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Scientists Blast Antimatter Atoms With a Laser For The First Time (npr.org)

For the first time, researchers from Indiana University were able to blast antimatter atoms with a laser to measure the light emitted from the anti-atoms. The researchers hope to answer one of the big mysteries of our universe: Why, in the early universe, did antimatter lose out to regular old matter? NPR reports: "The first time I heard about antimatter was on Star Trek, when I was a kid," says Jeffrey Hangst, a physicist at Aarhus University in Denmark. "I was intrigued by what it was and then kind of shocked to learn that it was a real thing in physics." He founded a research group called ALPHA at CERN, Europe's premier particle physics laboratory near Geneva, that is devoted to studying antimatter. That's a tricky thing to do because antimatter isn't like the regular matter you see around you every day. At the subatomic level, antimatter is pretty much the complete opposite -- instead of having a negative charge, for example, its electrons have a positive charge. And whenever antimatter comes into contact with regular matter, they both disappear in a flash of light. In the journal Nature, his team reports that they've now used the special laser to probe this antimatter. So far, what they see is that their anti-hydrogen atoms respond to the laser in the same way that regular hydrogen does. That's what the various theories out there would predict -- still, Hangst says, it's important to check. "We're kind of really overjoyed to finally be able to say we have done this," he says. "For us, it's a really big deal." From the journal Nature: "Researchers at CERN, the European particle physics laboratory outside Geneva, trained an ultraviolet laser on antihydrogen, the antimatter counterpart of hydrogen. They measured the frequency of light needed to jolt a positron -- an antielectron -- from its lowest energy level to the next level up, and found no discrepancy with the corresponding energy transition in ordinary hydrogen."

64 of 115 comments (clear)

  1. Well duh. by fahrbot-bot · · Score: 4, Funny

    Researchers ... trained an ultraviolet laser on antihydrogen, ... and found no discrepancy with the corresponding energy transition in ordinary hydrogen.

    Everyone knows you need to use an anti-laser to get the appropriate results.

    --
    It must have been something you assimilated. . . .
    1. Re:Well duh. by BitterOak · · Score: 5, Informative

      I know your comment was meant to be humorous, but it does raise an important point. There really is no such thing as an anti-laser since lasers produce photons, and photons are their own anti-particle. I.e. there's no such thing as an anti-photon, or to be more precise, a photon and anti-photon are the same thing! That's why an ordinary laser can be used in this experiment.

      --
      If I can be modded down for being a troll, can I be modded up for being an orc, or a balrog?
    2. Re: Well duh. by pollarda · · Score: 1

      I agree. Until they probe the antimatter with antiphotons the results will forever be incomplete. Additonally, using anti-hydrogen is a cop out. Using anti-U235 will create much more interesting results.

    3. Re: Well duh. by K.+S.+Kyosuke · · Score: 4, Funny

      I can't wait until they publish the anti-paper. It may bomb, though.

      --
      Ezekiel 23:20
    4. Re: Well duh. by Anonymous Coward · · Score: 1, Funny

      If so, it will be the antithesis of conventional matters.

    5. Re:Well duh. by FatdogHaiku · · Score: 1

      Dang, wikipedia has gone down hill son!

      Shine an anti-laser, get a black hole...

      --
      You have the right to remain sentient. If you give up the right to remain sentient, you will be elected to public office
    6. Re:Well duh. by slickwillie · · Score: 5, Funny

      You mean they shoulda used photoffs instead of photons?

    7. Re:Well duh. by bazorg · · Score: 2

      Everyone knows you need to use an anti-laser to get the appropriate results.

      no need. you can just turn the knob to "anti-blast".

    8. Re:Well duh. by gijoel · · Score: 1

      Will we have to invent an anti-shark, or should we get the anti-Pope to fire it?

    9. Re:Well duh. by blind+biker · · Score: 1

      You mean they shoulda used photoffs instead of photons?

      My hat is off to you, good sir. That was brilliant.

      --
      "The agriculture ministry is not in charge of Gundam" - Japanese ministry official.
    10. Re:Well duh. by Big+Hairy+Ian · · Score: 1

      The difficulty is attaching the Anti-Laser to an Anti-Shark

      --

      Build a Man a Fire, and He'll Be Warm for a Day. Set a Man on Fire, and He'll Be Warm for the Rest of His Life.

    11. Re:Well duh. by jafiwam · · Score: 2

      Will we have to invent an anti-shark, or should we get the anti-Pope to fire it?

      Do not invoke the anti-pope in public.

    12. Re:Well duh. by Anonymous Coward · · Score: 1

      I know where you can try a dark sucker for just $20 ...

    13. Re:Well duh. by strikethree · · Score: 1

      a photon and anti-photon are the same thing!

      Not that I expect you to have an answer... But why are a photon and an antiphoton the same thing but an electron and an anti-electron (positron) NOT the same thing. In theory, they are both electromagnetic waves. In reality, photons have no mass and electrons do have mass. Which is why, I guess, they call it anti MATTER.

      But then, how could there even be an anti photon?

      --
      "Someone needs to talk to the tree of liberty about its ghoulish drinking problem." by ohnocitizen
    14. Re:Well duh. by tendrousbeastie · · Score: 3, Insightful

      The reason is that an anti-particle is a particle with opposite charge (both electric and colour) compare to its partner. So an anti-electron has opposite charge to a normal electron, and an anti-quark has opposite colour-charge and electric charge to a normal quark.

      A photon does not have any charge, so an anti-photon would have identical properties to a normal photon - they would be identical, and so it makes no sense to talk about them as being different entities.

    15. Re: Well duh. by hAckz0r · · Score: 1

      Better stand back and hold your ears son, one mistake and the implosion from this device could be rather loud!

    16. Re: Well duh. by tom17 · · Score: 1

      You mean anti-laboratory.

      Not to be confused with an anti-lavatory. Messy.

    17. Re:Well duh. by BitterOak · · Score: 2

      The reason is that an anti-particle is a particle with opposite charge (both electric and colour) compare to its partner. So an anti-electron has opposite charge to a normal electron, and an anti-quark has opposite colour-charge and electric charge to a normal quark.

      A photon does not have any charge, so an anti-photon would have identical properties to a normal photon - they would be identical, and so it makes no sense to talk about them as being different entities.

      You're exactly right, but there is one other quantum number involved in particle/anti-particle duality, and that is lepton number. That is why neutrinos and anti-neutrinos are distinct particles despite having no electric or color charge: they have opposite lepton number.

      --
      If I can be modded down for being a troll, can I be modded up for being an orc, or a balrog?
    18. Re:Well duh. by BitterOak · · Score: 1

      In addition there is the bayron number. For instance a neutron has no charge and is composed of quarks. An anti-neutron also has no charge but is made up of anti-quarks and has a bayron number of -1 instead of 1.

      But the previous poster talked about color charge, and the baryon number is just the sum R+B+G where R, G, and B are the red, green, and blue color charge respectively. Actually, the individual color charges themselves are not constant, since they are scrambled around by the gluon field, but their sum, R+B+G which is just the baryon number is.

      --
      If I can be modded down for being a troll, can I be modded up for being an orc, or a balrog?
  2. Why lasers? by jmv · · Score: 3, Interesting

    Anyone with better physics knowledge can comment here? Why would you use lasers to measure differences between matter and anti-matter? As far as I know, the only difference between the two is supposed to involve the weak force rather than the electromagnetic force (on which light is based). Considering that these guys aren't idiots, I must be missing something. How are the lasers useful?

    1. Re:Why lasers? by NotInHere · · Score: 1

      I think they just wanted to confirm that antimatter doesn't behave differently here than matter does.

    2. Re:Why lasers? by mykepredko · · Score: 2

      The big reason I can think of why you would use lasers for this experiment is that you need to know precisely how much energy is being applied to the anti-hydrogen atoms. As lasers produced only one wavelength (energy level) of light, this becomes a non-issue.

      I imagine that the wavelength of laser light is different from the expected wavelength of the released photon from the anti-hydrogen atom, so it can be easily detected and not confused with light from any other source (ie the laser).

      Note that the "laser" being used here is not the same one as you would find in a dollar store laser pointer.

    3. Re:Why lasers? by Dorianny · · Score: 5, Interesting

      The C and P symmetries violations in weak interactions is not enough to explain why there is No detectable antimatter in the Universe. Scientists are performing experiments that they should know the results of in the hopes that it gives unexpected result. Ernest Rutherford's landmark experiment with gold foil and alpha particles is just one of many experiments yielding unexpected results, invalidating the wildly accepted Plumb Pudding theory of the atom and opening the door to Quantum Mechanics. The discovery of the expansion of the universe and later its acceleration were both unexpected results. Sometimes it pay to check if the sky is actually blue (which ironically only appears to humans as blue because of a quirk of our vision system. If human (or to alien) eyes were equally sensitive to all wavelengths the sky might look violet or ultra-violet)

    4. Re:Why lasers? by CaptainDork · · Score: 1

      The main reason is because so much data has been collected, over a such long period of time, using lasers to measure matter that the scientific method would require using a laser as a control yardstick to measure anti-matter.

      --
      It little behooves the best of us to comment on the rest of us.
    5. Re:Why lasers? by Harvey+Manfrenjenson · · Score: 2

      (disclaimer: I'm not a physicist.) I think the idea is they get the atom to flouresce? The atom absorbs a photon of light, which if it came from a laser we know the exact wavelength of, then emits a lower-energy photon at a longer wavelength, which we can then measure. The difference in energy gets absorbed by the electron (or positron) as it moves to a higher-energy orbital. (Or do you say anti-orbital?)

      What I wonder about is, if the anti-hydrogen atom reacts exactly the same way as a hydrogen atom... how can they be sure they didn't accidentally hit a stray hydrogen atom, instead of the antihydrogen atom they were aiming for? I understand they are shooting into a vacuum chamber, but even the vacuum of space has hydrogen atoms floating around in it.

    6. Re: Why lasers? by Anonymous Coward · · Score: 1

      Did they go Wep, Wep!? (That's Pew, Pew! backwards. Get it? Because "anti"? Oh well, never mind.)

    7. Re:Why lasers? by Hidyman · · Score: 1

      It's not in space.

      --
      You can't take the sky from me ...
    8. Re:Why lasers? by Big+Hairy+Ian · · Score: 1

      Anyone with better physics knowledge can comment here? Why would you use lasers to measure differences between matter and anti-matter? As far as I know, the only difference between the two is supposed to involve the weak force rather than the electromagnetic force (on which light is based). Considering that these guys aren't idiots, I must be missing something. How are the lasers useful?

      Given there's no such thing as an antiphoton how would you measure the spectrum of an Anti-Hydrogen atom? Laser is the only way to do it.

      --

      Build a Man a Fire, and He'll Be Warm for a Day. Set a Man on Fire, and He'll Be Warm for the Rest of His Life.

    9. Re:Why lasers? by TomGreenhaw · · Score: 2

      Q) Why would you use lasers to measure differences between matter and anti-matter?
      A) Because lasers can be controlled and tuned excite the electrons and positrons to just the right amount of energy for them to jump to their next energy state and when that energy is released can be measured to verify the accuracy of the mathematical model of the atom in question. Since you don't have a lot of anti-matter to play with, one needs a very well controlled light source with a high degree of precision and accuracy.

      Q) As far as I know, the only difference between the two is supposed to involve the weak force rather than the electromagnetic force (on which light is based).
      A) Antimatter exhibits the same properties of all forces the same way as matter. Antimatter particles however have opposite charge and spin in relation to matter. E.g. the electron has an opposite negative charge compared to the positron which is positively charged and the quarks that make up a proton have the opposite spin and charge compared to its antimatter counterpart the anti-proton.

      Bonus) ... the weak force rather than the electromagnetic force (on which light is based)
      A) It has been shown that the weak force which regulates radioactive decay of an atomic nucleus is actually a special case of the electromagnetic force.

      --
      Greed is the root of all evil.
    10. Re:Why lasers? by jmv · · Score: 1

      Given there's no such thing as an antiphoton

      Of course there is, and it's called a photon. The photon is its own anti-particle. Just line the other force carriers.

    11. Re:Why lasers? by Harvey+Manfrenjenson · · Score: 2

      Yes, thanks, I understand that their lab is not in outer space. The best man-made vacuums still contain about 1000 atoms per cubic centimeter(*). So my question stands-- how can they be sure their laser didn't hit a stray hydrogen atom?

      (*)Interesting link here on the subject of ultra-high vacuums: http://physics.stackexchange.c...

    12. Re:Why lasers? by TomGreenhaw · · Score: 1

      Good catch. I should have said "an aspect of the electro-weak force." instead of "a special case of the electromagnetic force."

      --
      Greed is the root of all evil.
  3. Not the first attempt. by Gravis+Zero · · Score: 5, Funny

    This actually isn't the first time they've run this experiment. The first time was back in 2005 but things didn't go as planned. What happened was really a cautionary tale because one scientist had their cat ("Schrodinger") at the lab and was enjoying the warm anti-matter containment unit. When the scientists began the experiment, the cat spotted the laser and lunged at it, coming into direct contact with the anti-matter. It was a mess and Schrodinger the cat was very very dead while the lab and experiment destroyed. After that, people started saying that you have to harness anti-matter with a cat or as one person put it, "grab them by the pussy." ;)

    --
    Anons need not reply. Questions end with a question mark.
    1. Re:Not the first attempt. by Anonymous Coward · · Score: 3, Funny

      Schrodinger the cat was very very dead

      Are you sure it was dead?

    2. Re:Not the first attempt. by slickwillie · · Score: 1

      Are you one of those anti-cat people?

    3. Re:Not the first attempt. by syntotic · · Score: 1

      Eddie: [Referring to the electrocuted cat] If that thing had nine lives, he just spent 'em all.

      Because the laser was broadband? This discussion needs someone to summarize the underlying theory, like in previous discussion.

  4. observation influences results by turkeydance · · Score: 1

    atomically anyway

  5. Oh great, a new SJW movement... by BronsCon · · Score: 4, Funny

    Hydrogen Lives Anti-Matter

    --
    APK quotes people (including myself) without context and should not be trusted. Just thought you should know.
    1. Re:Oh great, a new SJW movement... by Z80a · · Score: 1

      That would only happen if the anti matter tried to occupy wallstreet first and a distraction was needed to remove em.

    2. Re:Oh great, a new SJW movement... by stealth_finger · · Score: 1

      Hydrogen Lives Anti-Matter

      This hydrogen atom was just chilling out, not hurting anyone then along comes the scientist and shoots it with a laser completely unprovoked. How long will we let this madness continue?

      --
      Wanna buy a shirt?
      https://www.redbubble.com/people/stealthfinger/shop?asc=u
    3. Re:Oh great, a new SJW movement... by Shane_Optima · · Score: 1

      Don't lase me bro!

      No, wait, that dude was white.

  6. Alpha by Mysund · · Score: 1

    First time i heard of antimatter, was an episode of Moonbase ... Alpha....

  7. I have to ask... by hyades1 · · Score: 4, Funny

    The lasers...is it possible, just barely possible, that they were mounted on the heads of tiny sharks?

    --
    I've calculated my velocity with such exquisite precision that I have no idea where I am.
  8. Are you sure? by SuperKendall · · Score: 2

    There really is no such thing as an anti-laser

    Sure there is, you just need a coherent beam of Black-Light.

    --
    "There is more worth loving than we have strength to love." - Brian Jay Stanley
    1. Re:Are you sure? by thegarbz · · Score: 1

      I'm sure John Travolta could bring one to you from the 80s.

  9. Re: Coin flip by Reaper9889 · · Score: 1

    This is not really the point made. It is true as you say that in expectation after 100 coin flips you will have as many tails as heads, however it is also true that the absolute difference between number of heads and tails are 10 in expecatation. More precisely, after k^2 coin flips, you get k more heads than tails or k more tails than heads in expectation. This is his suggested resolution to the problem - we are simply in the 10 more heads case (he is wrong in thinking that this occours because of how it started though - it is not because the first 10 was something in particular that you get this).

  10. Ready, Set...Goooo! by dcw3 · · Score: 1

    Why, in the early universe, did antimatter lose out to regular old matter?"

    Was it a race to the event horizon?

    --
    Just another day in Paradise
  11. Baryogenesis has been solved, watch Supernatural. by sabbede · · Score: 1
    Why more matter than antimatter? There were innumerable cycles where there were equal amounts, but then the Darkness was cast out for constantly annihilating everything the Light (God) tried to create and the universe finally stuck.

    Granted, the show has gone downhill over the years and totally jumped the shark, but if you are in need of a metaphor to illustrate the baryogenesis question, there it is.

  12. Turn the knob by sjbe · · Score: 1

    no need. you can just turn the knob to "anti-blast".

    Does it go to -11?

  13. Is it just me? by Trailer+Trash · · Score: 1

    I mean, it seems like pissing off anti-matter isn't the brightest of ideas.

  14. Test EM Interactions by Roger+W+Moore · · Score: 4, Informative

    Actually it is a bit more specific than that because we already know that matter and anti-matter behave differently under some circumstances. The effect is called 'CP violation" but it only happens for one of the fundamental forces of nature called the weak force which is the one which causes nuclear beta decay.

    The atomic spectrum of anti-hydrogen is dependent almost entirely on EM interactions and any slight difference will have a measurable effect on the wavelengths emitted. Hence this gives a very good way to do a high precision test of the EM force for anti-matter to see whether it is at all different.

  15. Corrections by Roger+W+Moore · · Score: 5, Informative

    The C and P symmetries violations in weak interactions is not enough to explain why there is No detectable antimatter in the Universe.

    Actually it is the combined CP symmetry which is the important one to test. The C and P symmetries individually are already known to be broken in both weak and EM interactions. For example the different electric charge for anti-matter breaks the C symmetry for EM.

    Also the CP violation in the weak force might actually be enough to explain the universe if there is enough of it in the neutrino sector as well and if the neutrino is a majorana particle. These models are called leptogenesis and could explain the observed asymmetry. However that does not mean we should not look for CP violation elsewhere: we know it exists for the weak force, it could easily exist for the strong force but does not seem to (something called the strong CP problem) and so we really should test the EM interactions to see whether there is any effect there which is what this experiment does to a high degree of precision.

  16. That's assuming... by minogully · · Score: 1

    Why, in the early universe, did antimatter lose out to regular old matter?

    Who's to say that antimatter lost out? Perhaps, when matter/antimatter particles split, if there's an outside force upon them, matter parts ways in the one direction and antimatter parts ways in the opposite direction with respect to the external force. That would leave two universes, one of matter and the other of antimatter.

    1. Re:That's assuming... by dwye · · Score: 1

      If that occurred there should be an region where the two sides come in contact, which would be shining brightly in the x-ray portion of the spectrum. Since no "hoarfrost" region has been seen, it appears that hypothesis lacks evidence.

    2. Re:That's assuming... by minogully · · Score: 1

      Great point, there definitely should be a hoarfrost region that you speak of.

      Though, I would point out that since we know we cannot see our entire universe, one cannot state that a hoarfrost must be observable.

  17. I know why matter won by GuB-42 · · Score: 2

    Because if antimatter won it would have been called matter.
    Now where can I get my Nobel prize?

    1. Re:I know why matter won by strikethree · · Score: 1

      Because if antimatter won it would have been called matter.
      Now where can I get my Nobel prize?

      Nobel Prize... DENIED.

      Why did either of them win? Or, why are matter and antimatter not compatible. What is the mechanism? Answer that to get your Nobel. ;)

      --
      "Someone needs to talk to the tree of liberty about its ghoulish drinking problem." by ohnocitizen
  18. Scientists Blast Antimatter Atoms ... by CaptainDork · · Score: 1

    ... with laser containing the message, "Your mommy wears combat boots!"

    --
    It little behooves the best of us to comment on the rest of us.
  19. Re:Bullshit! by CaptainDork · · Score: 1

    Considering the OP is female, I would observe that chirality is dead.

    --
    It little behooves the best of us to comment on the rest of us.
  20. Re:Everyone Is Right by CaptainDork · · Score: 1

    The good news is the links still "pop up," and you can RTFA which provides information by real physicists.

    This is a public comment section.

    You're old enough to remember it was never different.

    I was there, too.

    --
    It little behooves the best of us to comment on the rest of us.
  21. In other news by kpainter · · Score: 1

    In an anti-universe: "The anti-researchers hope to answer one of the big mysteries of our anti-universe: Why, in the early anti-universe, did matter lose out to regular old antimatter? anti-NPR reports:"

  22. Re:Baryogenesis has been solved, watch Supernatura by dwye · · Score: 1

    As Chuck Shurley (aka, GOD) put it during the First Supernatural Convention (which was *A*W*E*S*O*M*E*, as the organizer put it), it isn't really "Jumping The Shark" if you never come down.

  23. Re:Baryogenesis has been solved, watch Supernatura by sabbede · · Score: 1

    Okay, good response but the show has really run its course. They've painted themselves into a corner where there's really nowhere else to go. Don't get me wrong - I love the show and never miss an episode. It's loss would make me sad, but it lived a long and full life that must come to an end.

  24. Re:Everyone Is Right by syntotic · · Score: 1

    Nawh, there is people missing online here as well.