Of Tea Leaves and Time Turners

Book 3 is my favorite in the Harry Potter series, so I was excited to re-read it this weekend. One thing that jumped out at me in the early part of the book is the trepidation and excitement of new classes. It’s been a while since I have taken a new class as a student, however over the years I’ve had the opportunity to teach new classes or revamp old ones in very different ways that the class feels new. At this point I have now taught 12-15 different courses or “preps” as a college professor and I’m looking forward to more!

The first new class Harry takes in his third year is Divination. Interestingly Professor Trelawney starts her class in the same way that Snape started his Potions class, i.e., with an admonishment. “So you have chosen to study Divination, the most difficult of all magical arts. I must warn you at the outset that if you do not have the Sight, there is very little I will be able to teach you.” This sounds like one of those dreaded weed-out classes common in the sciences, and my field of chemistry might be the guiltiest of the lot. Some years I have actually started my Quantum Physical Chemistry course by telling the students that this would probably be the hardest class they would take as a Chemistry or Biochemistry major. However I hasten to add that as they persevere through the course, they will discover and learn things at the heart of chemistry that will excite them. I also encourage them to come prepared for class and to visit my office early and often to get help on the (dreaded) problem sets.

Having pondered the subject of memory in Book 2, it is interesting to consider Divination, in terms of reading the future, as the opposite of memory. Why is it we remember things past but the future seems veiled? Why is the Arrow of Time unidirectional? There is an argument that makes use of probability, entropy and equilibrium in closed systems but that somehow feels unsatisfactory when pondering the deep mysteries of time. Now in the case of Trelawney and perhaps many a modern day seer who claims to read the future, common sense guesswork and broad strokes may be all that is needed. Human beings are narrators. We are particularly good at building and weaving stories to make sense of the events in our lives. A broad reading of the tea leaves or fortune cookies provides lots of room to play with when constructing a narrative. Maybe in a future post I will analyze more closely each of Trelawney’s pronouncements.

Of course one could accurately predict the future if one has already experienced it. The crux of the Prisoner of Azkaban narrative is the use of the Time Turner allowing Harry and Hermione to “know what will happen”, albeit at a different vantage point and with some amount of confusion on Harry’s part. Time travel, time loops, time paradoxes – these are all staples of sci-fi and have featured in many recent blockbuster movies (Interstellar, Edge of Tomorrow, X-Men: Days of Future Past, Men in Black 3, Looper, to name a few). As a part-time quantum mechanic, I have enjoyed reading, thinking, and speculating over the physics and metaphysics of the matter (or matter for that matter – pun intended).

However, let me ask a different question instead. Would you really want to know your personal future? When I was younger, I certainly did. But now I’m not so sure, and I think living life fully (one might say magically) is to experience it in the moment. It might be much blander and less interesting to go through life knowing what was going to happen especially if you had no power to change it. Not to mention, if the ending is “bad”, there is no hope. (It’s unclear if good and bad would exist the same way in a completely predictable choiceless life.) But even if time travel is possible, could you change your past or future? What would the limitations be?

Let’s ignore the brain-burning paradoxes for a moment and speculate on something simpler. If you had a time turner what would you use it for? Save the world? Or figure out ahead what will be on the next chemistry test?

A funny graphic I found browsing the web some time ago says it all.

P.S. Surprising tidbit I noticed in Book 3: In Potions class, when the shrinking solution is tested on Trevor (Neville's toad), he is turned into a tadpole. Trevor went back in time so to speak, instead of just getting physically smaller. Seems like a theme to me.