I know there are some CS people here (Pallas I think is one). Anyway, one thing I've been interested in doing this year to teach gravity is having students develop a simulator to model gravitational interactions between two bodies. One of the NGSS standards is developing computational models for this purpose, but I've been able to find precious few resources for teaching 9th graders how to program a simulation using a simple programming language for this purpose. The stuff I was able to find looked way too advanced and tricky for students to use, especially for the level of understanding that they're going to be learning at. I'm wondering if there are any resources you CS people might know, or some tips on how to get started? I'm thinking the best language for them to use might by Python as it's fairly simple and powerful. (trying to get away from the code blocks) But I also have very little understanding on how to take it from there to something the kids can work with and use.