Last night I spent some time going around the house with a large hand mirror, bouncing light reflections off the walls.
Sort of practical physics.
I did do a year of physics in high school. I was fourteen, couldn't make head nor tail of it and very nearly failed. I decided it wasn't for me, and continued with Biology instead. Now I discover that that was a bad idea; you need physics to write good fantasy. As I don't have the knowledge, I turn to the wonderful Phill Berrie instead (doesn't he just look like a physicist?) - or bounce light off walls and wonder if my hero and heroine can really do the same thing without a mirror and on a very large scale. Hmm.
And wonder, too, why I had that knowledgeable teacher fellow in Book One say that you couldn't do the impossible using magic... Darn. Confounded rules of magic.
Let me play with that mirror some more.