Breathless hype and misleading clickbait headlines have, whether we like it or not, become the bread-and-butter of internet news publishers. The trend to chase clicks and traffic has turned the internet into an echo chamber of fantastic claims that often bounce from one publication to another, with nary a moment for critical reflection or scrutiny of the wild and oftentimes wildly inaccurate claims contained in “news” stories.
Case in point: The scientists who turned back time with a quantum computer—or so we were told.
All day Wednesday, mainstream media publications like Newsweek, Discover, CNN, and The Independent, among many others, chased the viral dragon with headlines conveying the fantastic notion that a team of researchers had made a quantum leap toward time travel. Cosmopolitan magazine even went so far as to run a headline claiming that Scientists just turned back time and it’s like Back To The Future is coming true–an admirable example of clickbait hype that was accompanied by the simple sub-header, “WTF.”
Even U.S. Under Secretary of Energy for Science Paul Dabbar tweeted, along with the rest of the public, that the authors of the study had begun to “figure out how to travel backwards in time.”
— Paul Dabbar (@ScienceUnderSec) March 14, 2019
According to the story–which sounds amazing in headline form but impossibly wonky for those of us without a degree in quantum physics–researchers at Moscow’s Institute of Physics and Technology managed to move a few tiny particles back a fraction of a second into the past.
As lead researcher Gorey Lesovik said:
“We have artificially created a state that evolves in a direction opposite to that of the thermodynamic arrow of time.”
Does that make any sense to you? No? Well, you’re not alone–and we bet that most of the journalists who covered the story were just as dumbfounded by the story, which derived from a report in Scientific Reports journal titled “Arrow of time and its reversal on the IBM quantum computer.” The article explores the possibility of developing protocols to “circumvent the irreversibility of time” and how to implement such protocols in practical terms.
The study also explores quantum algorithms that include “complex conjugation and thus reverses a given quantum state.” Think of a pool cue breaking a triangle of billiard balls, with the balls flying out in all directions on the table–order becomes chaos, as dictated by the second law of thermodynamics–before the balls reverse back into order.
A simple excerpt should clearly illustrate what we’re dealing with here:
“Quantum entanglement introduces the next level of complexity for the time-reversal procedure. Consider a two-particle state Ψ(x1,x2)=|Ψ(x1,x2)|eiϕ(x1,x2)Ψ(x1,x2)=|Ψ(x1,x2)|eiϕ(x1,x2) with the non-separable phase function ϕ(x1,x2)=a1(x1)b1(x2)+ϕ(x1,x2)=a1(x1)b1(x2)+a2(x1)b2(x2)a2(x1)b2(x2). In this situation even for the non-overlapping particles with Ψ(x1,x2)=0Ψ(x1,x2)=0 for x1=x2x1=x2 the two-particle state can not be reversed by an interaction with classical fields. Let one access the particles by different fields which induce separate phase shifts Ψ(x1,x2)→Ψ(x1,x2)ei(φ1(x1)+φ2(x2))Ψ(x1,x2)→Ψ(x1,x2)ei(φ1(x1)+φ2(x2)).”
Yep. Agreed. Brilliant, sure!
However, the problem with lay reporters offering coverage of advanced quantum computing to a lay audience is that things often get drastically dumbed down.
So if our researchers didn’t crack open the space-time continuum in science fiction fashion, what did actually happen?
As MIT Technology Review explained:
“Think about pressing rewind on a video. That “reverses the flow of time,” in a way. If you’ve never seen it before, it’s kind of neat. It might let you see things—like steam flowing back into a tea kettle or Humpty Dumpty spontaneously assembling from a jumble of broken pieces—that appear to “reverse the arrow of time.” The paper in question describes a quantum-computing version of such a video running in reverse.
A closer analogy is a lens, like what one would find in a telescope, a microscope, or eyeglasses. A lens can be used to focus light—“reversing” the dispersal of light that had gone out of focus. The authors of the paper, from the Moscow Institute of Physics and Technology, Argonne National Laboratory in Illinois, and ETH Zurich, say their technique might be useful for testing quantum programs. This is correct. But it’s a lot less interesting than a time machine.”
So there you have it–even the authors of the paper admit that what actually happened was a snooze-fest compared to the incredible headlines that proliferated in its wake.
Even Scott Aaronson, the director of the University of Texas at Austin’s Quantum Information Center, admitted that he was confused by the original study:
“If you’re simulating a time-reversible process on your computer, then you can ‘reverse the direction of time’ by simply reversing the direction of your simulation. From a quick look at the paper, I confess that I didn’t understand how this becomes more profound if the simulation is being done on IBM’s quantum computer.”
Another unnamed expert told Technology Review that the hype surrounding the study “is going to give quantum computing a bad name.”
With science news coverage like this, no wonder why the public thinks we can use quantum computers for human teleportation, time travel, and eternal life… 🤦♂️ https://t.co/wMaM92oOvo
— YaleQuantumInstitute (@Yale_QI) March 13, 2019
But of course, the authors of the study aren’t actually the culprits here. As is so often the case, news-writers and journalists without the time, patience or wherewithal necessary, compile a quick story in hopes of satisfying their readers as well as their editors, garnish the jargon with sensationalistic headlines and, lo and behold–the story grows wings and bounces like a pinball across the world wide web.
So no, we’re sorry, a “huge development” hasn’t opened “the gateway to further research and breakthroughs relating to time travel.” Although it sounds tantalizing, nobody is stepping into a portal and going back in time to kill Hitler or Genghis Khan any time soon–at least not yet. But you can rest assured that quantum computing is incrementally becoming refined thanks to the scientific community, regardless of whether the story bores you to tears or not.