hi, I went to a lecture last january where it was mentioned that physicists don't work much on LQG and why it's such a dead end but m- theory isn't. Could someone explain this? Also, can someone give me references to explain why the problems of LQG are so serious and so why the above is true but m-theorys serious problems don't make it a dead end? I think it is safe to assume the above would not be thought for no good reason, I just couldn't understand the lecture. Also, is it better to start for m-theory with green schwartz witten or polchinski and what mininmum knowledge do I need? Also, is there an introduction or paper on line? Thanks.