"What if time is not as fixed as we thought?" That's the question raised in an announcement from the University of Surrey.

"Imagine that instead of flowing in one direction — from past to future — time could flow forward or backward due to processes taking place at the quantum level."

This is the thought-provoking discovery made by researchers at the University of Surrey, as a new study reveals that opposing arrows of time can theoretically emerge from certain quantum systems. For centuries, scientists have puzzled over the arrow of time — the idea that time flows irreversibly from past to future. While this seems obvious in our experienced reality, the underlying laws of physics do not inherently favour a single direction. Whether time moves forward or backwards, the equations remain the same....

This discovery provided a mathematical foundation for the idea that time-reversal symmetry still holds in open quantum systems — suggesting that time's arrow may not be as fixed as we experience it... The research offers a fresh perspective on one of the biggest mysteries in physics. Understanding the true nature of time could have profound implications for quantum mechanics, cosmology and beyond.
The university's announcement includes this quote from co-author Thomas Guff, a research fellow in quantum thermodynamics.

"The surprising part of this project was that even after making the standard simplifying assumption to our equations describing open quantum systems, the equations still behaved the same way whether the system was moving forwards or backwards in time. When we carefully worked through the maths, we found this behaviour had to be the case because a key part of the equation, the 'memory kernel,' is symmetrical in time."

And their research reminds readers that "the fundamental laws of physics in both the classical and the quantum realms do not manifest any intrinsic arrow of time. Newton's equations are time-reversal symmetric, as well as Schrödinger's equation. As a consequence, backward-in-time motion is equally possible as forward-in-time motion... Our findings are consistent with the second law of thermodynamics and emphasise the distinction between the concepts of irreversibility and time-reversal symmetry."

[ Read more of this story ]( https://science.slashdot.org/story/25/02/16/1850213/time-flows-forward-or-backward-at-quantum-levels-researchers-suggest?utm_source=atom1.0moreanon&utm_medium=feed ) at Slashdot.