My thought process:
My first thought was, "Hey, I should do something science-y!" The problem there, though, is that "science" is way too broad. I was implying to myself that I would restrict it to natural sciences, but again, that's way too broad. There's a reason there isn't just one giant Stack Exchange site for science. Also, I'm not knowledgeable in all areas of science, so it would be kind of inefficient to write up science posts and then not cover a good chunk of science.
So my thoughts shifted to physics and astronomy, the things I know best. Actually, perhaps I should stick to astronomy. I could answer a good portion of the physics questions raised on Worldbuilding - and in world building scenarios - but those questions are (no offense) pretty basic; blog posts about physics should be in-depth and come from someone with an in-depth knowledge of physics. Also, I'll be frank: Many of the physics questions here are speculative, in part because people like speculative stuff. I think that it would be tough to write realistic posts that would still engage people.
Okay, but what specific bits about astronomy could I focus on? I can't just do post after post on various planetary systems. I already answer a lot of questions about various scenarios, and I have to say, it's getting to be a bit mundane. Again, I don't want to offend anyone, but a lot of the stuff is kind of basic and repetitive.
So what I'm thinking of is something in-depth - perhaps a masterclass-type-thing in astronomy for people trying to learn how to figure out what will realistically happen in a certain scenario. I wouldn't go over any specific topic that could be used in building a specific world, but I'd go over the principles of something - the tools and building blocks of astronomy.
- Extreme Bombardment: How to calculate and control the amount of collisions a planet will undergo, and just how much is too much for life on it.
- Hydrogen, Helium and Heat: Strange things that can happen when a planetary system wanders through a gas cloud.
- Alternative Energy: How to provide astronomical sources of heat and/or light to planets and other bodies - no stars allowed.
- How to Make a Stellar System (Without Really Trying): Galaxy collisions and the incredible things that can happen afterwards.
I would not shy away from math, and I would use calculus, if necessary, but I promise to keep it to a minimum. I would try to focus on planetary and stellar systems (and then on cool things that can influence habitability), but I'd love to branch out more - I gave some more expansive ideas already.
I could find the time to do this perhaps once every week or two. It would take some time to write up, although that depends on how long the post would be.