Scientists Blast Antimatter Atoms With a Laser For The First Time (npr.org) 115
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."
Well duh. (Score:5, 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.
Re:Well duh. (Score:5, Informative)
Are you sure? (Score:2)
There really is no such thing as an anti-laser
Sure there is, you just need a coherent beam of Black-Light.
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I'm sure John Travolta could bring one to you from the 80s.
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I know where you can try a dark sucker for just $20 ...
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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?
Re:Well duh. (Score:4, 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.
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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.
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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.
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Dang, wikipedia has gone down hill son!
Shine an anti-laser, get a black hole...
Re: Well duh. (Score:2)
Re: Well duh. (Score:5, Funny)
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If so, it will be the antithesis of conventional matters.
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You mean anti-laboratory.
Not to be confused with an anti-lavatory. Messy.
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Re:Well duh. (Score:5, Funny)
You mean they shoulda used photoffs instead of photons?
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You mean they shoulda used photoffs instead of photons?
My hat is off to you, good sir. That was brilliant.
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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".
Turn the knob (Score:2)
no need. you can just turn the knob to "anti-blast".
Does it go to -11?
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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. [youtube.com]
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Why lasers? (Score:4, 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?
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I think they just wanted to confirm that antimatter doesn't behave differently here than matter does.
Test EM Interactions (Score:5, Informative)
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.
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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 "las
Re: Why lasers? (Score:1)
Did they go Wep, Wep!? (That's Pew, Pew! backwards. Get it? Because "anti"? Oh well, never mind.)
Re:Why lasers? (Score:5, Interesting)
Corrections (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.
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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.
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(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... ho
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It's not in space.
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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... [stackexchange.com]
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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.
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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.
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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
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Not the first attempt. (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." ;)
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Schrodinger the cat was very very dead
Are you sure it was dead?
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Are you one of those anti-cat people?
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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.
observation influences results (Score:2)
Re: Coin flip (Score:2)
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 s
Oh great, a new SJW movement... (Score:5, Funny)
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That would only happen if the anti matter tried to occupy wallstreet first and a distraction was needed to remove em.
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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?
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No, wait, that dude was white.
Alpha (Score:1)
First time i heard of antimatter, was an episode of Moonbase ... Alpha....
I have to ask... (Score:5, Funny)
The lasers...is it possible, just barely possible, that they were mounted on the heads of tiny sharks?
Ready, Set...Goooo! (Score:2)
Why, in the early universe, did antimatter lose out to regular old matter?"
Was it a race to the event horizon?
Baryogenesis has been solved, watch Supernatural. (Score:2)
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.
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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.
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Is it just me? (Score:2)
I mean, it seems like pissing off anti-matter isn't the brightest of ideas.
That's assuming... (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.
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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.
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Though, I would point out that since we know we cannot see our entire universe, one cannot state that a hoarfrost must be observable.
I know why matter won (Score:3)
Because if antimatter won it would have been called matter.
Now where can I get my Nobel prize?
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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. ;)
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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.
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Scientists Blast Antimatter Atoms ... (Score:2)
... with laser containing the message, "Your mommy wears combat boots!"
In other news (Score:2)
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Considering the OP is female, I would observe that chirality is dead.