Where can I ask physics questions?

The title says it really. Sometimes I have a thought, (this will be a revelation to some), and I really can't think of an answer, (this will suprise nobody).

I do not have a higher education in physics, it was an ancialliary subject for me at uni, (Geochemistry), but I've always been interested. I know the difference between a pion and a kaon and a charm and a top for example.

What I'm fishing for is a forum where I can ask physics questions in moderately simple terms and get answers back in terms that I will understand.

Any offers?

For the curious, my current worry is the "prevalence of matter over anti-matter in the universe". My question being, how is it known that, for example, the Virgo cluster is made of matter and not anti-matter? I'd expect anti-Hydrogen to fuse to form anti-Helium and emit "photons" in the same way as matter Hydrogen? etc., etc., I can't see an obvious way of determining at huge distance, the charge on the subatomic particles comprising the observed objects?

Indeed, a slight prevalence of anti-matter, which may have anti mass and feel gravity as a repulsive force, may explain the cosmological constant.