The article opens by acknowledging the widespread fascination with time travel in science fiction and raises the question of whether it could be a reality.
It discusses the unresolved scientific question of whether time is reversible, referencing the second law of thermodynamics, which suggests that the universe tends to move towards disorder and that time flows in one direction, much like a one-way street.
The concept of time relativity, as introduced by physicist Albert Einstein’s theory of special relativity, is explained. It describes how time passes at different rates for individuals in different frames of reference. The example of astronauts in orbit experiencing slower time compared to people on Earth is given, with the intriguing case of astronaut Scott Kelly aging slightly less than his twin brother, Mark Kelly.
The article introduces the theoretical concept of wormholes, which could potentially enable time travel by creating shortcuts through the universe. It explores the idea that traveling through a wormhole at near-light speed could result in time dilation, allowing someone to exit in their past. However, it emphasizes that wormholes remain theoretical and sending humans through them would be a significant challenge.
Paradoxes associated with time travel, such as the “grandfather paradox,” are mentioned, adding complexity to the idea. The article shares physicist Stephen Hawking’s humorous experiment involving invitations to a time-travel-themed dinner party, which received no responses.
Astrophysicists’ unique form of time travel through powerful telescopes is highlighted. By observing distant galaxies and stars, they effectively look into the past, as light takes time to travel. This phenomenon allows them to study the cosmos as it existed millions to billions of years ago.
The James Webb Space Telescope, NASA’s newest space observatory, is mentioned as an example of a telescope that can peer back in time by observing galaxies formed during the Big Bang.
The article concludes by noting that while time travel remains a popular concept in books, movies, and dreams, scientists continue to explore new ideas and theories, but practical time travel as depicted in fiction remains a distant possibility.