Category Archives: Quantum Physics

There are two kinds of geniuses, argued the celebrated mathematician Mark Kac. There is the ordinary kind, whom we could emulate if only we were a lot smarter than we actually are because there is no mystery as to how their minds work. After we have understood what they have done, we believe (perhaps foolishly) that we could have done it too. When it comes to the second kind of genius, the magician, even after we have understood what has been done, the process by which it was done remains forever a mystery.

Werner Heisenberg was definitely a magician, who conjured up some of the most remarkable insights into the nature of reality. Carlo Rovelli recounts the first act of magic performed by Heisenberg in the opening of Helgoland, his remarkably wide-ranging new meditation on quantum theory.

Rovelli has taken the title from the name of the rocky, barren, windswept island in the North Sea to where the 23-year-old German physicist fled in June 1925 to recover from a severe bout of hay fever and in need of solitude to think. It was during these few days on the island (also called Heligoland) that, on completing calculation after calculation, Heisenberg made a discovery that left him dizzy, shaken and unable to sleep.

With the light touch of a skilled storyteller, Rovelli reveals that Heisenberg had been wrestling with the inner workings of the quantum atom in which electrons travel around the nucleus only in certain orbits, at certain distances, with certain precise energies before magically leaping from one orbit to another. Among the unsolved questions he was grappling with on Helgoland were: why only these orbits? Why only certain orbital leaps? As he tried to overcome the failure of existing formulas to replicate the intensity of the light emitted as an electron leapt between orbits, Heisenberg made an astonishing leap of his own. He decided to focus only on those quantities that are observable the light an atom emits when an electron jumps. It was a strange idea but one that, as Rovelli points out, made it possible to account for all the recalcitrant facts and to develop a mathematically coherent theory of the atomic world.

For all its strangeness, quantum theory explains the functioning of atoms, the evolution of stars, the formation of galaxies, the primordial universe and the whole of chemistry. It makes our computers, washing machines and mobile phones possible. Although it has never been found wanting by any experiment, quantum theory remains more than a little disturbing for challenging ideas that we have long taken for granted.

One of the most well-known counterintuitive discoveries was arguably Heisenbergs greatest act of quantum conjuring. The uncertainty principle forbids, at any given moment, the precise determination of both the position and the momentum of a particle. It is possible to measure exactly either where a particle is or how fast it is moving, but not both simultaneously. In a quantum dance of give-and-take, the more accurately one is measured the less precisely the other can be known or predicted. Heisenbergs uncertainty principle is not due to any technological shortcomings of the equipment, but a deep underlying truth about the nature of things.

According to some, including Heisenberg, there is no quantum reality beyond what is revealed by an experiment, by an act of observation. Take Erwin Schrdingers famous mythical cat trapped in a box with a vial of poison. It is argued that the cat is neither dead nor alive but in a ghostly mixture, or superposition, of states that range from being totally dead to completely alive and every conceivable combination in between until the box is opened. It is this act of observation, opening the box, which decides the fate of the cat. Some would argue that the cat was dead or alive, and to find out one just had to look in the box. Yet in the many worlds interpretation of quantum theory, which is popular among physicists, each and every possible outcome of a quantum experiment actually exists. Schrdingers cat is alive in one universe and dead in another.

With the fate of Schrdingers cat in the balance and Heisenbergs idea that quantum theory only describes observations, Rovelli inevitably asks the tricky questions: what is an observation? What is an observer?

He admits he is not an innocent bystander; he has skin in the game when it comes to trying to understand the quantum nature of reality. He is the champion of the relational interpretation that maintains quantum theory does not describe the way in which quantum objects manifest themselves to observers, but describes how every physical object manifests itself to any other physical object. The world that we observe is continuously interacting; it is better understood as a web of interactions and relations rather than objects.

Individual objects are summed up by the way in which they interact. If there were an object that had no interactions, no effect on anything, it would be as good as non-existent. When the electron does not interact with anything, Rovelli argues, it has no physical properties. It has no position; it has no velocity.

If all wasnt challenging enough, Rovelli reveals that he is not afraid to mix quantum physics and eastern philosophy, something that others have done in the past with little success and some derision. It says much about him and his argument that he is not so easily dismissed. He has help in the form of one of the most important texts of Buddhism, Mulamadhyamakakarika, or The Fundamental Verses of the Middle Way. Written in the second century by the Indian philosopher Nagarjuna, its central argument is simply that there is nothing that exists in itself, independently from something else. Its a perspective that Rovelli believes makes it easier to think about the quantum world. He may be right, but the words of Niels Bohr still come to mind: Those who are not shocked when they first come across quantum theory cannot possibly have understood it.

Helgoland, translated by Erica Segre and Simon Carnell, is published by Allen Lane (20). To order a copy go to guardianbookshop.com. Delivery charges may apply.

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Helgoland by Carlo Rovelli review a meditation on quantum theory - The Guardian

We take for granted the western concept of linear time. In ancient Greece, time was cyclical and if the Big Bounce theory is true, they were right. In Buddhism, there is only the eternal now. Both the past and the future are illusions. Meanwhile, the Amondawa people of the Amazon, a group that first made contact with the outside world in 1986, have no abstract concept of time. While we think we know time pretty well, some scientists believe our linear model hobbles scientific progress. We're missing whole dimensions of time, in this view, and our limited perception could be the last obstacle to a sweeping theory of everything.

Theoretical physicist Itzhak Bars of the University of Southern California, Los Angeles, is the most famous scientist with such a hypothesis, known as two-time physics. Here, time is 2D, visualized as a curved plane interwoven into the fabric of the "normal" dimensionsup-down, left-right, and backward-forward. While the hypothesis is over a decade old, Bars isn't the only scientist with such an idea. But what's different with spacekime theory is that it uses a data analytics approach, rather than a physics one. And while it posits that there are at least two dimensions of time, it allows for up to five.

In the spacekime model, space is 5D. Besides the ones we normally encounter, the extra dimensions are so infinitesimally small, we never notice them. This relates to the KaluzaKlein theory developed in the early 20th century, which stated that there might be an extra, microscopic dimension of space. In this view, space would be curved like the surface of Earth. And like Earth, those who travel the entire distance would, eventually, loop back to their place of origin.

Kaluza-Klein theory unified electromagnetism and gravity, but wasn't accepted at the time, although it did help in the search for quantum gravity. The concept of additional dimensions was revived in the 1990s with Paul Wesson's Space-Time-Matter Consortium. Today, proponents of superstring theory say there may be as many as 10 different dimensions, including nine of space and one of time.

Spacekime theory was developed by two data scientists. Dr. Ivo Dinov is the University of Michigan's SOCR Director, as well as a professor of Health Behavior and Biological Sciences, and Computational Medicine and Bioinformatics. SOCR stands for: Statistics Online Computational Resource designs. Dr. Dinov is an expert in "mathematical modeling, statistical analysis, computational processing, scientific visualization of large datasets (Big Data) and predictive health analytics." His research has focused on mathematical modeling, statistical inference, and biomedical computing.

His colleague, Dr. Milen Velchev Velev, is an associate professor at the Prof. Dr. A. Zlatarov University in Bulgaria. He studies relativistic mechanics in multiple time dimensions, and his interests include "applied mathematics, special and general relativity, quantum mechanics, cosmology, philosophy of science, the nature of space and time, chaos theory, mathematical economics, and micro-and-macroeconomics."

Drs. Dinov and Velev began developing spacekime theory around four or five years ago, while working with big data in the healthcare field. "We started looking at data that intrinsically has a temporal dimension to it," Dr. Dinov told me during a video chat. "It's called longitudinal or time varying data, longitudinal time varianceit has many, many names. This is data that varies with time. In biomedicine, this is the de facto, standard data. All big health data is characterized by space, time, phenotypes, genotypes, clinical assessments, and so forth."

"We started asking big questions," Dinov said. "Why are our models not really fitting too well? Why do we need so many observations? And then, we started playing around with time. We started digging and experimenting with various things. And then we realized two important facts.

"Number one, if we use what's called color-coded representations of the complex plane, we can define spacekime, or higher dimensional spacetime, in such a way that it agrees with the common observations that we make in (the longitudinal time series in) ordinary spacetime. That agreement was very important to us, because it basically says, yes, the higher dimensional theory does not contradict our common observations.

"The second realization was that, since this extra dimension of time is imperceptible, we needed to approximate, model, or estimate, one of the unobservable time characteristics, which we call the kime phase. After about a year, we discovered that there is a mathematically elegant tool called the Laplace Transform that allows us to analytically represent time series data as kime-surfaces. Turns out, the spacekime mathematical manifold is a natural, higher dimensional extension of classical Minkowski, four-dimensional spacetime."

Our understanding of the world is becoming more complex. As a result, we have big data to contend with. How do we find new ways to analyze, interpret and visual such data? Dinov believes spacekime theory can help in some pretty impressive ways. "The result of this multidimensional manifold generalization is that you can make scientific inferences using smaller data samples. This requires that you have a good model or prior knowledge about the phase distribution," he said. "For instance, we can use spacekime process representation to better understand the development or pathogenesis to model the distributions of certain diseases.

"Suppose we are evaluating fMRIs of Alzheimer's disease subjects. Assume we know the kime phase distribution for another cohort of patients suffering from amyotrophic lateral sclerosis, Lou Gehrig's disease. The ALS kime-phase distribution could be used for evaluating the Alzheimer's patients," and many other neurodegenerative populations. Dinov also thinks spacekime analytics could help improve political polling, increase our understanding of complex financial and environmental events, and even the innerworkings of the human brain, all without having to take the huge samples required today to make accurate models or predictions. Spacekime theory even offers opportunities to design novel AI analytical techniques. But it goes beyond that.

Spacekime theory can help us make headway on some of the most pernicious inconsistencies in physics, such as Heisenberg's uncertainty principle and the seemingly irreconcilable rift between quantum physics and general relativity, what's known as "the problem of time."

Dinov wrote that the "approach relies on extending the notions of time, events, particles, and wave functions to complex-time (kime), complex-events (kevents), data, and inference-functions." Basically, working with two points of time allows you to make inferences on a radius of points associated with a certain event. With Heisenberg's uncertainty principle, according to this model, since time is a plane, a certain particle would be in one position or phase, time-wise, in terms of velocity, and another phase, in terms of position.

This idea of hidden dimensions of time is a little like Plato's allegory of the cave or how an X-ray signifies what's underneath, but doesn't convey a 3D image. From a data science perspective, it all comes down to utility. Dinov believes that if we can calculate the true phase dispersion of complex phenomena, we can better understand and control them.

Drs. Dinov and Velev's book on spacekime theory comes out this August. It's called "Data Science: Time Complexity, Inferential Uncertainty, and Spacekime Analytics".

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'Spacekime theory' could speed up research and heal the rift in physics - Big Think

For the real black holes that exist or get created in our Universe, we can observe the radiation ... [+] emitted by their surrounding matter, and the gravitational waves produced by the inspiral, merger, and ringdown phases. Although only a few X-ray binaries are known, LIGO and other gravitational wave detectors should be capable of filling in any mass gap ranges where black holes do abundantly exist.

If you take enough mass and compress it into a small enough volume of space, youll inevitably form a black hole. Any mass in the Universe will curve the fabric of spacetime around it, and the more severely curved that spacetime fabric is, the more difficult it is to escape from that masss gravitational pull. The smaller the volume becomes that your mass occupies, the faster youd have to travel, at the edge of that object, to actually escape it.

At some point, the escape velocity youd need to obtain would exceed the speed of light, which defines the critical threshold for forming a black hole. According to Einsteins General Relativity, any mass in a small enough volume would be sufficient to form a black hole. But in our physical reality, there are real limitations that our Universe is subjected to, and not every mathematical possibility comes to fruition. Many of the black holes that we could imagine forming simply dont in our Universe. To the best of our knowledge, heres whats impossible.

An illustration between the inherent uncertainty between position and momentum at the quantum level. ... [+] The better you know or measure a particle's position, the less well you know its momentum, as well as vice versa. Both position and momentum are better described by a probabilistic wavefunction than by a single value.

Black holes have a quantum limit. Below a certain scale, reality is not what it seems. Instead of matter and energy having specific properties that are limited only by our ability to measure it, weve found that there are inherently uncertain relationships between various properties. If you measure a particles position, youll know its uncertainty inherently less well. If you measure its lifetime or its behavior over extremely short timescales, the less well-known you can inherently know its intrinsic energy, or even its rest mass.

Theres an inherent limit to how well you can know any two complementary quantities simultaneously, which is the key point of the Heisenberg uncertainty principle. Even empty space if you were to remove all the various forms of matter and energy entirely exhibits this uncertainty. Well, if you consider a distance scale of ~10-35 m or smaller, the amount of time it would take a photon to cross it would be minuscule: ~10-43 s. On those short timescales, the Heisenberg uncertainty principle tells you that your energy uncertainty is so large, it corresponds (via E = mc) to a mass of about 22 micrograms: the Planck mass.

This visualization shows the fluctuations in the quantum vacuum under the strong interactions. On ... [+] smaller distance scales and over smaller timescales, the fluctuations in energy and momentum can be larger. Once you go down to Planck-scale sizes and distances, the fluctuations are indistinguishable from black holes: a clear indication that physics has broken down.

If you had a black hole a perfect singularity whose mass was 22 micrograms, how large would its event horizon be? The answer is that same distance scale (the Planck length) you started off with: ~10-35 m. This fact illustrates why physicists say that the laws of reality break down at the Planck scale: the quantum fluctuations that must spontaneously occur are so large in magnitude, on scales so minuscule, that theyre indistinguishable from black holes.

But those black holes would immediately decay, as the evaporation time due to Hawking radiation would be less than the Planck time: ~10-43 s. We know that the laws of physics we have, both in quantum physics and in General Relativity, cannot be trusted on these small distance scales or on these tiny timescales. If thats true, then we cannot accurately describe, with those same equations, a black hole whose mass is 22 micrograms or lower. Thats the quantum lower limit for how small a black hole can be in our Universe. Below it, any assertion we could make would be physically meaningless.

When a black hole is created of a very small mass, quantum effects arising from the curved spacetime ... [+] near the event horizon will cause the black hole to rapidly decay via Hawking radiation. The lower the mass of the black hole, the more rapid the decay is.

Black holes below a certain mass would all have evaporated away by now. One of the remarkable lessons from applying quantum field theory in the space around black holes is this: black holes arent stable, but will emit energetic radiation, eventually leading to their complete evaporation. This process, known as Hawking radiation, will someday cause every black hole within the Universe to evaporate.

Although theres a lot of confusion around why this happens much of which can be traced back to Hawking himself the key things you must understand are that:

As a result, lower-mass black holes evaporate more quickly than higher-mass ones. If our Sun were a black hole, it would take 1067 years to evaporate; if the Earth were one, it would evaporate much more quickly: in just ~1051 years. Our Universe, since the hot Big Bang, has existed for about 13.8 billion years, meaning any black holes less massive than ~1012 kg, or around the mass of all the humans on Earth combined, would already have evaporated away entirely.

Just as a black hole consistently produces low-energy, thermal radiation in the form of Hawking ... [+] radiation outside the event horizon, an accelerating Universe with dark energy (in the form of a cosmological constant) will consistently produce radiation in a completely analogous form: Unruh radiation due to a cosmological horizon.

Black holes below about ~2.5 solar masses probably dont exist. According to the laws of physics as we understand them, there are only a few ways that a black hole can be formed. You can take a large chunk of matter and let it gravitationally collapse; if theres nothing to stop or slow it down, it could collapse directly into a black hole. You could, alternatively, let a clump of matter contract down to form a star, and if that stars core is massive enough, it can eventually implode, collapsing down to form a black hole. Finally, you can take a stellar remnant that didnt quite make it like a neutron star and add mass, either through a merger or accretion, until it becomes a black hole after all.

In practice, we believe all of these methods occur, leading to the formation of the realistic black holes that form in our Universe. But below a certain mass threshold, none of these methods can actually give you a black hole.

The visible/near-IR photos from Hubble show a massive star, about 25 times the mass of the Sun, that ... [+] has winked out of existence, with no supernova or other explanation. Direct collapse is the only reasonable candidate explanation.

Weve seen clumps of matter suddenly wink out of existence, like stars that magically disappear. The most logical explanation, as well as the one that best fits the data, is that a fraction of stars do spontaneously collapse into a black hole. Unfortunately, they tend to be on the massive side: dozens of times as massive as our Sun at the very least.

Stars with massive cores do often end their lives in spectacular supernova explosions, where the cores of these stars do implode. If youre born with about 800% or more of our Suns mass, youre an excellent candidate for going supernova. The stars with less massive cores will eventually form neutron stars, with the more massive ones forming black holes. The heaviest neutron star ever discovered likely formed through this process, weighing in at 2.17 solar masses.

And finally, you can take object that are lighter than black holes like the aforementioned neutron stars and either allow them to accrete/siphon mass from a companion, or collide them with another massive, compact object. When they do, theres a chance they could form a black hole.

Numerical relativity simulation of the last few milliseconds of two inspiraling and merging neutron ... [+] stars. Higher densities are shown in blue, lower densities are shown in cyan. The final black hole is shown in gray; you can identify the transition from neutron star to black hole by the change in color.

Although there have been only two neutron star-neutron star mergers ever directly and definitively observed, theyve been incredibly informative. The second one, with a combined mass of about 3.4 solar masses, went directly to a black hole. But the first one, which had a combined mass of more like 2.7 solar masses, revealed a far more complex story. For a few hundred milliseconds, this rapidly-spinning, post-merger mass behaved like a neutron star. All of a sudden, however, it switched to behaving like a black hole. After that transition, it never went back.

What we now believe occurred is that theres a narrow mass range somewhere between 2.5 and maybe 2.8 solar masses where a collapsed objects like a neutron star can exist, but it requires a particularly high value for its rotation rate. If it drops below a critical value, and it will change its spin rate as it settles down to a more spherical shape, it will become a black hole. Below that lower value, there are only neutron stars and no black holes. Above that upper value, there are only black holes and no neutron stars. And in between, you can have both, but what youll ultimately wind up with depends on how fast the object is spinning.

The most massive black hole binary signal ever seen: OJ 287. This tight binary black hole system ... [+] takes on the order of 11-12 years to complete an orbit. Despite making an orbit 1/5th of a light year in size (hundreds of times the Sun-Pluto distance), it should merge in just thousands of years.

What about heavier black holes? Is there a gap where no black holes exist? Is there an upper limit to black hole masses? Black holes can get much, much heavier than just a few times the mass of our Sun. Initially, there were theoretical concerns that there might be a gap where black holes didnt exist; that appears to conflict with the data we now have after ~6 years of advanced LIGO. There was a worry that intermediate mass black holes might not exist, as theyve proven very difficult to find. However, they now appear to be out there as well, with superior data confidently revealing numerous examples.

There will be a limit to how big they can get, however, although we havent hit it just yet. Black holes approaching 100 billion solar masses have been found, and we even have our first candidate for crossing that vaunted threshold. As galaxies evolve, merge, and grow, so too can their central black holes. Far into the future, some galaxies may grow their black holes as large as ~100 trillion (1014) solar masses: 1000 times larger than todays largest black hole. Owing to dark energy, which drives distant galaxies apart in the expanding Universe, we fully expect that no black holes will ever grow substantially larger than this value.

Constraints on dark matter from Primordial Black Holes. There is an overwhelming set of pieces of ... [+] evidence that indicate there is not a large population of black holes created in the early Universe that comprise our dark matter.

What about primordial black holes: black holes that formed directly after the Big Bang? This is a sticky one, because theres no evidence that they exist. Observationally, many constraints have been placed on the idea, which has been around since the 1970s. When the Universe was born, we know some regions were denser than others. If one region was born with a density that was just ~68% greater than average, that entire region should inevitably collapse to form a black hole. While their masses cant be less than ~1012 kg, they could, in theory, have any value thats larger.

Unfortunately, we have the fluctuations in the cosmic microwave background to guide us. These temperature fluctuations correspond to the overdense and underdense regions in the early Universe, and show us that the overdense regions are only about ~0.003% denser than average. Its true: these are on larger scales than the ones wed look for black holes on. But with no compelling theoretical motivation for them, and no observational evidence in their favor, this idea remains purely speculative.

When matter collapses, it can inevitably form a black hole. Penrose was the first to work out the ... [+] physics of the spacetime, applicable to all observers at all points in space and at all instants in time, that governs a system such as this. His conception has been the gold standard in General Relativity ever since.

For a long time, the very notion of black holes was highly contentious. For about 50 years after they were first derived in General Relativity, no one was sure whether they could physically exist in our Universe. Roger Penroses Nobel-winning work demonstrated how their existence was possible; just a few years later, we discovered the first black hole in our own galaxy: Cygnus X-1. Now the floodgates are open, with stellar-mass, intermediate-mass, and supermassive black holes all known in great and ever-increasing numbers.

But theres a lower limit to black holes in the Universe: we believe that none exist below about 2.5 times the mass of the Sun. Additionally, while the heaviest black holes today are right around 100 billion solar masses, theyll eventually grow to be up to 1000 times as heavy as that. Studying black holes provides us with a unique window into the physics of our Universe and the nature of gravity and spacetime themselves, but they cant reveal everything. In our Universe, some black holes truly are impossible.

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Some Black Holes Are Impossible In Our Universe - Forbes

Peer long enough into the heavens, and the Universe starts to resemble a city at night. Galaxies take on characteristics of streetlamps cluttering up neighborhoods of dark matter, linked by highways of gas that run along the shores of intergalactic nothingness.

This map of the Universe was preordained, laid out in the tiniest of shivers of quantum physics moments after the Big Bang launched into an expansion of space and time some 13.8 billion years ago.

Yet exactly what those fluctuations were, and how they set in motion the physics that would see atoms pool into the massive cosmic structures we see today is still far from clear.

A new mathematical analysis of the moments after a period called the inflationary epoch reveals that some kind of structure might have existed even within the seething quantum furnace that filled the infant Universe, and it could help us better understand its layout today.

Astrophysicists from the University of Gttingen in Germany and the University of Auckland in New Zealand used a mix of particle movement simulations and a kind of gravity/quantum modelling to predict how structures might form in the condensation of particles after inflation occurred.

The scale of this kind of modelling is a little mind-blowing. We're talking about masses of up to 20 kilograms squeezed into a space barely 10-20 meters across, at a time when the Universe was just 10-24 seconds old.

"The physical space represented by our simulation would fit into a single proton a million times over," says astrophysicist Jens Niemeyer from the University of Gttingen.

"It is probably the largest simulation of the smallest area of the Universe that has been carried out so far."

Most of what we know about this early stage of the Universe's existence is based on just this kind of mathematical sleuthing. The oldest light we can still see flickering through the Universe is the Cosmic Background Radiation(CMB), and the entire show had already been on the road for around 300,000 years by then.

But within that faint echo of ancient radiation there are some clues on what was going on.

The CMB's light was emitted as basic particles combined into atoms out of the hot, dense soup of energy, in what's known as the epoch of recombination.

A map of this background radiation across the sky shows our Universe already had some kind of structure by a few hundred thousand years of age. There were slightly cooler bits and slightly warmer bits which might nudge matter into areas that would eventually see stars ignite, galaxies spiral, and masses pool into the cosmic city we see today.

This poses a question.

The space making up our Universe is expanding, meaning the Universe must once have been a lot smaller. So it stands to reason that everything we see around us now was once crammed into a volume too confined for such warm and cool patches to emerge.

Like a cup of coffee in a furnace, there was no way for any part to cool down before it heated up again.

The inflationary period was proposed as a way to fix this problem. Within trillionths of a second of the Big Bang, our Universe jumped in size by an insane amount, essentially freezing any quantum-scale variations in place.

To say this happened in the blink of an eye would still not do it justice. It would have begun around 1036 seconds after the Big Bang, and ended by 1032 seconds. But it was long enough for space to snap into proportions that prevented small variations in temperature from smoothing out again.

The researchers' calculations focus in on this brief instant after inflation, demonstrating how elementary particles congealing from the foam of quantum ripples at that time could have generated brief halos of matter dense enough to wrinkle spacetime itself.

"The formation of such structures, as well as their movements and interactions, must have generated a background noise of gravitational waves," says University of Gttingen astrophysicist Benedikt Eggemeier, the study's first author.

"With the help of our simulations, we can calculate the strength of this gravitational wave signal, which might be measurable in the future."

In some cases, the intense masses of such objects could have pulled matter into primordial black holes, objects hypothesized to contribute to the mysterious pull of dark matter.

The fact the behavior of these structures mimics the large-scale clumping of our Universe today doesn't necessarily mean it's directly responsible for today's distribution of stars, gas, and galaxies.

But the complex physics unfolding among those freshly baked particles might still be visible in the sky, among that rolling landscape of twinkling lights and dark voids we call the Universe.

This research was published in Physical Review D.

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Scientists Have Simulated The Primordial Quantum Structure of Our Universe - ScienceAlert

Department of Physics

Location: EghamSalary: 35,931 starting salary per annum - including London AllowanceClosingDate: Wednesday 12 May 2021InterviewDate: To be confirmedReference: 0321-077

Full-Time, Fixed Term (for 24 months)

The Quantum Matter Group of the Department of Physics, Royal Holloway, University of London, invites applications for a two-year Post-Doctoral Research Associate position to work on neutron scattering from frustrated magnets. The role is funded by EPSRC. It is hoped that the candidate would be in post by 1stOctober 2021.

The post holder will engage in experimental research in the group of Professor Jon Goff, with the specific aim to investigate the role of disorder in frustrated magnetism, encompassing both classical and quantum spin liquids. It is anticipated that neutron scattering experiments will be performed at the ISIS Facility in the United Kingdom, the ILL in France, FRM II in Germany and SNS in the United States. This work is part of an ongoing collaboration with experimental and theoretical groups in Oxford and Cambridge.

The successful candidate will be required to carry out experimental and computational research in Condensed Matter Physics, present results at international conferences and in high impact journals and collaborate with UK and international institutions. Applicants should hold (or be close to obtaining) a Ph.D. in Physics and have a track record of high-quality research. Preference will be given to candidates with experience in neutron scattering, and in research fields relevant to this post. Strong computing and communication skills would be highly beneficial.

The post is based in Egham, Surrey where the College is situated in a beautiful, leafy campus near to Windsor Great Park and Heathrow Airport, and within commuting distance from London.

For an informal discussion about the post, please contact Professor Jon Goff at:jon.goff@rhul.ac.uk.

To view further details of this post and to apply please visithttps://jobs.royalholloway.ac.uk.For queries on the application process the Human Resources Department can be contacted by email at:recruitment@rhul.ac.uk.

Please quote the reference:0321-077Closing Date: Midnight, 12 May 2021Interview Date:TBC

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Post-Doctoral Research Associate Experimental Condensed Matter Physics job with ROYAL HOLLOWAY, UNIVERSITY OF LONDON | 250229 - Times Higher Education...

"There are two kinds of people: 'Nothing but' and 'Something more.' " So said an old Jesuit spiritual director. Brilliant science teacher and world-renowned theoretical physicist Brian Greene is a "but" guy; I'm more of a "more" man.

Greene is one of today's best popularizers of science's teachings. Too many live with a worldview developed in the Middle Ages, or at least Newton's universe. Yet, evolution now colors all we know (and those who think they are defending the faith by denying evolution are doing bad biology and terrible theology). The revolutions of Einstein's theories, and the mysteries of quantum mechanics, are slowly seeping into consciousness and culture.

How we make meaning of reality is reoriented when our notions of what is "really real" are in new, and sometimes troubling, relations. Is the table on which I rest this laptop a solid thing or a whirling mass of electrons? Both. Greene is a great guide into these radically realized realms of meaning.

The Elegant Universemay not prove string theory, but it reveals the startling truth that the beauty of the equations often indicates scientific discovery.The Fabric of the Cosmostakes you from the Big Bang to time travel into the past (but not the future). One of hisNew York Timesop-eds presents this mind-blowing argument: As the galaxies accelerate their speed while moving farther and farther from each other, at some point, here on Earth, our most powerful instruments will not be able to register the light of distant stars. People in that far future will need to believe our testimony to know there is anything out there.

Greene argues, "physics in general, and quantum mechanics in particular, can only deal with the measurable properties of the universe. Anything else is simply not in the domain of physics."

In his latest book,Until the End of Time, his argument goes too far or not far enough. His view presents the kind of paradox you expect in a quantum universe that exhibits spooky relationships between particles, where "what is" isn't "what it is" until someone observes or judges "that it is" (think Schrdinger's cat).

Greene argues that much of what is generally outside the domain of physics, aspects of reality like thought, language, art, ourselves and the holy grail, consciousness, are nothing but particles set in motion at the Big Bang some 13.7 billion years ago.

Greene insists all that is all that exists consists only of particles and fields. Nothing but "Particles and fields . To the depths of reality that we have so far plumbed, there is no evidence for anything else."

Really? Nothing but particles? Plumb deeper, farther.

Greene's reduction of all reality to particles means there is no free will. Yet, Greene's ruminations uncover a chink in the reductionist armor. He asks why the particles that make up a big rock remain inert as a tree limb falls, threatening to land on someone, while the particles that are "you" or "me" will rush over and pull that someone out of danger. Note, we wouldn't worry about the rock getting smashed.

Greene argues that such salvific action is not free will or choice. The particles of the rock, "you" and "I" are all subject to the same inevitable and unchanging laws of physics. It is just that "you" or "I" have a more "sophisticated internal organization [that] allows for a rich spectrum of behavioral responses" not available to the rock. Curiously, Greene argues, "This notion of freedom does not require free will." He admits this use of the term "free" is a bit of a "linguistic bait and switch.

His admittance is more than that. It is more than particles of synapses firing in his fertile and impressive brain. It is an argument. And a person making an argument must be free, or it is no argument.

A belief in the mystery we call God, awareness and trust that there is a reality beyond physical reality, grounds assertions of free will and argues for purpose and ultimate meaning to our existence and the universe.

But we are more than the particles that physicists can measure. Reality is more than what our knowledge of physical reality reveals. Our knowledge itself, our consciousness, the laws of physics, math all transcend physical particles and fields.

Ironically, Greene loses the argument that the act of argument is unfree, and in the long run, meaningless. He loses by making an argument.

Early inUntil the End of Time, Greene refers to the famous argument between philosopher Bertrand Russell and Jesuit Fr. Frederick Charles Copleston about the existence of a necessary being, i.e., God.

Russell denied the meaning of the question of what causes contingent existence. We must ignore the question of Leibniz, Heidegger and Wittgenstein, "Why is there anything rather than nothing?" According to Copleston, Russell dodged the issue: "If one refuses to sit down at the chessboard, one cannot be checkmated."

InUntil the End of Time, Greene has taken a seat at the board. He checkmates himself.

An argument is indisputable, a reality that goes beyond the merely physical. It is not made up of particles but exists in the relationship between Greene's thought and my thought. It is beyond both of us. It connects both of us. It is spiritual.

If the argument were just a mass of particles, there would be no way to connect Greene's consciousness with mine or yours. That's the difference between a rock and me and Greene and you. Jesuit Fr. Pierre Teilhard de Chardin proclaimed we are radically spiritual beings having a human experience. We cannot reduce our embodied self-consciousness to particles. We are more than that, much more.

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No free will, no ideas: Physicist Brian Greene reduces everything to 'particles and fields' - National Catholic Reporter

My interactions with my surroundings define me. I do not exist in any meaningful sense independently of those interactions. Air molecules are bouncing off the atoms of my skin, photons of light are being absorbed by atoms in my eye, compressions and rarefactions of the air are jostling my eardrum. I also live in a complex web of social interactions. And, at this moment, via a transatlantic telephone line, I am interacting with Carlo Rovelli.

Rovelli has just come indoors from shovelling snow outside his house in Canada. The Italian theoretical physicist has been in London, Ontario, working at the University of Western Ontario, hunkered down through the Covid crisis. It has been sad to see what the rest of the world has been going through, he says. I have been very privileged to be here. Not only does Rovelli have a forest nearby but he has had the luxury of time to thinkand is no longer exhausted by his globetrotting tour as the author of Seven Brief Lessons on Physics. In the seven years since the book was published, it has been translated into 44 languages.

Rovelli has written a new book. Its title, Helgoland, refers to a barren island off the North Sea coast of Germany, where the 23-year-old physicist Werner Heisenberg (who would go on to work on the unrealised Nazi atomic bomb) retreated in June 1925. He was trying to make sense of recent atomic experiments, which had revealed an Alice in Wonderland submicroscopic realm where a single atom could be in two places at once; where events happened for no reason at all; and where atoms could influence each other instantaneouslyeven if on opposite sides of the universe.

Heisenbergs breakthrough was to realise that, as far as atoms and their components are concerned, everything is interaction. Subatomic particles such as electrons and photons are not objects that exist independently of being prodded and poked, but merely the sum total of their interactions with the rest of the world. Basically, physics confirmed what several philosophers over the centuries have suspectedthat the world is a web of interactions and nothing exists independently of that web, Rovelli tells me. It is at the atomic and subatomic, or quantum, level that we confront this truth most dramatically.

Rovelli points out that the great Danish physicist Niels Bohr, a friend of Heisenberg, inadvertently muddied the waters for a century by drawing a distinction between the quantum world of atoms and the everyday, or classical, world of the measuring apparatus observing those atoms. In reality, there is no such distinction, says Rovelli. We live in a quantum universe. Its just that, when many atoms come together, the quantum effects are washed out and it is possible to think of objects with an independent existence such as chairs and tables and people. Normal physics can thus be successfully applied, while it fails at the subatomic level.

Perhaps the most mind-blowing feature of the quantum worldso mind-blowing that Einstein believed it could not possibly be trueis non-locality. If two subatomic particles are born together, their properties are intertwined, or entangled. Say, for instance, two electrons are born with opposite spins: if the first spins clockwise, the other spins anticlockwise, and vice-versa. The electrons actually have no properties independent of interaction so if they are not observed in any way at their originsay in London, Englandtheir spins will be undetermined. Now imagine one is sent in a sealed box to London, Ontario, where its spin is measured. If it is clockwise, the electron in England becomes anti-clockwise. This instantaneous transatlantic influence is an apparent violation of Einsteins special theory of relativity, which forbids anything moving faster than light.

The seeming paradoxes here have consumed many great minds. But Rovelli provides the best explanation of non-locality that I have ever read. All that actually happened, he says, is that one electron was measured with respect to an apparatus in Ontario and the other with respect to an apparatus in England. There is no God-like perspective that sees both electrons at the same time so that their spins can be legitimately compared. How the spins relate to each other is undetermined until an experimenter in Ontario communicates information about their electron to their colleague in England. Regardless of whether the news bounces between the continents via satellite beam or through an internet cable, this information necessarily travels at less than the speed of light, says Rovelli. Non-locality is therefore no puzzle after all.

Rovellis passion for physics came by an unusual route: political activism. Born in 1956, he grew up in Verona, a provincial Italian town where people had strongly conservative views. Despite the disgracing of the Italian right over the preceding generation, some of my school teachers did not conceal their sympathies for fascism, says Rovelli.

An only child with a loving mother, Rovelli grew up in a happy and protected environment. The flip side of this was that he felt he could do nothing without his mothers approval and therefore was in a prison from which he needed to break free. His parents actually encouraged his independence by sending him twice, aged seven and eight, and alone, to England to learn English. This led to the 15-year-old Rovelli hitch-hiking alone from Paris to Sofia in Bulgaria, sleeping outside in the countryside, a trip that horrified his parents but made him very happy.

He rebelled against the close-mindedness of Verona, railing against the world of money and power and hierarchies. I travelled the world a lot, wanting to learn and experience all I could, he says. And everywhere I found like-minded young people who believed that a better, kinder, more compassionate world was possible. Rovelli was only 12 in 1968 but, like many of his generation, he was influenced by ideas lingering from that rebellion. Ultimately, however, the revolution he wanted failed. Sadly, we were never able to convince the majority, he says. Most people did not want to change the world.

When Rovelli became an orphan of the revolution, he was studying science at the University of Bologna. Fortuitously, his political dejection coincided with his discovery of the extraordinary magic of physics. A professor set him an essay on group theory and its applications to quantum theory. He confessed he knew nothing about quantum theory, and the professor answered: Well, go and read about it.

Rovelli spent a month reading, primarily the classic 1930 treatise of Paul Dirac. With mounting excitement, he realised that here was a window on the deep reality that underpinned the world. It was mind-blowingbetter than an LSD trip, he says. What is reality? And how does it work? What also impressed Rovelli was that quantum theory had been a successful revolution that really had durably overturned all previous, or classical, physics. We had not achieved a revolution in the human world, he says. But scientific revolutions were entirely possible, and this was a powerful realisation for me. I discovered also that I was good at physics.

The two great revolutions of 20th-century physics were quantum theorythat describes the small-scale realm of atoms and their constituents (though actually it describes everything)and Einsteins theory of gravity (also known as the general theory of relativity), which describes the large-scale realm of stars and galaxies and the entire universe. But once upon a timein the Big Bang, 13.82bn years agothe universe was very very small. So in order to address ultimate questions concerning its origin, it is necessary to unite quantum theory and general relativity.

The problem is that the two theories appear incompatible. Whereas general relativity is a theory of certainty, predicting the exact path of a body such as a planet, quantum theory is a theory of uncertainty, predicting only probabilities of events such as the possible trajectories of an atom flying through space. And whereas Einsteins theory of gravity views the world as continuous, quantum theory views it as grainy, like a newspaper photograph seen close-up, with everything from energy to spin and electric charge coming in tiny indivisible chunks, or quanta.

In the late 1980s, Rovelli roved around Italian, American and British universities. Along with other celebrated physicists such as Abhay Ashtekar at Syracuse and Lee Smolin at Yale, he attempted to show that space-time itselfthe currency of general relativityultimately comes in such indivisible chunks. Their equations revealed that, down at the impossibly small Planck scale, space-time is made of finite loops woven together into a complex shifting network. In principle, when we zoom out from this ultra-small, grainy scale, there emerges Einsteins theory of continuous space-time, says Rovelli.

Quantum theory impressed Rovelli as a successful revolution that really had overturned all previous physics

Loop quantum gravity, as Rovellis theory is called, reveals that the universe in the Big Bang had a minimum size and was not born from an infinitesimally small, infinitely dense singularity, as implied by general relativity. Instead, the theory hints that the universe may have contracted down in a Big Crunch before exploding in the Big Bang. The hope is that it might one day be possible to spot the signature of such a contracting phase on the cosmic background radiation, says Rovelli.

Rovelli is modest about quantum loop gravity. It is not an overly ambitious theory, he admits. Like everyone working at the frontier of physics, he knows he is groping in the dark. For four days a week I am completely convinced the theory is right, for two days I have doubts and for one day I think it is completely wrong! says Rovelli.

The best-known rival of quantum loop gravity is superstring theory, which views the fundamental building blocks of the world not as point-like particles but as tiny strings of mass-energy vibrating in space-time of 10 dimensions. Our current best picture of the fundamental worldthe Standard Modelfails to explain why the fundamental subatomic particles have the masses they have and why the fundamental forces have the strengths they have. The hope was that string theory would predict the magnitude of all the unknown parameters, says Rovelli. Unfortunately, we have discovered there is not one string theory but an astronomical number of them. Rovelli highlights another confidence-lowering problem: the failure to find particles predicted by supersymmetry, string theorys indispensable concomitant, at the Large Hadron Collider near Geneva.

Finding a theory of everything that unites quantum theory and Einsteins theory remains the Holy Grail of physics. But might the days of Covid give us hope of a breakthrough? In 1665, Isaac Newton self-isolated on his familys farm in Lincolnshire while bubonic plague raged across Britain. There, in lockdown, he discovered the universal law of gravity and changed the face of science. Is there a 21st-century Newton out there, perhaps, who will furnish us with the elusive theory of everything? I wouldnt totally exclude the possibility, says Rovelli. Many physicists are working without the normal distractions.

It is no coincidence that Einstein, who made the most discoveries, also made the greatest number of mistakes

The problem of finding a theory of everything is discussed in Rovellis popular books, starting with Seven Brief Lessons on Physics, which he proudly tells me has sold more than a million copies. His writing, like his career in physics, came about unexpectedly. I always recorded my thoughts in diaries and the things I learnt from my wide reading in notebooks, says Rovelli. It resulted in 2009 in a popular book on Anaximander, a 6th-century BC Greek philosopher who I believe was a proto-scientific thinker.

After the Anaximander book, Rovelli was asked to write a column for the Italian newspaper Il Sole 24 Ore. This led him to be poached by another, bigger-selling and more prestigious paper, the Corriere della Sera. The paper was in favour of Italian troops being sent to Iraq in the 2003 war, something to which the still-radical Rovelli was strongly opposed. He wrote his first column saying this, expecting his piece to be rejected. But to my surprise the paper published it, he says. It was a pivotal moment. I saw that I was free to write what I wanted.

The column led to an approach from the publisher Adelphi, which commissioned and published Seven Brief Lessons on Physics. And the rest is history. Rovellis books seamlessly interweave what he sees as the essence of physics with his personal views on subjects such as culture, society and politics. I seem to have two distinct audiences, he says. People who know nothing about physics and whose eyes are opened to the wonder of it, and people who know a lot about physics. Rovelli tells me how pleased he was when one of his scientific enemies, the Nobel laureate David Gross who is critical of loop quantum gravity, told him how much he had enjoyed one of his books. We found we shared the same deep appreciation of the beauty of physics, says Rovelli.

The worst thing about writing, says Rovelli, is the time it takes up, both in actually honing his thoughts into a succinct and captivating form and in publicising a finished book. But he also thinks there is something wonderful in it. I no longer feel alone, he says. I used to think my political ideas about the world were different from mainstream society and I didnt dare air them. But seeing many people take them seriously has re-connected me with humankind and stopped me feeling isolated.

More generally, Rovelli is convinced we must work together. Co-operation is better than competition, he says. Physics has reinforced the fact that we are all part of an interactive web and there are no solutions to our global problems without recognising and embracing that.

There is no getting away from interdependence, and Rovelli also sees it as a positive virtue to be open to changing your mind. Lots of people think they are smart, that they see things better than others, he says. But the scientific view has a lesson for the human world because it allows for changes. It is surely no accident that Einstein, who made the most discoveries, also made the greatest number of mistakes and changed his mind the most number of times.

We have now been talking for two hours. I end our conversation with a big question. What is the universe? Rovellis answer is unexpected. You are asking the wrong question. There is no God-like perspective, he says, from which the universe can be observed. There is no universe out there because we are in it. So we need to think from within: All we can ask is: what is our particular perspective from within and how does it relate to all the other possible internal perspectives?

Those words, at once modest and profound, travelat well within the speed of lightfrom London, England, to London, Ontario, conveying all the favourite themes of Rovellis work: interaction, contextuality, relationality. The things that make up the world at its deepest level are intertwined and work together. We too are intertwined and must work together. It is the only way ahead Rovelli sees for the human race.

Carlo Rovellis new book Helgoland (Allen Lane) is out now

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Carlo Rovelli on his search for the theory of everything - Prospect

(Machine Hallucination: New York)

Authors and filmmakers have long speculated on the existence of alternate realities, but L.A.-based visual artist Refik Anadol is working with an artificial intelligence to see if machines can do the samevia spectacular art installations.

The AI in question is tapping into quantum mechanics. "We in our daily lives are not able to see alternative dimensions, but in quantum mechanics [and] quantum computation, there is still a theory of many worlds. And in [the] subatomic world of quantum mechanics, you can see things in superposition, and we are speculating in this project that, perhaps, if AI can look at this complexity...it can see an alternative reality.

"So simply, we are watching an AI dreaming," Anadol says.

Anadols projects have appeared all over the world (Walt Disney Concert Hall, Centre Pompidou, Daejeon Museum of Art), and he served as an artist-in-residence for Googles Artists and Machine Intelligence program. Is this the future of art and architecture, and does Anadols AI know something about other worlds that we dont? We talked to him to find out.

How did you first deploy Generative Adversarial Networks (GAN) in order to teach your AIs to 'dream'?[RA] In 2016, I was an artist-in-residence at Google AMI (Artists and Machine Intelligence), which is where my team and I learned how to use AI algorithms for a project called Archive Dreaminga purposeful speculation about the future of libraries. This was the first time I was able to work with a Deep Convolutional Generative Adversarial Network, thanks to [artist, researcher, and Google engineer] Dr. Mike Tyka, who became my mentor, and a true supporter of my very first AI journey. Since then, Ive never stopped using GANs.

What was your source material for the AI to learn from on that project? What did you ask the AI to 'dream'?[RA] We were fortunate to have access to 1.7 million documents from a publicly open cultural archive, and we used this to create an installation, which, as far as I know, is the first of its kind in the world that truly used an AI in this way, to speculate an architectural future of a library. We asked ourselves: "Can a building dream? Can it hallucinate its own future?" A library in the near-future, that can learn its own content, and its own information then turns into knowledge, and eventually wisdom, then a dreamthis was the concept behind the project.

When did you first become aware of AIs?[RA] I was 8 years old when I saw Blade Runner, and, I clearly remember my cousin was saying: "These are not human. These are two androids and one is criticizing that the others memories are not real." I was totally inspired by this moment, thinking about what a machine can do with someone elses memories. In the same year, I got my first computer, and even though my computer was not an AI, I always remembered that there was a space inside it that was the mind of a machine. Then, of course I eventually read Philip K. Dick, William Gibson, and many others, and they all opened up my mind from a science-fiction perspective.

Youve partnered extensively with Nvidia to use its StyleGAN algorithm. What will you be exhibiting at Nvidia GTC in April?[RA] Firstly, Im deeply appreciative of the support that Nvidia gave me during my journey, not only for this particular project. Weve done many pioneering collaborations in the field of computer graphics/AI, I wouldnt be where I am without this specific support. At Nvidia GTC, we will be unveiling an exciting new project, inspired by the combination of AI and neuroscience.

We are exploring the worlds largest neuroscientific data set from the Human Connectome Project, in collaboration with UCLA's Dr. Taylor Kuhn, and with incredible support from Siemens who are behind the sensors recording all of the participants magnetic resonance imaging (MRI), electroencephalogram (EEG), and diffusion tensor imaging (DTI) data. We will be generating machine hallucinations from this enormous amount of information. It will be the worlds first iteration of letting AI speculate the architecture of the human mind and its unseen connections, in the form of 3D-printed sculpture.

That sounds incredible. So youre taking your AI inside the human mind, in the same way you let your AI 'dream' about the tech behind Machine Hallucination: New York project, where you 'fed' the StyleGAN with a 200 million-plus image dataset of NYC? [RA] Yes. And, as far as I know, that was the largest GAN ever trained on a specific concept such as the city of New York, which enabled the audience to use an interactive browser to virtually fly around the latent space and record their own journeys. It was truly inspiring seeing the AI reconstructing the city in any season, any time of the day, just fascinating. As an artist, the AI was a perfect team member, a 'thinking brush,' delivering these moments to me, giving me forms and visuals and colors that I could never dream of on my own.

Talk us through the tech behind this.[RA] For Machine Hallucination: New York, we used StyleGAN2, Nvidia DGX Station, 500 TFLOPS of AI power, and the worlds fastest workstation for leading-edge AI research and development. StyleGAN2 generated a model for the machine to process the archive, and the model was trained on subsets of the sorted images, creating embeddings in 4,096 dimensions. To understand this complex spatial structure visually, we utilized dimensional-reduction algorithms, such as cuml-UMAP, projecting to a navigable 3-dimensional universe.

Working alongside an AI must be a compellingand very differentexperience to a human collaborator.[RA] Ive been creating data universes since 2016, and the reason I enjoy working with AI is that Im heavily inspired by latent spacen-dimensional spacea mathematical space, and transforming this n-dimensional space into a space that we can perceive, we can fly in, or even step inside a specific story. AI data sculptures and AI data paintings come from latent space, and the core concepts of our work explore the ideas and narratives around this. Thanks to these algorithms and the computational power, we can constantly research, develop, understand, and repeat the same process over and over until we get the perfect result that feels artistically compelling.

More recently, you've been getting the AI to ingest multiple instances of quantum mechanics theory in a mission to explore the nature of possible new worlds. How did this come about?[RA] I've been deeply interested in quantum mechanics for a while, and then saw the Alex Garland show Devs, which inspired me to consider Hugh Everetts Many-Worlds Interpretation. Thanks to the Google AI Quantum team, we were able to examine the patterns of a quantum supremacy data set and try to navigate/connect the gap and ask: "If we are living in a world where machines are needed to understand many things, why not also use AI to navigate alternative dimensions?" To achieve this we spent a significant amount of time and ultimately were able to modify StyleGAN to the adaptive discriminator augmentation [ADA] algorithm and feed it noise distribution generated by the quantum supremacy data.

Quantum Memories, the output for this collaboration, was displayed at the National Gallery of Victoria, in Melbourne. Explain what it entailed.[RA] Quantum Memories utilizes Google AIs most cutting-edge, publicly available quantum computation research data and algorithms to explore the possibility of a parallel world. These algorithms allow us to speculate alternative modalities inside the most sophisticated computer available, and create new quantum noise-generated datasets as building blocks of these modalities. The 3D visual piece is accompanied by an audio experience that is also based on quantum noise-generated data, offering an immersive experience that further challenges the notion of mutual exclusivity. It was an amazing journey to tap into the random fluctuations of quantum noise as a unique realm of possibilities and predictions.

Some background on you. You were born in Istanbul, Turkey. What brought you to the US, and to Los Angeles, specifically?[RA] L.A. is the place of Blade Runner from my childhood. Later on, I was inspired by technology in my work, and knew that Los Angeles is the home of very creative minds. University of California, Los Angeles (UCLA), where I got my degree, is full of pioneers, so I was very fortunate to be able to train with the pioneers in my field. Being in L.A. also means being close to the creative community and pretty close to the tech giants of Silicon Valley. So, I find it a very fruitful space where art, science, and technology can naturally combine. Its the home of cinema, the home of entertainment. I find it a city that can hold many dreams in one location.

Talking of L.A., I first came across your work, not in a gallery, or museum, but in the Beverly Center Mall and was enthralled by the viscous textures seemingly spilling out of the frame.[RA] The Beverly Center curatorial team specifically asked for a site-specific piece, and so I was able to generate a whole new concept about the future of fashion by using GANs to imagine ever-changing patterns and forms and structures that cannot be done in the physical world, pushing the boundaries and the imagination, transforming an existing artificial space into an extremely unconventional way of looking at fabric from generative algorithms.

You've referred to your public art as 'post-digital architecture.' Do you consider your work as part of futuristic responsive and/or sentient environments?[RA] This is a speculation thats been going on in my work since Archive Dreaming. When I augment a library or Frank Gehrys Walt Disney Concert Hall, home of the Los Angeles Philharmonic, I have the same intention. I do believe that near future architecture is beyond glass, steel, or concrete, and I do believe that machines will emerge with spaces. But the big questions are: What will they remember? What will they learn? and What will they dream?

As were currently under the occupation of COVID-19, can you see a role for your in situ work in keeping us all somewhat sane?[RA] Yes, this really inspires me. The pure AI, neuroscience, and architecture speculation that we have been doing for the last five years has been leading us here, especially during COVID. I would be extremely delighted if the room I am living in every single day has an emotional sense, and could give me an intelligent response, when the world around us is collapsing. Eventually, this will happen. The spaces themselves will become creative.

Finally, if this isnt too out there, do you think theres a way to map our own individual subconsciousness, or a collective consciousness, merged with multiple AIs, through your work?[RA] Incredible question. First of all, as humans, we still dont know how our consciousness works. Its still a big debate. [University of Oxford] Professor Sir Roger Penrose is thinking about consciousness in the form of quantum physics, while others, such as [University of Sussex] Professor Anil Seth, think reality is a controlled hallucination. I think if we can ever really understand what consciousness is, it will allow us to go beyond what we can do at this moment of humanity.

If it were possible, where would you start in gathering that dataset? And what would you see as the final piece's purpose in existence?[RA] The data set will most likely come from an AI in a neuroscience project that will be completely engaged also with the arts because if you talk about consciousness I think imagination has to be in the game. In fact, for consciousness, every single discipline in the world has to converge. To understand consciousness, we have to understand everything and AI is the only way to achieve it, thats for sure. But, before that, we have to understand what consciousness is, and that may be one of the most exciting challenges of AIs journey in the next decade.

Refik Anadol will be speaking at Nvidia GTC on April 12, 2021.

Link:

Do Alternate Realities Exist? This Artist's Machines Are Ready to Find Out - PCMag

Through painstaking work, scientists have found evidence of a quasiparticle that was first imagined as a hypothesis almost 50 years ago: the odderon.

The odderon is a combination of subatomic particles rather than a new fundamental particle but it does act like the latter in some respects, and the way it fits into the fundamental building blocks of matter makes the discovery a huge moment for physicists.

The odderon was finally revealed through a detailed analysis of two groups of data, hitting the 5 sigma chance of probability researchers use as a threshold.

"This means that if the odderon did not exist, the probability that we observe an effect like this in the data by chance would be 1 in 3.5 million," says physicist Cristian Baldenegrofrom the University of Kansas.

Particles like protons and neutrons are made up of smaller subatomic particles: put simply,quarksare 'stuck together' with the force-carrying gluons. Smacking protons together in a particle accelerator gives us an opportunity to glimpse into their gluon-laden guts.

When two protons are smashed together but somehow survive the encounter, this interaction - a type of elastic scattering - can be explained by the protons exchanging either an even or odd number of gluons.

If that number is even, it's the work of apomeron quasiparticle;the other option which seems to happen much less often is an odderon quasiparticle, a compound with an odd number of gluons.

Until now, scientists have been unable to spot odderons in experiments, even though theoretical quantum physics has suggested they should exist.

Here, researchers crunched the numbers on a vast set of data from the Large Hadron Collider (LHC) particle accelerator at CERN in Switzerland and the Tevatron particle accelerator at Fermilab in the US.

Millions of data points were studied to compare proton-proton or proton-antiproton collisions, until the scientists were convinced they'd seen results - an odd-numbered gluonic compound - that would only be possible if the odderon existed.

The comparison between the two types of collisions revealed a distinct difference in energy being exchanged - that difference is evidence of the odderon. The team then combined more precise measurements from a previous experiment in 2018 that ruled out some of the uncertainties, allowing them to reach the high certainty level of detection for the first time.

This discovery also helps fill in some of the gaps in the modern idea of quantum chromodynamics or QCD, the hypothesis of how quarks and gluons interact at the smallest level. We're talking about the state of matter at the smallest scales, and how everything in the Universe gets put together.

What's more, the specialized technology developed to help track down the odderon could have a variety of other uses in the future, the researchers say: in medical instruments, for example.

While this research doesn't answer every question about the odderon and how it functions, it's the best proof yet that it exists. Future particle accelerator experiments will be able to add further confirmation, and no doubt raise a few more questions.

"Searching for signatures of the odderon is a very different task in comparison to what is traditionally done in particle physics," Baldenegro said.

"For instance, in searching for the Higgs boson or the top quark, one looks for a 'bump' over a smooth invariant mass distribution, which is already very challenging. The odderon, on the other hand, has much more subtle signatures. This has made the hunt for the odderon so much more challenging.''

The paper has been submitted for publication in Physical Review Lettersand is available as a preprinton arXiv; connected research has been published in the European Physical Journal C.

Read more:

After 50 Years, Physicists Confirm The Existence of an Elusive Quasiparticle - ScienceAlert

Carlo Rovelli, the Italian theoretical physicist, is one of the great scientific explicators of our time. His wafer-thin essay collection, Seven Brief Lessons on Physics, sold more than 1m copies in English translation in 2015 and remains the worlds fastest-selling science book. In The Order of Time and Reality Is Not What It Seems, Rovelli illuminated the disquieting uncertainties of Einsteinian relativity, gravitational waves and other tentative physics. Nobody said that post-Newtonian physics was easy, but Rovellis gift is to bring difficult ideas down a level. His books continue a tradition of jargon-free popular scientific writing from Galileo to Darwin that disappeared in the academic specialisations of the past century. Only in recent years has science become, in publishing terms, popular and attractive again.

Rovellis new book, Helgoland, attempts to explain the maddeningly difficult theory of quantum mechanics. The theory was first developed in 1925 by the young German physicist Werner Heisenberg during a summer holiday he spent on the barren North Sea island of Helgoland. It was there that the 23-year-old, stricken by hay fever, conceived of the strangely beautiful interior of an atoms mathematical structure and, at a stroke, overturned the certainties of classical physics. Gone was the old idea that atoms consisted of tiny electrons that moved mechanically round heavier protons as planets orbit the sun. Heisenbergs intuition was that electrons moved in diffuse, cloudlike waves.

Excited, he devised mathematical tables (matrices) to predict the electrons wave mechanics. His work was soon refined by other forward-looking physicists such as Erwin Schrdinger and Paul Dirac. Quantum theory was sired out of Heisenbergs observations and Einsteins earlier relativity theory. Until Einstein, scientists believed in a predictable, deterministic universe one driven by clockwork. Newtons idea of absolute true time ticking relentlessly across the universe was countered by the Einstein theory that there is no single now but rather a multitude of nows. Heisenberg and his followers, more radical even than Einstein, held that we cannot know the present state of the world in full detail, but only by models of uncertainty and probability. The riddle of quantum theory may ultimately be beyond our tentative, Earth-bound comprehension, says Rovelli; but Newtonian mechanics, though far from obsolete, can no longer account for every aspect of the world we live in.

Our world is understood to be non-deterministic and essentially unpredictable; moreover it works in ways that often strike us as non-intuitive. Quantum theory invites us to see the world as a giant cats cradle of relations, where objects exist only in terms of their interaction with one another. Ultimately, says Rovelli, Heisenbergs is a theory of how things influence one another. It forms the basis of all modern technologies from computers to nuclear power, lasers, transistors and MRI scanners.

Fortified with reflections on Vedanta Hinduism (the author has a hippyish past), Buddhism, Dante, Empedocles and Democritus, Rovelli applies quantum theory to various philosophies. Humans exist by virtue of their continuous interactions with one another; so, too, do atoms and electrons. As a happy integration of science, literature and philosophy, Helgoland owes something to the Italian chemist-writer Primo Levi, whose literary-scientific memoir, The Periodic Table, reached the UK bestseller list in 1985 alongside Dick Francis. Rovellis book displays a very Levi-like enthusiasm for abstruse facts of all kinds. (The German director FW Murnau, we learn, had filmed parts of Nosferatu on Helgoland in 1922 a couple of years before Heisenberg arrived.)

Undeniably, the book is hard going at times. (I hope I have not lost my reader, Rovelli says at one point.) The American physicist Richard Feynman presumably meant it when he said that nobody understands quantum mechanics. In his trademark lucid prose, Rovelli does his best to explain why this might be so. Known for his work on loop quantum gravity theory and the pre-Socratic Greek philosopher Anaximander, Rovelli is a deep-thinking, restlessly inquiring spirit who sees no incompatibility between physics and philosophy only mutual attraction.

Science, in Rovellis estimation, is not about certainty; it is informed by a radical distrust of certainty. What is real? What exists? Helgoland, beautifully translated by Erica Segre and Simon Carnell, is the beginning of wisdom in these things.

Helgoland by Carlo Rovelli, translated by Erica Segre and Simon Carnell, is published by Allen Lane (20). To order a copy go to guardianbookshop.com. Delivery charges may apply

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Helgoland by Carlo Rovelli review the mysteries of quantum mechanics - The Guardian