Particle Physics


Antimatter 101

Antimatter sounds like science fiction, and it has certainly powered its fair share of imaginary space ships and interplanetary blasters. But antimatter itself is fact, not fantasy. Antimatter is the opposite of matter: Bring the two of them into contact and they annihilate each other, generating energy according to Einstein’s famous equation E = mc2. For every kind of matter particle we know about, there is an antimatter “opposite.” Physicists have observed antimatter versions of electrons, protons and neutrons. We’ve even made a few antimatter atoms, including anti-hydrogen and anti-helium. In fact, the only thing stopping us from making an entire anti-universe—with an anti-you, anti-me, anti-everything—is that it’s very hard to make enough antimatter. And that’s a mystery too. Scientists think that, when the universe was young, antimatter and matter were made in equal quantities, yet in the universe we see only matter. Why is that? Nobody knows the answer, but it is one of the most pressing questions of modern physics.

Go Deeper
Editor’s picks for further reading

BigThink: The Search for Antimatter
In this video, Michio Kaku answers questions about antimatter.

CERN: Antimatter: Mirror of the Universe
Everything you want to know about antimatter.

Fermilab: What Is Antimatter?
In this video, Fermilab scientist Don Lincoln describes antimatter and its properties.

NOVA scienceNOW: Antimatter Engines
In this video, Neil deGrasse Tyson answers questions about antimatter propulsion.

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Don Lincoln

    Don Lincoln is a senior experimental particle physicist at Fermi National Accelerator Laboratory and an adjunct professor at the University of Notre Dame. He splits his research time between Fermilab and the CERN laboratory, just outside Geneva, Switzerland. He has coauthored more than 500 scientific papers on subjects from microscopic black holes and extra dimensions to the elusive Higgs boson. When Don isn’t doing physics research, he spends his time sharing the fantastic world of science with anyone who will listen. He has given public lectures on three continents and has authored many magazine articles, YouTube videos and columns in the online periodical Fermilab Today. His most recent book "The Large Hadron Collider: The Extraordinary Story of the Higgs Boson and Other Stuff That Will Blow Your Mind" tells the tale of the Large Hadron Collider, the physics and the technology required to make it all work, and the human stories behind the hunt for the Higgs boson.

    • Brianrdouglas1

      we are geared to see only Matter! in the universe of matter! Anti us already exists until we don’t

    • Colorqueen

      It would seem to me that antimatter would be the same thing as hate as it represents, anti which is death, the ultimate opposition of life. This can be equated to Original Sin or the ‘Bang’ also if we look at it in terms of the beginning and the concept of the Big Bang theory. How did matter mesh with or take in this antimatter if the intention of life was to expand itself rather than implode on itself? Why would it include opposition of itself by going into reversal of itself via death?
      There must have been a point of time in that single moment that a split in consciousness had occurred and separated from the ‘parents’ of this consciousness and received the judgement that something about its experience of itself didn’t matter. Hence the manifestation of an ‘invisible’ antimatter which manifested as invisible because it is an aspect of self which is in denial and therefore unconscious/hidden. It is the unconscious energy acting out the role of anti to that which it was ‘assigned’ from the original Creator to annihilate due to its position given of something that doesn’t matter.
      If we become fully conscious, will this antimatter exist in same way it does now? There is only One Way to find out. ;)

    • Anonymous

      watched the descriptive video. I couldn’t help but smile when, in Don Lincolns last statement, he stated ‘nobody knows the answer.’ (the answer is…….is there is no answer.) But, I do have a comment: IF (what I’ve heard is true from NOVA, etc) that every molecule of matter which has ever existed (like on planet earth…and elsewhere) continues to exist either here….or elsewhere in the universe…and is never truly destroyed, but goes on to become a part of whatever else in the universe, then…….anti-matter, IF it ever REALLY existed when the universe was young, must also continue to exist somewhere—-I think it might be an assumption to regard that early anti-matter as having converted over to matter. Perhaps this is all beyond the scope of human intelligence or knowledge yet. Any thoughts about this, Dr. Lincoln?

      • Don Lincoln

        Sorry if I was unclear. In the beginning of the universe we believe that for every 10,000,000,000 antimatter particles, there were 10,000,000,001 matter particles. The ten billion antimatter particles found ten billion matter particles and annihilated into energy. The remaining matter particle forms the basis of the visible universe. (Obviously there were more than ten billion particles and this just sets the ratios.)

        The matter and antimatter that annihilated, annihilated into photons, which is form of energy that was created. We see these photons in the universe today in the form of the 3K background radiation discovered in the mid 1960s. The WMAP satellite is staring at the same photons made in the early universe, stretched by the expansion of the universe to the radio hiss that fills the universe.

        • ben

          Here’s to an imperfect universe.

    • Heather

      The answer to the extra “1″ left is the shell or surroundings which encased the energy… Like when you eat an egg and the shell is left over, when you get mail but the envelope is left over, eating packaged foods… the food is eaten but the package still remains. Like when someone dies the energy is gone but the body is left behind. The answer is the one that is left behind. When something dies something else remembers what was therefore the energy of that life still lives zeven though it is gone. The answer to the “1″ is the case/shell/envelope/body/package/mode of delivery/house… whatever encased the energy is what is left behind

    • Maurice Tomford

      even ying needs yang!!!

    • oFEK


    • James Elger

      what if there is and was equal amounts of matter and antimatter. But there’s another equal and opposite potential out there and it’s time. In Albert Einstein’s equations it doesn’t matter where in space when in space just how fast and how close you are to traveling at near or above light speed. That defines a potential that can be positive and moving forwards in time or negative and moving backwards in time. Once upon a time, they were experimenting with positrons to see how many positrons they could place in a magnetic bottle, but annihilation didn’t explain how many positrons got out of the magnetic bottle. The gamma rays and x-rays were there to indicate annihilation for the full population of the loss. Okay, it’s antimatter is linked to a negative value of time in effect he could slip off of this universe and go into an anti-universe where the future is our past and by moving in that direction in time, cannot interact with any matter in this universe. In full effect, that whole universe is moving in a different direction, even though that direction is only in time. It is only to say that all of these basic particles that we see are linked to a positive value of time. Time may be the only thing giving the particle mass. Time,and how long it takes to get from point A to B, is inertia, and mass. The photon is the particle without mass, and muon gives away the truth. The muon can come from a supernova light years away and even though it has a half-life of millionths of a second. Therefore the particle can only be experiencing a few millionths of a second between where it left the supernova and where we detected it in the upper atmosphere. Light, the photon, the particle without mass, experiences no time in its travel across space. For a photon, it arrives when it leaves and there is no apparent time for the photon.

    • Gymleblanc

      so then energy can b created, if u have antimatter?

      • Don Lincoln

        Yes. This has been scientifically established for nearly a century. The problem is getting enough antimatter. The Fermilab antimatter facility is the most powerful antimatter generating equipment on the planet. However, after thirty years of operation, we made only enough antimatter to warm up a five gallon urn of coffee from room temperature to something drinkable.

        So an antimatter bomb like in Angels and Demons is a fiction. But the limitation is engineering, not physics. If you >>COULD<< get enough antimatter, antimatter would be a very dangerous substance.

    • Ujjal Goraya

      At the end of his comment Dr. Lincoln says ” why there is a bit of extra matter than Anti Matter in the universe No body knows” The answer to that Dr. Lincoln is ‘ God has something to do with it’ God wanted the Universe to survive, that’s why everything, universe, You and Me are Here!

      • Don Lincoln

        Well that is a popular hypothesis, but the universe would continue to exist even if the matter and antimatter had been created in identical quantities. It’s just that there would be no matter to make up us.

        The problem with invoking any explanation of the sort you propose is that it completely stymies further understanding. Science is about overcoming roadblocks to our knowledge, not putting ones in the way.

        The mechanism for matter/antimatter asymmetry is beginning to become understood. We already have ascertained physics processes that treat matter and antimatter differently. However the level at which we currently understand the processes is not sufficient to completely explain the mystery. One of the goals of the LHCb experiment at the LHC accelerator at CERN is to explore this question in more detail. I fully expect that their measurements will shed light on this question.

        Now as to the question of >>WHY<< the universe follows the laws that it does, you are welcome to invoke non-scientific explanations as long as those explanations do not disagree with data. We don't know the answer to the question of "Why is the universe the way it is," although there has been considerable scientific progress on the subject. I'm putting my money on the path being followed by cosmologists as the most likely way to answer the question. Certainly this has been the most productive approach for the last five centuries.

    • Lori Ross

      The electron is negatively charged not positive. Dirac was trying to find an equation that did not yield negative probabilities. Quantum deals with probabilities. Physicists at that time were ignoring the negative probabilities which Dirac said was inappropriate to do.

      • Don Lincoln

        It is true that the electron is negatively charged, but the positive solution to the equation still denoted the electron. Dirac’s equation combines the wave function and the energy. Essentially, the Dirac equation is the same as the Schroedinger equation, except it is explicitly relativistic, while Schroedinger’s equation is non-relativistic.

        The positive and negative in the pencast are not the charges, but the solution to the Dirac equation.

        Negative probabilities don’t make sense. I believe that you are talking about the eigenvalues of the wave function. The wave function squared is the probability.

    • Lori Ross

      When a positron hits an electron is the energy equivalent to both masses combined? If it is, then the antimatter must be resident in this universe. If it isn’t, then the positron must be from another dimension. What do you think?

      • Don Lincoln

        The rest energy of a positron is identical to that of an electron. If an electron and positron at rest combine, the resultant is two photons, with a combined energy that equals the mass of the electron plus the mass of the positron.

        Positrons certainly exist in our universe, as do other forms of antimatter, including antiprotons and antineutrons. However the question is why in the early universe for every ten billion antimatter particles there were ten billion + 1 matter ones.

        To the best of our knowledge, there are no unknown dimensions. That’s sort of by definition, but when antimatter is created it exists in the same way that matter does.

    • Carroll Young

      I find it strange that no one seems to notice that all the math and thinking and speculations are the product of human brains and therefore simply human constructs. They cannot be “proved” to be actual

      • Don Lincoln

        In some absolutist sense, nothing can be proven beyond Descartes’ certainty that he existed.

        On the other hand, to expect that level of proof quite misses the point. There are entire tomes on different ways of knowing things, ranging from the experiential (which are suspect) to the logical (which are generally empty). But science doesn’t really aspire to absolute knowledge. What science does is to construct models, driven by logic, math and empiricism. These models are then used to predict new phenomena. If the new phenomena are discovered, we know that the model has not yet been disproven. In fact, that’s the highest level of knowledge to which empirically-driven science can aspire: agrees with lots of phenomena and disagrees with none.

        Further, we know that all models have their problems. Newton’s theory of gravity fails in strong fields, although it doesn’t negate the fact that we can shoot a probe well over a billion miles to Pluto and hit a target less than a hundred miles wide. That’s a model that works well under many circumstances and fails under others. That makes it a good, if incomplete model. Since essentially all models have their limitations, we can expect to see this again.

        All models are wrong. But some are useful. And the degree to which they are useful is a measure of the degree to which they are right.

    • Pbarnes

      Don, Since you seem to be the only contributor to answer questions I want to ask you about the comment by Mohammad Kahn under George Mussers post “Could Simple Experiments…..” He claims in a peer reviewed article to have refuted Special Relativity and to show that gravity emerges from the electromagnetic forces. Have you read his article and what do you think?

      • Don Lincoln

        Give me an exact URL and I’ll look at it if I have time.

        This is science and there are no sacred cows. Special relativity can be completely overturned, but that would be a huge deal and you’d see it in all the newspapers. Remember the hoopla over the Fall 2011 announcement that neutrinos might go faster than light. This would be like that times 100.

        • Pbarnes

          Thanks for responding, here are the URL’s

          If you can take a look at this I would be most appreciative.

          • Don Lincoln

            So I looked at the URLs you mentioned. I couldn’t search the indjst site…it just wouldn’t let me type in the search box.

            The elixirjournal one I finally found the article, but I had to log in. I did so and read the article. I didn’t look it over carefully, as its conclusion is already a problem. I suppose I could have dug through the math to see if I can find the problem.

            However…and this is the bottom line…relativity works. Time dilation and length contraction are observed. There may be issues in any derivation, however any calculation that predicts something radically different from relativity is simply wrong, as measurements have validated the predictions of relativity.

            I did not see any papers linking gravity and E&M. Presumably this would have been in the indjst one.

            One thing I did notice is that the elixirjournal editorial board has no physicists….it is predominantly a medical/biological group. It is also true that the indjst editorial board contains no distinguished faculty. Indeed, the editorial board is spread predominantly over the Middle East, India and Africa, with a handful of Indian and Middle Eastern expatriots in Canada.

            Now intelligence respects no international borders and there are smart people everywhere. But it seems to me that an excellent journal should have a few distinguished members. Even the chief editor of the journal spent some time teaching in Eritrea, which is hardly a hot spot of international scholarship.

            Further, if the paper was as groundbreaking as the author no doubt claims, there are much better journals in which to publish this result.

            Questions of editorial boards aside, the most important thing is that no matter what criticism one can level at a specific derivation, the length contraction and time dilation predictions of relativity have been empirically demonstrated. Any calculation that give radically different results is wrong.

            • Pbarnes


    • Anand Deo

      How will antimatter react with other of its kind and the matter gravitationally?

      • Don Lincoln

        Antimatter is believed to interact with other antimatter (and matter) in the same way [gravitationally speaking]. Gravity reacts to concentrated energy (i.e. mass) and antimatter particles have mass in just the same way matter particles do

    • Aarnan Mugdho Halder

      the video was really cool but i think the last part should be wrong cause for example 2+2=4 (2 is matter) (and the other 2 is antimatter) and (4 is the energy) so it should be 4=2+2 not 4=2+”2+1″ (matter +1)

    • kate s

      Well, if spin can be stopped and reversed, that would allow all matter to exist. M Mathis says the particle exists even if its spin is stopped. And will eventually be respun oppositely by mechanical means.
      I am more fond of the Burbidges’ collapsing/inflating universe than bb.

    • antonio carlos motta

      is more understand that the relativistic equations to mesure the speed of bodies in the universe is not invariant,and the spaceand time for greatest velocities are asymmetrics,and therefore the left-right rotational invariance is not conserved totally.then the conjugation of space and time to space continuos in 4-dimensional manifolds lead us
      to imply that the MATTER IS ASYMMETRIC,and appear a space curved by the splitted time in two opposed orientations( in that asymmetry appear the symmetry as ANTIPARTICLES,and the “NEGATIVE SPACETIME” .the hyperbolic curved spacetime is
      originated by the OCTONIONS,that imply a torsion left-handed oriented and others right-handed oriented that are conjugated through the opperator PT




    • dubya

      i’m late to the party on this one but thank you for the quality responses in the comments section. you had to sift through some pseudo-philosphic useless posts, and expressed yourself very well. i wish i had that power of language(and scientific knowledge, obviously)