I’m sitting here on a Monday night watching Back to the Future (Three disc set!), thinking about how I don’t tend to blog as much as I’d like. I think this is mostly because I want to generate good content, but then again, this blog is for me. So I’ll write about what I want. So what better to discuss than my favourite time paradoxes!
The Grandfather Paradox is a paradox that I think everyone has thought through as a simple thought experiment on time travel. It’s a good argument and can pretty much apply to any activity you intend to do in the past with your time traveling delorean.
Suppose a man traveled back in time and killed his biological grandfather before the latter met the traveler’s grandmother. As a result, one of the traveler’s parents (and by extension, the traveler himself) would never have been conceived. This would imply that he could not have traveled back in time after all, which in turn implies the grandfather would still be alive, and the traveler would have been conceived, allowing him to travel back in time and kill his grandfather. Thus each possibility seems to imply its own negation, a type of logical paradox.
All You Zombies
My all-time favourite paradox is one from a short story “All You Zombies” written by Robert Heinlein. I strongly urge you to read this short story, preferably before you read a summary below, although not necessary.
A baby girl is mysteriously dropped off at an orphanage in Cleveland in 1945. “Jane” grows up lonely and dejected, not knowing who her parents are, until one day in 1963 she is strangely attracted to a drifter. She falls in love with him. But just when things are finally looking up for Jane, a series of disasters strike. First, she becomes pregnant by the drifter, who then disappears. Second, during the complicated delivery, doctors find that Jane has both sets of sex organs, and to save her life, they are forced to surgically convert “her” to a “him.” Finally, a mysterious stranger kidnaps her baby from the delivery room.
Reeling from these disasters, rejected by society, scorned by fate, “he” becomes a drunkard and drifter. Not only has Jane lost her parents and her lover, but he has lost his only child as well. Years later, in 1970, he stumbles into a lonely bar, called Pop’s Place, and spills out his pathetic story to an elderly bartender. The sympathetic bartender offers the drifter the chance to avenge the stranger who left her pregnant and abandoned, on the condition that he join the “time travelers corps.” Both of them enter a time machine, and the bartender drops off the drifter in 1963. The drifter is strangely attracted to a young orphan woman, who subsequently becomes pregnant.
The bartender then goes forward 9 months, kidnaps the baby girl from the hospital, and drops off the baby in an orphanage back in 1945. Then the bartender drops off the thoroughly confused drifter in 1985, to enlist in the time travelers corps. The drifter eventually gets his life together, becomes a respected and elderly member of the time travelers corps, and then disguises himself as a bartender and has his most difficult mission: a date with destiny, meeting a certain drifter at Pop’s Place in 1970.
The question is: Who is Jane’s mother, father, grandfather, grandmother, son, daughter, granddaughter, and grandson? The girl, the drifter, and the bartender, of course, are all the same person. These paradoxes can make your head spin, especially if you try to untangle Jane’s twisted parentage. If we draw Jane’s family tree, we find that all the branches are curled inward back on themselves, as in a circle. We come to the astonishing conclusion that she is her own mother and father! She is an entire family tree unto herself.
Phantom Time Hypothesis
It proposes that there has been a systematic effort to make it appear that periods of history, specifically that of Europe during Early Middle Ages (AD 614–911) exist, when they do not. Illig believed that this was achieved through the alteration, misrepresentation and forgery of documentary and physical evidence.
Another really crazy thing to read up on when you got a minute, is the Phantom Time Hypothesis which is the idea that through some crazy number shuffling and conspiracies by the Catholic Church and other people and organizations the year is really closer to 1700 and the dark ages never really happened. Crazy stuff, but extremly interesting.
And lets not forget the Time Travel article on Wikipedia, lots of great stuff.