For this little thought experiment, a tip of the pen goes to Tomás Vargas, a young man of sixteen who likes to ask questions, to ponder, to turn thinking upside down and try it out a different way. So regular and wide-ranging are his musings, I’ll bet he won’t even remember his comment to me on how in time travel you can alter the course of history.
I don’t know when Tomás came upon that idea, but it has long been in stories, on TV, and in movies. Growing up, my brother Jim and I watched a short-lived TV show, The Time Tunnel, in about 1966-67, when we were seven and eight, the show was about time travel. I don’t remember it well, but central to the episodes was the care you have to take in traveling to the past to not change history. This is a long-established moral, in fact, it figured in the plot of Mark Twain’s A Connecticut Yankee in King Arthur’s Court, published in 1889.
But I take this notion up with the future in mind. Suppose you travel forward in time. Your actions will alter the course of things too. What does that tell us? It says that every action, at any time, matters. And our focus forward, our simulating of time travel into the future, means seeing how actions large, but also small can alter the course of things, and how we may want them to. And I believe thinking about the future, trying out ideas and scenarios about it, can alter the future too, and we should put our thinking to work in just that way. So maybe it’s dangerous to go back and alter history, but it is critical to work intently at altering the future, and your actions, large and small, matter.