Anti-matter Globular Clusters?
Antimatter is exactly the same as matter except that it has opposite charge. So the electron has a positively-charged counterpart called a positron, the proton has a negatively-charged opposite called the anti-proton etc etc. And these anti-particles can build into opposites of those substances familiar to us – so anti-water, anti-ice-cream, even anti-people – yes there can be anti-stars and planets with life on them, following exactly the same chemistry as on our world. The only proviso is that when matter and anti-matter meet, they annihilate, exploding in a burst of radiation.
Considering the early universe, it is not understood if and why differing amounts of anti-matter and matter were created, or whether there was lots of annihilation, but physicists are sure that most of the visible universe is now made of matter, otherwise there would be tell-tale signs of radiation from annihilation in places where glaxies of the two different types get too close to one another.
We do detect anti-matter cosmic rays hitting Earth, but these may well be created in ultra-powerful processes such as supernovae. Because cosmic ray paths are curved by magnetic fields we cannot pinpoint their origin (as yet!).
In a recent research paper, it has been theorised that although something as large as an anti-galaxy is very unlikely, it would still be possible for smaller clumps to have survived from the early universe. Like for example globular clusters made of anti-matter which could orbit ordinary-matter galaxies without generally interacting with those galaxies. Globular clusters are very old clusters of maybe a million stars each – there are about 150 orbiting our own Milky Way.
We might be able to confirm the existence of an anti-globular-cluster by witnessing rare annihilations if it collided with a galaxy; or by somehow pinning down the source of stray anti-particles emanating from a cluster.
A tantalising idea…
