"This is one in a series of papers on the possibility of violating the second law of thermodynamics. That law is closely related to the notion of the arrow of time that posits the one-way direction of time: from the past to the future," commented the study's lead author Gordey Lesovik, who heads the Laboratory of the Physics of Quantum Information Technology at MIPT.
"We began by describing a so-called local perpetual motion machine of the second kind. Then, in December, we published a paper that discusses the violation of the second law via a device called a Maxwell's demon," Lesovik said. "The most recent paper approaches the same problem from a third angle: We have artificially created a state that evolves in a direction opposite to that of the thermodynamic arrow of time."
What makes the future different from the past
Most laws of physics make no distinction between the future and the past. For example, let an equation describe the collision and rebound of two identical billiard balls. If a close-up of that event is recorded with a camera and played in reverse, it can still be represented by the same equation. Moreover, one could not tell from the recording if it has been doctored. Both versions look plausible. It would appear that the billiard balls defy the intuitive sense of time.
However, imagine that someone has recorded a cue ball breaking the pyramid, the billiard balls scattering in all directions. One need not know the rules of the game to tell the real-life scenario from reverse playback. What makes the latter look so absurd is our intuitive understanding of the second law of thermodynamics: An isolated system either remains static or evolves toward a state of chaos rather than order.
Most other laws of physics do not prevent rolling billiard balls from assembling into a pyramid, infused tea from flowing back into the tea bag, or a volcano from "erupting" in reverse. But we do not see any of this happening, because that would require an isolated system to assume a more ordered state without any outside intervention, which runs contrary to the second law. The nature of that law has not been explained in full detail, but researchers have made great headway in understanding the basic principles behind it.
Spontaneous time reversal
Quantum physicists from MIPT decided to check if time could spontaneously reverse itself at least for an individual particle and for a tiny fraction of a second. That is, instead of colliding billiard balls, they examined a solitary electron in empty interstellar space.
"Suppose the electron is localized when we begin observing it. This means that we're pretty sure about its position in space. The laws of quantum mechanics prevent us from knowing it with absolute precision, but we can outline a small region where the electron is localized," says study co-author Andrey Lebedev from MIPT and ETH Zurich.
The physicist explains that the evolution of the electron state is governed by Schrödinger's equation. Although it makes no distinction between the future and the past, the region of space containing the electron will spread out very quickly. That is, the system tends to become more chaotic. The uncertainty of the electron's position is growing. This is analogous to the increasing disorder in a large-scale system - such as a billiard table - due to the second law of thermodynamics.
"However, Schrödinger's equation is reversible," adds Valerii Vinokur, a co-author of the paper, from the Argonne National Laboratory, U.S. "Mathematically, it means that under a certain transformation, called complex conjugation, the equation will describe a 'smeared' electron localizing back into a small region of space over the same time period." Although this phenomenon is not observed in nature, it could theoretically happen due to a random fluctuation in the cosmic microwave background permeating the universe.
The team set out to calculate the probability to observe an electron "smeared out" over a fraction of a second spontaneously localizing into its recent past. It turned out that even if one spent the entire lifetime of the universe - 13.7 billion years - observing 10 billion freshly localized electrons every second, the reverse evolution of the particle's state would only happen once. And even then, the electron would travel no more than a mere one ten-billionth of a second into the past.
Large-scale phenomena involving billiard balls, volcanoes, etc. obviously unfold on much greater timescales and feature an astounding number of electrons and other particles. This explains why we do not observe old people growing younger or an ink blot separating from the paper.
Reversing time on demand
The researchers then attempted to reverse time in a four-stage experiment. Instead of an electron, they observed the state of a quantum computer made of two and later three basic elements called superconducting qubits.
Stage 1: Order. Each qubit is initialized in the ground state, denoted as zero. This highly ordered configuration corresponds to an electron localized in a small region, or a rack of billiard balls before the break.
Stage 2: Degradation. The order is lost. Just like the electron is smeared out over an increasingly large region of space, or the rack is broken on the pool table, the state of the qubits becomes an ever more complex changing pattern of zeros and ones. This is achieved by briefly launching the evolution program on the quantum computer. Actually, a similar degradation would occur by itself due to interactions with the environment. However, the controlled program of autonomous evolution will enable the last stage of the experiment.
Stage 3: Time reversal. A special program modifies the state of the quantum computer in such a way that it would then evolve "backwards," from chaos toward order. This operation is akin to the random microwave background fluctuation in the case of the electron, but this time it is deliberately induced. An obviously far-fetched analogy for the billiards example would be someone giving the table a perfectly calculated kick.
Stage 4: Regeneration. The evolution program from the second stage is launched again. Provided that the "kick" has been delivered successfully, the program does not result in more chaos but rather rewinds the state of the qubits back into the past, the way a smeared electron would be localized or the billiard balls would retrace their trajectories in reverse playback, eventually forming a triangle.
The researchers found that in 85 percent of the cases the two-qubit quantum computer indeed returned back into the initial state. When three qubits were involved, more errors happened, resulting in a roughly 50 percent success rate. According to the authors, these errors are due to imperfections in the actual quantum computer. As more sophisticated devices are designed, the error rate is expected to drop.
Interestingly, the time reversal algorithm itself could prove useful for making quantum computers more precise. "Our algorithm could be updated and used to test programs written for quantum computers and eliminate noise and errors," Lebedev explained.The study reported in this story was conducted by researchers from MIPT (Gordey Lesovik, Andrey Lebedev, Mikhail Suslov), ETH Zurich (Andrey Lebedev), and Argonne National Laboratory, U.S. (Valerii Vinokur, Ivan Sadovskyy).
Reader Comments
The re-arrangement of the balls on the billiard table to the original state and the re-localization of the electron are due to application of external energy, a "kick" to the table and the fluctuation of the background radiation, respectively. This appears to be completely analogous to a refrigerator cooling its contents due to input of energy from an external source and in no way represents a violation of the 2nd Law.
If my conclusion in the previous paragraph is incorrect, I would welcome an explanation of why.
However, there are higher dimensions beyond this space, and in those dimensions time and distance do not exist, as you cannot measure or define time if there is no physical matter occupying physical space with which to measure time passing. Those higher dimensions may be defined for us, imprisoned in the physical, as the dimensions of thought and intention. Every action is preceded by a thought, but not every thought results in an action. Thus the dimensions of thought are far vaster than the physical dimensions, and everything that has ever happened in the past, or has potential to happen in the future, exists simultaneously in those dimensions of thought.
The number of potential connections between the trillions of neurons in our brains is greater than the number of atoms in the physical universe of which we are aware. We humans have no inkling of the immense power of our minds. We have the ability, if we could access it, to create entire universes out of our thoughts. Please see my PS below. Thanks, LG.
Nothing is more infinitely (literally) complex than the web of destiny that is unfolding before our eyes and all around us. If we went back in time and disrupted the smallest event, the consequences could be catastrophic - there is no way to tell what would happen, as the system is so infinitely complex. All we can say right now is that we made it this far by sheer good luck, and it would be extremely foolish to go back and change anything in the past, as we cannot know what changes this would precipitate in the future of that past - if we did so, we have no way of knowing if our species would, perhaps, have gone extinct by now as a result.
Our species has therefore gone extinct in alternate Earth timelines that obviously we are not sharing at this particular timeframe.
The idea of luck is magical or superstitious. While the Law of Attraction is promoted as 'make your own reality' it doesn't embrace the creative distortions effected by denials or 'unconscious' and repressed thought and feeling.
My sense is that we are already experiencing the catastrophic consequences of mis-creative thought and reaction. But that the true of Creation is not affected by split or fractured minds of complex defence against exposure.
I feel there is a sense in which we are not given what would hurt us even though it is not denied us - so much as held in trust for our awakening responsibility. Ultimately it comes down to trusting Life - not just our 'own' but Life. War with Life - though absurd - extends from war on self or self-conflict. To put it the other way around; war on self initiates nightmare as reality and would have no check but for limiting pain. But ways to limit the effects of a miscreative mind are not a resolving of the problem, so much as buying TIME in which to learn to use the mind differently.
Using time as a means to distance ourself from a denied or hidden past, is like using distance to separate (mind) from a denied and unrecognised brother (Life).
When your only alternative is god and you don't want to deal with that, you are forced to accept evolution
Intuitive Understanding does not require any faith in gods ... just an acceptance that a theory based on randomness is wrong
Beliefs are what is called reality, until its status as fact is challenged.
What we present or identify as beliefs are add-ons.
Anything that one tries to believe, or tries to believe against, is not a belief but a self conflict hiding beneath a narrative identity.
'True believers' would be more apt for your wit,
While truth is beyond believing - there is a capacity to wholly be-live the movement of being arising from wholeness - as a true witness or expression. Have you never really sung your heart's knowing?