Physicists successfully sent a simulated particle back in time

 

The TimeMachine, a story about an inventor who creates a gadget that travels through a fourth, temporal dimension, was published by H.G. Wells in 1895. Time travel occurred in the realm of imagination before Wells' tale. To pull it off, you'd need a deity, an enchanted sleep, or a whack on the head. Time travel became popularised as a possible scientific concept after Wells.

 

Then, thanks to Einstein's equations, we entered the quantum realm, where we gained a more complex understanding of time. Kurt Gödel, a mathematical logician, deduced that Einstein's equations permitted time travel into the past. What is the issue? None of the hypothesised time travel systems were ever workable "physically."

 

Before successfully sending a simulated elementary particle back in time, scientists from the Argonne National Laboratory, the Moscow Institute of Physics and Technology, and ETH Zurich questioned, "Why keep to physical grounds?"

 

Fair warning: their results are enticing, but any time lords in training will be disappointed in the end.

 

A quantum computer mixing chamber (Photo: IBM Research/Flickr)

THE GREAT QUANTUM ESCAPE

 

Many physics laws treat the future and the past as a distinction without a distinction. The second Law of thermodynamics, on the other hand, states that a closed system will always go from order to chaos (or entropy). When you scramble an egg to produce an omelette, you've added a lot of disorder to the closed system that was the original egg.

 

This leads to one of the second law's most crucial consequences: the arrow of time. If you don't provide more energy to a process that develops entropy, such as whisking your eggs, it will become irreversible. It's why an omelette won't reform into an egg after being broken, and why billiard balls won't reform into a triangle after being broken. The entropy moves in a single direction, like an arrow, and we see the effect as time passes.

 

The second law of thermodynamics keeps us confined, but an international team of scientists sought to investigate if it could be broken in the quantum realm. They employed the next best thing: an IBM quantum computer, because such a test is unachievable in nature.

 

A bit is a basic unit of information used by traditional computers, such as the one you're reading this on. A 1 or a 0 can be used to represent any bit. A quantum computer, on the other hand, makes use of a qubit, which is a fundamental unit of information. A qubit can be both a 1 and a 0 at the same time, allowing the system to calculate and process data significantly more quickly.

 

The researchers replaced these qubits with subatomic particles in their experiment and put them through a four-step process. They then entangled the qubits, putting them in a known and ordered state where everything that happened to one would influence the others. Then they utilised a quantum computer to run an evolution algorithm that used microwave radio pulses to break down the initial order into a more complicated state.

 

The third phase involves modifying the quantum computer with a specific algorithm that allows disorder to become more orderly. The qubits are hit by a microwave pulse once more, but this time they revert to their previous, ordered state. To put it another way, they are de-aged by a millionth of a second.

 

This is the equivalent of pushing against the ripples in a pond to return them to their source, according to research author Valerii M. Vinokur of the Argonne National Laboratory.

 

Because quantum mechanics is about probability rather than certainty, success was not a foregone conclusion. In a two-qubit quantum computer, however, the method was able to jump in time 85 percent of the time. When the number of qubits was increased to three, the success rate dropped to around 50%, which the authors attributed to flaws in contemporary quantum computers.

 

The researchers published their results recently in Scientific Reports.

 

IS NON-SIMULATED TIME TRAVEL POSSIBLE?

 

Einstein's equations may not prohibit the concept of time travel, as Kurt Gödel demonstrated, but they do erect an impossibly high barrier to overcome.

 

Michio Kaku, points out that these equations allow for a wide range of time travel scenarios. Gödel discovered that if the universe rotated at a rapid enough rate, someone may arrive at a location before leaving. Traveling around two colliding cosmic strings, through a spinning black hole, or stretching space via negative matter could all lead to time travel.

 

All of them are mathematically correct, but as Kaku points out, they cannot be produced using known physical means. In the same way, the power to shove physical particles back in time is still out of grasp. For all intents and purposes, time travel remains science fiction.

 

However, time travel in our computers may one day become commonplace, making us all time lords (in a narrow sense).