anti-matter "clumps" I was recently reading an article about the US Air Force creating advanced weapons using anti-matter particles (positrons, specifcally). It got me to thinking... What I'm curious about is this: are there macroscopic "clumps" of antimatter particles? In other words, normal matter particles combine to create macroscopic things (i.e. normal particles combine to create atoms, which combine to create molecules). Are there particular anti-atoms and/or anti-molecules? Presumably this would be a manifestation of some kind of symmetry. Thanks for your input.