Today’s Wonder of the Day was inspired by kyra from AL. kyra Wonders, “Is time travel possible?” Thanks for WONDERing with us, kyra!

From classic books like A Wrinkle in Time and Time and Again to classic movies like The Time Machine and Back to the Future, children and adults alike have been fascinated by the concept of time travel for hundreds of years. But is it even possible? If it were, where — or when? — would you go?

The concept of time travel sounds simple: you just move back and forth between different points in time like you would between different points in space. You could jump forward into the future, or you could jump back to sometime in the past.

Exactly how would this be done? Most artistic works that feature time travel accomplish it with the help of a special device usually called a time machine. The time machine features whatever technology has been developed to transport people successfully to other points in time.

But is time travel merely the stuff of science fiction? Or could it really happen? Some scientists believe that parts of Albert Einstein's theories of special and general relativity might allow for the possibility of time travel.

These theories are complex and very hard to understand. They involve exotic astronomical things like black holes and wormholes. Traveling faster than the speed of light might also be required!

To date, there are only theories and ideas…and hopes and dreams. Modern technology, as great and advanced as it is, has not yet begun to approach the level of sophistication that would allow humans to defy the laws of physics and travel through time.

It doesn't hurt, though, to think about what the ability to time travel might mean. Would you go forward to the future or back to the past? Would you rather see what things are going to be like or how things were long ago?

It can also be fun to think about what problems might be presented by time travel. Some scientists and philosophers are quick to point out that traveling backwards in time to the past creates the potential for paradoxes.

A paradox is a situation which appears absurd or self-contradictory. For example, let's say that you travel back in time to the day your parents met. Some people believe your very presence in the past could alter events.

What if your presence in the past did alter events? What if your showing up on the day your parents met caused a ripple in time that led to them not meeting? If they never met, you were never born. If you were never born, how could you ever exist to travel back in time to cause the problem you just caused?

If that doesn't twist your brain in knots, we're not sure what will! As confusing as it sounds, we hope that any scientist who ever manages to make time travel possible works out these paradoxes in advance!

Wonder What's Next?

Learn about an island that’s anything but deserted in tomorrow’s Wonder of the Day!