure positronium is anti-hydrogen? You'd need at least an anti-proton in there...
          It's faith-based science: I believe one is there, even though I can't see it. Now quit fucking up my joke. :)
    • You must be new here...
    • Chuck Norris picks his teeth with these things.

  • Someone get Wheaton in here (Score:5, Funny)

    by LiquidCoooled ( 634315 ) on Thursday September 13, 2007 @07:11AM (#20585911) Homepage Journal
    If ever there was a topic which he could explain it would be this.
  • Sweet, one step closer to me getting gamma-induced powers...HULK SMASH....
  • Dr. Evil: You know, I have one simple request. And that is to have sharks with frickin' laser beams attached to their heads! Now evidently my cycloptic colleague informs me that that cannot be done. Ah, would you remind me what I pay you people for, honestly? Throw me a bone here! What do we have?

    Number Two: Sea Bass.

    Dr. Evil: [pause] Right.

    Number Two: They're mutated sea bass.

    Dr. Evil: Are they ill tempered?

    Number Two: Absolutely.

    Dr. Evil: Oh well, that's a start.

  • Possibly on sharks? (Score:4, Funny)

    by fgaliegue ( 1137441 ) on Thursday September 13, 2007 @07:17AM (#20585955)

    From the end of the summary, the very end in fact:

    [...],possibly on sharks Can the author of the news please elaborate? I just don't see how this discovery possibly relates to an undeservedly frowned upon species of fish...

  • The State of Science Journalism (Score:1, Funny)

    by Anonymous Coward
    '"It's like having a trickle of water filling up a bath and then you empty it out and you get a big flush," said Dr Cassidy.'

    TFA fails to confirm whether or not this involved a series of tubes.
    • I tend to find that my baths don't work well for flushing.. wouldn't a toilet flush have been a better analogy? The plug hole in a bath doesn't drain much faster than the taps fill. Meh.

    • Re: (Score:3, Funny)

      by jollyreaper ( 513215 )

      '"It's like having a trickle of water filling up a bath and then you empty it out and you get a big flush," said Dr Cassidy.'

      TFA fails to confirm whether or not this involved a series of tubes.
      I think we need to explain to our tiny scientist the difference between a tub and a toilet. Someone else will have to explain that French thing that shoots water at yer bum.

  • On the good side (Score:5, Interesting)

    by Billosaur ( 927319 ) * <wgrother AT optonline DOT net> on Thursday September 13, 2007 @07:24AM (#20586013) Journal

    As a result, there is a huge interest in the technology from the military as well as energy researchers who believe the lasers could be used to kick-start nuclear fusion in a reactor.

    Well, I'm not sure if letting the military get their hands on it is such a good thing, but the use to initiate nuclear fusion could be the key to cleaner power for everyone. The hardest part of initiating fusion has been pouring enough energy in to start the reaction and allow it to become self-sustaining. This discovery might lead to technology capable of generating the necessary energy.

    • Re: (Score:3, Insightful)

      by ducomputergeek ( 595742 )
      It will probably be military funding that carries out the research. After all, we've mastered creating an uncontrolled, none contained fusion reaction: please see Hydrogen Bombs, Thermonuclear Weapons, fission-fusion weapons, etc.. The holy grail in Weapons research is the true 4th Generation Thermonuclear bomb that uses some method to trigger the reaction other than a fission weapon. (Personally I like to call them Fusion bombs because most people don't know the difference between a nuclear and thermonu

      • Re: (Score:2)

        by Alioth ( 221270 )
        Gasp! Gasp! GASP!

        The fusion reaction in an H-bomb is contained, or it wouldn't occur at all. It's just not contained for very long, that's all. The type of confinement in an H-bomb is called "inertial confinment".

        Fission's the same: the nuclear reaction can only take place while the critical mass remains assembled. By the time the nuke is actually destroying stuff (including things as close as the bomb casing), the reaction is already over. Much of a bomb's efficiency is related to how long you can keep the
      • The ecological damage of a fallout-free fusion bomb is still incredibly high, though. These sort of things would kick so much dust into the atmosphere that using more than a couple would carry just as much risk of 'nuclear winter.'

        In fact, it'd be even worse without the fallout, because we'd have the freezing cold and total collapse but no awesome mutants or psychic powers.

        • Re: (Score:2)

          by SEE ( 7681 )
          Nuclear winter resulting in freezing cold and total collapse? The scenario existed in the original 1980s papers, but those models have long since been shown to be erroneous. Modern science shows that if you detonate 5000 megatons of nukes, spread over a thousand cities, you get a nuclear winter roughly as bad as the volcanic winter of 1816.

  • Can you imagine (Score:5, Funny)

    by ciaohound ( 118419 ) on Thursday September 13, 2007 @07:29AM (#20586055)
    what would happen if Scotty reversed the polarity on those?
    • Instead of having an electron orbiting a positron, you'd have a positron orbiting an electron!

  • The "optics" of a gamma laser (Score:5, Informative)

    by Wilson_6500 ( 896824 ) on Thursday September 13, 2007 @07:41AM (#20586139)
    A gamma-ray laser would certainly have many applications. Maybe the energy density is so high that it becomes irrelevant, but the problem that jumps out at me is that you really can't refract high-energy photons. About all you can do is stop them. I don't see this type of "laser" being used in most applications where you traditionally think lasers would be useful, since you wouldn't be able to easily focus these beams, guide them in fiber, or anything like that. The most useful thing you could do with this type of laser, I would guess, would be ablation--THAT it should be pretty darn good at.

    Anyhow, it'll be interesting to see the radiometry for these lasers in however many years it'll take for them to be in a position where they can even think about that sort of thing. From that, you can figure out the dosimetry if you were to turn one onto a person. In this situation, a medical linac should be to this sort of thing what a flashlight is to a laser in terms of photon flux. When you're talking about gamma photons instead of visible ones, I imagine you could give someone a pretty serious radiation dose in pretty short order. From a military perspective I don't think that putting that in a hand-held weapon would exactly rival bullets (which are pretty good at disabling people quickly, something that radiation couldn't do reliably barring stupidly high doses over large areas of the brain or GI), especially considering the cost. Putting one on a satellite and blasting ICBMs in orbit, however, could be a very different story--you don't have nearly as much atmosphere to get through, and you ought to be able to put an awful lot more energy in that missile with similar fluxes of gamma photons versus lower-energy photons. The gammas would probably significantly penetrate the housing of the missile, too, which could be good or bad--bad in that it spreads out the heating effect you'd get, good in that you can significantly heat things that are behind a few layers of metal.

    Come to think of it, considering that medical linacs have caused serious burns (and then death from ARS) in the past, turning a gamma laser on someone would probably basically burn right through them--so maybe dosimetry really isn't an issue (for the target--for the operators, on the other hand...)

    Anyhow, that's way in the future. For now, all we have are jokes about sharks that can turn people into the Hulk from ten meters.

    • Re:The "optics" of a gamma laser (Score:5, Insightful)

      by marcosdumay ( 620877 ) <(marcosdumay) (at) (gmail.com)> on Thursday September 13, 2007 @08:14AM (#20586479) Homepage Journal

      "Putting one on a satellite and blasting ICBMs in orbit, however, could be a very different story"

      I doubt it. If you can't focus the bean, you don't have much chance of using it at distance.

    • Re: (Score:2, Insightful)

      by HaveNoMouth ( 556104 )

      ...but the problem that jumps out at me is that you really can't refract high-energy photons
      Of course you can. All you need is a small black hole.

    • Re: (Score:2)

      by sjames ( 1099 )

      You don't necessarily need a lens to focus a laser, the length of the laser tube takes care of that for you. Photons that happen to be traveling down the axis of the cylindar will stimulate more photon emissions in the same direction. Off axis photons will hit the wall of the tube before stimulating many emissions.

      If the lasing happens in a cylindrical tube, the beam will be a cone whose base is the end of the tube and whose apex is the center of the tube. A longer tube gives a less divergant beam. In the

  • FTFA (Score:2)

    by ArwynH ( 883499 )

    "The discovery, reported in the journal Nature, is a key step in the creation of ultra-powerful lasers known as gamma-ray annihilation lasers."

    Gamma-ray annihilation lasers!!! Oh yeah baby! Who says scientists can't think of cool names?!

  • First: "gamma-ray annihilation lasers". Say it out loud. I just want you to take in how immensely cool that sounds.

    Second, might these be the trick to powering Space Elevators? Admittedly materials is still the bigger problem there, but beaming power to the platform was always part of the master plan.

    • Re: (Score:2)

      by ceoyoyo ( 59147 )
      No. Creating antimatter is an incredibly inefficient process. The reason it's called a gamma ray ANNIHILATION laser isn't because of what happens to whatever it's aimed at, it's because the laser powers itself by annihilation and probably destroys itself in the process. So you only get one shot. Then you have to go make more antimatter.
    • And they could probably cut the carbon cord in a friction of second too. The falling cable could destroy cities, how fun.
      I believe the safest application of this thing would be a weapon.

      • I believe the safest application of this thing would be a weapon.
        "Ah, this is obviously some strange use of the word 'safe' that I wasn't previously aware of." --Arthur Dent

  • non-shark-related (Score:2, Insightful)

    by sexybomber ( 740588 )
    I read the article and I still don't get it. How can these positronium atoms possibly be stable? TFA says that they've "merged an electron and a positron", which is impossible, because when the electron and the positron touch, there's a relatively large explosion.

    So ... one of the particles has to be orbiting the other, like a regular atom. But wouldn't it blow up just the same if, say, a stray cosmic ray or a neutrino or something were to smack the nucleus? IIRC, photons are more like normal matter tha

    • Re:non-shark-related (Score:5, Informative)

      by Ecuador ( 740021 ) on Thursday September 13, 2007 @09:14AM (#20587467) Homepage
      First of all, the electrons orbiting around the atom's nucleus is an atomic model that was valid during the first couple of decades of the 20th century. Our atomic models of the last 80 years are not as simple as that.
      You are right about the electron and the positron being able to annihilate each other (producing a couple of photons IIRC, I guess your "explosion" of radiation). However, you are limited to high school level (particles orbiting each other) and Hollywood level (matter-antimater explosions) physics, but you are getting in quantum physics territory, where the particle-antiparticle annihilation does not exactly happen when the particles "touch". In fact we cannot even say that two particles "touch" in the traditional sense of the word.
      Anyway, without being a particle physicist and without RTFA (leaving for work now), I can tell you that I don't see a reason that a positron-electron pair could not survive for a brief time. Where "brief" in physics is measured in ps or at least ns. When you hear physics news like "we created the xxx exotic particle" they are usually referring to something that existed in their accellerator for a picosecond or so...

    • Re: (Score:2, Informative)

      by Anonymous Coward
      I am a physicist but not a particle physicist. Electrons and positrons are attracted to each other because one is negatively charged and one is positively charged. When they come together they can form a stable state which is a lot like a hydrogen atom, instead of a proton and an electron you have a positron and electron. The stable state is called "positronium". "Stable" is a relative term here, positronium lasts maybe 100 nanoseconds, which is a "long" time in some sense. After that the electron and posit
  • "These short-lived, hydrogen-like atoms consist of an electron and a positron, a positively charged antiparticle." I would think that an anti-proton and a positron (anti-electron) would be a "hydrogen-like atom." Why is the mating of an electron and an anti-electron considered an "atom?" And what force is keeping them from just annihilating each other? Why do they hook up and hang out, even for a brief time? I read about this on fark and got confused but came here to ask. So please, smart people of Sl

    • Re:Why is this an "atom?" (Score:5, Informative)

      by Remus Shepherd ( 32833 ) <remus@panix.com> on Thursday September 13, 2007 @08:42AM (#20586897) Homepage
      Calling an electron-positron pair an 'atom' is a bit suspect, but not too bad. Any semi-stable collection of elementary particles can be referred to as an 'atom'. They took the analogy even further, saying that when these 'atoms' met each other they formed 'molecules' -- large, electromagnetically bound accumulations of electron-positron pairs. Kinda cool.

      As for what's keeping them from annihilating each other...well, at first it's angular momentum and the Pauli exclusion principle [wikipedia.org]. Both the electron and the positron are fermions, and they must occupy discrete states. Give the pair enough energy and they will occupy a semi-stable state that does not allow them to contact and destroy each other.

      But before long they *do* annihilate each other. That's why it's called an 'annihilation laser'. The matter-antimatter pair collapses, liberating enormous amounts of energy in the form of gamma rays.

      I think 'matter-antimatter annihilation laser' sounds cooler, but there's a certain mad scientist flavor to the 'gamma ray' bit, too.
      • But the Pauli exclusion principle prevents two *identical* fermions from occupying the same quantum state simultaneously. Are an electron and positron considered identical fermions or is this between two electrons and positrons within the "molecule"?

        I'm also wondering just how stable the molecules are. Could they be used for a matter-antimatter propelled rocket?

        Today's Thursday. Must be my armchair physicist day.
        • Pauli exclusion, if I recall correctly, is also the principle that forces electrons into discrete energy states. An electron can go from state A to state B, but cannot exist in any state in between. That's what keeps the electron-positron system somewhat stable -- they have enough energy to occupy a mutually orbiting state. They have to lose all their energy at once -- not just some of it -- to exit that state and annihilate with each other. The higher the energy shift necessary, the longer it takes for

      • Re: (Score:2)

        by InfoVore ( 98438 ) *
        I think 'matter-antimatter annihilation laser' sounds cooler, but there's a certain mad scientist flavor to the 'gamma ray' bit, too.

        How about a compromise then: MAAG-LASER - Matter-Antimatter Annihilation Gamma-ray Laser

        Of course the "L" should be replaced with a "G" since the Gamma-rays are the EM waves being amplified: GASER - Gamma-ray Amplified Stimulated Emission of Radiation. But we may want to stick with MAAG-LASER since MAA-GASER sounds like a southerner commenting on the result of eating too man
      • "Any semi-stable collection of elementary particles can be referred to as an 'atom'."

        How do you define "semi-stable"? Because the last row of the Periodic Table of the Elements [wikipedia.org] on Wikipedia is populated largely by things starting with "un" that have half-lives in the millisceonds, which I don't consider to be particularly stable. But then, maybe it the world of physics, that's a long time compared to the lifespans of some of the other particles they look for these days.

  • Atoms? (Score:3, Interesting)

    by Tyler Durden ( 136036 ) on Thursday September 13, 2007 @08:26AM (#20586641)
    So positronium is an atom composed of an electron and a positron. Is this then an atom without a nucleus?

    Weird.
    • "Atom" comes from Greek and literally means unsplittable. Of course, you can split electrons away from the atom (ionization), thereby making it a misnomer. And we get atomic energy by splitting the nucleus of a heavy atom. To be completely literal-minded about it, the electron and the positron are the true atoms in positronium.

  • Can they take it to three? (Score:5, Funny)

    by Anonymous Coward on Thursday September 13, 2007 @08:28AM (#20586673)
    Although dipositronium (Ps2) is considered to be a huge advance, scientists will be disappointed to discover that tripositronium (Ps3) will never be as popular as tungsten-diiodide (WII).

    • Re: (Score:2)

      by Riktov ( 632 )
      But for smaller-scale applications, positronium-protonium (PSP) is pretty popular.

  • A potential use of these molecules is to make extremely powerful gamma-ray lasers, possibly on sharks.
    Finally! Now that the harmless sharks finally get some gamma-ray lasers on the tip of their nose, this will help them regain their position at the top of the food chain, ever since the nasty penguins started taking over their territory.
  • Forgive my ignorance but isn't a gamma ray pretty hard to shield against and focus, or was that some other form of radiation? It would seem to me making a focused beam of radiation would require very toxic materials for reflecting, and some radiation waves penetrate most anything.
    • Hard to shield against, yes. Focus, yes I think it's difficult focus at either extreme of the spectrum.
      However you don't necessarily need to focus a laser, eh? Just use a really aperture in your emission
      chamber? Toxicity has nothing to do with reflectivity.
  • Just in case no one has yet, I propose the acronym GRAIL: Gamma Ray AnnihIlation Laser. Sounds like they've been seeking it for a while, too...
  • I was creating di-positronium molecules almost 25 years ago on my Atari 2600 [youtube.com]

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