[Fozzie (OP)]

If matter and energy are fundamentally the same thing and matter cannot be destroyed - only turned into energy, what sort of material would be created if we could turn pure energy into matter?

[QuantumClue]

Any types of matter. In fact, photon energy can create all types of matter.

[graham.d]

I don't think it is right to say matter and energy are the same thing. They may be forms of the same thing and, much more deeply, they both may be the same thing as nothing at all! It is not known. What is correct is that MASS and energy are the same thing. The stuff we call mass is what is attracted to other masses via gravity and what leads to what we measure as weight (because of attractionto the mass of the earth). When we get energy from any source, like a chemical or nuclear reaction, the remnants of the reaction weigh a little less than before. Some mass has been converted to energy. Energy does not have any easily described common form so talking of pure energy would need a clear definition. But a simple example of energy conversion of one form into another is photosythesis where sunlight (electromagnetic energy) is converted into stored energy; in this case trapping carbon and releasing oxygen. If you get all the resulting carbon and oxygen it would actually weigh slightly more than the carbon dioxide from which it was derived.

[graham.d]

QuantumClue, your view here is somewhat contraversial. Do you not think it better to answer in the spirit intended? By all means give an extended view with whatever theories you favour, but it is probably more helpful to say what is reasonably accepted at least.

[QuantumClue]

I favor this theory for many reasons. Decay of annihilation creates two gamma photons always. We have already created matter out of light  http://www.sciencedaily.com/releases/1997/09/970918045841.htm and it is now generally accepted that it is believed all matter can be made from light.

[graham.d]

It is news to me that this idea is generally accepted at all. There are a number of enthusiastic supporters for such a view but the unification of particle physics into just variants of the photon would tend to be very big news if wholly verified or even justified theoretically. Matter - antimatter annhihilation generally produces other particles - it is not proven that only gamma rays result except in the case of electron-positron annihilation. In any case the apparent asymmetry betwen the amount of matter and antimatter is also highly problematic to such a theory. I'm not saying it is wrong, just that it far from being generally accepted.

[JP]

and it is now generally accepted that it is believed all matter can be made from light.

True, but there's nothing special about light in that context.  All matter can be made from energy so long as certain conservation laws are satisfied.  For example, a photon cannot make an electron-positron pair without some other matter in the vicinity to conserve momentum. 

You could also say that all matter can be made from protons, which would also be true, since they also have energy.

[QuantumClue]

JP

That depends on what one classes as being unique. To be contradictory, I state the process is very unique for one specific reason, and that is annihilation - the process which makes particles and their antipartners release what can be viewed as the fundmental energy making them. All particles have this ability to decohere with their antipartners. It is true you can say all protons make matter, but because protons are matter, then the question arises what matter makes a proton? Atleast with one universal particle, i.e. a photon, we can successfully say that if this is the case, then all matter would reduce to photons when annihilation is observed. And lo and behold, they do.

[JP]

Except that positron-electron annihilation can create W and Z bosons as well.

http://van.physics.illinois.edu/qa/listing.php?id=15838

[QuantumClue]

That is because it mediates the weak force, and are one of the four gauge bosons of the electroweak interaction, basically with a strict family consisting of the photons and three other bosonic particles. The product of one of these would not be a surprise.

[yor_on]

But a simple example of energy conversion of one form into another is photosythesis where sunlight (electromagnetic energy) is converted into stored energy; in this case trapping carbon and releasing oxygen. If you get all the resulting carbon and oxygen it would actually weigh slightly more than the carbon dioxide from which it was derived.

That was a lovely example Graham.
I will use that

[yor_on]

QC
"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. "

That's a pair-production actually, annihilating each other, isn't it?
Existing? a millisecond? less?

I wouldn't call that creating a lasting piece of matter.

[yor_on]

You see, if we cut through the BS.
It's only if and when doing it, it will be proved.
Until that creating lasting matter from light will be a theory.

Unless we changed the scientific standards of proving something.
And in that case all theory's 'exist' that we can 'believe in'
And people all seem to have their own, don't they?

As me )
==

Beliefs I mean, not theories.

[QuantumClue]

QC
"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. "

That's a pair-production actually, annihilating each other, isn't it?
Existing? a millisecond? less?

I wouldn't call that creating a lasting piece of matter.

Is that a time extracted from the text?

[yor_on]

No, just my guess, but I think that if they had particles, existing longer than what pair-production allows for normally, I would expect them to define a time to it.

[Geezer]

If we have a system that converts electromagnetic energy into matter, would that not reduce the entropy of the system in violation of the second law of thermodynamics?

[CPT ArkAngel]

They had to use an electron energy because their lasers are simply not powerful enough. And what is better than an electron as a quantum of energy to help photons to produce an electron-positron pair?

Supposing an electric charge has always a size of the Planck Length and supposing the mass (and gravity) of any particles including black holes is produced by the charges, I have just found the solution to a unification theory... A black hole has to have many charges to produce a stronger gravitation field than a minimal black hole of r=Lp and m=mp. So a black hole is not a singularity but grows with its mass... The total charge may be zero but the charges are still there...

α*G*Mp^2 = e^2/(4πξ0) = α*h*C/2π

where α is the coupling constant = 1/137
and e is the elementary charge.

Later this week i will post more explanations about how i got there and how it agrees with my theory.

[QuantumClue]

If we have a system that converts electromagnetic energy into matter, would that not reduce the entropy of the system in violation of the second law of thermodynamics?

No. Energy into matter is a purely relativistic term.

[Geezer]

If we have a system that converts electromagnetic energy into matter, would that not reduce the entropy of the system in violation of the second law of thermodynamics?

No. Energy into matter is a purely relativistic term.

So, does that mean we can build a perpetual motion machine as long as it a relativistic perpetual motion machine?

[QuantumClue]

If we have a system that converts electromagnetic energy into matter, would that not reduce the entropy of the system in violation of the second law of thermodynamics?

No. Energy into matter is a purely relativistic term.

So, does that mean we can build a perpetual motion machine as long as it a relativistic perpetual motion machine?

How do  you extrapolate the perpetual motion machine? Creating energy into matter and matter into energy results directly from E=Mc². The equation conserves their quantities using the speed of light as a universal measuring stick. There is nothing which suggests this violates thermodynamic rules.