Articles & Reviews
Authored by RSF Research Staff
Change for a Paradigm? New Experiment Shows How Time May Emerge From Quantum Entanglement
When cosmologists describe the formation of the Universe as occurring through the Big Bang – the logical question most people ask is “what happened before the Big Bang?” And the proper response to whatever explanation is given to that inquiry would logically be “oh, I see, well what happened before that?” This is much akin to asking what exists outside of the Universe – and it is an excellent line of inquiry because it forces our normally finite thought processes to ponder the nature of infinity. And perhaps most salient of all, it is an examination of the nature of causality and raises the question - What is time?
This is a question that has evaded a clear and definite answer within physics right up to our modern day theories. Time is absolutely fundamental to most of our conceptions of reality, and yet there is no consensus about what exactly time is. In the theory of Relativity, Einstein showed that time is relative – replacing the Newtonian framework of absolute time, wherein events in the Universe take place within an unchanging frame-of-reference, yet do not influence it in anyway. Interestingly, this still seems to be the conception of time harbored by most individuals (scientists included) – even after Einstein’s theory suggested that our experience of time is only relative to our frame of reference, such as how fast we are moving (different velocities will experience an objective difference in the passage of time, with inertial frames of reference that are traveling at greater velocities experiencing a slower progression of time relative to slower moving ones – so called time dilation factors). As Einstein put it – “put your hand on a hot stove for a minute, and it seems like an hour. Sit with a pretty girl for an hour, and it seems like a minute. THAT’S relativity.” Not so difficult to understand after all?
Note, since photons are moving at the velocity c (the speed of light, 300,000 km/s) – this would suggest that time is “standing still” for these particles – relative to an observer traveling at sub-c. Yet, saying that time is relative does not explain what time is. In his original publication– On the Electrodynamics of Moving Bodies - wherein the principle of relativity is proposed, Einstein explains his definition of time in the following way: The “time” of an event is that which is given simultaneously with the event by a stationary clock located at the place of the event, this clock being synchronous, and indeed synchronous for all time determinations, with a specified stationary clock. According to this definition, which is the basis for the theory of General Relativity, and hence modern physics - time is the correspondence of events with a particular configuration of the hands on a clock located at the place of that event. While this definition certainly sufficed to describe the principles behind the relativity of time – there are many major assumptions within the definition. Because the logical question to ask is, what is a clock? What is a clock’s relation to the concept of time? The answer to these questions is - yet again - that what we call time is the relative correspondence of the geometric configurations of objects in space. To a certain extent this makes sense as our entire conception of time is based on the Earth’s movement through space: its orbital rotation and revolution around the Sun, begging the question “does time perhaps arise from spin?” Regarding what Physics has to say on the nature of time, it is being shown more and more that time is perhaps an emergent phenomenon. That is, it does not underlie events, as something fundamental to physical processes - it emerges from them. Indeed, many posited solutions to quantum gravity do not involve time as a physical parameter within the calculations – such as the Wheeler-DeWitt equation, and more recently the geometric solution for particle interactions known as the Amplituhedron (see our article A Jewel at the Heart of Quantum Physics). For a truly enlightening exploration of the concept of time and a new theory regarding its nature, see the work of Julian Barbour, and his book The End of Time. Since this plays very predominantly into the framework of quantum gravity, understanding the nature of time may be instrumental to the unification of Physics – a Unified Field Theory. When General Relativity was first quantized (becoming a theory of quantum gravity) in the 1960’s by John Wheeler, the result predicted a static state of the Universe, that is – no change, i.e. timelessness. This particular solution to the quantization of General Relativity is known as the Wheeler-DeWitt equation. The result seemed to be paradoxical – because how can the Universe be static and unchanging – when our every experience is of change. Like the seeming axiom, ‘the only thing that stays the same is change’. Recently, an experiment has been performed with entangled photons that suggests time may be related to the quantum correlation – entanglement - of a subsystem with itself. A subsystem is much like the particular inertial frames of reference within General Relativity (an inertial frame of reference is an observer-dependent area that is defined as interacting uniquely from adjacent areas or systems). The static entangled photons appears to change to an internal observer when one of the photons is used as a clock to measure the evolution of the other. This is done by depriving the internal observer of an external clock, and only allowing the evolution of the subsystem to be determined by correlation measurements (such as changes in polarity). As the measurements are made, the internal observer becomes nonlocally correlated with the subsystem of photons, and this quantum spacetime interconnectivity makes it appear to the entangled observer that the photons have changed. The remarkable occurs when it is demonstrated that if the entangled photons are measured without becoming entangled with them – which is accomplished by measuring their global, or overall state instead of the correlation between them, as is done for the internal observer – it can be shown that no change has occurred. The experimenters utilize an interesting technique to accomplish measuring the state of the entangled photons without actually disturbing the quantum correlation between them. The experiment uses a form of quantum erasure, in which the measurement that normally destroys the quantum “superposition” of a wave-particle can be reversed through operations performed on an entangled counterpart.
Basic design of a quantum erasure experiment. The Down-Converter (a beta barium borate crystal) produces two quantum entangled photons, each directed into a separate channel. One of the photons goes directly to a detector, while polarizing filters “mark” the other photon as it passes through a double slit mask. Marking the photon in this way will inhibit formation of a wave interference pattern. If however, the other entangled photon (which does not pass through a double-slit but instead goes directly to a detector) is passed through a polarizing filter it “unmarks” the entangled counterpart – which will then produce a wave-interference pattern. In this way, it is thought that the operation on the first photon removes, or erases, the measurement performed on the second by the polarizing filters – allowing for “self-interference” of the photon passing through the double-slits, which will then result in a wave-interference pattern. Hence the appellation – quantum erasure.
Recall that one of the entangled photons was utilized as a clock to measure the evolution of the second, and this produces entanglement of the observer with that system. However, if those measurements are coherently erased, through a quantum erasure, then the observer can in a sense measure the global configuration of the subsystem without becoming entangled with it. From this vantage perspective, the so called super-observer can now determine if the global state of the photons evolves. And remarkably, the results suggest that the super-observer can show that there is no evolution of the subsystem, simply by not becoming correlated with the entangled photons. The photons remain unchanged and static even while the entangled measurement of their quantum correlation gives the internal observer an apparent change – but it is an apparition of time! While this is all accomplished with a very clever experimental design – it does demonstrate how the appearance of change, or time, can emerge even within a static, timeless Universe. In this sense, there is time, but it is only the appearance of change within subsystems that are strongly correlated together – but less so with the overall system, being the Universe itself, which at that global scale, according to their result, experiences no net change, and within this model would be eternal. In Haramein’s model (Quantum Gravity and the Holographic Mass) time is a function of the relationship of orbiting bodies relative to each other leaving a memory imprint on the structure of spacetime (encoded in Planck information pixels). In fact, he is able to show that the Planck pixels volume-to-surface ratio relationship generate the mass/energy of objects. However, the rotational relationships of all systems in an infinite boundary division Universe or multiverse would all cancel out so that each center of rotation would be the stillness that centers the rotation of all other relationships to infinity. Therefore, the global collective scale sees no change, while the local scale is obviously continuously changing. One could think of this as the center of your experience being the infinitely unchanging present emerging from the continuous changes of the past and the possible path of changes of the future.
By: William Brown
For more on this topic, see the Resonance Project Emmissary Brandon West's article 'Potential Conceptual Solution to the Illusion of Time in a Static Universe'.
Read more: Time from Quantum Entanglement: An Experimental Illustration
Quantum Experiment Shows How Time 'Emerges' from Entanglement