LAYING A TRAP: A fish-eye view of the ALPHA experiment at CERN, where anti-atoms have been created and trapped.
Image: Courtesy Maximilien Brice/CERN
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It is the stuff that both science fiction and a good part of author Dan Brown's fortune are made of—antimatter.
A research group at CERN, the European lab for particle physics in Geneva, has managed for the first time to confine atoms of the stuff. Fleeting antimatter atoms have been produced in the lab for years, but until now the ability to trap the elusive atoms for detailed study has been out of reach. (The confined amounts of antimatter are many orders of magnitude smaller than that swiped from CERN by insidious plotters in Brown's Angels & Demons.)
The new advance, published online November 17 in Nature by the ALPHA Collaboration experiment at CERN, is only a proof of principle—the anti-atoms have only been confined for less than two tenths of a second—but the research could set the stage for a new round of fundamental physics tests. (Scientific American is part of Nature Publishing Group.)
The ALPHA group mixed antiparticles in a vacuum trap to create atoms of antihydrogen, then held on to them briefly in the trap before turning them loose. Antimatter annihilates on contact with ordinary matter, so the anti-atoms disappear in a shower of secondary particles, known as pions, when they hit the walls of the trap. By tracking those annihilation products, the physicists conclude that they succeeded in producing, trapping and then releasing a few dozen atoms of antihydrogen.
Neutral hydrogen is made up of one proton and one electron; antihydrogen is composed of the corresponding antiparticles, the antiproton and the antielectron. The component antiparticles that make up an anti-atom are not on their own terribly exotic. Antielectrons, also known as positrons, are in wide use in PET (positron emission tomography) scanners. And antiprotons have been produced and accelerated to high energies for smashups in particle colliders for decades.
But marrying an antielectron to an antiproton to form a bound antimatter counterpart to the hydrogen atom was not achieved until the mid-1990s. And those early anti-atoms, produced at CERN and at Fermi National Accelerator Laboratory in the U.S., were "hot," zipping along near the speed of light. The difficulty of corralling anti-atoms with such potent kinetic energies led groups to pursue "cold" antimatter that could more easily be confined and studied.
"I was never too worried about producing antihydrogen, but holding on to it is another thing entirely," says ALPHA spokesperson Jeffrey Hangst, a physicist at the University of Aarhus in Denmark. "We're kind of overjoyed, to put it mildly, that this is working so well."
The challenge in confining antihydrogen, besides the fact that it annihilates on contact, is that it is electrically neutral, so the same traps that can be used to steer and confine the charged antiparticles are useless once those antiparticles bind together into an atom. On the bright side, the physicists can sweep the trap with applied electric fields after mixing the antiparticles to clear out any antiprotons and antielectrons that have not been bound into atoms of antihydrogen. "It's neutral, and so it's very difficult to influence in any way, but it still has a magnetic moment," Hangst says. "You can think of it as a little compass needle that responds to external magnetic fields."
With superconducting magnets, Hangst's group was able to manipulate the neutral anti-atoms, trapping them—however briefly—before switching off the magnets to let the antimatter wander off and reveal itself through annihilation. Key to detecting those confined anti-atoms was the development of superconducting magnets that can be shut off almost instantaneously, allowing the researchers to look for pions from matter–antimatter annihilations in a span of just 30 milliseconds. The detectors are struck regularly by cosmic rays, which can mimic the annihilation signal, so narrowing the window of time in which matter–antimatter annihilations should be taking place significantly reduces the background noise the physicists must sift through to identify genuine annihilation events.
The 38 annihilation signals detected by ALPHA were well above the expected background of 1.4 occurrences, strongly indicating that antihydrogen atoms were indeed slamming into the trap walls after being released from confinement. "I'm convinced that they have succeeded in trapping some antihydrogen atoms," says Fermilab physicist David Christian. "That's a big milestone in their experimental program."
If the proof of principle leads to more robust trapping of anti-atoms, researchers could test a number of long-standing theories for how antimatter should behave. For instance, all indications are that gravity should act on antihydrogen just as it acts on hydrogen, but empirical tests are not yet feasible. "There are lots of arguments why it should behave exactly as matter, but they are just arguments," says theoretical physicist Michael Nieto of Los Alamos National Laboratory.
Physicists would also like to study anti-atoms with laser spectroscopy to probe their energy level structure; according to fundamental physics theories antihydrogen should have the same spectrum as ordinary hydrogen. Any detected deviation "would be a huge thing," Christian says. "Whether or not they can do the spectroscopy is still a few steps off, but they've come a long way." As a ballpark figure, Hangst says researchers might need to confine 100 anti-atoms on a timescale of seconds to probe their structure. He notes that ongoing work to improve the trapped lifetime of the anti-atoms is coming along very well.
Meanwhile, a competing group at CERN, known as ATRAP, has been proceeding apace with their own cold antihydrogen program. Harvard University physicist Gerald Gabrielse, the ATRAP spokesperson, says he is "delighted" by the new announcement but that his group is taking a slightly different tack. "We have been focusing almost entirely of late on producing much colder antiproton plasmas that contain many more particles," Gabrielse says. "The hope is that with these we can make many more antihydrogen atoms that are cold enough to be trapped for the longer times needed for laser spectroscopy."
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22 Comments
Add CommentSo, how many antimatter particles would be required to annihilate CERN? If they could trap enough particles, I doubt they'd have to persist for very long...
Reply | Report Abuse | Link to thisQ: How many antimatter particles does it take to change a light bulb?
Reply | Report Abuse | Link to thisA: Nobody knows. By the time the light bulb needs to be changed, the antiparticle is long gone baby...
-------------------
-Knock Knock.
-Whos there?
-An antimatter particle.
-Antimatter particle who?
..Hello? um hello??? anyone there?...*looks around* thats strange...its not there anymore >=(
a lot of antimatter would be needed to destroy much of anything even the 100 anti-hydrogen atoms that would be needed to test the properties would never be noticed without extremely sensitive equipment. you probably would not even see a flash as they annihilated themselves with matter.
Reply | Report Abuse | Link to this1 gram of hydrogen apx.= 602,214,150,000,000,000,000,000 atoms
You see now the problem I've been wrestling with; manufacturing the universal solvent -- No where to store it.
Reply | Report Abuse | Link to thisCool stuff, though.
Does anti-matter also mean there is anti mass?
Reply | Report Abuse | Link to thisWe make a hypothesis. (Translate from Google with small correction from me)
Reply | Report Abuse | Link to thisUsing only the logical deduction and how much we already know a solution to the problems, the almost total absence of antimatter in our universe, the acceleration of the universe.
Suppose that the antimatter is perfectly mirrors the matter, with respect to our negative time and antigravity that causes repulsion between a star and a star made of antimatter to matter, but obviously has the same effects of gravity and remain in our orbits of planets around to itself if these are in turn composed of antimatter.
As a consequence of Einstein's relativity of time and the speed of light are closely related.
The gravity propagates instantaneously, anywhere, has no limit on the speed of light, and is indifferent to the time.
Think of the empty between groups of galaxies in our universe, if they were occupied by galaxies of antimatter their antigravity reject our galaxy causing the acceleration of the universe (dark energy).
Any object traveling at the speed of light or the temperature of absolute zero degrees, has no time, this is the only type of antimatter that we can see produced by the blacks hole of our universe, or in laboratories.
Why do not we see the galaxies of antimatter? Why from the big bang, the matter is separated from antimatter repulsion with the gravity and antigravity. Because of its negative time, the light emitted from antimatter for us is not visible (dark matter). From big.bang onwards, our universe travels forward in time, the universe of antimatter travels back in his time, for us the time of antimatter go before the big bang.
Think of three possible states of matter: matter, antimatter and blacks holes.
In the light of a black hole can not get out, if the light is related to time, in a black hole there is no time and inside a black hole, matter is no different from a black hole of anti-matter, outside differ their gravity and antigravity.
Were observed gravitational lenses convex created by super massive blacks hole, should be there antigravity concave lens.
We come to the string theory with its 11 dimensions: 4 dimensions for the matter, 4 for antimatter, three for black holes, these 3 dimension confined inside the black holes.
You could use a simulator to test the acceleration of the universe, use for antimatter, same amount of galaxies, black holes, cosmic dust and gas from our universe.
Or just wait for other solutions from CERN in Geneva.
From Italy
Sifimid: You asked: "Does anti-matter also mean there is anti mass?"
Reply | Report Abuse | Link to thisAntiparticles are considered to have identical mass and spin properties to their corresponding particles, but they have an opposite electrical charge. There is no anti-mass or any anti-gravity produced by it.
They are also considered in the Feynman-Stueckelberg interpretation of antipartles to propagate backwards in quantum time. IMO this may be merely an analytical convenience. There is no anti-photon, since photons have no charge: this seems unfortunate, as in accordance with this theory we should otherwise be able to observe anti-light emitted in the future - or is that wierd?
By the way, if anti-particles actually propagate backwards in time, wouldn't their capture only be possible _prior_to_ the particle collision or emission event that produced them? I don't think that is how it was done, but maybe this is why they're so difficult to capture...
Reply | Report Abuse | Link to thisExactly what is mass? We will need to answer this before any theoretical discussions of anti-mass. Mass was simply a constant Newton derived when defining his calculus and gravity. I suspect there is no such thing as anti-mass.
Reply | Report Abuse | Link to thisAlso, there is a speed limit for light, i.e. what we see and measure but not a speed limit for how matter may move.
So where did you guys get your information?
Rufus: Mass is a very real phenomenon you may begin to appreciate if you try to push your car up a hill. As I understand, if anti-matter had anti-mass, matter and anti-matter would likely never collide.
Reply | Report Abuse | Link to this"...not a speed limit for how matter may move" - do you assert that the speed of light limit does not apply to matter?
I typically use wikipedia, which is certainly not an authoritive reference but is conveniently and freely accessible on the web.
You didn't mention, but I'd be very interested in whatever sources you're using to 'get your information'...
Conservation of energy: antiparticles and particles must be produced in equal numbers. Thus they subsequently annihilate in equal numbers, giving no overall change.
Reply | Report Abuse | Link to thisThe CERN will provide great benefits to humanity, it will sooner compare to the invention of the train, the train has caused many victims in various incidents.
Reply | Report Abuse | Link to thisFor those few who say that the train is not good, in this case this person would go in the stone age and consequently their life average is only 20 years.
Excuse me but on the site: www.lescienze.it order of message is inverse, my message nr.13 is for message 1.
Reply | Report Abuse | Link to thisIn that case there's already an enormous supply of antiparticles waiting to be discovered and our local production of antiparticles must produce some unexpected and unwelcome particles somewhere...
Reply | Report Abuse | Link to thisIf, for example, the initial universe was rapidly rotating (as exceedingly dense/hot plasmas may want to do) it might have preferentially condensed only particles of matter without violating conservation of energy. I'm just guessing, of course.
How many particles does it take to run a star-ship?
Reply | Report Abuse | Link to thisLet us know when we have a kilo of it.
Reply | Report Abuse | Link to thisOne millionth of an ounce, alive for microseconds is a waste of money. Of couse it keeps a bunch of yahoos in a well paying job by screaming how smart and good they are.
Maybe you find better translation at comment 19/20 here:
Reply | Report Abuse | Link to thishttp://www.scientificamerican.com/article.cfm?id=dark-worlds-interactive
Yeah lets just drop the research programs until they can make a kilo of anti-matter. Then we will pay them again... are you joking? How would they possibly get a kilo without a few atoms first?
Reply | Report Abuse | Link to thisAlso, I think the randomness of terms just thrown out in the discussion is pretty funny. Conservation of energy/mass says nothing about the amounts of anti-matter and matter. They have equivalent mass and energy; if they combine they produce energy according to Einstein's E=mc^2 law. If the conservation of energy/mass suggested the amounts be split in halves, you would expect no radiation from that kind of recombination.
As far as I know, it's still an open-ended question as to why there is more matter than anti-matter. I don't think there is a specific method of distinguishing between matter/anti-matter besides observing a collision with matter, which I don't think has been done. If they collide they annihilate, and that showers radiation. If they collide and you don't get that, then it's the same type of matter. I am not familiar if the gamma radiation (high energy) from anti-matter and matter collisions is observably different than most other types of gamma radiation that we currently detect. So I guess it just boils down to, has it ever been demonstrated that other near-by galaxies are not anti-matter?
LOL!
Reply | Report Abuse | Link to thisThose are really good antimatter jokes.
Jim,
Reply | Report Abuse | Link to thisThe backwards in time thing was, as you rightly mentioned in your earlier post, more like an analytical construct. Most physical equations don't constrain time in any 'direction', which is why you can get an equation for antimatter moving normally with respect to time which reads the same as the equation as matter going backwards in time. In some examples, it is easier to interpret or calculate using the backwards in time construct, which is why it is still popularly used.
Since we have not observed (perhaps, cannot observe?) 'backwards' time, much of the speculation about matter moving backwards in time is just that--speculation. It makes for some cool science fiction plots, but don't expect any technology any time soon.
Anti-matter moving forward in time is identical--except for the electric charge--to matter moving forward in time. So, it necessarily will be detected after it was created, and not before.
McMalkimus, if you're interested in applications of anti-matter (including how much is needed to run a spaceship), try Robert L Forward's 'Indistinguishable from Magic'. Very lucid treatment; excellent book.
Ennui, read the book. I think you'll agree they should continue to pay the CERN team.
i am very interested in this matter. I know in my heart time travel is possible and is actual...search your feelings...you know it to be true...right now its happening just on the low...you think thats these billion dollar companies aren't interested in going back in time and making themselves more rich? of course they are dumbass and they have way more resources than the average human will ever have. They are and do study this subject. I can only hope that other travelers and timelines watch over us because we as a planet are having a hard time right now...well the surface at least...we all know the Earth is hollow...all planets are. google it hollow earth or google.com/images hollow planets. you think just because there are no pictures on google that it doesnt exist...are you serious? the government basically owns google now they can remove, change or cover up anything they want. I am a proud patriot of my great country America, and for some reason the powers the be think we don't need America any more. Bush signed a bill in 2005 that would erase the United states of america and combine it with canada and mexico to create the "north american union" this is fact people!! this has already happened....bye bye america. I for one cannot let that happen, and will not. This is OUR great country. once we become a union say goodbye to being a sovereign nation! we will be under the hand of the global actual NEW WORLD ORDER! If it comes to it i would gladly give my last breath for my great country and would be proud to be buried in her lands. I hope you reading this however little you think I can do or you can do. Trust me we can do this...where focus goes...energy flows! Stand strong comrades for no man, no matter how powerful can ever shake your beliefs if you make those beliefs apart of you. We are forever, we are eternal, we are powerful, we are one nation, one people. We must stand strong united in the devil's face.
Reply | Report Abuse | Link to thisYour Brother,
-Triple B
Big Boss Brian
i think that the antimatter doesnot exist in the nature.
Reply | Report Abuse | Link to thisthe antiparticles are phenomenological processes produced by STR through feynman equations,that transform particles into antiparticles,as "holes".these
holes of energy are ASSOCIATED to the variations of mass and energy with incresement of speeds nearest speed of light.
i believe that the universe is asymmetrical,between particles and antiparticles that both are transformed into other,in the continuos spacetime( left-right hande spins)the conservation stronger cp is generated by breakdown symmetry pt,where the violations of chiralities is measured by the contraction of space and
time dilatation that does speed of light appear as constant and limit speed to the universe.but c must be anysotropic,generated by pt,and appear speeds gtreater than the speed of light,and therefore explain
the asymmetry between particles and antiparticles