There’s an entire web site devoted to scientific speculation and associated SCI-FI stories about the future of space colonization called the Orion’s Arm Universe Project.
Terabytes of speculative data in thousands of pages and graphics...
Oh, thanks for that! I’m going over there right now to check it out.
His videos are about 30 minutes long. He is very thorough and discusses pretty much every angle imaginable on each subject he addresses. The only downside is that he plows through all of the information in a stream-of-consciousness method with no breaks. You really have to concentrate to take in everything he says.
Also, the production values are great as he is very popular and has some cool artists generating great video. So it's not just some nerd staring into a camera.