Science

Groundbreaking experiment aims to create matter from light

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Researchers at Imperial College London have devised a method of achieving light to matter transformation at power levels orders of magnitude lower than previously thought possible (Image: Shutterstock)
The seven simple ways that light and matter interact (Photo: Oliver Pike, Imperial College London)
Schematic of main elements of photon-photon collider
Researchers at Imperial College London have devised a method of achieving light to matter transformation at power levels orders of magnitude lower than previously thought possible (Image: Shutterstock)
Schematic of main elements of photon-photon collider
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In what could be a landmark moment in the history of science, physicists working at the Blackett Physics Laboratory in Imperial College London have designed an experiment to validate one of the most tantalizing hypotheses in quantum electrodynamics: the theory that matter could be created using nothing more than pure light.

Premised on a discussion that they had over one day and a few cups of coffee, the three physicists – two from Imperial College and one visiting from the Max Planck Institute in Heidelberg, Germany – recognized that their work on fusion energy also offered possibilities in the theory of light to matter creation, suggested in a theory 80 years ago by two American physicists, Breit and Wheeler. These two physicists had premised the idea that because annihilating electron-positron pairs produce two or more photons, then colliding photons should, in turn, produce electron-positron (or “Breit-Wheeler”) pairs.

In devising an experiment aimed at attempting to produce these Breit-Wheeler pairs, the physicists working at Imperial College propose a two-step process. Firstly, a high-energy electron beam accelerating electrons in a vacuum close to the speed of light would be fired into a target of pure gold several millimeters thick. Via a process called “Bremsstrahlung” (German for “Braking radiation”) the high-energy electrons bombarding the target would lose kinetic energy but, in so doing, release gamma-ray photons.

Schematic of main elements of photon-photon collider

Secondly, a magnetic field within the apparatus would collimate and direct this gamma-ray photon beam into a hohlraum (German for “cavity”). Simultaneously, to ensure that any subsidiary electron-positron pairs created at this point would be separated by a further magnet containment field, the hohlraum would be bombarded with a high-energy laser beam effectively rendering it as a black-body thermal radiation chamber. As the beam of high-energy photons entered the cavity they would rise to a super-excited state where they would collide en masse with the photons generated by the laser aimed at the hohlraum and, all going to plan, hundreds of thousands of Breit-Wheeler pairs would be generated to form a continuous stream from the cavity. In fact, it is anticipated that, in using a 2-GeV electron beam and a 400-eV hohlraum laser, the yield would be in excess of 100,000 electron-positron pairs.

The seven simple ways that light and matter interact (Photo: Oliver Pike, Imperial College London)

If this experiment comes to fruition it would represent not only the first realization of a pure photon–photon collider, but a method of achieving light to matter transformation at power levels orders of magnitude lower than previously thought possible. And, without the requirement for a massive particle accelerator, it could be easily achieved in a modestly-equipped laboratory.

Given the potential to open up a relatively low-energy, simple way to investigate a cornerstone of quantum electrodynamics, this proposal should allow many more researchers access to this field. As a result, this could help add to our knowledge of the processes that took place in the first 100 seconds of the universe and possibly shed more light on those mysterious denizens of deep-space: gamma-ray bursts emanating from exploding massive stars.

Lastly, validating the Breit-Wheeler theory would also provide the seventh and final in the line theories describing the simplest ways in which light and matter interact. These include Dirac's 1930 theory on the annihilation of electrons and positrons, Einstein's 1905 theory on the photoelectric effect, and Blackett and Occhialini’s single-photon annihilation. Those theories are all associated with Nobel Prize-winning research.

Details of the research were published this week in the journal Nature Photonics.

Source: Imperial College London

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9 comments
Skip Michael
And if you reverse the process, what do you get????
The Skud
They had better be careful! Every religious zealot on the planet will be on the warpath - After all, does not the 'holy book' claim: "And God said ... let there be light" as the first stage in His creation of it all? I can almost hear the TV evangelists getting ready ... preaching blasphemy and damnation. It was bad enough when that super cylotron was looking for the 'God particle"
neutrino23
If you reverse the process you get electron - positron annihilation resulting in some gamma rays. Combining two photons to make a particle happens, it is just very rare with the gamma rays we use. The value of this discovery is that they may have found a way to make the process much more efficient so that it can be observed.
Mr. Skud, I doubt very many fundamentalists read about this kind of research or care about the conclusions.
TheTimeTraveller
Wow, this is an absolutely fantastic article! This article is so informative and interesting and you explained the concept very well. I also really liked the diagram, as it shows the base of the experiment.
I believe this scientific breakthrough is unbelievable and could definitely make way for some very innovative ideas and inventions.
wle
hasn;t energy been converted to matter before?
m=sqrt((E))/c ?
Joe Morel
a ten second you tube video- 'vortex ring collision' shows two light fields colliding a forming a miniature galaxy.
Facebook User
I knew I was right but I didn't have the money or resources necessary to prove it, now these guys have, well done. And I liked the comment, "...let there be light", very clever.
William Carr
ahem.
This is close to a way to manufacture antimatter.
You got the “positron” bit?
If you pass the pair into a magnetic field, the Positron will spin one way and the Electron will spin the other.
Once separated, you’d need a way to store the Positrons in a magnetic bottle.
If someone finds a way to make anti-protons, you will have anti-hydrogen by combining anti-protons with positrons.
And once you have anti-hydrogen... can Warp Drive be far away?
Bob
Since an electron changing energy levels can absorb or emit many photons, this experiment seems a little too simplistic. Since a photon can exhibit the properties of a particle, it is already matter. How do they propose to create protons, neutrons and elements without bringing in all the other nuclear forces? This experiment is a long way from creating anything.