(The Conversation is an independent and nonprofit source of news, analysis and commentary from academic experts.)
Will it ever be possible for time travel to occur? – Alana C., age 12, Queens, New York
Have you ever dreamed of traveling through time, like characters do in science fiction movies? For centuries, the concept of time travel has captivated people’s imaginations. Time travel is the concept of moving between different points in time, just like you move between different places. In movies, you might have seen characters using special machines, magical devices or even hopping into a futuristic car to travel backward or forward in time.
But is this just a fun idea for movies, or could it really happen?
The question of whether time is reversible remains one of the biggest unresolved questions in science. If the universe follows the laws of thermodynamics, it may not be possible. The second law of thermodynamics states that things in the universe can either remain the same or become more disordered over time.
It’s a bit like saying you can’t unscramble eggs once they’ve been cooked. According to this law, the universe can never go back exactly to how it was before. Time can only go forward, like a...