# If antimatter and matter become pure energy when they combine and an

1. Mar 13, 2005

### bmurphy12345

If antimatter and matter become pure energy when they combine and an electron has an antiparticle (a positron) what is the energy that comes from their combination? I thought electrons were made of energy.
Thanks

2. Mar 13, 2005

### SpaceTiger

Staff Emeritus
I'm not sure I entirely understand your question, but when electrons and positrons collide (or annihilate), they create photons. Specifically, since the total energy of electron+positron >~ MeV, they'll form gamma-ray photons. It's just a matter of converting different forms of energy (mass energy+kinetic energy -> photon energy).

3. Mar 13, 2005

### dextercioby

In technical language,total 4 momentum in a Feynman diagram is zero.

Daniel.

4. Mar 13, 2005

### bmurphy12345

if matter is energy can it be converted into antimatter?

5. Mar 14, 2005

### ArielGenesis

I guess, when the condition is fit, then what will happen is that the energy form a matter and it's antimatter.

6. Mar 14, 2005

### masudr

As long as energy and momentum (and charge and all that) are conserved, almost anything can happen.

7. Mar 14, 2005

Staff Emeritus
And charge, and CPT, and maybe some other symmetries.

8. Mar 14, 2005

### masudr

I mentioned charge, and the "all that" stood for the stuff you say. As far as we know, anyway.

9. Mar 14, 2005

### ZapperZ

Staff Emeritus
For those who may not realize, or missed it, what SelfAdjoint and Masudr are trying to convey is that there are MORE consideration to be taken into account than just "energy goes to matter". One needs to consider a number of conservation laws for something to occur. You just cannot take energy and BAM, convert it into matter. Pair-production, for example, where high energy photons converts into a matter-antimatter pair can only occur in the vacinity of "massive" objects due to conservation of momentum issues.

There are specific rules and laws for things to occur in physics in which there are not only qualitative, but also quantative restrictions. Knowing just ONE of the rules does not tell you if something is possible or not.

Zz.