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Conservation of Photons?


Mr Skeptic

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A photon is considered an elementary particle.

 

In what sense? Photons are not constituents of any other particle. OTOH, there are no other particles that comprise a photon.

 

Well actually, all forms of matter have been proven to be differential forms of trapped light. This means that photon energy makes up all matter in the universe.

 

This would mean that the photon is very fundamental, if not primal.

 

I second the call. Cite a reliable source.

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In what sense? Photons are not constituents of any other particle. OTOH, there are no other particles that comprise a photon.

 

 

 

I second the call. Cite a reliable source.

 

From the University of Rochester

 

''OUT OF PURE LIGHT, PHYSICISTS CREATE PARTICLES OF MATTER

September 16, 1997

A team of 20 physicists from four institutions has literally made something from nothing, creating particles of matter from ordinary light for the first time. The experiment was carried out at the Stanford Linear Accelerator Center (SLAC) by scientists and students from the University of Rochester, Princeton University, the University of Tennessee, and Stanford. The team reported the work in the Sept. 1 issue of Physical Review Letters.

 

Scientists have long been able to convert matter to energy; the most spectacular example is a nuclear explosion, where a small amount of matter creates tremendous energy. Now physicists have succeeded in doing the opposite: converting energy in the form of light into matter -- in this experiment, electrons and their anti-matter equivalent, positrons.

 

Converting energy into matter isn't completely new to physicists. When they smash together particles like protons and anti-protons in high-energy accelerator experiments, the initial particles are destroyed and release a fleeting burst of energy. Sometimes this energy burst contains very short-lived packets of light known as "virtual photons" which go on to form new particles. In this experiment scientists observed for the first time the creation of particles from real photons, packets of light that scientists can observe directly in the laboratory.

 

Physicists accomplished the feat by dumping an incredible amount of power -- nearly as much as it takes to run the entire nation but lasting only for a tiny fraction of a second -- into an area less than one billionth of a square centimeter, which is far smaller than the period at the end of this sentence. They used high-energy electrons traveling near the speed of light, produced by SLAC's two-mile-long accelerator, and photons from a powerful, "tabletop terawatt" glass laser developed at Rochester's Laboratory for Laser Energetics. The laser unleashed a tiny but powerful sliver of light lasting about one trillionth of a second (one picosecond) -- just half a millimeter long. Packed into this sliver were more than two billion billion photons.

 

The team synchronized the two beams and sent the electrons head-on into the photons. Occasionally an electron barreled into a photon with immense energy, "like a speeding Mack truck colliding with a ping pong ball," says physicist Adrian Melissinos of the University of Rochester. That knocked the photon backward with such tremendous energy that it collided with several of the densely packed photons behind it and combined with them, creating an electron and a positron. In a series of experiments lasting several months the team studied thousands of collisions, leading to the production of more than 100 positrons.

 

The energy-to-matter conversion was made possible by the incredibly strong electromagnetic fields that the photon-photon collisions produced. Similar conditions are found only rarely in the universe; neutron stars, for instance, have incredibly strong magnetic fields, and some scientists believe that their surfaces are home to the same kind of light-to-matter interactions the team observed. This experiment marks the first time scientists have been able to create such strong fields using laser beams.

 

By conducting experiments like this scientists test the principles of quantum electrodynamics (QED) in fields so strong that the vacuum "boils" into pairs of electrons and positrons. The scientists say the work could also have applications in designing new particle accelerators.

 

Spokesmen for the experiment, funded by the U.S. Department of Energy, are Kirk McDonald, professor of physics at Princeton, and Melissinos, professor of physics at Rochester. Also taking part in the experiment were William Bugg, Steve Berridge, Konstantin Shmakov and Achim Weidemann at Tennessee; David Burke, Clive Field, Glenn Horton-Smith, James Spencer and Dieter Walz at SLAC; Christian Bula and Eric Prebys at Princeton; and seven other physicists from Rochester, including Associate Professor David Meyerhofer; graduate students Thomas Koffas, David Reis, Stephen Boege, and Theofilos Kotseroglou; research associate Charles Bamber; and engineer Wolfram Ragg.''

 

 

As you can see from this work i qoute, that particles have been made from the photon energy. We also see, that this must happen very frequently in high energy collisions in spacetime. In fact, this is why we are left with two photons when a positron and an electron come together, other than them evading destruction back to photon energy creating a positronium (If i have the name right).

 

Bottom line is, is that ordinary inertial mass can be made from photon energy, which would suggest all particles in the universe do revert back to the photon energy they fluxed from.

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Close, but that's not really a source. That's a press release. This is your source:

 

 

http://prola.aps.org/abstract/PRL/v79/i9/p1626_1

Positron Production in Multiphoton Light-by-Light Scattering

Received 2 June 1997

 

A signal of 106±14 positrons above background has been observed in collisions of a low-emittance 46.6 GeV electron beam with terawatt pulses from a Nd:glass laser at 527 nm wavelength in an experiment at the Final Focus Test Beam at SLAC. The positrons are interpreted as arising from a two-step process in which laser photons are backscattered to GeV energies by the electron beam followed by a collision between the high-energy photon and several laser photons to produce an electron-positron pair. These results are the first laboratory evidence for inelastic light-by-light scattering involving only real photons.

 

 

©1997 The American Physical Society

 

URL:

DOI: 10.1103/PhysRevLett.79.1626

PACS: 13.40.-f, 12.20.Fv, 14.70.Bh

 

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And all matter is but a different form of light. I thought this part would be obvious. Many many sicentists know this fact now. In fact, a scientist here called BenTheMan made a thread on sciforums recently, (embarrasingly to say the least) - where he challenged how matter could not be made up of light. Mysteriously, he retracted his statement, and apologized to two users there, saying ''yes, matter can be made of light.''

 

You will take his word for it surely, since, he is a user here, with some crudentials?

 

I speak the truth. I will not prance about here making wild claims if they are not backed up by some kind of truth. So here it is, matter can be made out of photons, and not only that, most matter we have experimented with is made of photons, as they can be manipulated back to that form. The form of E=Mc^2 allows this to happen, so yes, you are right.

 

Also, ask yourself what is more fundamental, the energy or matter? Obviously the energy is, for energy makes the forms of matter you and i observe, but it also means that if we have matter converting back to energy, then we have our proof that matter is but forms of trapped energy.

 

It's so obvious, why can no one see this just on the words i speak?

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By the same argument, you could say that light is made of mass, or that electricity is made of heat, plastic is made of turkeys, or that motion is made of lightning. The rest of us prefer to say that energy is converted from one form to another, not that things are "composed" of whatever they can be made from.

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And all matter is but a different form of light. I thought this part would be obvious. Many many sicentists know this fact now. In fact, a scientist here called BenTheMan made a thread on sciforums recently, (embarrasingly to say the least) - where he challenged how matter could not be made up of light. Mysteriously, he retracted his statement, and apologized to two users there, saying ''yes, matter can be made of light.''

 

You will take his word for it surely, since, he is a user here, with some crudentials?

 

I speak the truth. I will not prance about here making wild claims if they are not backed up by some kind of truth. So here it is, matter can be made out of photons, and not only that, most matter we have experimented with is made of photons, as they can be manipulated back to that form. The form of E=Mc^2 allows this to happen, so yes, you are right.

 

Also, ask yourself what is more fundamental, the energy or matter? Obviously the energy is, for energy makes the forms of matter you and i observe, but it also means that if we have matter converting back to energy, then we have our proof that matter is but forms of trapped energy.

 

It's so obvious, why can no one see this just on the words i speak?

 

I'd challenge anyone who claimed it to provide some evidence to back it up. It's not obvious to me. Photons are bosons and can be created and annihilated — they are not conserved. When a photon is absorbed it ceases to exist.

 

The only avenue I see here is with the unification of the interactions at very high energies.

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Photons are indeed conserved... in what sense do you mean? In the annihilation process, the conservation laws state that:

 

Conservation of charge. The net charge before and after is zero.

 

Conservation of linear momentum and total energy. This forbids the creation of a single gamma ray.

 

Conservation of angular momentum.

 

Properties of the photon are therefore conserved. However, it is debatable whether certain information about photons are indeed lost in absorption. It would not agree however, very well, with physics if information about it is completely lost.

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As swansont has stated, there is no law of conservation of photon number.

 

Actually, he never specified what conservation he was implying, until just now. In fact, the reason why photons are tend to be created from annihilation is because of no conservation in quantum number.

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