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Physicists believe they can create matter from colliding photons
- venomsnake 11y agoCan anyone explain when and where the Higgs enters the reaction? That is the most interesting for me, since we don't have anti Higgs.
- drdeca 11y agoI thought that the Higgs Boson was its own antiparticle, like the photon? I am not sure.
- georgeaf99 11y agoI will preface this by saying my understanding of particle physics is very basic... Yes, that is correct. The Higgs particle is also extremely unstable and decays into two photons almost immediately.
- eli_gottlieb 11y agoWait, why does the field-quantum for inertia decay into the field-quantum for light?
- drdeca 11y agoI am not at all sure, but my guess is that: the results must be electrically neutral in total the results must have the same total spin (0) (this might require that all the resulting things have spin 0 but I don't know) the results must conserve a variety of other quantities, I think maybe pairs photons are (one of?) the only things that meets these requirements? I'm not sure. I'm mainly guessing. But, if proton collisions can cause Higgs Bosons, I think maybe the idea is that so long as all the quantities are conserved(charge, mass, color, spin, momentum, etc. etc.), any particles with small enough energy can be the result maybe? I don't know if that is the idea. I'm just guessing based on how things are described wrt protons, but I might be misinterpreting things.
- georgeaf99 11y agoI will preface this by saying my understanding of particle physics is very basic... Yes, that is correct. The Higgs particle is also extremely unstable and decays into two photons almost immediately.
- georgeaf99 11y agoI will preface this by saying my understanding of particle physics is very basic... Yes, that is correct. The Higgs particle is also extremely unstable and decays into two photons almost immediately.
- yk 11y agoIt does not, it is just pair creation by photons. So two photons react to a electron positron pair. (The inverse process of anti-matter anhilation.
- blazar 11y agoThis YouTube video explains it really well. https://youtu.be/kixAljyfdqU https://youtu.be/kixAljyfdqU
- KenoFischer 11y agoIn theory if you crank up the energy high enough, you'll create a bunch of Higgs bosons as well, though of course as always, they'll immediately decay.
- grondilu 11y agoDidn't we know that ever since E=mc² ?
- garrettgrimsley 11y agoThey knew that it was possible in theory, as the article mentioned. This experiment will be a concrete demonstration of that theory.
- ambrop7 11y agoI imagine "matter" as commonly understood would contain at least electrons and protons, but they would just be making electrons and positrons. Can we make protons/neutrons out of light too?
- GFK_of_xmaspast 11y agohttps://en.wikipedia.org/wiki/Positronium https://en.wikipedia.org/wiki/Positronium
- pythonlion 11y agocool but there are no quarks involved..(?)
- GFK_of_xmaspast 11y agoWho says there has to be?
- tux3 11y agoWith a lifetime on the order of a microsecond at best, it would be an interesting challenge to build anything out of it. Assuming I understood Wikipedia correctly.
- KenoFischer 11y agoYes, in theory quarks and their anti-particles will be created just the same as electrons/positrons. However, a) it is a lot easier to detect electrons/positrons than it is to detect quarks and b) protons are significantly heavier, so you'd need quite a bit more energy. Really the best way to think about this is just a particle collider, but colliding photons instead of matter. You'll still get a whole sea of debris that you can sort through and find interesting physics, but just detecting electrons would be a good first step.
- dosh 11y agoThis is exciting. Not sure how they will go from electron-positron creation to protons which needs quarks, but according to https://en.wikipedia.org/wiki/Matter_creation https://en.wikipedia.org/wiki/Matter_creation Summary: Matter creation is the conversion of massless particles into one or more massive particles. Since all known massless particles are bosons and the most familiar massive particles are fermions, usually what is considered is the process which converts two bosons (e.g. photons) into two fermions (e.g., an electron–positron pair). This process is known as pair production. So technically, it is a matter creation.
- KenoFischer 11y agoIn theory all you have to do to get protons is crank up the energy.
- dlsx 11y agoIt's exciting if you are an alien race hell bent on sucking the chakra energies from human beings. This website is infected. If you are on the conputer most of the day you are under their spell. Aliens are real and they are a parasite that operates off of black programmable matter found all over the world.
- dlsx 11y agoAnd matter can be programmed. There need to be some laws and regulations against Artificial Intelligence. What if an A.I. Became airborne and it already knows how the human anotomy works with robotic presicion it can create our own demise. A.I. is the next nuclear bomb and people are not thinking or even smart enough to really grasp the responsibility of creating dark matter / programmable matter.
- maplechori 11y agoAre we going to be able to materialize dinner soon?
- clavalle 11y ago1 lb of food would take about 10 megatons of TNT of energy. I'm not sure you'd want whatever that device is sitting on everyone's kitchen counter.
- rm_-rf_slash 11y agoI imagine if you had that kind of Star Trek replicator technology it would be more feasible to use existing matter and rearrange it as desired.
- clavalle 11y agoPlus, a starship is already strapped to a huge energy source so the additional risk is probably minimal.
- eloff 11y agoHas anyone ever wondered why the C^2 in E=MC^2 I'm sure it wasn't chosen at random just because a large constant was needed, it must fall out of some other physics equations. But still, what does that mean? What does the transmutation of energy into mass or visa versa have to do with the universal speed limit? I am always struck by the inexplicable power of mathematics to describe the physical laws of the universe, in often simple equations like this. It doesn't have to be that way as far as we know.
- _-__--- 11y agomore completely, it's E^2 = (m c^2)^2 + (p c)^2 where m is the rest mass of the particle and p is the current momentum. It's a nice triangle relationship. As for the interpretation thereof, you're going to need someone else.
- tanishq 11y agoE = mc^2 is the energy contained within a particle of mass m, IF it is at rest (has zero velocity with respect to your frame). If it is moving, it's energy is given by E = ymc^2, where y (gamma) is 1/sqrt(1 - v^2/c^2). This may sound like the particle has somehow "gained" or "lost" energy just by switching frames, but so has everything else. The differences in energy have been kept the same, which is all that really matters. When deriving this formula for the energy it becomes clear that _any_ multiple of ymc^2 is conserved. We choose E = ymc^2 and not, say, E = 5ymc^2 because in the Newtonian limit (as speeds approach zero), the ymc^2 formula reduces to the well-known E = 1/2 mv^2, which is the kinetic energy of an object obtained from classical mechanics. I'd really recommend reading a mathematical treatment of special relativity, because you'll be exactly clear on where this formula comes from.
- raziel2702 11y agoI think the answer we want now is a non-mathematical one. It gets tiresome how most of the "answers" are just too afraid( or maybe naive?) to just say "we don't know" why the speed of light is the constant of proportionality in the mass-energy conversion equation. You can answer the "how" very well which is what the mathematical derivation is, and which is what most people are answering in this thread but you see that none of those answers start with "Because..." but rather just keep on spitting out more math. And what we want is an explanation for why c^2 is there and what it means. We don't know what it means, we haven't answered that question and we don't know how to answer it. It's similar to how pi keeps coming up in a lot of equations and we struggle to understand why.
- jp555 11y agoIf we could trap those positrons somehow in large numbers... Antimatter production?
- ars 11y agoThere are much easier ways to make positrons.
- mrerrormessage 11y agoIf this can be made practical at any scale, I think the most exciting applications will be in long-range space drives. Although it sounds as though immense amounts of energy are needed, not needing to take along matter to eject in order to move is a game changer for space exploration.
- vbezhenar 11y agoI think you can use photon engines in the first place.
- KenoFischer 11y agoYep, you'd be significantly better off just shining the laser behind you.
- JabavuAdams 11y agoNo, for the same reason that burning fuel in a cylinder to turn a crankshaft is more efficient than using fuel to make fertilizer to grow feed to feed horses to pull your cart.
- fatuna 11y agoThis article appears to be 1,5 years old. So at least the 1 year deadline was missed.
- dspeyer 11y agoThe timeline: 1934: This is predicted 1997: This is done http://www.nytimes.com/1997/09/16/science/scientists-use-light-to-create-particles.html 2014: We will "demonstrate the feat within the next 12 months" 2015: Didn't bother
- TTPrograms 11y agoThe 1997 experiment is slightly different, as it involves electrons instead of just photons. See https://en.wikipedia.org/wiki/Schwinger_limit https://en.wikipedia.org/wiki/Schwinger_limit: "Photon–photon scattering and other effects of nonlinear optics in vacuum is an active area of experimental research, with current or planned technology beginning to approach the Schwinger limit.[5] It has already been observed through inelastic channels in SLAC Experiment 144.[6][7] However, the direct effects in elastic scattering have not been observed. As of 2012, the best constraint on the elastic photon–photon scattering cross section belongs to PVLAS, which reports an upper limit far above the level predicted by the Standard Model.[8] Proposals have been made to measure elastic light-by-light scattering using the strong electromagnetic fields of the hadrons collided at the LHC.[9] Observation of a cross section larger than that predicted by the Standard Model could signify new physics such as axions, the search of which is the primary goal of PVLAS and several similar experiments. Even the planned, funded ELI–Ultra High Field Facility, which will study light at the intensity frontier, is likely to remain well below the Schwinger limit[10] although it may still be possible to observe some nonlinear optical effects.[11] Such an experiment, in which ultra-intense light causes pair production, has been described in the popular media as creating a "hernia" in spacetime.[12]"
- negamax 11y agoSo was light first or matter? Was there early radiation (light != visible light only) which created matter. H -> He -> Stars. Or matter preexisted?
- ars 11y ago> So was light first or matter? On a fundamental level there is no difference between the two things. There is just energy in various shapes.
- ackfoo 11y agoIn the beginning, there was nothing. But it was a very active kind of nothing that, because of the Uncertainty Principle, allowed bits of energy to be borrowed from nothing, leaving behind holes as a sort of IOU. The likelihood of a virtual particle pair arising was inversely proportional to the energy difference across the pair. Since you need a fair bit of energy to do anything interesting, nothing happened for a very long time. However, since there was an abundance of very long time, eventually two of the photons borrowed out of the vacuum with sufficient energy interacted in such a way as to give rise to matter. Multiply that very long time by all of the matter in the universe (a very long time, squared; lucky we had lots of it) and we have beaches and sunsets. The only remaining question is how all that matter was gathered into the singularity that gave rise to our present universe about 13.8 (or whatever) By ago. Maybe it accreted out of the original matter over another very long time. Or maybe the idea that when you run the expansion of the universe backward you get a singularity is wrong. Maybe matter arising out of the vacuum disappears back where it came from when you run the picture backwards and it only looks like the universe started 13.8 By ago because that's how far out the event horizon sits. Maybe the cosmic background is the signature of the vacuum-derived pairs creating matter. Maybe this experiment will demonstrate an alternative origin for the cosmic background.