Even if one includes hidden download-sites and special access by university subscriptions, only sources at the low or medium levels are available in a sufficient amount.
How advanced are you referring to? There are many resources at the advanced undergraduate or beginning graduate level (this is biased towards computer science and math, so maybe this is not true for the sciences):
This is a link to a freely available 4-volume set on measure theory
Here is a book on information-theoretic approaches to machine learning and inference
Here is one on statistical learning theory
To get to the research level you certainly need journal access, which, as far as I know, is pricy for an individual, hence unrealistic. Hopefully more journals switch to open acccess.
In mathematics, I would call "advanced" roughly what is above the average of "Springer Graduate Text" book series level. Of course, I do not say that one finds nothing, e.g. the Bourbaki seminar series is very good for autodidacts, or this site. It is a bit like the difference between a complex organism and the bunch of isolated cells.
If this post is inappropriate, I apologize.
I stumbled upon this site after reading "Harry Potter and the Methods of Rationality". The story so far has really moved me on multiple levels and sent me here in a quest to learn more about rationality as a philosophy/way of thinking about the world. I have read Ayn Rands published works and loved the stories and most of the message. The characters always seemed like titans that were far and above me, but now, I've seen a character that is a bit more approachable.
I've started to go through the "Map and Territory" section of the "Core Sequences" and this whole project and community makes me ecstatic. I'm currently working my way through the Bayes's Theorem article with some success. The more I read, the more I realize I may have a problem.
I'm pretty dumb.
Is higher level reasoning "use it or lose it" ? I like learning new things and love reading but any new ideas require a ton of thought and re-reading. I think I have enough interest to keep plugging away at it, but I'm not sure I'm going at things the right way. Is there a "Kid's Table" for lesswrong.com?
For "Priors": I'm 28 years old, white male, married, no children, poor economic upbringing, solid emotional upbringing, currently lower to middle class, high school diploma, US Navy, currently a civilian electronics technician, raised Baptist currently Agnostic/Atheist (recently).
I guess that's it. Thanks!
--John