Here are the abstract tools physicists have been developing to play with the very very small. Leonard and Art assume we know calculus and linear algebra so they can give us a gentle presentation of Hilbert’s Place. Bad news. You are too big and too slow to touch, smell or see anything at this place. Without intuition you may even get a bit dizzy with spins of ONE qubit (the simplest system).  Before giving up the whole thing, I started watching Leonard’s classes on youtube. Good news. Dirac’s bra-ket notation is intriguing and you may feel like playing with vector spaces that can be disturbed by a single photon. Be careful and get ready to fire those GIGANTIC neurons of yours. This is life long homework for the curious readers.