While scientists have observed photons smashing together and "creating" matter we're just observing matter after photons collide, we really don't know whats happening but we can observe matter that seems to magically appear. We can't see that small and scientists may draw diagrams of photons colliding with lots of fancy arrows and say "yay we made matter"
Whats really happening?
Scientists have drawn up images like these to explain colliding gamma rays creating particles like these.
Evidence for this exists in bubble chambers because this is what we can see. Gamma rays colliding just turn into matter. Poof.
Lets look at Electron-Positron annihilation to start out with.
Above we can see an electron and a positron flying towards each other about to collide. This pair will soon be turned into gamma rays. Right, no wrong!
How exactly does this take place? Standard science texts are silent on the question; only reporting that it happens, but without providing any explanation of the possible mechanisms involved. Unfortunately this is not very helpful. What we need is a slow-motion version of events, particularly what happens at the moment the particles ‘make contact’.
There is no way of seeing anything on such a small scale. The best we can do is look at the available evidence and speculate on what could be taking place. Ideally this speculation should be something that makes sense in terms of a classical model. With that in mind, the following is a version of what might be happening.
Close up look:
At this point it appears that the process will repeat itself, then again, and again. Basically the particles will oscillate through each other, as though connected via a spring. Will the oscillation continue forever? This appears to be a frictionless system. As it happens, they won’t oscillate forever. The VDCL (Velocity Dependant Coulomb’s Law) tells us that as oppositely-charged particles move together the force between them decreases. As they move apart the force increases. This effectively acts as a form of damping which will slowly bring the oscillation to a stop.
Eventually stops moving.
After the oscillations have stopped we are left with a sort of ghost particle.
It has twice the mass of an electron but more importantly a charge of zero.
It goes without saying that a particle without charge is not going to have much of an impact on anything, nor will it be impacted by anything. For all practical purposes it may as well not exist. And that’s just the point. In electrical terms this composite particle is effectively invisible. The electron and positron have not been annihilated after all. They are still there.
There is one other aspect of the extinction process that needs explaining and that is the emission of photons.
To understand this, consider radio transmissions. We know that when you oscillate electrons in an antenna it produces radio waves, which are just low frequency electromagnetic waves.
What if that antenna contained both electrons and positrons, and they oscillated in opposing directions? Rather than cancel each other’s signal, the two sets of charges would combine to produce a wave of double the amplitude.
Now look again at the electron-positron interaction. They are oscillating through each other, just like in the antenna. Therefore we should also expect them to produce an electromagnetic wave. In this case the frequency would be much higher due to the lightweight nature of the particles involved. It may even be so high as to be in the gamma ray spectrum.
Thus the most likely explanation for the emission of photons is that the brief oscillating interaction between these particles produces an electromagnetic wave, or more correctly two waves (one for each particle), which have frequencies in the gamma ray spectrum.
So in conclusion to creating light (energy) from matter, we can't. What's actually happening is that oscillations of positrons and electrons at high speeds create these gamma rays.
So now that we know we can't turn matter into energy, how do we know we can't turn energy into matter?
How do we turn energy into matter? Scientists know (or think they know) it's possible.
For sake of discussion let’s call this composite positron-electron particle a ‘poseltron’. Is there any way for a poseltron to come undone, i.e. to be broken into its constituent particles? One method would be to expose it to a strong electric field which polarized the component particles and pulled them apart. But it would need to be extremely strong because the positron and electron are in direct contact.
So if you shook the two particles together you can possible shake them apart. If there are reactions like this happening it's likely a speeding gamma ray could easily hit a poseltron and shake it apart.
Poseltrons vibrate at the frequency of gamma rays so doesn't it make sense that that same frequency could vibrate them apart?
Lets say poseltrons exist but think about it, how often is an electron going to meet a positron. Not very often so if they do exist then they are probably very widespread.
The low density of poseltrons in nature would also explain why electron-positron pairs are only created occasionally – there needs to be an existing poseltron in place before conversion can occur. Under the current scientific model a photon with enough energy can convert into an electron-positron pair, but would do so for no apparent reason, i.e. at random without cause & effect. This model defies common sense.
Another reason why "poseltrons" exist,
There is another way in which positrons can be created, and that is via a process known as ‘proton conversion’. When Sodium-22, an unstable isotope of sodium, decays it turns into Neon-22. When it does this it also releases a positron and a gamma ray.
Standered theort tells us there are two means of proton conversion. One in wich a proton an and electron form a neutron. The other in which an electron-positron pair being created followed by the electron being absorbed and the positron ejected. When you think about it the second mean of proton conversion is more likely in this case. While protons and electrons probably can join together. According to current theories, Sodium-22 can just magically, out of no where, create this electron positron pair and converts one of its protons into a neutron. Lets say this is true, where is all that energy coming from that you need to create the electron positron pair. The nucleus can't create it unless it has an external source of energy.
So whats really happening?
First a poseltron drifts into the nucleas of the Sodium-22 atom.
The movement caused by strong forces in the atoms nucleus then tears the poseltron apart into an electron and positron. The electron gets absorbed by the proton and it becomes a neutron. The positron is ejected due to it's positive charge and it grabs an electron on the way out or stays as a positron. Gamma rays are generated by the breaking apart oscillations of the poseltron.
So in conclusion,
An electron and positron collide, they meet and pass through each other generating gamma rays and then form an undetectable zero charge poseltron. It's pretty much invisable.
Scientists: "yay we made energy from matter"
All that matter is still there, the energy they created is electromagnetic fields created by oscillation.
Some gamma rays bump into a poseltron by chance, they cause it to shake apart and break up the two particles. At the same time some of this energy has been absorbed by the particles.
Scientist: "yay we made matter from energy, we're so smart"
Nothing has actually been made, the matter just became visable again.
Therefore conservation of mass and conservation of energy have not been broken and the universe makes sense again. Yay
Sorry for spelling errors, this is so long spell check just died. ;)