No, You Don’t Want to Time Travel

What’s forgotten when imagining time travel

Douglas Giles, PhD

--

The idea of time travel has long captured the human imagination. How many times in novels, movies, and TV shows have the plots involved characters traveling back in time? What an exciting thought to be able to witness events in the past or see what will happen in the future!

Time travel has been a staple of science fiction since its modern inception with H.G. Wells’s The Time Machine. It is overused now as a plot device, but the dramatic possibilities of time travel intrigue both writers and audiences.

Physicists debate whether it is possible to travel through time. Some say it is possible. Others say it is not possible. The physicists’ conjectures are based on discussions of relativity, spacetime, the massive energy required, and whether time exists as something real outside of human perception.

These conjectures and discussions grapple with deep and meaningful issues but ignore one simple fact: time travel is a very bad idea.

Time to Think about What Really Would Happen

So, let’s say that you, being the genius you are, have solved the physics problems of traveling through time. You have invented and built a time machine and are eager to use it. Before you start your career as a chronic argonaut, you should remember one very important fact. Even if time is the fourth dimension, you cannot forget about the first three dimensions. Moving through time also means moving through space. Let me explain.

Earth’s rotation tangential speed.

The first problem with your time travel is that Earth rotates on its axis. A spot on the Earth’s equator is rotating at 1,674.4 km/h. Other locations on the planet are rotating at a slower speed, as figured out by those kids who paid attention in trigonometry class, and is indicated in the graphic to the right. If you could stand still, the Earth’s surface would be speeding past you faster than a commercial jet. That includes the location from which you start off in your time machine. So, if you launched your time machine from Cape Canaveral and set the clock for one hour in the future, you’d end up near the west coast of Mexico.

--

--

Douglas Giles, PhD

Philosopher by trade & temperament, professor for 21 years, bringing philosophy out of its ivory tower and into everyday life. https://linktr.ee/dgilesphd