This past December, the Nobel Prize in Physics was awarded for the experimental confirmation of a quantum phenomenon known for more than 80 years: entanglement. Envisioned by Albert Einstein and his collaborators in 1935, quantum objects can be mysteriously correlated even if they are separated by large distances. But as strange as the phenomenon may seem, why is such an old idea still worthy of physics’ most prestigious prize?
Coincidentally, just weeks before the new Nobel laureates were honored in Stockholm, a different group of distinguished scientists from Harvard, MIT, Caltech, Fermilab and Google reported that they had run a process on Google’s quantum computer that could be interpreted as a wormhole. . Wormholes are tunnels through the universe that can act as a shortcut through space and time and are beloved by science fiction fans, and although the tunnel realized in this latest experiment only exists in a 2-dimensional toy universe, it could constitute a breakthrough for the future. . Research at the forefront of physics.
But why entanglement with space and time? And how could it be important for the future success of physics? Properly understood, entanglement implies that the universe is “monistic,” as philosophers call it, in that at the most fundamental level, everything in the universe is part of a single, unified whole. It is a defining feature of quantum mechanics that its underlying reality is described in terms of waves and requires a universal function for a nondual universe. Already decades ago, researchers such as Hugh Everett and Dieter Zeh showed how our everyday-life reality could emerge from such a universal quantum-mechanical description. But now only researchers like Leonard Susskind or Sean Carroll are developing ideas about how this hidden quantum reality can explain not only matter, but also the fabric of space and time.
Entanglement is much more than just another strange quantum phenomenon. It is the working principle behind both why quantum mechanics holds the world together and why we experience this fundamental unity as many separate objects. At the same time, it is the reason why we seem to live in a classical reality. It is – quite literally – glue and the creator of the world Entanglement applies to objects composed of two or more components and describes what happens when the quantum principle that “whatever can happen does happen” is applied to such composed objects. Accordingly, a bounded state is the superposition of all possible combinations of the elements of a composed object that can produce the same overall result. It is again the wave nature of the quantum domain that can help explain how entanglement actually works.
Picture a perfectly calm, glassy sea on a windless day. Now ask yourself, how can such a plane be created by overlaying two separate wave patterns? One possibility is that superimposing two completely flat surfaces again results in a completely flat surface. But another possibility that can produce a flat surface is if two identical wave patterns shifted by half an oscillation cycle are superimposed, so that the wave crest of one pattern destroys the wave trough of the other and vice versa. If we just observed the sea of glass, treating it as the result of two blooms coming together, we would have no way of knowing the patterns of the individual blooms. What sounds perfectly normal when we talk about waves has the most bizarre consequences when applied to competitive reality. If your neighbor tells you that he has two cats, one alive and one dead, it means that the first cat or the second is dead and the other cat is alive, respectively – that would be strange and sick. Way to describe one’s pets, and you may not know which of them is lucky, but you’ll get a neighborly flow. Not so in the quantum world. In quantum mechanics, the same statement implies that two cats are combined in a superposition of cases, in which the first cat is alive and the second is dead, and the first cat is dead while the second is alive, but there is also the possibility of both cats. Half alive and half dead, or the first cat is one-third alive, while the second cat adds the missing two-thirds of life. In a quantum pair of cats, the fates and states of individual beings dissolve completely. Similarly, in a quantum universe, there are no individual objects. All that exists is united into a single “One”.
“I’m almost certain that space and time are illusions. These are primitive concepts that will be replaced by something more sophisticated.“
– Nathan Seaberg, Princeton University
Quantum entanglement opens up a vast and entirely new territory for us to explore. It defines a new foundation for science and reverses our search for a theory of everything—one based on quantum cosmology rather than particle physics or string theory. But how realistic is it for physicists to follow such an approach? Surprisingly, it’s not only realistic – they’re actually doing it already. Researchers at the forefront of quantum gravity are beginning to rethink space-time as a result of entanglement. A growing number of scientists have come to base their research on the non-divisibility of the universe. Hopefully by following this method they will finally understand what space and time, deep in the foundations, really are.
Whether space is stitched together through entanglement, physics is described by abstract objects outside of space and time, or by probability space represented by Everett’s universal wave function, or everything in the universe is captured in a single quantum object — all these concepts share a distinctive It is currently difficult to judge which of these ideas of monistic flavor will inform the future of physics and which will eventually disappear. Interestingly, while the concepts were often first developed in the context of string theory, they seem to have outlived string theory, and strings no longer play a role in recent research. A common thread now seems to be that space and time are no longer considered fundamental. Contemporary physics does not begin with space and time to continue with things placed in this pre-existing background. Instead, space and time themselves are considered products of a more fundamental projected reality. Nathan Seaberg, a leading string theorist at Princeton’s Institute for Advanced Study, says, “I’m almost certain that space and time are illusions. They are primitive concepts that will be replaced by something more sophisticated.” Furthermore, in most of the scenarios proposed for emergent space-time, entanglement plays a fundamental role. As philosopher of science Rasmus Jaksland points out, this ultimately implies that there are no more separate objects in the universe; that everything belongs to everything else. Linked with: “Accepting entanglement as a world-making relation comes at the price of abandoning separation. But those willing to take this step should perhaps look to entanglement for the fundamental relation with which this world will be constituted (and perhaps all other possibilities).” Thus, when space and time disappear, the unified One emerges.
Courtesy Hachette Book Group
Conversely, from the perspective of quantum monism, such mind-bending consequences of quantum gravity are not far-fetched. Already in Einstein’s theory of general relativity, space is no longer a fixed phase; Rather, it is derived from the mass and energy of matter. Much like the German philosopher Gottfried W. According to Leibniz, it describes the relative order of things. Now if, according to quantum monism, there is only one thing left, there is nothing left to arrange or arrange, and ultimately the concept of space is no longer needed at this most fundamental level of description. It is “the One”, a single quantum universe that gives rise to space, time and matter.
“GR = QM,” Leonard Susskind boldly claims in an open letter to researchers in quantum information science: General relativity is nothing more than quantum mechanics—a hundred-year-old theory that has been applied very successfully to all sorts of things but never fully understood in practice. goes As Sean Carroll points out, “Perhaps quantification of gravity was a mistake, and space-time was always hidden in quantum mechanics.” For the future, “instead of measuring gravity, we should try to find gravity in quantum mechanics. Or, more accurately but less evocatively, ‘find gravity inside quantum mechanics,'” Carroll suggests on his blog. Had it been taken seriously, if it had been understood as a theory that occurred not in space and time but in a more fundamental projected reality, many dead ends in the pursuit. Quantum gravity could have been avoided. If we had accepted the duality effect of quantum mechanics—a A three-thousand-year-old philosophical tradition that had been accepted in antiquity, persecuted in the Middle Ages, revived in the Renaissance, and tempered with romanticism—as Everett and Jeh pointed out—rather than sticking to the pragmatic interpretations of influential quantum pioneer Niels Bohr—made quantum mechanics a tool. , we are further along the path of demystifying the foundations of reality will go
Adapted from One: How an ancient idea holds the future of physics By Heinrich Pass. Copyright © 2023. Available from Basic Books, an imprint of Hachette Book Group, Inc.
