Meditações - o tempo não vai existir para sempre

Lido aqui:

Physics has a decades old equation that describes the entire universe with one glaring omission, it has no variable for time at all. A new theoretical study from Brazilian physicist Anderson Gama Fernandes de Freitas at the Universidade Federal de Itajubá adds a fresh twist to that mystery, suggesting time isn't just missing from the math by accident, it might be a feature that only exists under certain conditions, and could eventually fade out entirely.

The root of the problem traces back to 1967, when physicists John Wheeler and Bryce DeWitt tried to combine general relativity with quantum mechanics into a single equation describing the whole universe. What they got, now called the Wheeler DeWitt equation, works mathematically but strips time out completely, a puzzle physicists still call "the problem of time" nearly 60 years later. Wheeler himself, who also coined the term black hole, admitted having an equation is one thing, but actually interpreting what it means is an entirely different, ongoing challenge.

Fernandes de Freitas's new approach proposes that time doesn't function as some fixed universal backdrop, instead it emerges from the geometry and curvature of spacetime itself, essentially acting like a clock built out of the universe's own shape. That has a strange consequence: as the universe continues expanding and flattening over unimaginable timescales, that curvature weakens, and with it, this geometric clock gradually winds down. In this framework, time wouldn't get switched off abruptly, it would slowly lose operational meaning as the conditions that let it exist in the first place fade away.

This sits alongside separate, related work, including a University of Birmingham experiment earlier this year that built a tiny "mini universe" from 24,000 ultracold atoms specifically to test whether time can emerge from a system's internal changes rather than ticking forward on some external master clock. Together, these efforts represent physicists trying to actually test ideas about time that used to live purely in theoretical papers.

Source: Anderson Gama Fernandes de Freitas, Universidade Federal de Itajubá, sciandnature.com