There's been some science news stories about a Nature Photonics paper A photon–photon collider in a vacuum hohlraum. See the report from Imperial:
Scientists discover how to turn light into matter after 80-year quest:
"Imperial physicists have discovered how to create matter from light - a feat thought impossible when the idea was first theorised 80 years ago. In just one day over several cups of coffee in a tiny office in Imperial’s Blackett Physics Laboratory, three physicists worked out a relatively simple way to physically prove a theory first devised by scientists Breit and Wheeler in 1934..."
You can also google on "turning light into matter", but note that some of the reports are a little sensationalist, as if this is something totally novel. It isn't, see this report which also refers to SLAC and pair production:
Experiment to Turn Light Into Matter : Discovery News
Note the the bit that says "matter was first created out of pure energy in 1997 at the Stanford Linear Accelerator Center". However even that is arguably incorrect, see pair production, and read this about Patrick M.S. Blackett in 1933. It's the Blackett lab at Imperial for a reason. The general idea has been around for even longer than that. You can trace it back to 1704 and Newton's Opticks. See query 30 where Newton said "Are not gross bodies and light convertible into one another?" Matter is converted into light in something as simple as a fire. Not much, but that that's what E=mc² is all about of it. If you could collect all the ash and smoke and weigh it, it would weigh just a little but less than the original coal. It's somewhat similar for an atom bomb, where the conversion rate is about 0.1%, and similar again for matter-antimatter annihilation where the conversion rate is 100%. The inverse of this is the pair production which is "turning light into matter". Also see two photon physics on Wikipedia:
"Two-photon physics, also called gamma–gamma physics, is a branch of particle physics that describes the interactions between two photons. If the energy at the center of mass system of the two photons is large enough, matter can be created..."
Note thought that the article says "From quantum electrodynamics it can be found that photons cannot couple directly to each other". That's wrong. Pair production doesn't occur because pair production occurs, instead two photons interact. Recognition of this is the arguably the most important aspect of this news. It may lead to an important advance in physics.
Scientists discover how to turn light into matter after 80-year quest:
"Imperial physicists have discovered how to create matter from light - a feat thought impossible when the idea was first theorised 80 years ago. In just one day over several cups of coffee in a tiny office in Imperial’s Blackett Physics Laboratory, three physicists worked out a relatively simple way to physically prove a theory first devised by scientists Breit and Wheeler in 1934..."
You can also google on "turning light into matter", but note that some of the reports are a little sensationalist, as if this is something totally novel. It isn't, see this report which also refers to SLAC and pair production:
Experiment to Turn Light Into Matter : Discovery News
Note the the bit that says "matter was first created out of pure energy in 1997 at the Stanford Linear Accelerator Center". However even that is arguably incorrect, see pair production, and read this about Patrick M.S. Blackett in 1933. It's the Blackett lab at Imperial for a reason. The general idea has been around for even longer than that. You can trace it back to 1704 and Newton's Opticks. See query 30 where Newton said "Are not gross bodies and light convertible into one another?" Matter is converted into light in something as simple as a fire. Not much, but that that's what E=mc² is all about of it. If you could collect all the ash and smoke and weigh it, it would weigh just a little but less than the original coal. It's somewhat similar for an atom bomb, where the conversion rate is about 0.1%, and similar again for matter-antimatter annihilation where the conversion rate is 100%. The inverse of this is the pair production which is "turning light into matter". Also see two photon physics on Wikipedia:
"Two-photon physics, also called gamma–gamma physics, is a branch of particle physics that describes the interactions between two photons. If the energy at the center of mass system of the two photons is large enough, matter can be created..."
Note thought that the article says "From quantum electrodynamics it can be found that photons cannot couple directly to each other". That's wrong. Pair production doesn't occur because pair production occurs, instead two photons interact. Recognition of this is the arguably the most important aspect of this news. It may lead to an important advance in physics.
Aucun commentaire:
Enregistrer un commentaire