Making the computations type-level correct would be really neat! That'd be a huge improvement! I don't think the language needs to be statically-typed to do th

Making the computations type-level correct would be really neat! That'd be a huge improvement! I don't think the language needs to be statically-typed to do that. I could easily extend Scheme or Python to support that. All you need to do is make sure that if you add 5 meters to 5 seconds, you raise an exception. There's no reason that exception has to happen at compile-time. Going Scheme -> typed Scheme is a manageable step which I could envision taking a few weeks of hard work. Changing languages would be an incredible amount of work (especially with things like the JIT compiling MIT-Scheme does for SICM, where you can symbolically derive equations of motion, compile them, and run them as high-performance native code). I've been using programming to teach kids math and physics, and the lack of units IS a serious pedagogical problem. I think that's doubly true here. I think you're really onto something.