Hello, I'm about to start a master's program in teaching secondary physics. Its been about 7 years (!) since I finished my undergraduate astrophysics degree (without any education courses). I'd like to write a thesis which would enable me to do a PhD in astronomy/physics down the road if I decide to (say in another 9 years). I just thought I'd post to get the gears turning, it needs to have enough of an education slant to be relevant to the master's but technical enough to lead to a PhD... My only real teaching experience is Peace Corps, where I taught teachers how to teach in an African village for 3 years. My biggest scientific interest is probably cosmic rays, but I suppose "biggest interest" and "best thesis" don't often equate. Then again, I don't even know what most people write about to be honest, I'm really starting here. Any general advice appreciated, thanks.