Can light become matter ?

[interested]

Some time ago I suggested that if electrons and positrons could become gamma rays then gamma rays could become particles. I played with the idea for a while and lost interest. Recently I stumbled across this link to a planned experiment https://phys.org/news/2018-03-underway.html#nRlv converting photons into particles.

Could radiation from a black hole become particles? Could radiation from the Big Bang become particles? 

[Strange]

4 minutes ago, interested said:

Some time ago I suggested that if electrons and positrons could become gamma rays then gamma rays could become particles.

Yes: https://en.wikipedia.org/wiki/Pair_production

But it requires very special conditions, such as the presence of an atomic nucleus (to conserve momentum). The experiment your link talks about is attempting to do it with no other particles involved.

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Could radiation from a black hole become particles? Could radiation from the Big Bang become particles?

In principle. But, as with all forms of pair production, they will quickly annihilate again to proceed the original photons.

[interested]

15 minutes ago, Strange said:

In principle. But, as with all forms of pair production, they will quickly annihilate again to proceed the original photons.

Is this where a black hole event horizon comes in useful. Similar to Hawking radiation.

 

17 minutes ago, Strange said:

But it requires very special conditions, such as the presence of an atomic nucleus (to conserve momentum). The experiment your link talks about is attempting to do it with no other particles involved.

Could the experiment work, and would it have to produce a particle and antiparticle?

[Strange]

7 minutes ago, interested said:

Is this where a black hole event horizon comes in useful. Similar to Hawking radiation.

Similar to Hawking radiation? I though you were talking about Hawking radiation?

8 minutes ago, interested said:

Could the experiment work,

I assume it could work, or they wouldn't be doing it.

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and would it have to produce a particle and antiparticle?

Yes.

[mathematic]

Immediately after the big bang the universe was a sea of photons.  Baryons and leptons were formed in particle-antiparticle pairs from photon-photon collisions.  Big mystery - why was there an excess of particles?

[Mordred]

That isn't completely accurate the BB was is a thermal equilibrium state where the particle sea becomes indistinquishable from one another. This isn't quite the same as everything is photons. Other particles can form but quickly destabilize. The expansion rate assists particles dropping out of thermal equilibrium by assisting in seperation of the particle/antiparticle pairs as well as temperature reduction.

 The thermal equilibrium state is conveniently modelled by its temperature with photons being the gauge boson however this is a convenient approximation not an absolute.

 The entirety of the SM particles cannot be formed from photons as the ultimate starter particle due to the various conservation laws involved in the Eightfold wayen such as charge, color, flavor, isospin, energy/momentum, parity etc.

Edited April 21, 2018 by Mordred

[interested]

On 4/21/2018 at 1:45 PM, Strange said:

 

Yes.

Why would two photons interacting have to produce a particle and antiparticle. 

On 4/21/2018 at 10:11 PM, Mordred said:

The expansion rate assists particles dropping out of thermal equilibrium by assisting in seperation of the particle/antiparticle pairs as well as temperature reduction.

Could Dark Energy in outer space assist in the separation of particle antiparticle pairs. Would the pairs produced have to be initially entangled. 

If dark energy is due to random quantum fluctuations, could these be the source of any of the outstanding particles in the SM. 

Edit: Can 2 virtual particles combine to form a real particle. Energy can not be created or destroyed! would virtual particles in the early universe be more energetic than they are today. 

 

On 4/21/2018 at 8:49 PM, mathematic said:

Big mystery - why was there an excess of particles?

Do you have any insight into this mystery. 

Edited April 24, 2018 by interested

[Strange]

12 minutes ago, interested said:

Why would two photons interacting have to produce a particle and antiparticle. 

Conservation laws. For example, if one of the particles is an electron, you need an positron to balance the charge (and all the other quantum numbers).

13 minutes ago, interested said:

Could Dark Energy in outer space assist in the separation of particle antiparticle pairs.

I can't imagine how it would make any difference. It has a relatively small effect across the whole millions of light years, so I don't see it making much difference to a coupe of particles. (The antiparticle would annihilate with another particle sooner to later anyway).

16 minutes ago, interested said:

If dark energy is due to random quantum fluctuations

The vacuum energy is about 10¹²⁰ times too large. Another great mystery waiting to be solved....

16 minutes ago, interested said:

could these be the source of any of the outstanding particles in the SM. 

There are no outstanding particles int eh standard model. The last one was the Higgs boson. And, sadly, there is still no evidence of particles beyond the standard model. (See the recent thread about results from the LHC - which unfortunately got hijacked by an irrelevant discussion of dark matter).

17 minutes ago, interested said:

Do you have any insight into this mystery. 

No.