Who among us has never dreamed of time travel? Who among us has never thought of changing the course of events, of correcting their course or meeting their ancestors? Of course, to do so would carry a terrible risk – by traveling through time, one could easily change the future in ways we cannot imagine. Perhaps you’ve heard of a scientific metaphor called the Butterfly Effect? The dictum comes from Edward Lorenz, who in 1972 famously wondered: “Can a butterfly beating its wings in Brazil cause a hurricane in Texas?” This is a way of explaining the idea that even a tiny modification to an initial set of conditions can lead to unpredictable results. So, if you decide to climb into a DeLorean you might be putting the entire future in peril. When you come back, what state might you find the world in?
Everyone knows the famous DeLorean from Back to the Future – the car that could achieve time travel by hitting a speed of 88mph. Though certainly entertaining, the science behind the DeLorean is a little wonky. In fact, according to the principle of General Relativity, in order to journey through time one would need to travel at the speed of light, i.e. 300,000 km per second. At light speed, time slows down, but even the tiniest particle in the universe is incapable of traveling at this speed. So how can a body with significant mass travel through time? To do so would require immeasurable, infinite amounts of energy. Let’s imagine that humans had managed to develop an extremely powerful energy source – all you would need to do is take off from earth and then travel at light speed for a few days before returning to terra firma. To your initial delight, you would find yourself living several years in the future. Still, such an adventure would likely fail to live up to our expectations of time travel: we would be ‘coming back’ to a world in which our loved ones had learned to live without us, and we were forgotten. We would no longer be familiar with the technology around us. We would learn that some of those we knew had died, and some had been born, and we would be absent from all the events of those few years that had gone by without us. Such a voyage through time would undoubtedly be a one-way ticket to sorrow.
To travel into the past, as the DeLorean does, the methods required would be even more complex. Have you ever heard of a wormhole? It’s a sort of tunnel that crosses space-time. But the wormhole is only a theory in quantum mechanics, and has never yet been observed. Try to go through one in a DeLorean and you’ll face a slight obstacle: a wormhole has an extremely limited lifespan, lasting only a few seconds. Making matters worse, if you want to expand the hole in order to fit your car through it, the hole will collapse in on itself like a burst balloon.
So you see, you’re unlikely to be shaking your great-grand-parent’s hand any time soon – fortunately, the worlds of cinema, literature and our own imaginations afford us all the time travel that’s good for us.
Alan Alfredo Geday
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