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Author Topic: What happens when two photons collide?  (Read 2236 times)

Offline jaiii

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What happens when two photons collide?
« on: 25/02/2014 11:33:36 »
Good day.

I want to ask what happens when two photons collide together?

My native language is not English but Slovak.
For the translation I use Google translator.
If you do not understand so I turn elsewhere.

Thank you.
« Last Edit: 08/03/2014 17:38:10 by chris »


 

Offline Soul Surfer

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Re: Dynamic Casimir Effect
« Reply #1 on: 03/03/2014 23:01:51 »
Absolutely nothing.   In the absence of any other material very close to the two photons photons do not interact with each other.

However if there is another electromagnetic field involved photons can interact and break up into lower energy photons.
 

Offline yor_on

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Re: Dynamic Casimir Effect
« Reply #2 on: 04/03/2014 01:08:10 »
Photons are strange Jaii. They exist though, or something so similar to it that we have to call that too for a 'photon'. http://scitation.aip.org/content/aapt/journal/ajp/72/9/10.1119/1.1737397

And it's as soulsurfer write, as far as I understand they do not interact normally, but at very high energies you have something called 'two photon' physics.https://en.wikipedia.org/wiki/Two-photon_physics

And to get to the point of it, I'll leave you with this one to ponder :) http://www.fromquarkstoquasars.com/science-creates-a-quantum-link-between-photons-that-dont-exist-at-the-same-time/
 

Offline Soul Surfer

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Re: Dynamic Casimir Effect
« Reply #3 on: 04/03/2014 18:05:59 »
sorry yor-on I was forgetting to say that if we have enough energy the interactions could include particle pairs and include the fact that if the energy was high enough massive particles could be created.

In general electrons and positrons are the lowest mass particles considered for this process but I cannot see any good reason why neutrinos or other very low mass particles should not be possible the big problem is observing the result of this sort of interaction because it would probably be very rare and the particles are extremely difficult to detect.
 

Offline yor_on

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Re: Dynamic Casimir Effect
« Reply #4 on: 05/03/2014 18:24:18 »
Why not :)

If I would consider it a field, just as a guess, with 'excitations' that then gets defined as photons in our measurements. Then it is the field that defines what we see, isn't it?  The field defines our reality. Photons are strange, then again, remember a nuclear reaction? In where you have to hit an atom with just the right 'speed' to start that chain reaction? How does that work? Thinking of it it confuses the he** out of me. Why does it have to have that precise speed in the collision? Somewhere I read about it as 'deforming' the atom? Sorry, went on another tangent here :)
 

Offline Soul Surfer

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Re: Dynamic Casimir Effect
« Reply #5 on: 05/03/2014 23:21:40 »
It's all about resonances.  If you hit a particle with just the right energy to do the job it is more likely to work whereas a much higher energy particle might just zip right through.

A very good example of this is the fission reactor where U235 needs low energy neutrons to cause the fission but when it splits the excess neutrons come out with a high energy and the reactor needs a moderator that does not absorb neutrons but cools them down so they work better and the reaction can be stabilised.
 

Offline yor_on

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Re: Dynamic Casimir Effect
« Reply #6 on: 06/03/2014 13:22:24 »
Resonances sounds interesting Soulsurfer. Any more examples of that?
 

Offline evan_au

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Re: Dynamic Casimir Effect
« Reply #7 on: 07/03/2014 10:59:48 »
As I understand it, many of the short-lived subatomic particles don't live long enough to be detected directly, but they can be detected by adjusting the energy of the colliding particles. At certain energy levels, production of the short-lived particle is enhanced, and this can be seen as a spray of debris with a certain energy.
This is a type of resonance effect.
 

Offline yor_on

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Re: Dynamic Casimir Effect
« Reply #8 on: 07/03/2014 13:02:50 »
It is interesting Evan. Been reading up on quarks and flux tubes, and now this :) A resonance is something demanding a arrow, well, as I think. Anything that change needs a arrow, or something so similar that it doesn't really matter what words we use for it, it still must be equivalent to a arrow. As well as it is a question of the degrees of freedom we describe it through. A vibration is one degree of freedom, in its simplest description, isn't it?
 

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Re: Dynamic Casimir Effect
« Reply #8 on: 07/03/2014 13:02:50 »

 

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