I'm currently working on a fantasy/horror novel and hopefully some short stories set in the same shared universe, and I've joined Worldbuilding and other StackExchange sites to be able to find the answers to science-y questions and hopefully be able to add increased realism and sci-fi elements to my stories. To give the characters challenges thrown up by the way the real world works, even if they can often address these problems through magical means, and to make my universe more thoroughly grounded in this one.
Science Fiction & Fantasy
Q&A for science fiction and fantasy enthusiasts
Biology
Q&A for biology researchers, academics, and students
Astronomy
Q&A for astronomers and astrophysicists
Worldbuilding
Q&A for writers/artists using science, geography and culture to construct imaginary worlds and settings
Space Exploration
Q&A for spacecraft operators, scientists, engineers, and enthusiasts
Mythology & Folklore
Q&A for enthusiasts and scholars of mythology and folklore
Literature
Q&A for scholars and enthusiasts of literature
Role-playing Games
Q&A for gamemasters and players of tabletop, paper-and-pencil role-playing games
Retrocomputing
Q&A for vintage-computer hobbyists interested in restoring, preserving, and using the classic computer and gaming systems of yesteryear
Meta Stack Exchange
Q&A for meta-discussion of the Stack Exchange family of Q&A websites
History
Q&A for historians and history buffs
Physics
Q&A for active researchers, academics and students of physics
Geographic Information Systems
Q&A for cartographers, geographers and GIS professionals
Operations Research
Q&A for operations research and analytics professionals, educators, and students
Server Fault
Q&A for system and network administrators
Writing
Q&A for the craft of professional writing, including fiction, non-fiction, technical, scholarly, and commercial writing
Bitcoin
Q&A for Bitcoin users, developers, and enthusiasts
Anime & Manga
Q&A for anime and manga fans
The Workplace
Q&A for members of the workforce navigating the professional setting
Cryptography
Q&A for software developers, mathematicians and others interested in cryptography
Arqade
Q&A for passionate videogamers on all platforms
Chess
Q&A for serious players and enthusiasts of chess
Aviation
Q&A for aircraft pilots, mechanics, and enthusiasts
Unix & Linux
Q&A for users of Linux, FreeBSD and other Un*x-like operating systems
Super User
Q&A for computer enthusiasts and power users
Ethereum
Q&A for users of Ethereum, the decentralized application platform and smart contract enabled blockchain
Psychology & Neuroscience
Q&A for practitioners, researchers, and students in cognitive science, psychology, neuroscience, and psychiatry
Linguistics
Q&A for professional linguists and others with an interest in linguistic research and theory
Board & Card Games
Q&A for people who like playing board games, designing board games or modifying the rules of existing board games
Bricks
Q&A for LEGO® and building block enthusiasts
Stack Overflow
Q&A for professional and enthusiast programmers
Puzzling
Q&A for those who create, solve, and study puzzles