B Regarding electron-positron annihilation

[Rev. Cheeseman]

When an electron meets an anti-electron which is also known as positron and collide, the particles will become photons. But where did the photons go after the electron-positron annihilation happened?

 

[Vanadium 50]

Outward.

 

[Rev. Cheeseman]

Outward.

I mean do they ended up absorbed by something or simply gone?

 

[phyzguy]

They simply propagate out away from the point of annihilation at the speed of light. Whether they get absorbed depends on what they encounter along the way. It's similar to what happens to the photons that leave your flashlight.

 

[jtbell]

If the photons have high enough energy, they can in turn produce new electron-positron pairs. This bubble-chamber picture shows a positron (orange) entering from the lower left and annihilating with an electron in the bubble-chamber fluid. One of the photons (purple-dot path) produces an electron-positron pair (green) at upper right. The other photon (invisible) leaves the field of view.

(Source at CERN)

 

[Vanadium 50]

I mean do they ended up absorbed by something or simply gone?

Depends on what they hit. Just like photons from a light bulb or a star.