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Q & A: Light and anti-matter

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Most recent answer: 07/16/2008
Q:
If light is technically antimatter, and antimatter explodes on contact with matter, does that mean that the light we see is really tiny little explosions that the photons create when they touch matter?
- Emily H.
Brooklyn, NY, USA
A:
Light is technically not anti-matter in the sense that this term is usually used as a description of particles of opposite quantum numbers of particles that have mass, such as a proton or electron or such.  For example an anti-proton can interact with a proton and cause an  "explosion" in the sense that the two disappear into a conglomerate of other particles.  The total energy of the final products is always conserved.

The light we see when photons interact with matter is due to the fact that the light can transfer energy to an atom and excite it into a higher energy level state.   When the atom decays into its lowest level 'ground state' it emits a photon that the eye can see.

LeeH

Light is the same as its own antiparticle.  However the rate at which colliding light rays convert to other particles is very low even when the light is high enough frequency to supply enough energy. Ordinary light doesn't have enough energy per photon to make any ordinary particles.  Mike W.

(published on 07/16/2008)

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