Category Archives: Quantum Physics

In the publics mind, Stephen Hawking is a giant of 20th century science. He burst onto the popular stage with the 1988 publication of A Brief History of Time, which presented his esoteric ideas of evaporating black holes and the birth of the universe. It was an international bestseller, but given the complexity of its ideas, A Brief History has been called the most unread book of all time.

Hawking continued to explore the fundamental nature of the universe until his death in 2018. In a new book, On The Origin of Time, Belgian physicist Thomas Hertog unravels Hawkings final theory, which focuses upon one of the biggest questions of all just why our universe is the way it is.

Review: On the Origin of Time: Stephen Hawkings Final Theory Thomas Hertog (Penguin Random House)

Hertog is no passive player in this story, having been a student and collaborator of Hawking. He is, instead, an active participant. Intriguingly, as Hertog explains, we are all active participants in Hawkings final theory, shaping the universe by observing it.

In this new book, Hertog tells us that Hawkings final theory tries to address one of the deep mysteries of the universe, something known as the problem of cosmological fine-tuning.

Cosmologists have realised that the more they peer at the underlying nature of the universe (for instance the strengths of fundamental forces and the masses of fundamental particles), the more the cosmos seems tuned for our existence.

If the universe had been born with slightly different values for these fundamental properties, it would be dead and sterile, lacking the complexity and energy essential for life.

For some, the solution to cosmological fine-tuning lies in the multiverse, the idea that our universe is just one of countless others. Our universe, and all the others, crystallise out of a bout of eternal inflation, a super-energetic cosmic expansion. Each individual universe, at birth, is written with its own unique laws of physics. Most of these universes in the multiverse are dead, but our cosmic home won the physics lottery. We, unsurprisingly, find ourselves in a universe that can host life.

However, as Hertog writes in this new book, Hawking dismissed the multiverse and went on the hunt for an alternative solution to cosmic fine-tuning.

To get to this point, Hertog treads some very familiar ground, discussing the history of modern cosmological ideas. This includes the theoretical groundwork of Albert Einstein and Georges Lemaitre, and the observational insights of Edwin Hubble that revealed the expansion of the universe.

Hertog interweaves the story with the development, over the 20th century, of that other great pillar of physics, the strange behaviour in the world of the quantum, where the deterministic world of Isaac Newton, in which things have precise locations at precise times, is replaced by a fuzzy world of probabilities and uncertainties.

Usually we think of quantum mechanics describing the subatomic world, of electrons and atoms, but Hawking was thinking of the entire universe as a quantum system. The tale is brought up to date with the idea of cosmic inflation in the earliest instances of the universe and the surprising discovery of the dominance of dark energy in the closing years of the last century.Hawkings own story is similarly interwoven in the book including his revelation that black holes are not truly black.

Combining Einsteins general theory of relativity, which dictates the space-time curvature of a black hole, with quantum field theory, which describes the strange, ephemeral nature of seemingly empty space, Hawking showed that black holes actually radiate. Through this dribble of energy, black holes steadily evaporate into an eventual nothingness.

But if you are looking for an accurate description of just how Hawkings idea of black hole radiation operates, unfortunately Hertog relies on the same flawed picture of particles popping into existence at the edge of the hole as Hawking presented in A Brief History of Time. A copy of A Brief History of Time featuring a thumbprint of its author at an auction at Christies London in 2018. Neil Hall/AAP

Hertog also tells us that Hawking explored the state of the universe at the very beginning, arguing that at this initial point, at least in terms of general relativity, the density of stuff in the universe must have been infinite, (this idea is formally known as a singularity).

Hawking returned to this question with physicist Jim Hartle in the early 1980s to try and wrap quantum mechanics into the picture. Hartle and Hawking claimed that if you wind the universe back to the beginning, time loses its distinct nature and effectively becomes space. With this no boundary hypothesis, the universe did not have an origin, not at least one we would ever really understand.

Hawkings motivation for disliking the multiverse is a somewhat subtle argument, built on the idea of the anthropic principle, the fact that we should not be surprised to find ourselves in a universe which allows us to be here.

Hertog tells us that we should be, in some sense, typical of the possible observers who could inhabit the universes in the multiverse. But quite what typical means is a complicated topic. Does it mean that other life in other universes should be like life on Earth? Or typical in a more broader sense, that life should be composed of the same elements as us? Typical can be judged on many different criteria. And how will we ever find out how typical we are if we are forever limited to the observations of our one universe?

To posit an alternative solution, Hawkings first step was to upend the approach to understanding the universe.

The goal of modern science has been to unravel the fundamental operations of the universe and use these to predict how physical systems evolve. To do this, we need more than the laws of physics, but we need to know the starting point, the boundary conditions. But for a universe emerging from the strange singular state at its origin, where infinities abound, just what are these boundary conditions, and do they uniquely define the universe we inhabit?

Hertog explains that he and Hawking adopted a different view, a top-down view of the universe. Quantum mechanics is again wrapped into the picture, and the life of the universe is treated as a quantum system, described in terms of possibilities and probabilities.

It is here that Hugh Everett IIIs many-worlds interpretation of quantum mechanics makes its appearance. According to Everett, all of the possible outcomes of a quantum experiment play out in parallel existences, and it is this notion that Hawking applies to the universe.

Within this final theory, as expressed by Hertog, the observer now plays a central role. The fact that we all exist and observe the world around it, means we participate in shaping the universe we appear to inhabit.

Of all of the possible histories of the universe that could potentially exist in a sea of parallel universes, the fact that we are here observing this universe, singles out this universe, with all the others lost in a sea of quantum uncertainty. The situation becomes strangely self-referential.

At this point, the general reader is quite possibly going to be confused. This is, of course, quite a radical notion in understanding the nature of the universe. And, quite frankly, the reader might wonder what separates Hawkings final theory from what some might consider pseudo-scientific ramblings.

The idea that we, as observers, are essential for bringing the universe into being is not a new one, and is often the source of ridicule. Of course, given the scientific weight of the authors, this final theory must be given merit, but whether this hypothesis is a true contender for an accurate description of the life of our universe is hard to judge.

This should not put the reader off. Hertogs easy writing style jumps from topic to topic and provides an overview of the development of modern cosmology and the need for quantum mechanics in understanding the ultimate origins of the universe.

But when the going gets tough and the intricate ideas of Hawkings cosmos are explored, some things are stepped over a little too quickly and a little more time lingering on what might seem straightforward to quantum cosmologists would have been a benefit.

In closing, it is worth pointing out that there are some irritating features to the writing, including the almost hero worship Hawking receives. Clearly given the close relationship between the author and his subject, this is somewhat understandable, but can still be grating.

The text also mixes the philosophy-bashing that appears to be a badge of honour of modern physicists with various philosophical musings that underpin the cosmological and quantum thinking. But given the scope of the topic, and with a mix of anecdotes, quotes and analogies, Hertog provides an intriguing snapshot of our pondering of the ultimate origin of our universe.

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Stephen Hawking's final, god's-eye view of the cosmos ponders the ultimate origin of our universe - The Conversation

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Transporting energy is costly. When a current runs through conductive materials, some of the energy is lost due to resistance as particles within the material interactjust notice the warmth from your phone or laptop. This energy loss presents a hurdle to the advancement of many technologies and scientists are searching for ways to make superconductors that eliminate resistance.

Superconductors can also provide a platform for fault-tolerant quantum computing if endowed with topological properties. An example of the latter is the quantum Hall effect where the topology of electrons leads to universal, "quantized," resistance with accuracy up to one part in a billion, which finds uses in meteorology. Unfortunately, the quantum Hall effect requires extremely strong magnetic fields, typically detrimental to superconductivity. This makes the search for topological superconductors a challenging task.

In two new papers in Physical Review Letters and Physical Review B UConn Physicist Pavel Volkov and his colleagues propose how to experimentally manipulate the quantum particles, called quasiparticles, in very thin layers of ordinary superconductors to create topological superconductors by slightly twisting the stacked layers.

Volkov explains there is a lot of research being done on ways to engineer materials by stacking layers of two-dimensional materials together:

"Most famously, this has been done with graphene. Stacking two graphene layers in a particular way results in a lot of interesting new phenomena. Some parallel those in high-temperature superconductors, which was unexpected because, by itself, graphene is not superconducting."

Superconductivity happens when a material conducts current without any resistance or energy loss. Since resistance is a challenge for many technologies, superconducting materials have the potential to revolutionize how we do things, from energy transmission to quantum computing to more efficient MRI machines.

However, endowing superconductors with topological properties is challenging, says Volkov, and as of now, there are no materials that can reliably perform as topological superconductors.

The researchers theorize that there is an intricate relation between what happens inside the twisted superconductor layers and a current applied between them. Volkov says the application of a current makes the quasiparticles in the superconductor behave as if they were in a topological superconductor.

"The twist is essentially determining the properties, and funnily enough, it gives you some very unexpected properties. We thought about applying twisting to materials that have a peculiar form of superconductivity called nodal superconductivity," says Volkov.

"Fortunately for us, such superconductors exist and, for example, the cuprate high-temperature superconductors are nodal superconductors. What we claim is that if you apply a current between two twisted layers of such superconductors, it becomes a topological superconductor."

The proposal for current-induced topological superconductivity is, in principle, applicable at any twist angle, Volkov explains, and there is a wide range of angles that optimize the characteristics, which is unlike other materials studied so far.

"This is important because, for example, in twisted bilayer graphene, observation of interesting new phenomena requires to align the two layers to 1.1 degrees and deviations by .1 degrees are strongly detrimental. That means that one is required to make a lot of samples before finding one that works. For our proposal this problem won't be as bad. If you miss the angle even by a degree, it's not going to destroy the effect we predict."

Volkov expects that this topological superconductor has the potential to be better than anything else currently on the market. Though one caveat is they do not know exactly what the parameters of the resulting material will be, they have estimates that may be useful for proof of principle experiments.

The researchers also found unexpected behaviors for the special value of twist angle.

"We find a particular value of the angle, the so-called 'magic angle,' where a new state should appeara form of magnetism. Typically, magnetism and superconductivity are antagonistic phenomena but here, superconductivity begets magnetism, and this happens precisely because of the twisted structure of the layers." says Volkov.

Demonstrating these predictions experimentally will bring more challenges to overcome, including making the atoms-thick layers better themselves and determining the difficult-to-measure parameters, but Volkov says there is a lot of motivation behind developing these highly complex materials.

"Basically, the main problem so far is that the candidate materials are tricky to work with. There are several groups around the world trying to do this. Monolayers of nodal superconductors, necessary for our proposal have been realized, and experiments on twisted flakes are ongoing. Yet, the twisted bilayer of these materials has not yet been demonstrated. That's work for the future."

These materials hold promise for improving materials we use in everyday life, says Volkov. Things already in use that take advantage of the topological states include devices used to set resistance standards with high accuracy. Topological superconductors are also potentially useful in quantum computing, as they serve as a necessary ingredient for proposals of fault-tolerant qubits, the units of information in quantum computing. Volkov also emphasizes the promise topological materials hold for precision physics,

"Topological states are useful because they allow us to do precision measurements with materials. A topological superconductor may allow us to perform such measurements with unprecedented precision for spin (magnetic moment of electron) or thermal properties."

More information: Pavel A. Volkov et al, Current- and Field-Induced Topology in Twisted Nodal Superconductors, Physical Review Letters (2023). DOI: 10.1103/PhysRevLett.130.186001

Pavel A. Volkov et al, Magic angles and correlations in twisted nodal superconductors, Physical Review B (2023). DOI: 10.1103/PhysRevB.107.174506

Journal information: Physical Review Letters , Physical Review B

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The exciting possibilities of tiny, twisted superconductors - Phys.org

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by Ingrid Fadelli , Phys.org

When light strongly interacts with matter, it can produce unique quasi-particles called polaritons, which are half light and half matter. In recent decades, physicists explored the realization of polaritons in optical cavities and their value for the development of highly performing lasers or other technologies.

Researchers at University of Manitoba recently developed a highly performing device based on cavity magnon polaritons that can emit and amplify microwaves. This device, introduced in Physical Review Letters, was found to significantly outperform previously proposed solid-state devices for coherent microwave emission and amplification at room temperature.

"In 1992, Claude Weisbush, a French semiconductor physicist working in Japan, discovered cavity exciton polariton by confining light in a quantum microcavity to interact with semiconductors," Can-Ming Hu, the researcher who directed the study, told Phys.org.

"This led to the invention of polariton lasers with superior performance that have transformed solid-state laser technology. Two decades later, the magnetism community re-discovered cavity magnon polariton by confining microwaves in a cavity to interact with magnetic materials, such a half photon and half magnon quasi-particle was first discovered by Joe Artman and Peter Tannenwald in 1955 at MIT, which went largely unnoticed until recently."

Wireless communication and quantum information technologies require coherent on-chip microwave sources. Motivated by this need, Hu and his colleagues set out to explore the potential use of cavity magnon polaritons to achieve high-quality microwave emission and amplification.

"Intrigued by the resemblance between cavity magnon polariton and cavity exciton polariton, I became curious whether the cavity magnon polariton might help us to make better solid-state microwave sources," Hu said. "So, in 2015, my group launched a study to explore microwave emission of cavity magnon polaritons."

The researchers initially set out to create a lightmatter coupled system based on cavity magnon polaritons for coherent microwave emission. They ultimately hoped to achieve a higher performance than those reported in previous works, while retaining their device's stability and controllability as a hybrid lightmatter coupled system.

"First, we follow the principle proposed in 1920 by Dutch physicist van der Pol: using nonlinear damping to balance gain in an amplified oscillatory system, one can design and optimize a stable gain-driven cavity," Bimu Yao, an associate professor from the Chinese Academy of Sciences who carried out this study at the University of Manitoba, told Phys.org. "Then, we set a magnetic material into such a gain-driven microwave cavity, letting the amplified microwaves to strongly interact with magnons."

The strong interaction between amplified microwaves and magnons in the researchers' system produces a new type of polariton, which they dubbed a "gain-driven" polariton. Compared to conventional polaritons realized in previous studies, this gain-driven polariton has a stable phase, which in turn enables the coherent emission of microwave photons.

"For decades, the magnetism community has been working on spin-toque oscillator (STO), which is a solid-state device that utilizes magnons to produce coherent microwaves," Yongsheng Gui, a research associate at the University of Manitoba who carried out the study, told Phys.org. "The major hurdle is that the emission power of the STO is typically limited to less than 1 nW. Our device's output is a million times more powerful, and the emission quality factor is a thousand times better."

In initial evaluations, a proof-of-principle device created by this team of researchers achieved remarkable results, outperforming both STOs and solid-state masers developed in the past. Masers are devices that use the stimulated emission of radiation by atoms to amplify or generate microwave radiation.

"Outside of the magnetism community, there have been divers efforts for developing masers," Gui said. "Compared with the best solid-state maser, our device's output is a billion times more powerful, with a comparable emission quality factor."

The new gain-driven polariton realized by Hu and his colleagues could open exciting new possibilities for the development of highly performing solid-state microwave sources that can be integrated on-chip. In addition to their compact sizes, these polariton microwave sources are frequency tunable due to the fabulous controllability of light-matter interaction. They could ultimately be integrated in a broad range of technologies and devices, including wireless communication systems and quantum computers.

"As the physics of gain-driven light-matter interaction is new, our study may also lead to new discoveries beyond microwave applications," Hu added. "We have now submitted a patent application, and my students are working on developing prototype devices together with industry partners."

More information: Bimu Yao et al, Coherent Microwave Emission of Gain-Driven Polaritons, Physical Review Letters (2023). DOI: 10.1103/PhysRevLett.130.146702

Can-Ming Hu, Dawn of Cavity Spintronics, arXiv (2015). DOI: 10.48550/arxiv.1508.01966

Journal information: Physical Review Letters , arXiv

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A highly performing device for polariton-based coherent microwave emission and amplification - Phys.org

Newswise NEWPORT NEWS, VA Experts in high-performance computing and data management are gathering in Norfolk next week for the 26th International Conference on Computing in High Energy and Nuclear Physics (CHEP2023). Held approximately every 18 months, this high-impact conference will be held at the Norfolk Marriott Waterside in Norfolk, Va., May 8-12. CHEP2023 is hosted by the U.S. Department of Energys Thomas Jefferson National Accelerator Facility in nearby Newport News, Va. This is the first in-person CHEP conference to be held since 2019.

Science is driven by data. As research has progressed, so has the sheer volume of scientific data. The CHEP2023 conference will host more than 500 top computational scientists, data scientists, experimentalists and data center managers as they address the computing, networking and software issues for the worlds leading dataintensive science experiments.

Conference attendees will be welcomed to Virginia by Representative Robert C. Bobby Scott (VA-03), who represents the congressional district that includes Jefferson Lab and the conference venue. Old Dominion University Dean of the College of Sciences and Professor of Physics Gail Dodge, Jefferson Lab Director Stuart Henderson, and Jefferson Lab Associate Director of the Computational Sciences and Technology Division and Chief Information Officer Amber Boehnlein will also welcome attendees to these discussions at the intersection of physics and computing.

The CHEP conferences highlight key trends, challenges and solutions in computing as it applies to research in nuclear and high energy physics. This edition of the conference will place special emphasis on high-performance data organization, management and access, a topic of interest and relevance throughout the scientific community.

CHEP2023 features twelve parallel session tracks, where attendees will discuss such topics as: online and offline computing, data organization, software engineering, analysis tools, AI & machine learning, exascale science and quantum computing. The conference will also feature a special workforce development roundtable with speakers who are building an equitable STEM workforce for the future through mentorship programs that promote STEM education for students of all levels.

The CHEP conference location rotates among the Americas, Asia and Europe. It is typically held every 18 months. This is the first in-person CHEP conference to be held since 2019.

-end-

Jefferson Science Associates, LLC, manages and operates the Thomas Jefferson National Accelerator Facility, or Jefferson Lab, for the U.S. Department of Energy's Office of Science. JSA is a wholly owned subsidiary of the Southeastern Universities Research Association, Inc. (SURA).

DOEs Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit https://energy.gov/science.

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Jefferson Lab Hosts International Computing in High Energy and Nuclear Physics Conference - Newswise

History of science provides some interesting examples of important scientific and technological discoveries which will hibernate for some duration and suddenly resurrect in future with new nomenclature separated in space and time.

Two such examples that come to our mind are the Geometrical Phase discovered by Pancharatnam in 1931 and its rediscovery by Berry which came to be known as Berry Phase in 1982. The third example is Joshy Effect in 1941 which describes interesting observations in Optical interaction with low-density discharge plasma.

Joshy effect provided valuable data on the nature of excited states of atomic, and molecularspecies present in the plasma discharge. Prof Joshy was a chemistry professor at Banaras HinduUniversity when he discovered an interesting phenomenon in gas discharge tube under lightirradiation.

His colleagues in the Physics department did not accept the discovery and sarcastically called it the Joshy effect. Later on, the Joshy effect was rediscovered as the Optogalavanic effect and provided a new spectroscopic technique to study optical absorption spectroscopy with non-optical detection in 1982 by Green et al . Then only BHU people and physicists elsewhere in Indian laboratories found that OGS is, in fact, the rediscovery of Joshy effect.

Prof S Chandrashekar, the astrophysicist Nobel laureate, was ridiculed by Eddington for his theory of the possible existence of a Black hole. Without initiating to fight with Eddington, Chandra wrote a book describing his discoveries and published it in Chicago. USA received Chandra with admiration to become Physics Professor at Chicago University. He was an excellent teacher and boasted that even if he did not get the Nobel Prize, the whole of his call got the Nobel Prize in Physics.

It is clear that the non-recognitions of a scientist's discovery by his colleagues is based on non-academic reasons rather than academic and logical arguments.

The latest of the Indian psyche to ignore path-breaking discoveries by one of their colleagues is that of the work by Prof C S Unnikrishnan. He discovered serious faults in Einsteins Special Theory of Relativity and developed an alternate theory called Cosmic Relativity. The entire STR has to be replaced by CR because they are antipodal. All the verified results of STR are also part of CR, but they have very different predictions for the most crucial aspects. In STR, the relative velocity of light is an invariant constant; in CR it is Galilean, like sound so the velocity of light depends on the velocity v of the observer so that.

The Galilean nature of light is confirmed in direct experiments at TIFR. This is further supported amply by facilities like the GPS. Coming to more recent experimental results, even the LIGO findings are consistent only in a new General Theory of Relativity, that is modified with CR as the basis; this is because the relative velocity of gravitational waves is also Galilean, as verified in the simultaneous detection of light (gamma) rays and gravitational waves. In CR, all the relativistic effects are because of the gravitational influence of matter and energy in the universe.

Since cosmic matter and its average density are observed and measured, its enormous gravity is the natural consequence.. After formulating CR, Prof Unnikrishnan also found serious inconsistencies in STR, due to a vital error Einstein made in the discussion of simultaneity and synchronization of clocks. That theory is to be completely replaced because its basic postulate is refuted (falsified) experimentally. Predictions like mass-energy equivalence and Lorentz- Fitz Gerald transformations in STR have logically-consistent concrete proofs in CR. Without assuming the constancy of the velocity of light, as Einstein did in his STR, Prof Unnikrishnan described an alternate theory of Relativity with the Universe as an absolute frame of reference for all dynamics, with respect to which light can have non-constant speed.

In spite of several experimental proofs to support CR from experiments like GPS and LIGO, and special optical interferometry using lasers in Prof Unnikrishnans laboratory itself, the scientific community in India does not acknowledge Unnikrishnans findings. Instead, he was not given an extension of service as a Professor of Physics in TIFR so that he can complete his experimental works and was unceremoniously removed from the investigation group of LIGO India (now Unnikrishnan is a professor at the Defence Institute of Advanced Technology, of the DRDO, in Pune).

One can also remember the case of Prof E C G Sudarshan whose two seminal discoveries in weak interaction and quantum optics were ignored while considering the Nobel Prize inphysics. In the first case, one can admit that he was a research scholar at that time and his guide did not allow him to speak on the subject during an international Physics colloquium.

Sudarshan commented on the 1967 NP in Physics, "What I did for my PhD thesis in 1957 was probably one of the most important things in physics and they (the Nobel Foundation) should have nominated me at that time. If not then ten years later. No, they didnt. Instead, they gave the prize to somebody who did something on top of it. I usually say if you want to awardsomebody, you take the person who built the ground floor, not someone on the second andthird floors. That is what they did. Glashow, Salam and Weinberg did the next step to what Idid. Without the first step, they couldnt have done it."But, in the case of Quantum Optics, the situation is different. Sudarsan was a senior physicistwith the distinction of several discoveries and awards including the Dirac Medal, at the time. Usually, when one got Dirac Medal, he/she is sure to win NP. The work he developed was re-described by Glauber in detail including the fundamental physics of optics involved in the findings, so that his paper will seem to be more extensive than that of Sudarshan who wrote a short paper highlighting the gist of his discovery. In spite of the fact that Sudarshan should have given a major share in the NP, the committee recognized only Glauber for the award. Sudarshan did not hide his disagreement with the recommendation of the NP committee regarding the nonrecognition of his work.

Nothing happened anything more in this case even though the scientific community aroundthe globe stood up to talk against the decision of the NP committee. "I can assure you that it isnot impartial. For example, the prize given to Glauber, it is my prize. They gave it to him for things which I did. The prize is coveted because it is identified with excellence, and themajority of people who have got it, have gotten it for very good reasons. The very firstprize was given to Rontgen, who discovered X-rays. At that time it was because of the factthat people recognised that X-rays were very important for medicine. But afterwards, theygave it for all kinds of things. Like my friend, Glauber got the prize for... I dont knowwhat; it cannot be because of the excellence of his work."One of the latest works by Sudarshan is the resurrection of an aether and how this explains light propagation as waves. It is interesting to note that the algorithm for factual GPS corrections developed by Prof Unnikrishnan for his CR is also based on an absolute frame (matter-filled Universe) as the background, according to a recent conversation given by Prof Unnikrishnan to Asianet News Online. To watch the full interview, click the link.

One should not forget the Late Prof Thanu Padmanabhan (IUCAA, Pune, yet another scientist fromKerala) who described GTR in the light of classical thermodynamics and fused QuantumMechanics with GTR which was a task ( fusion of GTR with QM) taken up by many scientistswithout success. His untimely demise was a loss to the scientific community since he had moretheories which could have made physics more rich. In the following sections, we will describethe details of Unnikrishnans theory. Assuming that the velocity of light is an absolute fundamental constant only in the cosmic rest frame, determined physically by the gravitational interaction of light with the Universe Prof Unnikrishnan was able to show that CR implies all relativistic effects and that the velocity of light is Galilean in all other frames. It is very important to realize that the effects are gravitational in origin and that in an empty Universe, there will not be any relativistic effects, unlike in SR. It is possible to get convinced of this by considering the effect of distant galaxies on local physics.

For example, a moving clock experiences a cosmic gravitational potential that is different from what is experienced by a clock stationary in the Universe. Then it is gravitational time dilation that is responsible for the experimentally verified motional time dilation. Obviously, this solves the much-debated twin-paradox consistently and easily. The more fundamental theory -- Cosmic Relativity -- is based on the gravitational effects of the Universe and it is not limited to reference frames moving with uniform velocity.

Results for clock comparison experiments

Time dilation effects are very important for the experimental validation of cosmic relativityConsider a frame moving at velocity V with respect to the cosmic frame. We consider experiments in which there are clocks moving within this frame, which will be compared among themselves and with other clocks that are at rest within the frame. Consider a clock within this frame that is moving at velocity u relative to the coordinates inside the frame. SR asserts that no special relativistic time dilation expression should contain the velocity of the frame (with respect to some hypothetical frame in which the moving frame is embedded) in which the experiment is performed.

The cosmic gravitational time dilation has the characteristic imprint of the fact that there is a preferred cosmic frame with reference to which the time dilation is calculated. The clock that is stationary within the frame itself has a time dilation with respect to the clocks in the cosmic rest frame. (Such a clock is notionally provided by the temperature of the CMBR). We have to calculate the time dilation of the stationary clock and the moving clock with respect to the cosmic frame and then compare them.

The surprising new result is the dependence of the time dilation factor on the velocity of the frame. This is equivalent to considering all velocities relative to the cosmic rest frame or CMBR for calculating the time dilation effect. It is possible to have a moving clock inside a local frame age faster than a stationary clock in the same frame, in complete contrast to the special relativistic prediction. In SR, no local experiment should have a dependence on the velocity of the frame.

If a clock is taken around the earth along the equator at constant ground speed u, and brought back after a round trip, its time dilation with respect to a clock stationary on the surface is not given by the special relativistic factor predicted by Einstein in 1905. The correct result is given by Cosmic Relativity.The result that the clock in motion can age faster than a clock at remaining at rest within the laboratory frame is devastating for Einsteins SR. This can never happen in SR. For a clock moving at ground speed u along the instantaneous surface velocity (440 m/s) of the rotating earth with respect to the cosmic frame, and another one moving opposite (eastwards and westwards). If the clocks are taken around in aircraft with a velocity 220 m/s (average ground speed of about 800 km/hour), then the predicted asymmetry would be T 310 ns This is several times larger than the special relativistic time dilation, t 50 nsThe total time dilation asymmetry depends only on just the total path length covered in the experiment. It does not matter how fast the clocks are moved, provided we move them by the same distance. Slow transport will need more time, and the asymmetry depends only on the product of the velocity and duration. Thus if the clocks are taken around by walking around the earth eastwards and westwards along the equator, the clocks will show an asymmetry that is exactly equal to the one predicted for clocks taken around in fast flights! All these results have been already verified in the results of clock transport experiments, done as early as 1970 (Hafele-Keating experiment).

Experimental Evidence for Cosmic Relativity

The Sagnac effect was first discovered in optical interferometry. The phase shift in a rotating planar interferometer with area A, in which light travels in two opposite paths and returns to their starting point is given by .This expression is the same as the expression for the time asymmetry in round-trip clock comparisons. It is implied that the physical interaction responsible for the Sagnac effect is the gravity of the Universe.

Here we merely note that the total equivalence of the expression for the Sagnac effect forlight and matter waves arises from the fact that gravitational interaction is universal, and therefore the Sagnac effect does not depend on the group velocity of waves used in Sagnac interferometry (this result is not intuitively obvious, for example in a Sagnac interferometer that uses optical fibres, since the light pulse takes more time to circle around and yet the time difference between the clockwise and counterclockwise pulses is still given by the same equation.) Thus Cosmic Relativity is the generalized theory of relativity in flat spacetime since it does not distinguish between inertial and non-inertial motion.

Cosmic Relativity and physical effects in quantum systems

In cosmic relativity, the enigmatic connection between spin and statistics in quantum theory is seen to be a consequence of the gravitational interaction of the spin with the Universe. The interaction is gravitomagnetic in nature and gives us the result that identical integer spin particles obey Bose-Einstein statistics and identical half-integer spin particles obey Fermi-Dirac statistics. This is a deep result, and for the first time might answer the long-standing query-what are the physical reasons behind the spin-statistics connection? It also answers why the connection is valid in non-relativistic, two-particle situations despite the general impression that it is a consequence of relativistic field theory.

The fine structure in atoms, Spin in CR, and the Spin-Statistic connection

When the idea of electron spin was first proposed by Uhlenbeck and Goudsmit, they had not resolved the problem that the simple spin-orbit coupling ( L-S coupling) gives twice the experimentally observed value for the fine structure splitting. CR shows that the correct fine structure is obtained from a cosmic gravitational interaction. Spin in gravity is the equivalent of a magnetic moment in electrodynamics.

Any physical effect that exclusively depends on spin must be of gravitational origin. The spin-statistics connection is the following: a) Particles with integer spin are bosons and they obey the Bose-Einstein statistics. b) Particles with half-integer spin are fermions and they obey the Fermi-Dirac statistics. This simple division is behind most of the material variety in the physical world. A geometric understanding of these statements was published by Berry and Robbins and several authors have invoked the relation between rotation operators and exchange of particles in quantum mechanics to prove the spin-statistic theorem.

Sudarshan has been arguing for the existence of a simple proof that is free of argumentsspecific to relativistic quantum field theory. While these attempts have clarified several issues regarding the connection, none provides a physical understanding of the connection. It may be noted that physically the connection is applicable for any two identical particles, in non-relativistic quantum mechanics. Thus we should expect that the physical proof need not depend on relativistic quantum field theory.

Cosmic relativity shows that it is the gravitational interaction of the quantum particles with theentire Universe that is responsible for the spin-statistics connection. In other words, the Pauli exclusion is a consequence of the relativistic gravitational interaction with the critical Universe, which is always present.

The fundamental principle regarding the velocity of light

The fundamental principle of Cosmic Relativity is that the velocity of light is a fundamental constant only in the cosmic rest frame, determined by the local average gravitational potential due to the entire Universe in the cosmic rest frame. Relative to a moving observer, the relative velocity of light varies, just as for sound and other familiar waves. In SR, the constancy of the velocity of light in all frames is the defining assumption. So, the measurement of the one-way relative velocity can decisively settle which theory is correct. (Note that the Michelson-Morley experiment uses a two-way propagation of light and it's not suitable for deciding this fundamental issue of the nature of propagation of light, contrary to the general belief). An experiment was done in Unnikrishnans lab, progressively refining, to determine the genuineone-way relative velocity of light, and compare it to the behaviour of sound. The result decisively refutes and falsifies the defining postulate of Einsteins theory, and therefore, the theory itself.

Why is E=mc2?

We now discuss the physical relation between the velocity of light and the average gravitational potential of the Universe at any point. If the Universe started from pure nothingness, then it is expected that every constituent of this Universe has zero energy. One part of the energy is the gravitational interaction energy. Clearly, every mass at rest with respect to the cosmic frame should possess energy and can be seen as and thus E = mc2 as predicted by SR.

Conceptual and philosophical implications

There has been a significant change, in fact, the most profound and far-reaching, in the philosophical view on space and time after Einsteins relativity theory became understood. The development of Cosmic Relativity and experimental evidence favouring it will imply a large shift in our worldview. The new world-view will of course be different from the one that existed in pre-SR days, though Cosmic Relativity brings into focus a preferred frame we call the cosmic rest frame or the absolute frame. Since there is no aether, and since new circumstances arise in acknowledging the gravitational presence of the Universe, a world-view based on Cosmic Relativity will be different from the one induced by Special Relativity. It is important to note that the only aspect of the cosmos we have used in deducing a new theory of relativity is its approximate homogeneity and isotropy, and the fact that the Universe is nearly at critical density. These results imply a critical modification of General Relativity as well, in which the theory is endowed with the absolute matter frame of the Universe. This makes GTR totally Machian, which was indeed one of Einsteins passionate desires for his theory of General Relativity. There is also the question of whether there should be a change in our attitude towards quantizing gravity.

Space and time are un-observables, and really have no meaning in the absence of matter. It is a matter that defines, facilitates, and modifies measurements of spatial and temporal intervals. At present it suffices to mention that everything we know in General Relativity is consistent with Cosmic Relativity, and the harmony between the two is even better than in the case of General Relativity and Special Relativity.

We can now answer some of the doubts raised by Julian Barbour in his book, Absolute or Relative Motion?: Discovery of Dynamics .Cosmic Relativity strengthens these connections further, that relativistic modifications of spatial and temporal intervals, as well as several important effects specific to quantum systems, are the results of the gravitational interaction of the Universe with the local physical system. Thus the construction of Cosmic Relativity answers the important questions left unanswered by the pioneers like Newton, Mach and Einstein. A major monograph written by Unnikrishnan was published recently by Springer Nature (Nov. 2022) in which it is stated the theory of cosmic relativity addresses and answers all long-standing questions and puzzles in relativity and dynamics.

Conclusion

We discussed some of the revolutionary discoveries made by Prof C S Unnikrishnan through the proposal of Cosmic Relativity. There is no place for an axiom that the velocity of light is constant in all frames of reference as Einstein imposed to describe SR. It is high time that Prof Unnikrishnans CR should be discussed by the Physics community in India without any prejudices. One should note that when a new theory is emerged by shattering the foundations of existing theory, there is always an inertia among the specialists to accept it just as the inertial forces described by Newton in his laws of motion. Hope that we will hear positive discussions among the specialists so that a new paradigm shift will be created in unravelling the secrets of nature.

Prof V P N Nampoori is visiting scientist at the Cochin University of Science and Technology, Kerala University and M G University. Views expressed are personal

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India's Physics community must lend its ears to Cosmic Relativity that challenges Einstein's theory - Asianet Newsable

Software engineers get the ball rolling as they wait for quantum computers to arrive, a number of public Salesforce sites leak private data and the first wooden transistor is here.

These top tech news stories and more for Wednesday, May 3rd, 2023. Im your guest host, James Roy.

Weve heard a lot of endless superpowers of quantum computers, be it to revolutionize medical research or solve climate change. Millions are being poured into these machines, hailed as being a million times faster than todays fastest computers. But they are yet to hit the market.

However, quantum startups are getting creative despite lacking these powerful computers.

QC Ware, a software startup initially focused only on software that could run on quantum computers.

But the company now said it needed to change tack to find a solution until the future quantum machines arrive.

Investors are not shying away either, despite the dismal stock performance of publicly-listed quantum computer companies. QC Ware, in fact, raised more than $33 million.

What these startups are doing is nothing short of brilliant;

They are developing a new breed of software inspired by algorithms used in quantum physics which is a branch of science that studies the fundamental building blocks of nature.

These algorithms, once too big for conventional computers, are being put to work thanks to todays powerful artificial intelligence chips.

QC Ware CEO, Matt Johnson said it turned to Nvidias GPUs to figure out how can we get them something that is a big step change in performance and build a bridge to quantum processing in the future.

This week, QC Ware is unveiling a quantum-inspired software platform called Promethium that will simulate chemical molecules to see how they interact with things like protein on a traditional computer using GPUs.

The companys head of quantum chemistry said the software can cut simulation time from hours to minutes for molecules of 100 atoms, and months to hours for molecules of up to 2000 atoms, compared with existing software solutions.

Source: Reuters

According to a report by KrebsOnSecurity, a number of organizations, including banks, healthcare and government agencies are leaking private and sensitive information through their public Salesforce Community websites.

Reportedly, the leaking stems from a misconfiguration in Salesforce Community that allows an unauthenticated user to access records that should only be available after logging in.

Salesforce Community is a widely-used cloud-based software that makes it easy for organizations to create websites.

Customers can access a Salesforce Community website by either logging in or through guest user access, which allows unauthenticated users to view specific content and resources, without logging in.

But sometimes Salesforce administrators also mistakenly grant users access to internal resources which can cause unauthorized access and data leaks.

The state of Vermont, for instance, allowed guest access to sensitive data to at least five separate Salesforce Community websites, including one for a Pandemic Unemployment Assistance program that exposed applicants full name, SIN number, phone number, bank account number and more.

Vermonts Chief Information Security Officer Scott Carbee said, During the pandemic, we were largely standing up tons of applications, and lets just say a lot of them didnt have the full benefit of our dev/ops process. In our case, we didnt have any native Salesforce developers when we had to suddenly stand up all these sites.

But, Carbee also denounced the permissive nature of the platform

On Monday, KrebsOnSecurity notified Washington D.C. city administrators that at least five different public DC Health websites were leaking sensitive information.

Interim CISO, Mike Rupert said the District had hired a third party to investigate and it revealed that the Districts IT systems were not vulnerable to data loss.

But after being presented with a document including the Social Security number of a health professional in D.C. that was downloaded in real-time from the DC Health public Salesforce website, Rupert acknowledged his team had overlooked some configuration settings.

Meanwhile, Salesforce maintains that the data exposures are not the result of a vulnerability inherent to Salesforce but occur when customers access control permissions are misconfigured.

In a written statement, Salesforce said it is actively focused on data security for organizations with guest users, and that it continues to release robust tools and guidance for our customers.

Source: KrebsOnSecurity

The Federal Trade Commission (FTC) has a new proposed rule to fight the absolute headache that canceling subscriptions can be.

The proposed provision, Click-to-Cancel, seeks to make it as easy to cancel enrollment as it was to sign up.

FTC Chair Lina M. Khan said, Some businesses too often trick consumers into paying for subscriptions they no longer want or didnt sign up for in the first place.The proposal would save consumers time and money, and businesses that continued to use subscription tricks and traps would be subject to stiff penalties.

The new proposal will mandate a simple cancellation mechanism. For instance, if you signed up online, you must be able to cancel on the same website in the same number of steps.

Secondly, the proposal would require sellers to ask customers whether they want to be pitched other offers upon cancellation. Sellers must take no for an answer if thats the case and immediately expedite the cancellation process.

Finally, and that, no doubt would be helpful to many of us, the proposed rule would require sellers to provide an annual reminder to consumers enrolled in subscriptions, before they are automatically renewed.

Source: FTC

Akash Nigam, CEO of avatar technology company Genies revealed to Insider that he is spending $2,400 a month on ChatGPT accounts for all 120 of his employees as part of an experiment to boost productivity.

Nigam says he is already seeing stuff getting done faster.

He said that Genies R&D team, for instance, has used ChatGPT to answer math and coding questions, get advice on how to debug code, and generate scripts for presentations based on outlines. Other employees have used it to generate creative briefs, write legal documents and answer technical questions.

Not everyone is using ChatGPT but he is encouraging everyone to make learning the technology a priority.

Employees who are more productive as a result of using ChatGPT will be up for a raise or a promotion. Others, he says, will fall behind

He also believes that the use of the technology can help his company reduce costs as he will need to hire less employees.

Genies is not the only company diving head first with ChatGPT. Amazon, Microsoft and design firm Pure Fusion Media have also strongly encouraged employees to use AI.

Source: Insider

The link between increased cyberthreats and AI however, remains unclear. Some say it might be overblown.

John Dwyer, head of research at IBM Security X-Force, told Axios, Cybercriminals are often looking for the simplest, quickest schemes to make money, and bringing todays AI into play doesnt fit that bill.

If anything, its cyber defenders who will exploit AI to counter the run-of-the-mill security holes that criminals keep exploiting.

Palo Alto Networks and Mandiant are the big names already playing around ChatGPT and other AI tools to improve their security products.

Michael Sikorski, CTO of Palo Alto Networks threat intelligence team revealed that most of the malicious code spewed by AI tools are repurposed from previous attacks. He adds, maybe they are faster, but they are not new. And its definitely not trained on how to write a zero-day or find or exploit a vulnerability.

Plus, according to Chester Wisniewski, field CTO of applied research at Sophos, most hackers do not double up as data scientists or are not training the AI models themselves. Theyll need to bring make enough money from the malicious AI for it to be worth it.

But, Wisniewski says, the upside is the good guys do have data scientists, and many of us do spend millions of dollars in the cloud on GPUs

However, we still need to be wary. Many cybercriminals are using simple AI tools to get people to respond to phishing emails and scam texts.

And many companies continue to suffer from attacks with already publicly known flaws that companies failed to patch.

Rob Joyce, director of cybersecurity at the National Security Agency, said during the RSA Conference, Ill tell you, buckle up. Next year, if were talking a similar year in review, well have a bunch of examples of where its been used and where its succeeded.

Source: Axios

Swedish researchers have built what they claim is the worlds first wooden transistors.

Its shaped like a T and made from three pieces of balsa wood.

The top of the T served as the transistor channel, with a source at one end and a drain at the other, while the vertical portion of the T used two pieces of balsa with a gap between them to form the transistors gate pieces.

Before you start gathering your tools and your balsa wood, remember that in order to make the wood conductive, the researchers had to expose it to heat and use chemicals to replace the lignin with conductive polymer.

Once filled with the polymer and assembled, the Swedish team achieved conductivity up to 69 Sm-1, and were also able to prove the devices effectiveness as a double-gate organic electrochemical transistor and functional on/off switch.

Previous wooden transistors could only regulate ions transport and would stop functioning once the ion ran out. This one does not work like that and still functions without deteriorating.

But, unfortunately this breakthrough is not going to revolutionize the semiconductor industry. The balsa wood transistor is neither small nor fast. Its so slow its unable to switch off under a second and switching on takes a full five seconds. Not exactly super computing speeds.

But for the researchers, this proves that it is possible to modulate the electrical conductivity of the electroactive wood by applying an external voltage.

Source: The Register

One of our listeners sent in a note about yesterdays story where we reported that Pornhub was pulling out of Utah. Apparently searches for Virtual Private Networks (VPNs) that allow people to disguise their location went off the charts. Probably a coincidence just a lot of folks trying to watch Charles coronation on BritBox. I mean its Utah they wouldnt.

Thanks to Nemanja for that we love your comments, keep it coming.

Thats the top tech news for today. We go to air with a daily newscast five days a week, as well as a special weekend interview with an expert on topics relevant to todays tech news.

Follow Hashtag Trending on Google, Apple, Spotify or wherever you get your podcasts. And you can even get us on your Alexa or Google smart speaker. You can even find us on YouTube as TechNewsDay.

You can reach our CIO, Jim Love on LinkedIn, Twitter, or on Mastodon as @therealjimlove on our Mastodon site technews.social. Or if thats too much, just leave a comment under the text version at itworldcanada.com/podcasts Click the check mark or the X youll get to send a message that comes right to me.

Im your host, James Roy. Have a Wonderful Wednesday!

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Hashtag Trending May 3- Quantum startups get creative while waiting for quantum computers to arrive; sites built on Salesforce Community leak private...

This article has been reviewed according to ScienceX's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility:

fact-checked

peer-reviewed publication

trusted source

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by Jos Tadeu Arantes , FAPESP

Quantum theory, which was formulated in the first three decades of the twentieth century, describes a wide array of phenomena at the molecular, atomic and subatomic scales. Among its many technological applications, three have become ubiquitous in daily life: laser barcode scanners, light-emitting diodes (LEDs) and the global positioning system (GPS).

Nevertheless, quantum physics is still not entirely understood, and some of the phenomena concerned appear to fly in the face of common sense or everyday empirical experience, surprising not only the average layperson but also physicists and philosophers of science. Some of the counterintuitive aspects of quantum theory are due to its probabilistic nature. It offers a set of rules for calculating the probabilities of the possible measurement outcomes of physical systems and in general cannot predict the actual result of a single measurement.

One of the challenging ideas presented by quantum physics is non-locality, an aspect of reality manifested when two or more systems are generated or interact in such a way that the quantum states of any system cannot be described independently of the quantum states of the others. Technically speaking, scientists call such systems entangled, since they are strongly correlated even at a distance and their quantum state is not defined by the quantum states of their component parts.

Another challenging idea, which seems to point in the opposite direction, is contextuality, according to which the outcome of measuring a quantum object depends on the context, meaning other compatible measurements performed at the same time.

Non-locality and contextuality were born with quantum theory but followed independent paths for several decades. In 2014, scientists conducted a study involving a particular case in which they showed that only one of them can be observed in a quantum system. This finding became known as monogamy. The authors conjectured that non-locality and contextuality were different facets of the same general behavior observed either in one way or the other.

Now, however, a study by Brazilian and Chinese researchers has shown both theoretically and experimentally that this is not so. An article on the study is published in Physical Review Letters and highlighted as an Editors' Suggestion.

The research was led by Rafael Rabelo, last author of the article and a professor at the State University of Campinas's Gleb Wataghin Institute of Physics (IFGW-UNICAMP) in Brazil.

The first authors are Peng Xue and Lei Xiao of Beijing Computational Science Research Center in China. The other co-authors, all affiliated with Brazilian institutions, are Gabriel Ruffolo and Andr Mazzari, also researchers at IFGW-UNICAMP; Marcelo Terra Cunha of the same university's Institute of Mathematics, Statistics and Scientific Computing (IMECC-UNICAMP); and Tassius Temstocles of the Federal Institute of Alagoas.

"We proved that both phenomena can indeed be observed concurrently in quantum systems. The theoretical approach was developed here in Brazil and validated in a quantum optics experiment by our Chinese collaborators," Rabelo told Agncia FAPESP.

The new study shows definitively that two of the fundamental ways in which quantum physics differs from classical physics can be observed at the same time in the same system, contrary to the usual belief. "Non-locality and contextuality, therefore, are clearly not complementary manifestations of the same phenomenon," Rabelo said.

In practical terms, non-locality is an important resource for quantum encryption, while contextuality is the basis for a specific quantum computing model, among other applications. "The possibility of having both at the same time in the same system could pave the way to the development of new quantum information processing and quantum communications protocols," he said.

The idea of non-locality was a sort of answer to the objection raised by Albert Einstein (1879-1955) to the probabilistic nature of quantum physics. In a seminal article published in 1935, Einstein, Boris Podolsky (1896-1966) and Nathan Rosen (1909-1995), or EPR, questioned the completeness of quantum theory.

They proposed a thought experiment known as the EPR paradox: to justify certain non-classical correlations deriving from entanglement, distant quantum systems would have to exchange information instantly, which is impossible according to the special theory of relativity. They concluded that this paradox was due to the incompleteness of quantum theory. The incompleteness, EPR argued, could be corrected by including local hidden variables that would make quantum physics as deterministic as classical physics.

"In 1964, British physicist J.S. Bell (1928-1990) revisited the EPR argument, introducing an elegant formalism that encompassed all theories of local hidden variables regardless of the particular properties each variable might have. Bell proved that none of these theories could reproduce the correlations between measurements performed on two systems predicted by quantum physics. In my view, this result, later known as Bell's theorem, is one of the most important pillars of quantum physics. The property of having strong correlations that can't be reproduced by any local theory is now known as Bell non-locality. Alain Aspect, John Clauser and Anton Zeilinger were awarded the 2022 Nobel Prize in Physics for observing Bell non-locality experimentally, among other achievements," Rabelo said.

Another important result deriving from the discussion of hidden variables was presented in an article by Simon Kochen (1934-) and Ernst Specker (1920-2011), published in 1967. The authors demonstrated that, owing to the structure and mathematical properties of quantum measurements, any theory of hidden variables that reproduces the predictions of quantum physics must exhibit a contextuality aspect.

"Despite the common motivation, studies of Bell non-locality and Kochen-Specker contextuality followed independent paths for quite a long time. Only recently has there been growing interest in finding out whether both phenomena could be manifested concurrently in the same physical system. In an article published in 2014, Pawel Kurzynski, Adn Cabello and Dagomir Kaszlikowski said no. They showed why through a particular case but an interesting one, nonetheless. We've now refuted that 'no' in our study," Rabelo said.

More information: Peng Xue et al, Synchronous Observation of Bell Nonlocality and State-Dependent Contextuality, Physical Review Letters (2023). DOI: 10.1103/PhysRevLett.130.040201

Journal information: Physical Review Letters

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Study proves compatibility of two fundamental principles of quantum theory - Phys.org

Science and nature books

Quantum computers will transform our world, curing cancer and fixing the climate crisis, says the scientist and sci-fi fan but can they be made to work?

Sat 22 Apr 2023 04.00 EDT

Have you been feeling anxious about technology lately? If so, youre in good company. The United Nations has urged all governments to implement a set of rules designed to rein in artificial intelligence. An open letter, signed by such luminaries as Yuval Noah Harari and Elon Musk, called for research into the most advanced AI to be paused and measures taken to ensure it remains safe trustworthy, and loyal. These pangs followed the launch last year of ChatGPT, a chatbot that can write you an essay on Milton as easily as it can generate a recipe for everything you happen to have in your cupboard that evening.

But what if the computers used to develop AI were replaced by ones able to make calculations not millions, but trillions of times faster? What if tasks that might take thousands of years to perform on todays devices could be completed in a matter of seconds? Well, thats precisely the future that physicist Michio Kaku is predicting. He believes we are about to leave the digital age behind for a quantum era that will bring unimaginable scientific and societal change. Computers will no longer use transistors, but subatomic particles, to make calculations, unleashing incredible processing power. Another physicist has likened it to putting a rocket engine in your car. How are you feeling now?

Kaku seems pretty relaxed about it all some might say boosterish. He talks to me via Zoom from his apartment on Manhattans Upper West Side. Seventy-six and retired from research, he still teaches at the City University of New York where he is professor of theoretical physics and gets to do the fun stuff. A fan of Isaac Asimov, he tells me that hes currently teaching a course on the physics of science fiction. I talk about what is known and not known about time travel, space warps, the multiverse, all the things you see in Marvel Comics, I break it down. His website describes him as a futurist and populariser of science and his new book, Quantum Supremacy, sketches out all the promise of quantum computing and very little of the downside. Though he has the long white hair of the stereotypical mad scientist, it is swept back elegantly. He speaks at the pace of a practised lecturer, with the occasional outbreak of mild bemusement pitching his voice a little higher.

Kaku has a simple explanation for the doom-mongering around ChatGPT: Journalists are hyperventilating about chatbots because they see that their job is on the line. Many jobs have been on the line historically, but no one really said much about them. Now, journalists are right there in the crosshairs. This is a somewhat partial view a report by Goldman Sachs recently estimated that 300m jobs are at risk of automation as a result of AI. Kaku does admit that we might see sentient machines emerging from laboratories but reckons that could take another hundred years or so. In the meantime, he thinks theres a lot to feel good about.

The rocket engine of quantum computing will, Kaku says, completely transform research in chemistry, biology and physics, with all sorts of knock-on effects. Among other things, it will enable us to take CO2 out of the atmosphere and turn it into fuel, with the waste products captured and used again so-called carbon recycling. It will help us extract nitrogen from the air without the high temperatures and pressures that mean fertiliser production currently accounts for 2% of the energy used on Earth, leading to a new green revolution. It will allow us to create super-efficient batteries to help renewables go further (todays lithium-ion batteries only carry about 1% of the energy stored in gasoline). It will solve the design and engineering challenges currently stopping us from generating cheap, abundant power via nuclear fusion. And it will lead to radically effective treatments for cancer, Alzheimers and Parkinsons diseases, alongside a host of others.

How? The main thing to understand is that quantum computers can make calculations much, much faster than digital ones. They do this using qubits, the quantum equivalent of bits the zeros and ones that convey information in a conventional computer. Whereas bits are stored as electrical charges in transistors etched on to silicon chips, qubits are represented by properties of particles, for example, the angular momentum of an electron. Qubits superior firepower comes about because the laws of classical physics do not apply in the strange subatomic world, allowing them to take any value between zero and one, and enabling a mysterious process called quantum entanglement, which Einstein famously called spukhafte Fernwirkung or spooky action at a distance. Kaku makes valiant efforts to explain these mechanisms in his book, but its essentially impossible for a layperson to fully grasp. As the science communicator Sabine Hossenfelder puts it in one of her wildly popular YouTube videos on the subject: When we write about quantum mechanics, were faced with the task of converting mathematical expressions into language. And regardless of which language we use, English, German, Chinese or whatever, our language didnt evolve to describe quantum behaviour.

What were left with are analogies of varying helpfulness, for example the toy trains with compasses on them and mice in mazes that Kaku invokes to explain such complex ideas as superposition and path integrals. Beyond these, there is one important takeaway: reality is quantum, and so quantum computers can simulate it in a way that digital ones struggle to. Mother Nature does not compute digitally, he tells me. Quantum computers should [be able to] unravel the secrets of life, the secrets of the universe, the secrets of matter, because the language of nature is the quantum principle. If you want to know precisely how photosynthesis works (still a mystery to modern science), or how one protein interacts with another in the human body, you will be able to use the virtual lab of a quantum computer to model it precisely. Designing medicines to interrupt biological processes gone awry, like the proliferation of cancer cells or the misfolding of proteins in Alzheimers disease, could become much easier. Kaku even reckons that the riddle of ageing will be unravelled so that we can arrest it one of the chapters in his book is called simply Immortality.

At this stage, its worth introducing an important caveat. Quantum computers are very, very hard to make. Because they rely on tiny particles that are extremely sensitive to any kind of disturbance, most can only run at temperatures close to absolute zero, where everything slows down and theres minimal environmental noise. That is, as you would expect, quite difficult to arrange. So far, the most advanced quantum computer in the world, IBMs Osprey, has 433 qubits. This might not sound like much, but as the company points out the number of classical bits that would be necessary to represent a state on the Osprey processor far exceeds the total number of atoms in the known universe. What they dont say is that it only works for about 70 to 80 millionths of a second before being overwhelmed by noise. Not only that, but the calculations it can make have very limited applications. As Kaku himself notes: A workable quantum computer that can solve real-world problems is still many years in the future. Some physicists, such as Mikhail Dyakonov at the University of Montpellier, believe the technical challenges mean the chances of a quantum computer that could compete with your laptop ever being built are pretty much zero.

Kaku brushes this off. He points to the billions of dollars being poured into quantum research the Gold Rush is on he says and the way intelligence agencies have been warning about the need to get quantum-ready. Thats hardly proof positive theyll live up to expectations it could be tulip mania rather than a gold rush. He shrugs: Lifes a gamble.

In any case, hes far from the only true believer. Corporations such as IBM, Google, Microsoft and Intel are investing heavily in the technology, as is the Chinese government, which has developed a 113 qubit computer called Jiuzhang. So, assuming for a moment quantum dreams do become a reality: is it responsible to accentuate the positive, as Kaku does? What about the possibility of these immense capabilities being used for ill?

Well, thats the universal law of technology, that [it] can be used for good or evil. When humans discovered the bow and arrow, we could use that to bring down game and feed people in our tribe. But of course, the bow and arrow can also be used against our enemies.

Advances in physics, in particular, have always raised the prospect of new and more fearsome weapons. But you cant hold back research as a result: you make the discoveries, then you deal with the consequences. Thats why we regulate nuclear weapons. Nuclear weapons are a rather simple consequence of Einsteins E=mc2. And they have to be regulated, because the E would be enough to destroy humanity on planet Earth. At some point, were going to reach the boundaries of this technology, where it impacts negatively on society. Right now, I can see a lot of benefits.

In any case, for Kaku, knowledge is power. Its part of the reason hes moved from the lab to TV, radio and books. The whole purpose of writing books for the public is so that [they] can make educated, reasonable, wise decisions about the future of technology. Once technology becomes so complicated that the average person cannot grasp it, then theres big trouble, because then people with no moral compass will be in charge of the direction of that technology.

There are other reasons, as well. From an early age, Kaku was, unsurprisingly, a science fiction nut. But he wasnt content to simply swallow the stories, and wanted to know if they were really possible, whether the laws of physics might verify or contradict them. And in the science section, there was nothing, absolutely nothing. And I was [also] fascinated by Einsteins dream of a theory of everything, a unified field theory. Again I found nothing, not a single book, on Einsteins great dream. And I said to myself, when I grow up, and I become a theoretical physicist, I want to write papers on this subject. But I also want to write for myself as a child, going to the library and being so frustrated that there was nothing for me to read. And thats what I do.

Kakus parents were among those American citizens of Japanese descent who were interned during the second world war, despite having been born in the country. Like his father, he was raised in Palo Alto, California, the ground zero of the tech revolution. The irony isnt lost on him. I saw Silicon Valley grow from nothing. When I was a child, it was all alfalfa fields, apple orchards. I used to play in the apple orchards of what is now Apple, he chuckles. If his predictions about the quantum revolution are correct, it could soon be transformed again. Silicon Valley could become a rust belt a junkyard of chips that no one uses any more because theyre too primitive. Or, more likely, a gleaming new centre of quantum computation, as todays tech giants scramble to redeploy their immense intellectual and financial capital. Whether Kakus quantum revolution lives up to the hype remains to be seen. But if he is right and all that is digital passes into dust, were in for one hell of a ride.

Quantum Supremacy by Michio Kaku will be published by Allen Lane on 2 May. To support the Guardian and Observer order your copy at guardianbookshop.com

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Physicist Michio Kaku: We could unravel the secrets of the universe - The Guardian

Picture a cat. Im assuming youre imagining a live one. It doesnt matter. Youre wrong either waybut youre also right.

What Is Carbon Capture? With Gizmodos Molly Taft | Techmodo

This is the premise of Erwin Schrdingers 1935 thought experiment to describe quantum states, and now, researchers have managed to create a fat (which is to say, massive) Schrdinger cat, testing the limits of the quantum world and where it gives way to classical physics.

Schrdingers experiment is thus: A cat is in a box with a poison that is released from its container if an atom of a radioactive substance, also in the box, decays. Because it is impossible to know whether or not the substance will decay in a given timeframe, the cat is both alive and dead until the box is opened and some objective truth is determined. (You can read more about the thought experiment here.)

In the same way, particles in quantum states (qubits, if theyre being used as bits in a quantum computer) are in a quantum superposition (which is to say, both alive and dead) until theyre measured, at which point the superposition breaks down. Unlike ordinary computer bits that hold a value of either 0 or 1, qubits can be both 0 and 1 simultaneously.

Now, researchers made a Schrdingers cat thats much heavier than those previously created, testing the muddy waters where the world of quantum mechanics gives way to the classical physics of the familiar macroscopic world. Their research is published this week in the journal Science.

In the place of the hypothetical cat was a small crystal, put in a superposition of two oscillation states. The oscillation states (up or down) are equivalent to alive or dead in Schrdingers thought experiment. A superconducting circuit, effectively a qubit, was used to represent the atom. The team coupled electric-field creating material to the circuit, allowing its superposition to transfer over to the crystal. Capiche?

By putting the two oscillation states of the crystal in a superposition, we have effectively created a Schrdinger cat weighing 16 micrograms, said Yiwen Chu, a physicist at ETH Zurich and the studys lead author, in a university release.

16 micrograms is roughly equivalent to the mass of a grain of sand, and thats a very fat cat on a quantum level. Its several billion times heavier than an atom or molecule, making it the fattest quantum cat to date, according to the release.

Its not the first time physicists have tested whether quantum behaviors can be observed in classical objects. Last year, a different team declared they had quantum-entangled a tardigrade, though a number of physicists told Gizmodo that claim was poppycock.

This is slightly different, as the recent team was just testing the mass of an object in a quantum state, not the possibility of entangling a living thing. While thats not in the teams plans, working with even larger masses will allow us to better understand the reason behind the disappearance of quantum effects in the macroscopic world of real cats, Chu said.

As for the true boundary between the two worlds? No one knows, wrote Matteo Fadel, a physicist at ETH Zurich and a co-author of the paper, in an email to Gizmodo. Thats the interesting thing, and the reason why demonstrating quantum effects in systems of increasing mass is so groundbreaking.

The new research takes Schrdingers famous thought experiment and gives it some practical applications. Controlling quantum materials in superposition could be useful in a number of fields that require very precise measurements; for example, helping reduce noise in the interferometers that measure gravitational waves.

Fadel is currently studying whether gravity plays a role in the decoherence of quantum states, namely if it is responsible for the quantum-to-classical transition as proposed a couple of decades ago by Penrose. Gravity doesnt seem to exist on the subatomic level and is not accounted for in the Standard Model of particle physics.

The quantum world ripe for new discoveries, but alas, its crammed full of unknowables, dead ends, and vexing new problems.

More: Scientists Save Schrdingers Cat

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Physicists Create the Fattest Schrdinger's Cat Ever - Gizmodo

When new assistant professor of physics Lee McCuller was young, he liked to build things. His uncle made him a power supply, which he integrated with electronic hobby kits from RadioShack to do simple things like use analog circuits to switch lights and motors on and off. Today, McCuller tinkers with what some would call the most advanced measurement device in the world: LIGO, or the Laser Interferometer Gravitational-wave Observatory.

McCuller is an expert on quantum squeezing, a method used at LIGO to make incredibly precise measurements of gravitational waves that travel millions and billions of light-years across space to reach us. When black holes and collapsed stars, called neutron stars, collide, they generate ripples in space-time, or gravitational waves. LIGO's detectorslocated in Washington and Louisianaspecialize in picking up these waves but are limited by quantum noise, an inherent property of quantum mechanics that results in photons popping in and out of existence in empty space. Quantum squeezing is a complex method for reducing this unwanted noise.

Research into quantum squeezing and related measurements ramped up as far back as the 1980s, with key theorical studies by Caltech's Kip Thorne (BS '62), Richard P. Feynman Professor of Theoretical Physics, Emeritus, along with physicist Carl Caves (PhD '79) and others worldwide. Those theories inspired the first experimental demonstration of squeezing in 1986 by Jeff Kimble, the William L. Valentine Professor of Physics, Emeritus. The next decades saw many other advances in squeezing research, and now McCuller is at the leading edge of this innovative field. For example, he has been busy developing "frequency-dependent" squeezing that will greatly enhance LIGO's sensitivity when it turns back on in May of this year.

After earning his bachelor's degree from the University of Texas at Austin in 2010, McCuller attended the University of Chicago, where he earned his PhD in physics in 2015. There he began work on an experiment called the Fermilab Holometer, which looked for a speculative type of noise that would link gravity with quantum mechanics. It was during this project that McCuller met LIGO scientists, including MIT's Rai Weisswho together with Thorne and Barry Barish, the Ronald and Maxine Linde Professor of Physics, Emeritus, won the Nobel Prize in Physics in 2017 for their groundbreaking work on LIGO. McCuller was inspired by Weiss and the LIGO project and decided to join MIT in 2016. He became an assistant professor at Caltech in 2022.

In the future, McCuller hopes to take the quantum measurement tools he has developed for LIGO and apply them to other problems. "If LIGO is the most precise ruler in the world, then we want to make those rulers available to everyone," he says.

We met with McCuller over Zoom to learn more about quantum squeezing and its future applications to other fields as well as what inspired McCuller to join Caltech.

After I graduated from University of Chicago in 2015, I went to work on LIGO at MIT. When I walked in the door, they were having a meeting about the first detection of gravitational waves! The public didn't know yet, but there had been rumors. It was exciting to learn the rumors were true, and it was nice to see everyone overjoyed that things were working.

There was a local experiment taking place at that time on using squeezed light in the frequency-dependent manner that will start up at LIGO later this year. My job was to help build the first full-scale demonstration of this. The group, before me, had previously demonstrated the concept but not at the full scale. I was there was to show exactly what would be needed to employ it in the LIGO observatories. This required a particularly challenging experimental setup.

At each of the observatory locations, LIGO uses laser beams to measure disturbances in space-timethe gravitational waves. The laser beams are shot out at 90-degrees from each other and travel down two 4-kilometer-long arms. They reflect off mirrors and travel back down the arms to meet back up. If a gravitational wave passes through space, it will stretch and squeeze LIGO arms such that the lasers will be pushed out of sync; when they meet back up, the combined laser will create an interference pattern.

At the quantum level, there are photons in the laser light that hit the mirrors at different times. We call this shot noise, or quantum noise. Imagine dumping out a can full of BBs. They all hit the ground and click and clack independently. The BBs are randomly hitting the ground, and that creates a noise. The photons are like the BBs and hit LIGO's mirrors at irregular times. Quantum squeezing, in essence, makes the photons arrive more regularly as if the photons are holding hands rather than traveling independently. And this means that you can more precisely measure the phase or frequency of the light inside LIGOand ultimately detect even fainter gravitational waves.

To squeeze light, we are basically pushing the uncertainty inherent in light waves from one feature to another. We are making the light more certain in its phase, or frequency, and less certain in its amplitude, or power [the uncertainty principle says that both the exact frequency and amplitude of a light wave cannot be known at the same time]. To really explain the details of how squeezing actually works is very hard! I primarily know how to use math to describe it.

An interesting thing about squeezed light is that we aren't doing anything to the actual laser. We don't even touch it. When we operate LIGO, we offset the arms so that its wave interference is not perfectly darka small amount of light gets through. The little bit of light that remains has an electrical field that interferes with quantum fluctuations in the vacuum, or empty space, and this leads to the shot noise or the photons acting like BBs as we talked about earlier. When we squeeze light, we are actually squeezing the vacuum so that the photons have lower uncertainty in their frequency.

Up until now, we have been squeezing light in LIGO to reduce uncertainty in the frequency. This allows us to be more sensitive to the high-frequency gravitational waves within LIGO's range. But if we want to detect lower frequencieswhich occur earlier in, say, a black hole merger, before the bodies collidewe need to do the opposite: we want to make the light's amplitude, or power, more certain and the frequency less certain. At the lower frequencies, the shot noise, our BB-like photons, push the mirrors around in different ways. We want to reduce that. Our new frequency-dependent cavity at the LIGO detectors is designed to reduce the frequency uncertainty in the high frequencies and the amplitude uncertainties in the low frequencies. The goal is to win everywhere and reduce the unwanted mirror motions.

Part of the reason this technology is more important in the next run is because we are turning up the power on our lasers. With more power, you get more pressure on the mirrors. Our new squeezing technology will allow us to turn the power up without creating the unwanted mirror motions.

What this means is that we will be even more sensitive to the early phases of black hole and neutron star mergers, and that we can see even fainter mergers.

One project I'm working on involves Kathryn Zurek and Rana Adhikari. We are building a tabletop-size detector that will attempt to pick up signatures of quantum gravity, or pixels in space and time as some people say. The idea there is to make interferometers more like high-energy-physics detectors. The detectors would click when something passes through it, largely circumventing the impacts of shot noise. I love the motivation of the projectquantum gravity, which is the quest to merge theories of gravity with quantum physics. It is a very lofty goal.

In general, what I hope to do is grow from the LIGO work and apply quantum measurement techniques to not only enhance the gravitational wave detectors but also to see where other fundamental physics experiments or technologies can be improved. I want to use quantum optics not necessarily for computation or for information but for measurement. Squeezing light is one of the first demonstrations of these concepts in a real experiment. The hope is that we can keep using these quantum techniques in more and more experiments. We want to take the advantages of LIGO and find all the places where we can apply them.

Caltech has a lot of mission-oriented scientists. It's not just about learning or demonstrating or exploringit's the mix of all these things. I like a place where the goal is to integrate technologies and do new experiments. Take LIGO for instance. Few people know how the whole thing works and many of them are here. Caltech is a place where people understand that what we are doing is hard. Good projects require both narrow and broad expertise, and a combination of the right people. The students are similarly motivated by both the science goals and the process. We are not just trying to build something that reliably works, we are also trying to build something that's at the edge of what is possible.

Excerpt from:

At the Edge of Physics - Caltech