The prospect of revisiting the past or jumping to the future has captured people's imaginations for centuries. Our contemporary understanding of time travel is a marriage of theoretical physics and science fiction.
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While the author discounts the possibility of traveling to the past, it lays out five hypothetical modes of catapulting into the future: speed, gravity, suspended animation, wormholes, and light. Each has some scientific basis, but none are realistic for humans. Read the article to learn where they offer promise and where they fall short.
In 2009, Hawking hosted a reception but only sent out invitations afterward, hoping that time travelers from the future would attend and prove time travel possible. He later joked it was "experimental evidence" that time travel doesn’t exist.
When you look up at a constellation with your naked eye, you’re looking thousands of years into the past. The stars are so far away that it takes their light that long to reach us. Today’s most powerful telescopes, such as the James Webb Space Telescope, can see billions of years into the past. So, as this article suggests, looking through a telescope (or even up at the stars with your own eye) could be considered a form of time travel.
If you went back in time and killed your grandfather when he was a child, what would happen to you? One of your parents would never be born, so you wouldn’t be born either. But, if you’re never born, how could you kill your grandfather in the first place? This so-called grandfather paradox is something physicists, philosophers and sci-fi writers constantly ponder. Read the piece to learn how they’ve been trying to reconcile it.
Time travel has fascinated humans for centuries. It appears in myths, literature, and science fiction. One of the earliest examples comes from the 400 BCE Hindu epic Mahabharata, describing time dilation long before Einstein’s Theory of Relativity. By the 19th century, stories introduced machines enabling time travel—setting the stage for modern sci-fi.
This 8-minute video explores how time travel influences the narrative arc of several movies, books and video games, from Harry Potter to A Christmas Carol. (Warning: it contains spoilers!) J.K. Rowling and Charles Dickens set myriad parameters as they’re worldbuilding to avoid paradoxes and create quasi-logical timelines. By drawing diagrams as he’s speaking, the video breaks down how time works in some of popular culture’s most beloved fictional universes.
These hypothetical distortions in the fabric of spacetime may connect vast distances across or even between universes. While science fiction often portrays them as traversable tunnels, the energy and matter required to keep a wormhole open defy current physical understanding.
Take a step back with this 5-minute video that raises questions about the very existence of time. Does it physically exist, or is it just in our heads? Einstein’s theories of relativity, which explain the behavior of large objects, assert that time is a fundamental property of the universe. But, as physicists try to develop a Theory of Everything that explains the behavior of large and small things, they’ve begun to ponder if time might just be an illusion.
Humans have been captivated by the prospect of leaping forward and backward in time for thousands of years. Georgia Institute of Technology Science Fiction Studies Professor Lisa Yaszek recounts how the concept has been utilized by storytellers from 400 BCE to modern-day to explore our relationship with the supernatural, technology, and the past. In a way, this historical recounting is a journey through time.
The grandfather paradox doesn’t exist, according to research out of the University of Queensland in Brisbane, Australia in 2020. They ran some models to determine that, if one traveled back in time and made changes to the past, those changes couldn’t dramatically alter the present. The original outcome that propelled the time traveler to visit the past would still find a way to happen. If true, would this make time travel less intriguing? Less scary and more attractive?