What’s Ziggy got to say about it, Al?
If you’re a fan of time travel stories, well, for the first time ever, you’ve got a real one. Well… sort of.
A team of quantum physicists were able to undo the aging of a single simulated particle by one-millionth of a second. This was accomplished due to the use of an IBM quantum computer, and a computer algorithm they wrote for it. But, it essentially demonstrates how hard it is to put the genie back in the bottle, so to speak. More importantly, how unlikely it is for such a thing to occur naturally. An example they used was the scrambling of an egg:
We demonstrate that time-reversing even ONE quantum particle is an unsurmountable task for nature alone.
The system comprising two particles is even more irreversible, let alone the eggs — comprising billions of particles — we break to prepare an omelet.
Valerii M. Vinokur, of Argonne National Laboratory
Functionally, knowing everything you’d need to to reverse such a process is impossible. You would have to know everything about the wave that particle is riding on to even hope to do so. And there are far more ways of getting it wrong than right.
Dr. Vinokur uses another metaphor to illustrate; this time, hitting a billiard ball and returning it to its original location:
Because of the uncertainty principle, the quantum ball will never return back to the point of the origin.
Valerii M. Vinokur
That doesn’t even bring into it how much more energy it would take to actually reverse such a thing, while it was in motion.
But, thanks to quantum computing, the team was able to make a simulated particle, for lack of a better way of saying it, go back in time.
The quantum computer they used to do this is, neatly enough, available online to the public. That said, it’s not the cutting edge when it comes to quantum computers; It has a total of 5 qubits, while computers with up to 20 exist. There’s even Google’s 72 qubit “Bristlecone” computer.
The experiment was far more simple than the amount of jargon you’d need to know to understand it. They lined qubits up in an artificial atom, they were, as stated, entangled by “spooky action at a distance“. Which meant that whenever something happened to one qubit, it affected the measurements of the others.
They then hit them with microwave radio pulses, causing all of them to go from a simple to a complex state. After one-millionth of a second, they turned this “evolution program” off, then hit them with another pullse to prepare them for the trip back. Finally, they turned the evolution program back on, which reverted them to their original alignment, effectively de-aging them by a millionth of a second.
In graphic language, we convert spreading rings in the pond into the rings that are ready to go back to their origin.
Valerii M. Vinokur
The algorithm had about an 85% success rate with two qubits, but that dropped to around 50% with three. Mostly, that seems to be chalked up to errors with current quantum computing. That said, the team’s algorithm is, itself, proven. which means that as quantum computing moves forward, their test will be easier to test on new machines.
It does, however, leave Dr. Sam Beckett stuck somewhere in the past, possibly as a space chimp.
Source: The New York Times