Parallel Worlds Probably Exist. Here’s Why

The most elegant interpretation of quantum mechanics is the universe is constantly splitting. I learned quantum mechanics the traditional ‘Copenhagen Interpretation’ way. We can use the Schrödinger equation to solve for and evolve wave functions.

Then we invoke wave-particle duality, in essence things we detect as particles can behave as waves when they aren’t interacting with anything. But when there is a measurement, the wave function collapses leaving us with a definite particle detection.

If we repeat the experiment many times, we find the statistics of these results mirror the amplitude of the wave function squared. Hence the Born rule came into being, saying the wave function should be interpreted statistically, that our universe at the most fundamental scale is probabilistic rather than deterministic. This did not sit well with scientists like Einstein and Schrödinger who believed there must be more going on, perhaps ‘hidden variables’.


In the 1950’s Hugh Everett proposed the Many Worlds interpretation of quantum mechanics. It is so logical in hindsight but with a bias towards the classical world, experiments and measurements to guide their thinking, it’s understandable why the founders of quantum theory didn’t come up with it. Rather than proposing different dynamics for measurement, Everett suggests that measurement is something that happens naturally in the course of quantum particles interacting with each other.

The conclusion is inescapable. There is nothing special about measurement, it is just the observer becoming entangled with a wave function in a superposition. Since one observer can experience only their own branch, it appears as if the other possibilities have disappeared but in reality there is no reason why they could not still exist and just fail to interact with the other branches. This is caused by environmental decoherence.


Universal Computer Memory

A new type of computer memory which could solve the digital technology energy crisis has been invented and patented by Lancaster scientists. The electronic memory device – described in research published in Scientific Reports – promises to transform daily life with its ultra-low energyconsumption.  In the home, energy savings from efficient lighting and appliances have been completely wiped out by increased use of computers and gadgets, and by 2025 a ‘tsunami of data’ is expected to consume a fifth of global electricity. But this new device would immediately reduce peak power consumption in data centres by a fifth. It would also allow, for example, computers which do not need to boot up and couldinstantaneously and imperceptibly go into an energy-saving sleep mode – even between key stokes.“Universal Memory” which has preoccupied scientists and engineers for decades.

The device is the realisation of the search for a “Universal Memory, which hasrobustly stored data that is easily changed, is widely considered to be unfeasible, or even impossible, but this device demonstrates its contradictory properties,” explains Physics Professor Manus Hayne of Lancaster University.

US patent has been awarded for the electronic memory device with another patent pending, while several companies have expressed an interest or are actively involved in the research. The inventors of the device used quantum mechanics to solve the dilemma of choosing between stable, long-term data storage and low-energy writing and erasing. The device couldreplace the $100bn market for Dynamic Random Access Memory (DRAM), which is the ‘working memory’ of computers, as well as the long-term memory in flash drives. While writing data to DRAM is fast and low-energy, the data is volatile and must be continuouslyrefreshed’ to avoidit being lost: this is clearly inconvenient and inefficient. Flash stores data robustly, but writing and erasing is slow, energy intensive and deteriorates it, making it unsuitable for working memory.
The ideal is to combine the advantages of both without their drawbacks, and this is what we have demonstrated. Our device has an intrinsic data storage time that is predicted to exceed the age of the Universe, yet it can record or delete data using 100 times less energy than DRAM,” said Professor Hayne.


Quantum Computer Can See 16 Different Futures Simultaneously

When Mile Gu boots up his new computer, he can see the future. At least, 16 possible versions of it — all at the same time. Gu, an assistant professor of physics at Nanyang Technological University in Singapore, works in quantum computing. This branch of science uses the weird laws that govern the universe’s smallest particles to help computers calculate more efficiently.

Tiny particles of light can travel in a superposition of many different states at the same time. Researchers used this quantum quirk to design a prototype computer that can predict 16 different futures at once.

Unlike classical computers, which store information as bits (binary digits of either 0 or 1), quantum computers code information into quantum bits, or qubits. These subatomic particles, thanks to the weird laws of quantum mechanics, can exist in a superposition of two different states at the same time.

Just as Schrödinger‘s hypothetical cat was simultaneously dead and alive until someone opened the box, a qubit in a superposition can equal both 0 and 1 until it’s measured. Storing multiple different outcomes into a single qubit could save a ton of memory compared to traditional computers, especially when it comes to making complicated predictions.

In a study published April 9 in the journal Nature Communications, Gu and his colleagues demonstrated this idea using a new quantum simulator that can predict the outcomes of 16 different futures (the equivalent of, say, flipping a coin four times in a row) in a quantum superposition. These possible futures were encoded in a single photon (a quantum particle of light) which moved down multiple paths simultaneously while passing through several sensors. Then, the researchers went one step further, firing two photons side-by-side and tracking how each photon’s potential futures diverged under slightly different conditions.

It’s sort of like Doctor Strange in the ‘Avengers: Infinity War‘” movie, Gu told Live Science. Before a climactic battle in that film, the clairvoyant doctor looks forward in time to see 14 million different futures, hoping to find the one where the heroes defeat the big baddie. “He does a combined computation of all these possibilities to say, ‘OK, if I changed my decision in this small way, how much will the future change?’ This is the direction our simulation is moving forwards to.


Conflicting Realities

Physicists have long suspected that quantum mechanics allows two observers to experience different, conflicting realities. Now they’ve performed the first experiment that proves it. Back in 1961, the Nobel Prize–winning physicist Eugene Wigner outlined a thought experiment that demonstrated one of the lesser-known paradoxes of quantum mechanics. The experiment shows how the strange nature of the universe allows two observers—say, Wigner and Wigner’s friend—to experience different realities.

Since then, physicists have used the “Wigner’s Friend” thought experiment to explore the nature of measurement and to argue over whether objective facts can exist. That’s important because scientists carry out experiments to establish objective facts. But if they experience different realities, the argument goes, how can they agree on what these facts might be?
That’s provided some entertaining fodder for after-dinner conversation, but Wigner’s thought experiment has never been more than that—just a thought experiment. Last year, however, physicists noticed that recent advances in quantum technologies have made it possible to reproduce the Wigner’s Friend test in a real experiment. In other words, it ought to be possible to create different realities and compare them in the lab to find out whether they can be reconciled.

And today, Massimiliano Proietti at Heriot-Watt University in Edinburgh and a few colleagues say they have performed this experiment for the first time: they have created different realities and compared them. Their conclusion is that Wigner was correct—these realities can be made irreconcilable so that it is impossible to agree on objective facts about an experiment.Wigner’s original thought experiment is straightforward in principle. It begins with a single polarized photon that, when measured, can have either a horizontal polarization or a vertical polarization. But before the measurement, according to the laws of quantum mechanics, the photon exists in both polarization states at the same time—a so-called superposition.

Wigner imagined a friend in a different lab measuring the state of this photon and storing the result, while Wigner observed from afar. Wigner has no information about his friend’s measurement and so is forced to assume that the photon and the measurement of it are in a superposition of all possible outcomes of the experiment.

But this is in stark contrast to the point of view of the friend, who has indeed measured the photon’s polarization and recorded it. The friend can even call Wigner and say the measurement has been done (provided the outcome is not revealed). So the two realities are at odds with each other. “This calls into question the objective status of the facts established by the two observers,” say Proietti and co. That’s the theory, but last year Caslav Brukner, at the University of Vienna in Austria, came up with a way to re-create the Wigner’s Friend experiment in the lab by means of techniques involving the entanglement of many particles at the same time.

The breakthrough that Proietti and co have made is to carry this out. “In a state-of-the-art 6-photon experiment, we realize this extended Wigner’s friend scenario,” they say. They use these six entangled photons to create two alternate realities—one representing Wigner and one representing Wigner’s friend. Wigner’s friend measures the polarization of a photon and stores the result. Wigner then performs an interference measurement to determine if the measurement and the photon are in a superposition.

The experiment produces an unambiguous result. It turns out that both realities can coexist even though they produce irreconcilable outcomes, just as Wigner predicted.  That raises some fascinating questions that are forcing physicists to reconsider the nature of reality.


Quantum Computer Controls One Billion Electrons Per Second One-by-One.

University of Adelaide-led research in Australia has moved the world one step closer to reliable, high-performance quantum computing. An international team has developed a ground-breaking single-electronpump”. The electron pump device developed by the researchers can produce one billion electrons per second and uses quantum mechanics to control them one-by-one. And it’s so precise they have been able to use this device to measure the limitations of current electronics equipment. This paves the way for future quantum information processing applications, including in defence, cybersecurity and encryption, and big data analysis.

This research puts us one step closer to the holy grail – reliable, high-performance quantum computing,” says project leader Dr Giuseppe C. Tettamanzi, Senior Research Fellow, at the University of Adelaide’s Institute for Photonics and Advanced Sensing.

Published in the journal Nano Letters, the researchers also report observations of electron behaviour that’s never been seen before – a key finding for those around the world working on quantum computing.

Quantum computing, or more broadly quantum information processing, will allow us to solve problems that just won’t be possible under classical computing systems,” says Dr Tettamanzi. “It operates at a scale that’s close to an atom and, at this scale, normal physics goes out the window and quantum mechanics comes into play.  To indicate its potential computational power, conventional computing works on instructions and data written in a series of 1s and 0s – think about it as a series of on and off switches; in quantum computing every possible value between 0 and 1 is available. We can then increase exponentially the number of calculations that can be done simultaneously.”