Time Travel

Is Time Travel Possible According to Physics?

The concept of time travel has been a popular theme in science fiction, from Doctor Who to Back to the Future. To celebrate the 60th anniversary of Doctor Who, let’s explore the scientific underpinnings of time travel. The burning question: Is it possible to journey into the past or the future?

In the realm of Doctor Who, the Tardis effortlessly travels through time and space, challenging our understanding of physics. However, in reality, building a time machine and venturing into the distant past or future involves grasping the complex nature of time itself — a challenge physicists are still deciphering.

Albert Einstein’s theories of relativity shed light on the fluidity of time. Time isn’t a constant flow; it can speed up or slow down depending on various factors. For instance, as you approach the speed of light, time dilation occurs, a phenomenon verified by the twin paradox. This means time travel to the future is theoretically achievable by traveling at extreme speeds or experiencing intense gravitational fields.

In contrast, journeying backward in time presents more significant hurdles. Theoretically, space-time could fold, creating a closed time-like curve, but the feasibility of this remains uncertain. Wormholes, another theoretical concept, could serve as shortcuts through space-time. However, their existence and practicality are still unproven.

Quantum mechanics, exploring the subatomic realm, introduces the concept of non-locality. Events in one location can instantaneously affect entangled particles elsewhere, challenging our understanding of time. Some interpretations suggest a form of retrocausality, where events in the future influence the past.

However, these quantum phenomena, while intriguing, do not provide a practical means for human time travel. Scaling up these effects to a human level presents immense challenges and ethical dilemmas.

In conclusion, our current understanding of physics allows for potential travel into the future, but the complexities surrounding backward time travel remain elusive. The incongruities between relativity and quantum mechanics suggest that a unified theory is needed to unravel the mysteries of time travel. Until then, the journey through time remains a thought-provoking concept, reminding us that, in the time it took to read this article, you’ve already traveled a few minutes into the future.

If the mysteries of time travel fascinate you, share this article with fellow time travel science fiction enthusiasts! Explore the boundaries of science and imagination together. Thank you!

Source: BBC · by Michael Marshall · November 12, 2023

Brenda Neece, DPhil (Oxon), is a cellist, organologist, writer, and teacher specializing in the history of the cello.