HOW WOULD HERMIONE’S TIME-TURNER WORK?

Picture this: Hermione is standing at the Crucifixion. Spellbound and open-mouthed, she can’t help but stare at the scene. Perhaps the most famous in all of history. It was one of the benefits of time travel. Experiencing history unfolding firsthand. Just a few points to remember: she must do nothing to disrupt history. (Note to self: no stone throwing this time.) And when the crowd is asked who should be saved, she should join in with the call, “Give us Barabbas!” Suddenly, Hermione realizes something about the crowd. Not a single soul from 33 AD is present. The mob condemning Jesus to the cross is made up lock, stock, and smoking wand, of wizards from the future.

The entire scene is not just littered with wizards from the future. They’ve actually changed the outcome of history itself, by being present at the Crucifixion. The wizards think they know the way the story is meant to go. Rather than Jesus being set free, the crowd is meant to choose Barabbas, the bandit. But the decision only goes that way because the wizards are witness to the scene. Would Jesus have been set free instead, if they hadn’t interfered? This would be exactly the kind of chaotic paradox that explains why The Ministry of Magic placed hundreds of laws around the most common wizard means of time travel: the time turner.

Time Turners

These time travel devices resembled an hourglass on a necklace. The number of times the hourglass was turned determined the number of hours a traveler could go back in time. Typical time turners, supplied by the Ministry of Magic, had an hour-reversal charm worked into them. This hour-reversal charm, encased within the device, was for added stability, and ensured that the longest period relived, without the prospect of serious harm to the traveler, was around five hours.

There also existed a “true” time turner that allowed the traveler to visit whatever time they liked, and far beyond the five-hour boundary. But few travelers ever survived such journeys. Trials with true time turners ended in 1899, when traveler Eloise Mintumble got trapped for five days in 1402 AD. Her body aged five centuries when it returned to the present and was fatally wounded.

Hermione was given a time turner by Professor McGonagall so that she could attend more classes than the Hogwarts timetable would allow. At the end of the school year, she and Harry also used it to travel in time to save Sirius Black and Buckbeak from certain death.

The prospect of the time travel paradox is common to most forms of time travel, and not just time turners. It’s one of the reasons Professor Stephen Hawking refuses to believe such travel is possible. His argument goes something like this: “if time travel really is possible, then where are the time tourists of the future? Why aren’t they visiting us, telling us all about the joys of time travel?”

Time Travel

Tampering with time has long been a sorcerer’s dream. What if time could be mastered? What if this brutal agent, which devours beauty and life, could be tamed? The wizard world has four dimensions. Three dimensions are space; time is the fourth. There appears to be no difference between time and any of the three dimensions of space, except that our consciousness moves along it.

There have been folkloric flirtations with time, where dreamy magic is mixed with myth. And there has been the mechanized notion of time travel. Time travel devices are tied up with the concept of time itself. The ancient Greeks had two words for time, chronos and kairos. Kairos suggests a moment of time, in which something special happens. Chronos is more concerned with measured, sequential time. Natural philosophy brought a mechanistic approach to nature. Chronos came to the fore, and time travel devices were born.

Time was in the ether. It splashed upon the canvas of the Cubists. Artists such as Picasso and Braque produced paintings where various viewpoints were visible in the same plane, at the same time. All dimensions were used to give the subject a greater sense of depth. It was a revolutionary new way of looking at reality. Time was captured in cinema, and the stop-motion photography of Étienne-Jules Marey. It inspired Marcel Duchamp to paint his highly controversial Nude Descending a Staircase, which depicted time and motion by successive superimposed images. Americans were scandalized.

Spacetime was born. Einstein gave us a new perspective on the fourth dimension. Moving clocks run slow. Time is slowed down by gravity. And the speed of light is the same no matter how the observer is moving. It was a revolution in time. And it seemed to worry Salvador Dali. For many, his anxiety is palpable in his famous painting, The Persistence of Memory. The floppy clocks are history’s most graphic illustration of Einsteinian gravity distorting time.

How Time Turners Tick

How would a time turner work? One possible way is through the creation of a wormhole. Famous American science fiction writer John Campbell was the man who invented such space warps. In his 1931 story, Islands of Space, Campbell used the idea as a shortcut from one region of space to another. And in his 1934 story, The Mightiest Machine, he called this same shortcut hyperspace, another now-familiar phrase.

A year later, world-famous Nobel Prize–winning scientist, Albert Einstein, with his colleague, Nathan Rosen, came up with the science behind the invention of time travel. They worked out the scientific theory that explained the notion of bridges in space. It was much later that scientists started calling these bridges wormholes.

Imagine we create a wormhole. A wormhole is a region of space that is warped. It’s basically a shortcut in space and time through which to travel. The trouble is, though, wizard time travelers would not be able to travel back in time to a date before the wormhole was created. For example, if a wizard managed to create a wormhole on April 1, 1666, they wouldn’t be able to go back in time before 1666. So, some splendid wizard in the distant past must have conjured up a wormhole to get the whole thing going.

So, what does a wormhole look like? It’s the kind of swirly cosmic tunnel often depicted in movies when something is on a journey through space and time. A wormhole has at least two mouths, connected to a single throat. And scientists really do believe they exist. At least in theory. And, as that theory is Einstein’s, people take it seriously. Stuff may travel from one mouth to the other by passing through the wormhole. We haven’t found one yet, but the universe is immense. And we haven’t really been looking very long.