>>11576966I have a PhD in theoretical physics. I'm doing a post-doc now.
Martin Bojowald has a nice popular science book: Once before time. It's not cringy like a lot of other popsci books, and has a broad overview of string theory and lqg.
For getting a picture of the landscape of quantum gravity theories this arxiv paper is very useful: 1708.07445
Carlo Rovelli also has a nice series of lectures on youtube that are easy to follow. Just search Carlo Rovelli lecture and the playlist is the first result.
Abhay Ashtekar has a nice intro on the arxiv: 1201.4598
I don't know much about string theory besides what I've heard in seminars and read on the internet. If you ever want to learn something though, just go on the arxiv and search Introduction to... and you'll usually get something palatable. Also paperscape is a good way to efficiently explore the arxiv because it shows you directly which papers got the most citations.
