So, there's this book called "God's Debris" - it's a "Socratic dialogue between a package delivery person and an old man in a comfy chair", full of little mind-#&*$s about space and time. Bonus: it's a curt 144 pages (haven't read it yet, but it looks awesome)
Also, if you're looking for something a little more story-ish, and theoretical math / computer science is close enough to your fancies, I recently read this really cool book, "A Madman Dreams of Turing Machines" - it's a sort of dramatized side-by-side biography of Alan Turing and Kurt Godel, who are pretty much my favorite thinkers of the 20th century. Really well researched, their ideas are made really approachable and interesting, and it's very human, considering the subject matter (240 fairly small pages of fairly big print)
Also, if you're looking for something a little more story-ish, and theoretical math / computer science is close enough to your fancies, I recently read this really cool book, "A Madman Dreams of Turing Machines" - it's a sort of dramatized side-by-side biography of Alan Turing and Kurt Godel, who are pretty much my favorite thinkers of the 20th century. Really well researched, their ideas are made really approachable and interesting, and it's very human, considering the subject matter (240 fairly small pages of fairly big print)