This website contains a lot of short and easy-to-access articles about science and technology related articles (although they are usually very lightweight, you don't need to actually be a professional to understand this). There are lots of sections on this site and I want to point to one in particular (apart from the front page). 小学堂 explains different science-related questions, such as how do scientists deduce the age of planets, where does the water on Earth come from and why is spicy food spicy?