Time has puzzled scientists for many decades. Does it meaningfully exist apart from our experience of it as everything moves toward the disintegration of entropy along its irrefutable arrow? You can’t put the “spilled milk” of the weirdness of time back in the jug.
In new research published in the American Physical Society's peer-reviewed journal Physical Review A, scientists from Italy (led by Alessandro Coppo) try to translate one theory of time into real life—or, at least, closer to it. The theory is called Page and Wootters mechanism, and Coppo has studied it for years. It’s a quantum mechanics idea that dates back to 1983.
While general relativity (in the classical physics model) lets time be a variable—like the perception-dependent difference between time on Earth and time in space in stories like Interstellar—quantum physics requires it to be nailed down. That means instead of a dependent variable (something defined by an external property, like local gravity or an object’s distance from Earth), time must be independent, and there must be some way to measure it as such.
This may seem counterintuitive. After all, quantum mechanics is considered the newer version of things—the one that destabilizes the foundation of physics in order to be reconciled with the classical model. But time has a unique role in quantum systems. After all, everything in a particular time, defined in some objective way, is knitted together through quantum interactions until it forms a capture of the entire universe (if you zoom out enough).
In their paper, Coppo and his coauthors turn the Page and Wootters approach into a real concept for a clock. Within quantum physics, a clock isn’t much like the one you wear on your wrist or hang in your office—it’s anything that has a predictable and uniform behavior that can be used as a measurement. (For example, this 2021 Quanta article lists increasingly stinky garbage as a kind of clock!)
More at https://www.popularmechanics.com/science/a61021621/is-time-just-an-illusion/
In new research published in the American Physical Society's peer-reviewed journal Physical Review A, scientists from Italy (led by Alessandro Coppo) try to translate one theory of time into real life—or, at least, closer to it. The theory is called Page and Wootters mechanism, and Coppo has studied it for years. It’s a quantum mechanics idea that dates back to 1983.
While general relativity (in the classical physics model) lets time be a variable—like the perception-dependent difference between time on Earth and time in space in stories like Interstellar—quantum physics requires it to be nailed down. That means instead of a dependent variable (something defined by an external property, like local gravity or an object’s distance from Earth), time must be independent, and there must be some way to measure it as such.
This may seem counterintuitive. After all, quantum mechanics is considered the newer version of things—the one that destabilizes the foundation of physics in order to be reconciled with the classical model. But time has a unique role in quantum systems. After all, everything in a particular time, defined in some objective way, is knitted together through quantum interactions until it forms a capture of the entire universe (if you zoom out enough).
In their paper, Coppo and his coauthors turn the Page and Wootters approach into a real concept for a clock. Within quantum physics, a clock isn’t much like the one you wear on your wrist or hang in your office—it’s anything that has a predictable and uniform behavior that can be used as a measurement. (For example, this 2021 Quanta article lists increasingly stinky garbage as a kind of clock!)
More at https://www.popularmechanics.com/science/a61021621/is-time-just-an-illusion/
