An old "dilettante" of mathematical logic , philosophy of science and history of science.
Mathematics
Q&A for people studying math at any level and professionals in related fields
Philosophy
Q&A for those interested in the study of the fundamental nature of knowledge, reality, and existence
History of Science and Mathematics
Q&A for people interested in the history and origins of science and mathematics
MathOverflow
Q&A for professional mathematicians
Area 51
Q&A for proposing new sites in the Stack Exchange network
English Language & Usage
Q&A for linguists, etymologists, and serious English language enthusiasts
Mathematics Educators
Q&A for those involved in the field of teaching mathematics
Meta Stack Exchange
Q&A for meta-discussion of the Stack Exchange family of Q&A websites
Academia
Q&A for academics and those enrolled in higher education
Computer Science
Q&A for students, researchers and practitioners of computer science
Latin Language
Q&A for linguists, teachers, and students wanting to discuss the finer points of the Latin language
Writing
Q&A for the craft of professional writing, including fiction, non-fiction, technical, scholarly, and commercial writing
Project Management
Q&A for project managers
Physics
Q&A for active researchers, academics and students of physics
Engineering
Q&A for professionals and students of engineering
Christianity
Q&A for committed Christians, experts in Christianity and those interested in learning more
Literature
Q&A for scholars and enthusiasts of literature
Politics
Q&A for people interested in governments, policies, and political processes
Hinduism
Q&A for followers of the Hindu religion and those interested in learning more about Hinduism
Stack Overflow
Q&A for professional and enthusiast programmers
Proof Assistants
Q&A for mathematicians and computer scientists who develop and use proof assistants