Why Time Travel is Impossible

or, What about all those atoms?

Like everyone, I love a good time travel yarn. As a boy, I immersed myself into H.G. Wells’ classic, “The Time Machine.” I recently read a novella by John Crowley, “Great Work of Time,” which was perhaps the most satisfying time travel story I’ve encountered. Paradoxes, mind bending changes, alternate time loops, what’s not to love? A beautifully written and convincingly presented story, I knew the entire time it was a fantasy which could never happen, but that didn’t take away any of the fun.

All the best philosophers and sages have pointed us in the direction of the now. The charm and fascination with traveling through time is a psychological by-product of having to deal with and live through whatever current chaos we, as human beings, find ourselves in. Wouldn’t it be nice to go back to some small-town America where things were simple, or to our unblemished ancestral lands to see how we began, or to a future where, like on Star Trek, poverty and ignorance have been eradicated from the earth, and everyone has a dedicated purpose. The notion of time travel is, at its heart, an escape wish – to inhabit a fantasy land, find a private heaven, see some historic figure you admire.

When Lao Tzu, Buddha and other sages said that the only reality is now, they meant it. They didn’t simply mean it’s best to focus your mind on the present, forget your transgressions, start fresh – they meant that the ever-present now is all that exists. Period. The past is gone, the future hasn’t happened yet. This, they were trying to tell us, is how the universe works, how its mechanism functions, and to be in accord with the universe as it actually works is the only sane way to live.

In one sense, the past and future are with us in the present now. From the Big Bang onward, we, the planet we live on, all the other galaxies and stuff of the universe are the resultant evolutionary product. Time doesn’t tick in measured bits, like our clocks. It, in fact, doesn’t truly exist. Time, as we use it, is just a measure we devised to get us to the train on time. The reality of time we live in is one eternally flowing, everchanging continuous now, which we call the present moment. This is what we, along with the rest of the universe, exist in.

Now, enough with metaphysics, you say, what about the possibilities of time travel, that physicists teasingly hint at as having a basis in science. Well, most quantum physics theories actually nix the idea. From Einstein’s blackboard, we get the possibilities that wormholes might take us through time, though we’ve never seen a wormhole. We’ve seen black holes, and they’re an alternative method, but good luck with that. You can also fly in a ship near the speed of light, come back to Earth five years later, and your twin brother, as well as the rest of the Earth, is thirty years older. Well, that’s not traveling to the future, that’s just aging more slowly, which lots of infomercials can also help you do. Since flying near the speed of light is another thing that no one’s ever tried, who’s to say moving at near light speed doesn’t age human beings in some accelerated way we don’t know about, so it all turns out the same. These are things we’ll never know.

Fortunately, we can know something with certainty about time travel. It’s impossible. In order to definitively demonstrate this, one needs only to go back to Isaac Newton, and classical physics. Or to the Greeks, to our friend, the atom.

Things are made of atoms. Everything, sentient, non-sentient, gases, liquids, solids, everything. Us. I think we all agree on that. I don’t believe there are any anti-atom people, analogous to flat earthers. How atoms form to create what we see in this diverse world is unimaginably complex and still somewhat mysterious. The number of books that have been and could be written on the subject would be countless.

What we do know is that atoms, or more accurately the particles atoms are made of, are the ultimate recyclable material. They never go away, they’re just repurposed. And we also know that things decay. They change. The London of H.G. Wells’ time is not the London of today. Some of the same pubs are there, some historic buildings – but most of it has gone through numerous changes, destructions by war, constant rebuilding and renovation, new innovations. The people are all different people. Time has changed, and during that time, those atoms have changed. Let me say that again, the atoms of H.G. Wells’ London are not doing the same things they did back then. They’ve been repurposed.

This is why time travel is impossible. In order to go back in time, in order to create again the London of H.G. Wells, every atom from that time would have to be reconfigured to recreate that London. All the buildings that have been smashed to dust. All the water in the Thames gone off to the sea. All the tea, drunk and peed. And so on. And those atoms that once made up old London are now doing something else. Imbedded in some existing new thing. In the simplest terms, say you have an antique desk that came from the London of that period – every time a time traveler went there, your desk would have to be unceremoniously whisked off to the past. How kind of time machine would be doing this, exactly? Say some atoms from that time have made their way into your body, you ate some nice Stilton made in the English countryside which are now atoms in your muscles. Well, those atoms, which were repurposed from H.G. Wells’ time, over a century, to soil to grass to cow to milk to cheese, would have to be ripped out of you in order to recreate the exact, actual, authentic, merry old London.

See? It’s what the English call a sticky wicket, which has something to do with the game of cricket and the rain. What it means here is, it’s a problem you just can’t work out. All the atoms that were doing something in the past are doing something new, thank you very much.

Reach your hand back to touch the past and what you’ll find in your hand is nothing. Not even dust. The lesson is, live here, live now, learn from the past, don’t wish you could go there. And as far as the future, if you want to know what it’ll be like, try making it better. In the precious now that we have.