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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."

115 comments

  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: 0

      Dang, wikipedia has gone down hill son!

    5. Re: Well duh. by Anonymous Coward · · Score: 1, Funny

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

    6. 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
    7. Re:Well duh. by slickwillie · · Score: 5, Funny

      You mean they shoulda used photoffs instead of photons?

    8. 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".

    9. 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?

    10. Re:Well duh. by Anonymous Coward · · Score: 0

      Anti-lasers are known as dark suckers. Unfortunately you need to power them with anti-electrons.

    11. Re: Well duh. by Anonymous Coward · · Score: 0

      But to use the anti-U235 you'd need to first find it in the depths of anti-Kattegat where it was sunk in anti-1945. Recovering it and delivering it to the laboratory would be way too much work.

    12. 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.
    13. 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.

    14. 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.

    15. Re:Well duh. by Anonymous Coward · · Score: 0

      Wikipedias' fundraising efforts have gone too far!

    16. Re: Well duh. by Anonymous Coward · · Score: 0

      Using anti-U235 will create much more interesting results.

      Too `heavy` to be properly contained.

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

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

    18. 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
    19. 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.

    20. 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!

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

      You mean anti-laboratory.

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

    22. Re:Well duh. by Anonymous Coward · · Score: 0

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

      In the anti-verse you should say "That was very dim".

    23. Re:Well duh. by Anonymous Coward · · Score: 0

      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.

      You just need a laser of pure anti-matter.

    24. 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?
    25. Re:Well duh. by Anonymous Coward · · Score: 0

      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.

    26. Re: Well duh. by Anonymous Coward · · Score: 0

      =) hopefully we'll never end discovering thing if it were otherwise that would be sad

    27. Re: Well duh. by Anonymous Coward · · Score: 0

      But what if they are different in some key attribute that we haven't discovered?

    28. 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 Anonymous Coward · · Score: 0

      What else would you use? You can't use anything made out of matter, as it would destroy the antimatter.

    3. 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.

    4. Re:Why lasers? by Anonymous Coward · · Score: 0

      Because lasers are cool and sciency.

    5. 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)

    6. 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.
    7. 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.

    8. Re: Why lasers? by Anonymous Coward · · Score: 0

      Lasers don't produce a single wavelength, but have some amount of bandwidth. Things can be done to make that band very narrow, but without that the band can be large. Things like supercontiuum lasers can go the opposite extreme and have a bandwidth wider than the visible spectrum.

    9. 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.)

    10. Re: Why lasers? by Anonymous Coward · · Score: 0

      true, but they'll run the beam across a diffraction grating, and then send that one packet of particular frequency at the atoms.
      the atoms capture photons, the increased energy pumps orbit electrons up to next level. but it is a pulse. the atom relaxes, and then emits a photon of wavelength of the energy difference (way too simplified). college physics.

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

      It's not in space.

      --
      You can't take the sky from me ...
    12. Re:Why lasers? by Anonymous Coward · · Score: 0

      They did a spectroscopic measurement of the 1S-2S transition in antihydrogen to determine the transition energy to extremely high accuracy. If CPT are somehow violated, these kinds of transitions are
      a good candidate for showing it, and spectroscopy based on laser techniques has the required accuracy to resolve the tiny differences there might be.

      Captcha: theory

    13. 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.

    14. Re:Why lasers? by Anonymous Coward · · Score: 0

      As far as I know, the only difference between the two is supposed to involve the weak force rather than the electromagnetic force

      That's the assumption. But they would like to test to make sure.

    15. 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.
    16. Re:Why lasers? by Anonymous Coward · · Score: 0

      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.

      No, the weak force is quite distinct from the electromagnetic force. The latter involves photons & charge, while the former uses Z and W bosons (with some EM interaction for the charged ones). You can write a combined description of the two, but it is just by putting all of the separate effects together (a Lagrangian with terms for all of the photon, Z, and W interactions). At high energies, that description simplifies and you get the two forces behaving the same and a combined electroweak force, but that is not the same as a special case of the electromagnetic force.

    17. 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.

    18. 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...

    19. Re:Why lasers? by Anonymous Coward · · Score: 0

      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)

      Maybe the anti-matter really is there, but it just doesn't matter.

    20. 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.
    21. Re: Why lasers? by Anonymous Coward · · Score: 0

      You can put any light source into a monochromator (whether a grating, multiple gratings, or a cavity), lasers just tend to be a convenient bright source. A monochromator still produces an output with some linewidth. Especially for a pulse, since you need a minimum bandwidth to make a pulse. The theoretical minimum linewidth of a typical YAG 10ns pulse for example would be a bit to wide to resolve Doppler broadening at room temperature.

  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: 0

      Funny... Tortured, but funny...

    2. Re:Not the first attempt. by Anonymous Coward · · Score: 3, Funny

      Schrodinger the cat was very very dead

      Are you sure it was dead?

    3. Re:Not the first attempt. by Anonymous Coward · · Score: 0

      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." ;)

      This proves the empirical method _trumps_ theoretical physics.

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

      Are you one of those anti-cat people?

    5. Re:Not the first attempt. by Anonymous Coward · · Score: 0

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

      http://www.imdb.com/title/tt00...

    6. Re:Not the first attempt. by Anonymous Coward · · Score: 0

      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." ;)

      Would have been funnier and much less political if had said....

      The cat was there..and then it wasn't....

      For those that truly understand the "Schrodinger's Cat" thought experiment.

    7. Re: Not the first attempt. by Anonymous Coward · · Score: 0

      Congratulations - I think you have just discovered "anti-humour".

    8. 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.

    9. Re: Not the first attempt. by Anonymous Coward · · Score: 0

      Completely false - they hadn't even trapped antimatter yet in 2005.

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

    atomically anyway

  5. Coin flip by Anonymous Coward · · Score: 0

    Quite simply a coin flip.

    If matter and antimatter are identical and have equal probability of being created, and if a matter+antimatter will cancel, then a simple coin flip will give you all matter or all antimatter depending on the random result of the first few created particles.

    Take a coin heads is matter, tails is antimatter. Flip it 10 times.

    Here I did it:
    tails heads tails tails tails tails heads tails heads heads

    a+m = 0 + a = 1a + a= 2a + a = 3a + a = 4a + m = 3a + a = 4a + m = 3a + m = 2a

    So at this point we need a run of two heads in the NEXT two coin throws simply to bring this back to a balanced state.
    So we need something that has a 0.25 probability to happen simply to restore an equal probability state!
    There is a 0.5 probability of the current state being kept and a 0.25 probability of another antimatter antimatter flip cementing an antimatter universe.

    You see how simple it is? We simply have matter or antimatter by virtue of the first few random particles created.

    1. Re:Coin flip by Anonymous Coward · · Score: 0

      Not exactly. It is very simple, which makes me wonder why the researchers are clueless on the matter.
      Matter is attractive with a negative charge. All matter wants to be together.
      Anti-matter is repulsive because of a positive charge. It is likely that there is equal matter and anti-matter, but most of the anti-matter would have been repelled far away from all the matter that has now collected itself together.

    2. Re: Coin flip by Anonymous Coward · · Score: 0

      There is no known process that creates matter and antimatter with equal probability. Almost all known processes create equal amounts of both, not some flip of a coin amount of each.

    3. Re:Coin flip by Anonymous Coward · · Score: 0

      Oh lordy please tell me no-one else fell for this.

      Yes, it is a 0.25 chance of the overall numbers balancing on the VERY NEXT two coin tosses.. but who says it has to happen in the very next two goes? What about the next 5? next 10, next quadrillion?. The odds are that, overall, virtually every single particle would be annihilated because as the series tends to infinity, the overall distribution tends to 50%.

      Now it's an interesting thought experiment to suggest that in fact, the universe attempted to create many, many times more particles than ended up and the entire universe of matter is that one little outlier in the coin toss chain, the 'odd roll' from a series of otherwise matching, equal-but-opposite rolls of head and tail... but that is completely separate from the point you tried to make above regarding probability..

      captcha ' tricky'. Not really, but you tried...

    4. Re:Coin flip by Anonymous Coward · · Score: 0

      Same debunking AC as above. This is also bunkum.

      "Matter is attractive with a negative charge". If all matter had a negative charge, it would all repel.

      If you mean 'gravity'.. then the general consensus opinion is that matter and antimatter attract in the same way, though this has, to my limited viewpoint, yet to be tested...

      LOL. Captcha "Presumed"..

    5. Re:Coin flip by Anonymous Coward · · Score: 0

      Here you go:
      http://cerncourier.com/cws/article/cern/56224

      Summary: An active field of study for many years, Gravity has yet to show preference for either Matter or Antimatter, but the studies are continuing.

    6. Re:Coin flip by Anonymous Coward · · Score: 0

      yes indeed... a field of active ongoing study, the current consensus being that antimatter experiences positive gravity, and at least three (to my knowledge) theories regarding possible mechanisms for antimatter experiencing 'antigravity' - i.e. repulsive gravity.

      My point was that as a good general rule, whenever one sees a post that starts "It is very simple, which makes me wonder why the researchers are clueless on the matter", one can safely assume that the poster is an idiot, a troll, or both.

      Note that all of the CERN work is about exploring the matter-antimatter interactions to determine if that's positive or negative. OP was suggesting antimatter-antimatter interaction is negative, which is why, to paraphrase, all of the matter in the universe has clumped together in the middle, and all of the antimatter has whizzed off into the unknown...

    7. Re:Coin flip by Anonymous Coward · · Score: 0

      "one can safely assume that the poster is an idiot, a troll, or both."
      Or a researcher commenting on the work of a competing researcher.

    8. 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).

    9. Re:Coin flip by Anonymous Coward · · Score: 0

      At Berkeley back in the Sixties, they set up a long TOF experiment for Thermal Neutrons to confirm that they obeyed the "Law" of Gravity, which they did. Then they sent thermalized Antineutrons, (Antiprotons on Protons have a small yield of Neutron-Antineutron pairs.), through the same TOF with mixed results. So much "Garbage" was coming down the line that the Antineutrons couldn't be cleanly identified. Segre doubted that the Detector tech of the time was capable. Clyde Wiegand pursued this on and off for a couple of decades, but the funding never came through to confirm what was back then considered a then unimportant matter. When the Bevatron was repurposed into the Heavy-Ion Bevalac, and then later shut down, that was the end of their very limited supply of Antineutrons.
      Research moved recently to CERN and their new AD- Antiproton "Decelerator". Thermal Antineutrons, being for the most part electrically neutral, are pretty much sensitive only to Gravity. (Anti neutrons, like Neutrons, are a bit lopsided when it comes to Charge, which means they can be Polarized, which is another emerging field.)
      (My own involvement was on the Heavy Ion end, working on getting the once Proton-only Bevatron to accelerate Uranium, so you can take much of the above as hearsay, over morning coffee in the EM Shop.)

  6. Let that be a lesson... by Anonymous Coward · · Score: 0

    to the rest of you anti-matter.

    Annihilate them before they annihilate us.

  7. 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 Anonymous Coward · · Score: 0

      BlackLight Anti-Matter

    2. 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.

    3. Re:Oh great, a new SJW movement... by Anonymous Coward · · Score: 0

      Is that what they use to look for anti-semen stains?

    4. 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
    5. Re:Oh great, a new SJW movement... by Shane_Optima · · Score: 1

      Don't lase me bro!

      No, wait, that dude was white.

    6. Re: Oh great, a new SJW movement... by Anonymous Coward · · Score: 0

      It's only a half-life

  8. Alpha by Mysund · · Score: 1

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

  9. 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.
    1. Re: I have to ask... by Anonymous Coward · · Score: 0

      Why does that anti-matter?

  10. 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 Anonymous Coward · · Score: 0

      They " trained an ultraviolet laser" on the anti-hidrogen. So yeah, they used black light laser.

    2. Re:Are you sure? by thegarbz · · Score: 1

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

  11. Donald Trump's First Executive Order by Anonymous Coward · · Score: 0

    In accordance with President Trump's First Executive Order, all news stories must be about President Trump, including those in the past, already published, which will require someone to travel backwards in time to be edited if necessary, such as this one does.

    Scientists Blast Donald Atoms With a Trump For The First Time

    For the first time, scientists blasted atoms of Trumpnium with an ultradonald Trump, allowing them to observe, for the first Trump that atoms of antidonald behave largely as atoms of ordinary President do, in accordance with the generally Trumped theory.

    Just go along with it. Donald Trump's ego is like Bill Clinton's dick. If it isn't stroked every five or ten minutes, he'll freak out and bomb Kosovo or some shit.

  12. What about gravity? by Anonymous Coward · · Score: 0

    The thing that interests me the most that is, to my knowledge as of yet unanswered, is if the gravitational "charge" of antimatter is the same or opposite of regular matter? Basically, could matter and antimatter be gravitationally pushing each other away instead of pulling each other closer?

  13. 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
  14. 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.

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

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

    Does it go to -11?

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

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

  17. Re:Bullshit! by Anonymous Coward · · Score: 0

    This must be Moron Appreciation Week at Slashdot...
    There is such a thing as Antihydrogen. The Antiproton, which is the Nucleus of Antihydrogen was first created artificially in 1955 by Chamberlain and Segre. Anderson first identified the Positron in 1932. All three got Nobel Prizes for their work.
    It does not contradict everything that is. In fact, the Standard Model falls apart without its possible existence.
    Structures like DNA can be made of Antimatter, including Antihydrogen, and will obey all the usual DNA Rules, including chirality. Why anybody would bother...
    It's "Enzymes" you baboon. (Sorry if I offended any real Baboons out there.)

  18. 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.

  19. 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.

  20. 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.

  21. 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
  22. Who says anti-matter lost out? by Anonymous Coward · · Score: 0

    Whichever form of matter "won" would be considered "normal" matter by us as we are composed of that matter.
    Whichever form "lost out" would be considered "anti" matter.

    Duh! Sometimes the smartest minds are also the dumbest.

  23. Everyone Is Right by Anonymous Coward · · Score: 0

    I've been an cowardly AC here since the late 90's, and today I'm sad.

    I used to get real discussion of physics when these kinds of posts popped up, by real physicists. I came to love physics well past my school years, those debates would jump start my knowledge.

    Today most of the replies are modded funny. Like so many people have been saying for years, Slashdot is dead.

    Please mod me 'unfunny'. Bye.

    1. 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.
    2. Re: Everyone Is Right by Anonymous Coward · · Score: 0

      I've watched quite a few scientists stop answering questions here and on other sites because crackpots and overconfident armchair scientists can just brute force spam their BS. It takes time to write up actual details and/or provide citations that doesn't amount to much when a small number of people can post garbage over and over and get modded up by those that confuse confidence with correctness.

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

      Nawh, there is people missing online here as well.

  24. 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.
  25. 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.
  26. 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:"

  27. 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.

  28. 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.

  29. Indiana university was Not involved by Anonymous Coward · · Score: 0

    There is a quote from a physicist at IU - a physicist at Purdue was actually involved - Francis Robicheaux- is part of the Alpha Collobration and is the theorist on the project.