Expert: Philip Stahl - 7/10/2011

Question
sir, we know that among matter and anti matter nature seems to prefer matter. why is this so? also what will happen if matter and antimatter come into contact? as we see in films this contact leads to huge explosions, can this be used in making some kind of weapons or bombs one day?

Answer
Hello,

Truthfully, we don't know WHY there is this asymmetry, but it may have something to do with Fitch and Cronin's (1963-64) discovery of a violation of CPT invariance. (C for charge conjugation, P for parity (spatial reflection) and T for time reversal. Up until their 1960s investigations, it was widely accepted by physicists that nature played no favorites where charge conjugation, parity and time reversal were concerned. The discovery of a fundamental violation(Fitch and Cronin found a tiny fraction - 45 out of 22,700 - K2 mesons, spontaneously disintgrate into 2 pions, e.g. pi mesons, instead of the usual 3) changed all this.

It was suggested by them that this CPT invariance violation might also  - in some way - account for the apparent asymmetry in the distribution of matter with respect to anti-matter.

If matter and anti-matter come into contact, they mutually annhilate each other, with the subsequent conversion of their respective masses into energy ...according to Einstein's equation: E = mc squared.

Obviously, the magnitude of the explosion would depend on the respective masses used.

I seriously wouldn't worry about any weapons being developed using this technique, since: a) no one has figured out how to form anti-matter as any more than occasional (e.g. anti-hydrogen)atoms, and b) no one has a clue how to contain it, say in an extended form, for weaponry applications.