Those are exceptional. I remember gaining really nice math and physics intuition from his "applets" years ago. Yes, those started as Java applets if anyone stil

Those are exceptional. I remember gaining really nice math and physics intuition from his "applets" years ago. Yes, those started as Java applets if anyone still remembers those. Here are math and physics ones: https://falstad.com/mathphysics.html https://falstad.com/mathphysics.html I like the 2D vector field one https://falstad.com/vector https://falstad.com/vector (2d) and the 3d one https://falstad.com/vector3d https://falstad.com/vector3d. Antenna simulator: https://falstad.com/antenna https://falstad.com/antenna Waveguide is awesome too https://falstad.com/embox/guide.html https://falstad.com/embox/guide.html. Don't forget to pick various modes in the little square at the bottom. If Paul Falstad comes around these parts, thank you for creating and sharing those!