Sending information from one place to another without sending any particles or energy seems to go against everything we've learned about physics.
However, there is some compelling evidence to suggest that this "counterfactual communication" is not only thinkable but, depending on how it works, can reveal previously overlooked fundamental truths about reality.
The concept of "counterfactual physics", which describes the method of extracting activity from the lack of something, is not new. It's pretty simple in a certain sense. When the front door opens and it's quiet and your dog barks at visitors, you have evidence that a familiar person has entered your home despite the absence of a sound.
Recently, however, a quantum version of such transmission has come to the fore, and physicists have begun to explore the possibility that quantum information can be transmitted without an exchange of particles.
This idea is not just abstract. By using a split pair of entangled photons, ghost imaging can learn details about an item without absorbing or transmitting any of the photons.
An experimental plan to study the physics underlying a type of non-exchange communication he calls counter-portation has been put forward by one of the best experts in the field.
Quantum computing is predictably important given the nature of the underlying physics. This idea proposes to transfer information from one place to another without ever touching it, using qubits, which are probabilistic iterations of traditional binary information carriers.
In Salih's previous work, light was split through complex arrays of separators and detectors, revealing the unexpected result that information reaches a target even when there is no particle to transmit it.
The physicist's new computer blueprint builds on his earlier theoretical protocol, published in 2013.
According to physicist Hatim Salih of the University of Bristol in England, counter-teleporting miraculously fulfills the ultimate purpose of teleportation, namely, disembodied transport, without any observable information carriers moving.
In order for counter teleportation to be realized, an exchangeless quantum computer must be built in which the communicating parties do not exchange any particles.
A well-known method of transporting a quantum state from one place to another is teleportation. The process involves entangling multiple objects together, separating them by an arbitrary amount, and then carefully measuring the separated objects in a space using a very specific method. The teleporting action only takes place when the separated object is likewise measured against the results and transmitted by conventional means.
The result is an extremely special quantum state, rather than a solid object being transmitted. When the measurements on the original object are complete, the object is effectively destroyed and the situation changes from one to the next.
Similar to teleportation, counter teleportation is a quantum-type counterfactual communication that results in the transmission of quantum information (just without the added hassle).
How it happened is an open question. The overlap or connection between entangled elements is assumed to be represented by a particular type of Einstein-Rosen (ER) bridge or wormhole.
Salih suggested that such a local wormhole could serve as a conduit for counter-portation.
Although wormholes have traditionally been associated with black holes, it is possible that they can explain entangled events at smaller scales. If wormholes do exist, identifying them could help us better understand the fundamental properties of matter.
Salih states that their goal is to recently physically create such a wormhole in the lab so that it can be used as a testbed for competing physical theories, including quantum gravity.
Our ultimate goal is to provide physicists, physics amateurs and enthusiasts with direct access to nearby wormholes so they can investigate fundamental issues related to the Universe, such as the existence of higher dimensions.
Although for now it is stated that this is all theoretical and based on theories that not all scientists can agree on, it adds an additional layer of intrigue to the ongoing scientific debate about quantum counterfactual communication and its potential application in research.
Says Saleh: “We've been working for several years to reach this milestone. It offers a theoretical and practical framework for reconsidering the perennial mysteries of the cosmos, such as the true nature of space-time.
Source: ScienceAlert
📩 16/03/2023 15:06