Sue, just a guess without more context, but I can imagine several places my DS might have found such concepts at that age, such as physics books, or some of the more conceptual science or science fiction. Has yours been reading the Stephen Hawking novels, perchance? Your DS is quite exceptional - I would imagine it wouldn't take a detailed prompt to get his brain spinning on such a concept!

Last edited by MichelleC; 01/11/15 07:22 AM. Reason: reducing pre-coffee incoherence...