Researchers have discovered how to rewind time in massive scientific breakthrough

A massive breakthrough in quantum mechanics has been made. Researchers in Austria have discovered how to reverse the flow of time for a single particle within a quantum system, effectively bending the laws of physics.

Does this mean we’re anywhere close to sending people back to the age of dinosaurs? No. We’re a long ways away, and a diagram created by scientists conducting the experiment at the Austrian Academy of Sciences shows that the flow of time in the normal world is very difficult to break even though it’s theoretically possible.

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That said, within the realm of quantum mechanics working at a subatomic level, the laws of the universe change. A lot more is possible when you get that small.

And, by building what’s called a quantum switch in order to create a controlled environment for photons within a system, scientists have managed to figure out how to return a particle to where it came from without having to observe it.

Scientists discover how to rewind time for one particle

So, why in the world would you want to rewind time for a single particle? What does this actually mean, and why is it important?

The key to quantum computing and why it has the potential to be so much more powerful than normal computers is the power of a quantum superposition.

Normal computers have binary bits, with every process being driven by either a 1 or a 0. Even the most powerful computers are still, at their core, based on a binary input/output system.

Meanwhile, quantum computing utilizes the concept of qubits, adding a third possibility to the system: A superposition. A bit can be a 1, a 0, or both at the same time. Adding that third possibility creates the potential for supercomputers that dwarf what’s currently possible in the realm of standard computing.

If you’re still a little lost, a superposition is the idea that the hypothetical of Schrodinger’s Cat is built upon. The cat being alive or dead is 1 or 0, but the possibility of it being either or is the superposition. Recent breakthroughs there allow for quantum systems to operate at a much higher temperature than previously thought, referred to as a “hot state”, bringing it closer to real world application.

So, what these researchers in Austria discovered was how to rewind time for a particle back to where it was without having to find the position of that particle within the quantum system.

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A diagram of the setup scientists made to prove their theory about reversing time.

This allows it to maintain that superposition of being a 0 and a 1 at the same time, theoretically making it possible mistake to be undone without having to ruin the superposition by pinpointing the location of that particle.

Researchers also discovered this concept of “rewind protocol” can be used to play with and manipulate time as a concept, fast forwarding time by several years or rewinding it at will.

This is done by interfering with the possible timelines of the particle and manipulating its path based on all possible directions in which the photon could bounce. In other words, they merge every possible timeline into the outcome they want regardless of which path the photon takes.

“We have demonstrated a universal time-rewinding protocol for two-level quantum systems. Unlike previously proposed protocols, ours can reach an arbitrarily high probability of success and is asymptotically optimal in the time required to perform the rewinding, answering the question of whether or not such processes are permitted by the laws of quantum mechanics,” the research paper explains.

“We emphasize that our results are in principle not restricted to photonic quantum systems, since the concepts used do not make any assumptions about the physical system the protocol is applied to.”

In other words, this effect could theoretically be replicated in the real world, though we’re a very, very, very long way away from it. The paper says “implementations utilizing massive particles would still likely prove challenging,” meaning that you won’t be able to teleport to the grocery store or go see the dinosaurs any time soon.

However, this gets humanity one step closer to time travel. Researcher Miguel Navascués even believes that it’d be “theoretically possible” to rewind someone in time even if very unlikely, a concept explained in an article from The Brighter Side of News that also has more information about this discovery.

It’s more meant for quantum computing and error correction within a closed system, but the concept itself has so many possibilities if it can reach larger scale application.