Scratch

I thought so, but this is for physics of any kind...

Non-theoritical physics, or not...
and it doesn't change topics once every week.

Rather than just throw out a topic for discussion - it's a much better idea to start the conversation off with a concrete description of what you have been reading or watching that you find interesting about the topic.  This helps frame the conversation and gets it off to a good start with a strong infusion of your own enthusiasm.  It's one of the reasons the forums were named the way they are..."Things I'm Reading...etc.".  So I'll close this one up - please feel free to reframe and restart the topic with a concrete example