Time: it's constantly running out and we never have enough of it. Some say it’s an illusion, some say it flies like an arrow. Well, this arrow of time is a big headache in physics. Why does time have a particular direction? And can such a direction be reversed?
A new study, published in Scientific Reports, is providing an important point of discussion on the subject. An international team of researchers has constructed a time-reversal program on a quantum computer, in an experiment that has huge implications for our understanding of quantum computing. Their approach also revealed something rather important: the time-reversal operation is so complex that it is extremely improbable, maybe impossible, for it to happen spontaneously in nature.
As far as laws of physics go, in many cases, there’s nothing to stop us going forward and backward in time. In certain quantum systems it is possible to create a time-reversal operation. Here, the team crafted a thought experiment based on a realistic scenario.
The evolution of a quantum system is governed by Schrödinger’s Equation, which gives us the probability of a particle being in a certain region. Another important law of quantum mechanics is the Heisenberg Uncertainty Principle, which tells us that we cannot know the exact position and momentum of a particle because everything in the universe behaves like both a particle and a wave at the same time.