Turning Light into Matter via Photon-Photon Collision

Here’s an interesting piece of scientific news that comes via Phys.org.

Scientists at the Imperial College London think they have discovered a method that can turn light into matter — a concept that was theorized in in 1934 by Breit and Wheeler, but has never been experimentally demonstrated. Physicists Oliver Pike, Steve Rose and others believe that the technology needed to carry out a demonstration of this process is now available using a collider, and they came up with the idea as they were working in the field of fusion physics. The experiment is described as follows in the article:

The collider experiment that the scientists have proposed involves two key steps. First, the scientists would use an extremely powerful high-intensity laser to speed up electrons to just below the speed of light. They would then fire these electrons into a slab of gold to create a beam of photons a billion times more energetic than visible light.

The next stage of the experiment involves a tiny gold can called a hohlraum (German for ’empty room’). Scientists would fire a high-energy laser at the inner surface of this gold can, to create a thermal radiation field, generating light similar to the light emitted by stars.

They would then direct the photon beam from the first stage of the experiment through the centre of the can, causing the photons from the two sources to collide and form electrons and positrons. It would then be possible to detect the formation of the electrons and positrons when they exited the can.

For a light-to-matter process demonstrable experimentally would of course be a remarkable scientific breakthrough — and it will be interesting to follow progress in this area. The full report of their research can be found in Nature Photonics here (full access is only available for paid subscribers)

  • jousterusa

    Imagine this hooked to a 3D printer. One day, as in old sci-fi novels, we’ll be able to order bacon and eggs and get them seconds later from a device ready to eat (the food, not the device!).

    • Andreas Moraitis

      250 g bacon and eggs:

      Relativistic energy equivalent = 2.25*10^16 J = 6.25 billion kWh
      Nutritional value = 2.602*10^6 J = 0.7228 kWh

      Not a good deal, I would say.

      • Fortyniner

        Simple – just put 625 million 10kW e-cats in your basement, and… breakfast is served.

  • Obvious

    Seems to be an “obvious” embodiment of the rearrangement of the E=mc^2 formula.

    • Ged

      It’s not as easy as it sounds though, as usually light does not interact with light (other than constructive/destructive interference). That’s why the photonic matter using a near vacuum of rubidium atoms was such a huge breakthrough, as it showed under such a specific case photons could be forced to interact with each other for the first time ever.

      Colliding photons in such a way as that they interact in the first place, and then “fuse” into matter, is extremely nontrivial and was always believed to be impossible till this latest advance. In fact, it may well still be! They’ve just drawn up the idea of how to test this hypothesis, and then we’ll see if it’s true or not and if it’s possible to make matter from light, or not.

      • Obvious

        The idea is obvious. Pulling it off is of course another matter all together.

        • Ged

          The idea has been around for a very long time, as your picture should help indicate ;). This isn’t about the idea, just about the possible implementation though one particular method. Light smashing into light isn’t the only option for turning types of energy into mass, not at all. Probably not the best one either even if it does work, but we’ll see.

  • GreenWin

    Why use a fancy collider? Just have at a light bulb: http://bit.ly/1tajL5z 🙂 Thought experiment: create a matrix of photon emitters on X-Y-Z axes, paint a “raster” with timed photon collisions creating virtual pixels… you may not make matter, but you could have a nice 3D volumetric display.

    • Ged

      It’s such a very interesting and frontier topic. See, the problem has always been that photons do not interact with photons — they carry no charge and are “invisible” to each other. However, photons are weeeeeiirrrd. A photon can turn into a fermion-antifermion pair (virtual particle, I guess) randomly, such as into an electron and positron, or quark and antiquark. In two photon interactions, one photon becomes the pair fermion-antifermion and the other photon then interacts with -that-. Only by such a method can two photons interact with each other.

      So, the idea behind making matter from light is that you get two photons in this special interaction mode, each with enough energy at their combined center of mass that you split that fermion-antifermion pairing and blast the two away from each other (bringing the virtual particles into reality, so to speak), meaning the two photons get transformed into an electron and a positron (one photon makes the pair, one photon separates them, might be a way of thinking about it).

      • GreenWin

        Thanks Ged. Very helpful!

  • pelgrim108

    Creating matter would be good for space propulsion perhaps.
    Create electron positron, keep them separated, expell them at high velocity.

    • Ophelia Rump

      Or just use an old tv tube and shoot out two electrons instead.

      • pelgrim108

        Wouldnt you run out of electrons after some time?

        • Ophelia Rump

          Not if you power it with LENR.

  • Ophelia Rump

    Aren’t positrons antimatter?

    So the only way we can make matter is by destroying an equivalent amount?

    Well at least no harm can come from being able to make that!

    • MasterBlaster7

      positrons are anti-matter….and I think the electrons and positrons would annihilate each-other within a pico-second of exiting the golden can….and 2 high energy gamma released. Judges?

      • Ged

        That’s kinda the rule and problem posed by symmetry. There could be ways to separate the two, and prevent annihilation, such as doing this in a strong enough magnetic field that’ll force the two apart due to their opposite charges.

        • Ophelia Rump

          Could you annihilate something other than an electron with a positron, like a neutron? It might make for interesting transmutation.

  • bachcole

    Am I the only one suffering from Disqusitis? I can’t login automatically or manually and have to sign-in as a Guest.

    • Krish


    • work for me (through old twitter session)

    • BroKeeper

      It’s an open collision experiment between Frank and Disqus creating negative

    • US_Citizen71

      My account automatically logged in and I haven’t been signed into this computer since Friday. Cookie issue?