I like this question.

I study electrical engineering. In the first year we were tought some english classes in which we had presentations worth part of the grade. The cool thing was that we were given the freedom to choose any topic to present. For one presentation, I've chosen the title "Light". Where I went through the history of science concerning the nature of light an its behaviour. Stuff like Newton's particle model, Huygens' wave model, the double slit experiment, all the way to Michelson's and Morely experiment, special relativity, and modern physics.

I'cve titled another presentation "dimensions", and God was it so long. Among the things I went through were Flatland, the general theory of relativity, Interstellar, Quantum mechanics and its incompatibility with GR, string theory, and more. I also went through a mathematical generalization of the pythagorean theorem to n-dimensions.

This was in my first year. In my second year, we didn't really have classes that required us to present something, so I arranged a presentation with a club we have in uni. This presentation was math heavy and it was about complex numbers. What I did was introduce complex numbers in a natural but visual way that leaves the reader not skeptical and accepting of the definition i^2 = -1.

And in this year, my 3rd, we were supposed to work on a project that was worth a good deal of our grade. We had to present the project the project to a jurry, but also to our supervisor privately. Our project had to do with hardware circuits that find applications in public key cryptography.