Category Archives: Quantum Physics

Almost 400 years ago, in The Assayer, Galileo wrote: Philosophy is written in this grand book, the universe [But the book] is written in the language of mathematics. He was much more than an astronomer, and this can almost be thought of as the first writing on the scientific method.

We do not know who first started applying mathematics to scientific study, but it is plausible that it was the Babylonians, who used it to discover the pattern underlying eclipses, nearly 3,000 years ago. But it took 2,500 years and the invention of calculus and Newtonian physics to explain the patterns.

Since then, probably every single major scientific discovery has used mathematics in some form, simply because it is far more powerful than any other human language. It is not surprising that this has led many people to claim that mathematics is much more: that the universe is created by a mathematician.

So could we imagine a universe in which mathematics does not work?

The Sapir-Whorf hypothesis asserts that you cannot discuss a concept unless you have the language to describe it.

In any science, and physics in particular, we need to describe concepts that do not map well on to any human language. One can describe an electron, but the moment we start asking questions like What colour is it? we start to realize the inadequacies of English.

The colour of an object depends on the wavelengths of light reflected by it, so an electron has no colour, or more accurately, all colours. The question itself is meaningless. But ask How does an electron behave? and the answer is, in principle, simple. In 1928, Paul A.M. Dirac wrote down an equation that describes the behaviour of an electron almost perfectly under all circumstances. This does not mean it is simple when we look at the details.

For example, an electron behaves as a tiny magnet. The magnitude can be calculated, but the calculation is horrendously complicated. Explaining an aurora, for example, requires us to understand orbital mechanics, magnetic fields and atomic physics, but at heart, these are just more mathematics.

But it is when we think of the individual that we realize that a human commitment to logical, mathematical thinking goes much deeper. The decision to overtake a slow-moving car does not involve the explicit integration of the equations of motion, but we certainly do it implicitly. A Tesla on autopilot will actually solve them explicitly.

So we really should not be surprised that mathematics is not just a language for describing the external world, but in many ways the only one. But just because something can be described mathematically does not mean it can be predicted.

One of the more remarkable discoveries of the last 50 years has been the discovery of chaotic systems. These can be apparently simple mathematical systems that cannot be solved precisely. It turns out that many systems are chaotic in this sense. Hurricane tracks in the Caribbean are superficially similar to eclipse tracks, but we cannot predict them precisely with all the power of modern computers.

However, we understand why: the equations that describe weather are intrinsically chaotic, so we can make accurate predictions in the short term, (about 24 hours), but these become increasingly unreliable over days. Similarly, quantum mechanics provides a theory where we know precisely what predictions cannot be made precisely. One can calculate the properties of an electron very accurately, but we cannot predict what an individual one will do.

Hurricanes are obviously intermittent events, and we cannot predict when one will happen in advance. But the mere fact that we cannot predict an event precisely does not mean we cannot describe it when it happens. We can even handle one-off events: it is generally accepted that the universe was created in the Big Bang and we have a remarkably precise theory of that.

A whole host of social phenomena, from the stock market to revolutions, lack good predictive mathematics, but we can describe what has happened and to some extent construct model systems.

So how about personal relationships? Love may be blind, but relationships are certainly predictable. The vast majority of us choose partners inside our social class and linguistic group, so there is absolutely no doubt that is true in the statistical sense. But it is also true in the local sense. A host of dating sites make their money by algorithms that at least make some pretence at matching you to your ideal mate.

A universe that could not be described mathematically would need to be fundamentally irrational and not merely unpredictable. Just because a theory is implausible does not mean we could not describe it mathematically.

But I do not think we live in that universe, and I suspect we cannot imagine a non-mathematical universe.

This article by Peter Watson, Emeritus professor, Physics, Carleton University, is republished from The Conversation under a Creative Commons license. Read the original article.

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Why mathematics is essential to understanding our universe - The Next Web

Peter Morgan; Yale University, Department of Physics

Abstract: The connection between classical mechanics and quantum mechanics has historically been dominated by quantization and, in the opposite direction, the correspondence principle and Ehrenfest's theorem, which fall far short of the clarity of isomorphisms between mathematical structures. In contrast, we can use Koopman's Hilbert space formalism for classical mechanics to construct isomorphisms between classical and quantum Hilbert spaces and between classical and quantum algebras of operators, which allows a unified approach to joint and incompatible measurements. With a common measurement theory in place, other differences between classical and quantum can be more clearly described. At the level of field theories, signal analysis can be adopted as an empiricist way to unify QFT and random fields, which allows a carefully judged classical intuition to suggest several ways to rethink QFT.

Zoom ID: 956 5927 4425

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Math Physics Seminar - Peter Morgan | Physics and Astronomy | The University of Iowa - The University of Iowa

Abstract artists concept of neutrino particles.

Physicists are closing in on the true nature of the neutrino and might be closer to answering a fundamental question about our own existence.

In a Laboratory under a mountain, physicists are using crystals far colder than frozen air to study ghostly particles, hoping to learn secrets from the beginning of the universe. Researchers at the Cryogenic Underground Observatory for Rare Events (CUORE) announced this week that they had placed some of the most stringent limits yet on the strange possibility that the neutrino is its own antiparticle. Neutrinos are deeply unusual particles, so ethereal and so ubiquitous that they regularly pass through our bodies without us noticing. CUORE has spent the last three years patiently waiting to see evidence of a distinctive nuclear decay process, only possible if neutrinos and antineutrinos are the same particle. CUOREs new data shows that this decay doesnt happen for trillions of trillions of years, if it happens at all. CUOREs limits on the behavior of these tiny phantoms are a crucial part of the search for the next breakthrough in particle and nuclear physics and the search for our own origins.

CUORE scientists Dr. Paolo Gorla (LNGS, left) and Dr. Lucia Canonica (MIT, right) inspect the CUORE cryogenic systems. Credit: Yury Suvorov and the CUORE Collaboration

Ultimately, we are trying to understand matter creation, said Carlo Bucci, researcher at the Laboratori Nazionali del Gran Sasso (LNGS) in Italy and the spokesperson for CUORE. Were looking for a process that violates a fundamental symmetry of nature, added Roger Huang, a postdoctoral researcher at the Department of Energys Lawrence Berkeley National Laboratory (Berkeley Lab) and one of the lead authors of the new study.

CUORE Italian for heart is among the most sensitive neutrino experiments in the world. The new results from CUORE are based on a data set ten times larger than any other high-resolution search, collected over the last three years. CUORE is operated by an international research collaboration, led by the Istituto Nazionale di Fisica Nucleare (INFN) in Italy and Berkeley Lab in the US. The CUORE detector itself is located under nearly a mile of solid rock at LNGS, a facility of the INFN. U.S. Department of Energy-supported nuclear physicists play a leading scientific and technical role in this experiment. CUOREs new results were published on April 6, 2022, in Nature.

Neutrinos are everywhere there are trillions of neutrinos passing through your thumbnail alone as you read this sentence. They are invisible to the two strongest forces in the universe, electromagnetism and the strong nuclear force, which allows them to pass right through you, the Earth, and nearly anything else without interacting. Despite their vast numbers, their enigmatic nature makes them very difficult to study, and has left physicists scratching their heads ever since they were first postulated over 90 years ago. It wasnt even known whether neutrinos had any mass at all until the late 1990s as it turns out, they do, albeit not very much.

One of the many remaining open questions about neutrinos is whether they are their own antiparticles. All particles have antiparticles, their own antimatter counterpart: electrons have antielectrons (positrons), quarks have antiquarks, and neutrons and protons (which make up the nuclei of atoms) have antineutrons and antiprotons. But unlike all of those particles, its theoretically possible for neutrinos to be their own antiparticles. Such particles that are their own antiparticles were first postulated by the Italian physicist Ettore Majorana in 1937, and are known as Majorana fermions.

CUORE detector being installed into the cryostat. Credit: Yury Suvorov and the CUORE Collaboration

If neutrinos are Majorana fermions, that could explain a deep question at the root of our own existence: why theres so much more matter than antimatter in the universe. Neutrinos and electrons are both leptons, a kind of fundamental particle. One of the fundamental laws of nature appears to be that the number of leptons is always conserved if a process creates a lepton, it must also create an anti-lepton to balance it out. Similarly, particles like protons and neutrons are known as baryons, and baryon number also appears to be conserved. Yet if baryon and lepton numbers were always conserved, then there would be exactly as much matter in the universe as antimatter and in the early universe, the matter and antimatter would have met and annihilated, and we wouldnt exist. Something must violate the exact conservation of baryons and leptons. Enter the neutrino: if neutrinos are their own antiparticles, then lepton number wouldnt have to be conserved, and our existence becomes much less mysterious.

The matter-antimatter asymmetry in the universe is still unexplained, said Huang. If neutrinos are their own antiparticles, that could help explain it.

Nor is this the only question that could be answered by a Majorana neutrino. The extreme lightness of neutrinos, about a million times lighter than the electron, has long been puzzling to particle physicists. But if neutrinos are their own antiparticles, then an existing solution known as the seesaw mechanism could explain the lightness of neutrinos in an elegant and natural way.

But determining whether neutrinos are their own antiparticles is difficult, precisely because they dont interact very often at all. Physicists best tool for looking for Majorana neutrinos is a hypothetical kind of radioactive decay called neutrinoless double beta decay. Beta decay is a fairly common form of decay in some atoms, turning a neutron in the atoms nucleus into a proton, changing the chemical element of the atom and emitting an electron and an anti-neutrino in the process. Double beta decay is more rare: instead of one neutron turning into a proton, two of them do, emitting two electrons and two anti-neutrinos in the process. But if the neutrino is a Majorana fermion, then theoretically, that would allow a single virtual neutrino, acting as its own antiparticle, to take the place of both anti-neutrinos in double beta decay. Only the two electrons would make it out of the atomic nucleus. Neutrinoless double-beta decay has been theorized for decades, but its never been seen.

The CUORE experiment has gone to great lengths to catch tellurium atoms in the act of this decay. The experiment uses nearly a thousand highly pure crystals of tellurium oxide, collectively weighing over 700 kg. This much tellurium is necessary because on average, it takes billions of times longer than the current age of the universe for a single unstable atom of tellurium to undergo ordinary double beta decay. But there are trillions of trillions of atoms of tellurium in each one of the crystals CUORE uses, meaning that ordinary double beta decay happens fairly regularly in the detector, around a few times a day in each crystal. Neutrinoless double beta decay, if it happens at all, is even more rare, and thus the CUORE team must work hard to remove as many sources of background radiation as possible. To shield the detector from cosmic rays, the entire system is located underneath the mountain of Gran Sasso, the largest mountain on the Italian peninsula. Further shielding is provided by several tons of lead. But freshly mined lead is slightly radioactive due to contamination by uranium and other elements, with that radioactivity decreasing over time so the lead used to surround the most sensitive part of CUORE is mostly lead recovered from a sunken ancient Roman ship, nearly 2000 years old.

Perhaps the most impressive piece of machinery used at CUORE is the cryostat, which keeps the detector cold. To detect neutrinoless double beta decay, the temperature of each crystal in the CUORE detector is carefully monitored with sensors capable of detecting a change in temperature as small as one ten-thousandth of a Celsius degree. Neutrinoless double beta decay has a specific energy signature and would raise the temperature of a single crystal by a well-defined and recognizable amount. But in order to maintain that sensitivity, the detector must be kept very cold specifically, its kept around 10 mK, a hundredth of a degree above absolute zero. This is the coldest cubic meter in the known universe, said Laura Marini, a research fellow at Gran Sasso Science Institute and CUOREs Run Coordinator. The resulting sensitivity of the detector is truly phenomenal. When there were large earthquakes in Chile and New Zealand, we actually saw glimpses of it in our detector, said Marini. We can also see waves crashing on the seashore on the Adriatic Sea, 60 kilometers away. That signal gets bigger in the winter, when there are storms.

Despite that phenomenal sensitivity, CUORE hasnt yet seen evidence of neutrinoless double beta decay. Instead, CUORE has established that, on average, this decay happens in a single tellurium atom no more often than once every 22 trillion trillion years. Neutrinoless double beta decay, if observed, will be the rarest process ever observed in nature, with a half-life more than a million billion times longer than the age of the universe, said Danielle Speller, Assistant Professor at Johns Hopkins University and a member of the CUORE Physics Board. CUORE may not be sensitive enough to detect this decay even if it does occur, but its important to check. Sometimes physics yields surprising results, and thats when we learn the most. Even if CUORE doesnt find evidence of neutrinoless double-beta decay, it is paving the way for the next generation of experiments. CUOREs successor, the CUORE Upgrade with Particle Identification (CUPID) is already in the works. CUPID will be over 10 times more sensitive than CUORE, potentially allowing it to glimpse evidence of a Majorana neutrino.

But regardless of anything else, CUORE is a scientific and technological triumph not only for its new bounds on the rate of neutrinoless double beta decay, but also for its demonstration of its cryostat technology. Its the largest refrigerator of its kind in the world, said Paolo Gorla, a staff scientist at LNGS and CUOREs Technical Coordinator. And its been kept at 10 mK continuously for about three years now. Such technology has applications well beyond fundamental particle physics. Specifically, it may find use in quantum computing, where keeping large amounts of machinery cold enough and shielded from environmental radiation to manipulate on a quantum level is one of the major engineering challenges in the field.

Meanwhile, CUORE isnt done yet. Well be operating until 2024, said Bucci. Im excited to see what we find.

Reference: Search for Majorana neutrinos exploiting millikelvin cryogenics with CUORE by The CUORE Collaboration, 6 April 2022, Nature.DOI: 10.1038/s41586-022-04497-4

CUORE is supported by the U.S. Department of Energy, Italys National Institute of Nuclear Physics (Instituto Nazionale di Fisica Nucleare, or INFN), and the National Science Foundation (NSF). CUORE collaboration members include: INFN, University of Bologna, University of Genoa, University of Milano-Bicocca, and Sapienza University in Italy; California Polytechnic State University, San Luis Obispo; Berkeley Lab; Johns Hopkins University; Lawrence Livermore National Laboratory; Massachusetts Institute of Technology; University of California, Berkeley; University of California, Los Angeles; University of South Carolina; Virginia Polytechnic Institute and State University; and Yale University in the US; Saclay Nuclear Research Center (CEA) and the Irne Joliot-Curie Laboratory (CNRS/IN2P3, Paris Saclay University) in France; and Fudan University and Shanghai Jiao Tong University in China.

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Physicists Are Closing In on the Next Breakthrough in Particle Physics And the Search for Our Own Origins - SciTechDaily

An ultraprecise measurement of the mass of a subatomic particle called the W boson may diverge from the Standard Model, a long-reigning framework that governs the strange world of quantum physics.

After 10 years of collaboration using an atom smasher at Fermilab in Illinois, scientists announced this new measurement, which is so precise that they likened it to finding the weight of an 800-pound (363 kilograms) gorilla to a precision of 1.5 ounces (42.5 grams). Their result puts the W boson, a carrier of the weak nuclear force, at a mass seven standard deviations higher than the Standard Model predicts. That's a very high level of certainty, representing only an incredibly small probability that this result occurred by pure chance.

"While this is an intriguing result, the measurement needs to be confirmed by another experiment before it can be interpreted fully," Joe Lykken, Fermilab's deputy director of research, said in a statement (opens in new tab).

The new result also disagrees with older experimental measurements of the W boson's mass. It remains to be seen if this measurement is an experimental fluke or the first opening of a crack in the Standard Model. If the result does stand up to scrutiny and can be replicated, it could mean that we need to revise or extend the Standard Model with possibly new particles and forces.

Related: Physicists get closer than ever to measuring the elusive neutrino

The weak nuclear force is perhaps the strangest of the four fundamental forces of nature. It's propagated by three force carriers, known as bosons. There is the single Z boson, which has a neutral electric charge, and the W+ and W- bosons, which have positive and negative electric charges, respectively.

Because those three bosons have mass, they travel more slowly than the speed of light and eventually decay into other particles, giving the weak nuclear force a relatively limited range. Despite those limitations, the weak force is responsible for radioactive decay, and it is the only force (besides gravity) to interact directly with neutrinos, the mysterious, ghost-like particles that flood the universe.

Pinning down the masses of the weak force carriers is a crucial test of the Standard Model, the theory of physics that combines quantum mechanics, special relativity and symmetries of nature to explain and predict the behavior of the electromagnetic, strong nuclear and weak nuclear forces. (Yes, gravity is the "elephant in the room" that the model cannot explain.) The Standard Model is the most accurate theory ever developed in physics, and one of its crowning achievements was the successful prediction of the existence of the Higgs boson, a particle whose quantum mechanical field gives rise to mass in many other particles, including the W boson.

According to the Standard Model, at high energies the electromagnetic and weak nuclear forces combine into a single, unified force called the electroweak interaction. But at low energies (or the typical energies of everyday life), the Higgs boson butts in, driving a wedge between the two forces. Through that same process, the Higgs also gives mass to the weak force carriers.

If you know the mass of the Higgs boson, then you can calculate the mass of the W boson, and vice versa. For the Standard Model to be a coherent theory of subatomic physics, it must be consistent with itself. If you measure the Higgs boson and use that measurement to predict the W boson's mass, it should agree with an independent, direct measurement of the W boson's mass.

Using the Collider Detector at Fermilab (CDF), which is inside the giant Tevatron particle accelerator, a collaboration of more than 400 scientists examined years of data from over 4 million independent collisions of protons with antiprotons to study the mass of the W boson. During those super-energetic collisions, the W boson decays into either a muon or an electron (along with a neutrino). The energies of those emitted particles are directly connected to the underlying mass of the W boson.

"The number of improvements and extra checking that went into our result is enormous," said Ashutosh V. Kotwal, a particle physicist at Duke University who led the analysis. "We took into account our improved understanding of our particle detector as well as advances in the theoretical and experimental understanding of the W boson's interactions with other particles. When we finally unveiled the result, we found that it differed from the Standard Model prediction."

The CDF collaboration measured the value of the W boson to be 80,433 9 MeV/c2, which is about 80 times heavier than the proton and about 0.1% heavier than expected. The uncertainty in the measurement comes from both statistical uncertainty (just like the uncertainty you get from taking a poll in an election) and systematic uncertainty (which is produced when your experimental apparatus doesn't always behave in the way you designed it to act). Achieving that level of precision of an astounding 0.01% is itself an enormous task, like knowing your own weight down to less than a quarter of an ounce.

"Many collider experiments have produced measurements of the W boson mass over the last 40 years," CDF co-spokesperson Giorgio Chiarelli, a research director at the Italian National Institute for Nuclear Physics, said in the statement. "These are challenging, complicated measurements, and they have achieved ever more precision. It took us many years to go through all the details and the needed checks."

The result differed from the Standard Model prediction of the W boson's mass, which is 80,357 6 MeV/c2. The uncertainties in that calculation (the "") come from uncertainties in the measurement of the Higgs boson and other particles, which must be inserted into the calculation, and from the calculation itself, which relies on several approximation techniques.

The differences between the results aren't very large in an absolute sense. Because of the high precision, however, they are separated by seven standard deviations, indicating the presence of a major discrepancy.

The new result also disagrees with previous measurements from other collider experiments, which have been largely consistent with the Standard Model prediction. It's not clear yet if this result is caused by some unknown bias within the experiment or if it's the first sign of new physics.

If the CDF result holds up and other experiments can verify it, it could be a sign that there's more to the W boson mass than its interaction with the Higgs. Perhaps a previously unknown particle or field, or maybe even dark matter, is interacting with the W boson in a way the Standard Model currently doesn't predict.

Nonetheless, the result is an important step in testing the accuracy of the Standard Model, said CDF co-spokesperson David Toback, a professor of physics and astronomy at Texas A&M University. "It's now up to the theoretical physics community and other experiments to follow up on this and shed light on this mystery," he said.

The researchers described their results April 7 in the journal Science (opens in new tab).

Originally published on Live Science.

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Oddly heavy particle may have just broken the reigning model of particle physics - Livescience.com

Yales hub for quantum research will soon entangle the campus in the best possible sense in a full week of mind-bending science, artistry, and discussion devoted to the wonders of quantum research.

Quantum Week at Yale, organized by the Yale Quantum Institute (YQI), will feature a hackathon, a lab tour, a movie screening, a record launch party, hands-on computer programming, a superconductive jewelry display, and an assortment of quantum-related library and museum exhibits.

The activities begin April 8 and run through April 14. A full list of events is available here.

Yales quantum scientists are at the very top of this field, said Florian Carle, YQI manager and coordinator for the event. We want to take some of the excitement we see in the labs and at YQI and share it with the rest of the campus.

Quantum science delves into the physical properties that explain the behavior of subatomic particles, atoms, and molecules. Over the past century, quantum research has transformed disciplines as diverse as physics, engineering, mathematics, chemistry, computer science, and materials science.

Over the past 20 years, Yale researchers have propelled quantum research, particularly in quantum information science and quantum computing, with a series of groundbreaking discoveries including the first demonstration of two-qubit algorithms with a superconducting quantum processor.

Yales research has led to unprecedented control over individual quantum objects, whether those objects are naturally occurring microscopic systems such as atoms, or macroscopic, human-made systems with engineered properties. Researchers say these advances may soon enable them to perform otherwise intractable computations, ensure privacy in communications, better understand and design novel states of matter, and develop new types of sensors and measurement devices.

This is the time when computer scientists, mathematicians, physicists, and engineers are all coming together, said Yongshan Ding, assistant professor of computer science, who will lead a programming workshop on April 14 that shows visitors including those without any experience with quantum computing how to play with quantum interference patterns.

People can just code away, Ding said. My vision is that by exposing people to these activities, we can build a quantum-native programming language. This is a new paradigm of computation, so were going to need new ways to program for it.

YQI has partnered with 18 Yale departments and centers to create 23 events for Quantum Week at Yale. One of the challenges in organizing the week, Carle explained, was developing an engaging mix of activities suited for both experienced researchers and quantum science novices.

To that end, the week is organized around four components: Understanding Quantum, Art & Quantum, Career and Entrepreneurship, and For Researchers.

The hands-on programming event, for example, comes under the Understanding Quantum banner. Other include an April 9-10 Quantum Coalition Hack, hosted by the Yale Undergraduate Quantum Computer Club; an April 11 tour of superconducting qubit laboratories; and a quantum-related exhibit of rare books at the Beinecke Rare Book and Manuscript Library on April 11.

Were always looking for ways that our libraries can engage with the academic work going on at Yale, said Andrew Shimp, who consulted on Quantum Week events at Yale libraries. Shimp is Yales librarian for engineering, applied science, chemistry, and mathematics. One of the unique things a Yale library can offer is the chance to view rare collections that arent necessarily digitized yet.

The quantum exhibit at the Beinecke Library, for example, includes materials from quantum science pioneers such as Albert Einstein, Werner Heisenberg, and Max Planck. There is also an astronomy textbook, published in 1511, that includes the word quantum in its title. The title is Textus de Sphera Johannis de Sacrobosco: cum additione (quantum necessarium est) adiecta / Nouo commentario nuper edito ad vtilitate[m] studentiu[m] philosophice Parisien[em]. A brief English translation would be Sphere of Sacrobosco.

Under the Art & Quantum heading, there will be an April 8 screening of the 2013 indie thriller Coherence; a visual arts competition called Visualize Science hosted by Wright Lab on April 13; a launch party for Quantum Sound (a record project begun at YQI in 2018) on April 13; a display of Superconductive Jewelry throughout the week at YQI; a Quantum and the Arts exhibit all week at the Arts Library; an April 13 event hosted by the Yale Schwarzman Center devoted to historical preservation of technology ephemera, called Dumpster Diving: Historical Memory and Quantum Physics at Yale; and a new exhibit at the New Haven Museum, The Quantum Revolution, that opens April 13 and features drawings by former YQI artist in residence Martha Willette Lewis.

Carle is curator for the New Haven Museum exhibit. We wanted to show the evolution of quantum science at Yale, he said. It will take people from some of the first qubits in 1998 to Badger, the dilution refrigerator that ran the first two-qubit algorithms with a superconducting quantum processor in 2009.

Quantum computers require extremely cold temperatures near absolute zero in order to reduce operational errors.

The weeks Career and Entrepreneurship component will include a discussion of quantum startups hosted by The Tsai Center for Innovative Thinking at Yale (Tsai CITY) on April 12; a conversation with IBMs Mark Ritter on the global implications of quantum research, hosted by the Jackson Institute for Global Affairs on April 12; a session on how to access market research for major industry analysts, hosted by the Yale University Library, on April 12; and a series of panel discussions on how to join the quantum workforce.

Finally, the For Researchers component of Quantum Week at Yale will feature a quantum sensing workshop at Wright Lab on April 8; and an April 14 lecture by quantum researcher Nathan Wiebe of the University of Washington.

The final day for Quantum Week at Yale, April 14, also happens to be World Quantum Day, Carle said. Our hope is that by then, students all over campus will be aware of quantum work being done here and want to explore it themselves in some way.

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Quantum Week at Yale geared toward novices and experts alike - Yale News

Robert Mann, a professor in theDepartment of Physics and Astronomy, has been named aUniversity Professorby the University of Waterloo. This designation recognizes exceptional scholarly achievement and international pre-eminence, and is given to a maximum of two faculty members each year. Robert Mann will be honoured for his outstanding achievement at the convocation ceremony this June.

Since this designations inception in 2003, this prestigious title has only been given to six other professors in the Faculty of Science. Robert Mann is the first University Professor chosen from the Department of Physics and Astronomy.

Professor Manns research focuses on gravitation, quantum physics, and the overlap of these physics topics.He wrote the first paper that examined how the idea of a minimal length in quantum gravity would affect our understanding of quantum mechanics.He has made a number of contributions to black hole thermodynamics,showing that black holes behave like everyday chemical systems, having phase transitions similar to those of liquids and gases, gels, polymers, and even superfluids.The subject is now called "black hole chemistry.He also was one of the founders of a subfield called relativistic quantum information, which investigates how relativistic effects modify quantum computation, and how quantum computation can exploit relativistic effects.

The most rewarding thing about being a professor is the ongoing adventure of training students to participate in scientific discovery," says Mann."It is an honour to be recognized by the University of Waterloo for doing something that I love to do.

Professor Mann will be honoured alongsideJohn Hirdesfrom theFaculty of Healthat the convocation ceremonies this June. Only 16 other individuals across the University of Waterloo currently hold this title.

Current University Professors in Science includeDr. Lyndon Jonesfrom theSchool of Optometry and Vision Science, and ProfessorsLinda NazarandJanusz Pawliszynfrom theDepartment of Chemistry.

This title has previously been held by retired Dean of ScienceTerry McMahonfrom the Department of Chemistry, Dr. Jacob Sivak from the School of Optometry and Vision Science, and late professor Robert Le Roy from the Department of Chemistry.

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Physicist Robert Mann named University Professor | Physics and Astronomy - The Iron Warrior

Apr 9th 2022

A CENTURY AGO, on April 6th 1922, the worlds most famous philosopher debated against the most famous physicist and lost. Henri Bergson, a French thinker who caused Broadways first traffic jam when he gave a lecture in New York, had challenged the notion of time advanced by Albert Einstein, the discoverer of relativity. Bergson was putting his thoughts into book form when Einstein came to Paris.

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At a gathering hosted by the Socit franaise de philosophie, which followed a talk by Einstein on relativity, they finally locked horns. Bergson summarised part of his forthcoming book, Duration and Simultaneity. Einsteins rebuttal was withering. There is no such thing as a philosophers time, he asserted. Bergsons version of it was merely psychological time. Their stilted non-conversation was a major anticlimax, says Elie During, a (living) French philosopher. Bergsons reputation waned; Time magazine named Einstein its person of the century.

Lopsided though the contest was, philosophers and scientists still ponder it. At stake is not just the momentous question of what time is. The debate was a key event in the separation of sciences and humanities into what C.P. Snow, a British novelist, later called two cultures. Einstein saw science as the ultimate arbiter of truth, says Jimena Canales, author of The Physicist and the Philosopher, a book about the episode. Bergson insisted that science did not have the last word. Their clash, Ms Canales says, raised the question, What is the relation between the subjective and the objective, and can we have a form of knowledge that includes both?

The philosopher was in the time business long before the physicist. Bergson published his first book, Time and Free Will, in 1889, when Einstein was ten years old. Initially an adherent of the idea that the world works like a machine, in the course of investigating evolution he encountered what he came to regard as sciences mistaken notion of time.

This views time in terms of space: an hour measures one-twenty-fourth of the Earths rotation. While useful, clock time misses what is most important about time, Bergson decided, namely duration. Rather than being disconnected from the past, the way one point on a ruler is separated from another, the present is suffused with it. Music is an example: each instant consists not only of itself but of what came before it. Pure duration is the form that the succession of our states of consciousness adopts when the self lets itself live, when it stops establishing a separation between its present and former states, Bergson wrote.

The passage of timethe present billowed with the pastprovides escape from a clockwork universe. This approach does not deny the importance of matter, but places life partially outside it. It is duration that permits novelty, both in the life forms that emerge from evolution and in the acts that proceed from the exercise of free will. Bergson applied his most famous epithet to lifes struggle with the material world, with which it is also bound up: lan vital. Peoples very identities are the temporal synthesis that is duration, as Mark Sinclair puts it in a recent book on Bergson.

His ideas were hugely influential. The literature of his day teems with Bergsonian characters, living between durational and clockwork worlds. T.S. Eliot (who heard him speak) seems to lament the splaying of time in space in The Love Song of J. Alfred Prufrock, writing of the evening spread out against the sky/Like a patient etherised upon a table. For the narrator of In Search of Lost Time, the memories awakened by a madeleines taste are enough to abolish clock time. Bergson married a cousin of Marcel Proust, the novels author, who was best man at his wedding. A spellbinding writer himself, Bergson won the Nobel prize in literature in 1927.

Even before his showdown with Einstein, though, Bergson was mocked for purveying metaphysical mumbo-jumbo. His exaltation of intuition, the faculty through which duration is apprehended, over intellect provided a fat target for Bertrand Russell, a British logician. According to Russell, writing in 1912, Bergson thought that the universe was a vast funicular railway, in which life is the train that goes up, and matter the train that goes down. Like advertising men Bergson relied upon picturesque and varied statement. In his History of Western Philosophy (1945), Russell added that the irrationalism of Bergsons philosophy harmonised easily with the movement which culminated in Vichya brutal comment about a Jew who refused special treatment from the Nazi-backed regime.

Einstein and Bergson were a study in contrasts. The German-born physicist was a pacifist and, until just before his death, a meat-eater; Bergson found philosophical grounds for Frances role in the first world warand was a vegetarian. Their clash in Paris was principally over Einsteins special theory of relativity, which had supplanted the unvarying time of Isaac Newtons physics.

Relativity states that time flows at different ratesfaster or slowerfor observers moving with respect to each other, as most do. Space compresses too, with the result that simultaneity is not absolute. This means that, in general, distinct observers witness events separated in space in different orders. Time and space blur together in a way implying that the past and future may be as real as the present, just as the Moon is as real as the Earth, a view sometimes called eternalism. The distinction between past, present and future is only a stubbornly persistent illusion, Einstein famously wrote.

This was a frontal challenge to Bergsons central idea. If time, he wrote, is thus spread out in spaceit takes account neither of what is essential to succession nor of duration in so far as it flows. Bergson did not deny Einsteins discoveries; philosophy must be constantly verified by contact with the positive sciences, he averred. But he maintained that relativitys profusion of times are not all equally real. It could not overthrow the common-sense belief in a single time, the same for all beings and all things. In fact, properly understood, relativity confirms that.

In defending this position, Bergson denied the consequence of the special theory illustrated by the twin paradox: if Peter remains on Earth while Paul rides a rocket into space and then returns, Peter will have aged more than Paul. Special relativity says that the faster something moves relative to you, the slower its clock will tick, from your point of view. Bergson insisted that the reunited twins will have aged by the same amount. This proved to be his Achilles heel, writes Ms Canales.

Most physicists continue to disdain Bergson, not mainly because of his twin gaffe but because of his attempted prison-break from the material world. Carlo Rovelli, an Italian theoretical physicist, makes one dismissive reference to the philosopher in his recent book The Order of Time. Bergson correctly pointed out that experiential time has more features than the time the physicists were talking about, Mr Rovelli says. But he incorrectly deduced from that there must be something that escapes physics in the real world. Now, when science is under attack from anti-vaxxers and others, Bergsons spiritualism seems to some not just wrong-headed but dangerous. Ms Canales says a physicist warned her that my career would be finished if she published a book that took Bergson seriously.

Yet he still matters, in two ways. He continues to influence thinkers who deem a materialistic account of the world to be inadequate, such as Rupert Sheldrake, author of The Science Delusion. And some who do not agree that science is deluded still find inspiration in Bergsons ideas, and seek to reconcile them with Einsteins.

Louis de Broglie, a pioneer of quantum physics, recognised Bergson as a seer. Had he studied quantum theory he would doubtless have observed with joy that in the image of the evolution of the physical world which it offers us, at each instant nature is described as if hesitating between a multiplicity of possibilities, de Broglie wrote. Jenann Ismael, a philosopher of science, argues that any being, man or machine, that gathers and uses information would perceive time as passing and the future as open. That time is no less real than Einsteins static four-dimensional spacetime, she says. There is a sense of conflict being replaced by a bridge.

The debate in Paris found both thinkers at their most dogmatic. Afterwards Bergson seems to have had second thoughts about some aspects of Duration and Simultaneitythough he never abandoned his basic position. In subsequent decades Einstein seemed to budge more. He acknowledged that metaphysics plays a role in science, and became more troubled by the failure of physics to give a complete description of time.

The problem of Now worried him seriously, wrote the philosopher Rudolf Carnap. It means something essentially different from the past and the future, yet this important difference does not and cannot occur within physics. Perhaps the ageing physicist came close to admitting that a philosophers time exists after all.

This article appeared in the Culture section of the print edition under the headline "Time v the machine"

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When Albert Einstein and Henri Bergson rowed about time - The Economist

Most people who talk about free will seem to assume that everyone knows what the words free will mean. But what do they mean? The only time we use these words in everyday conversation is when we say things like, You cant complain. You signed the contract of your own free will and Many people will never be vaccinated of their own free will. That is, doing something of your own free will means that no one forced you to do it or threatened you with unpleasant consequences if you didnt do it.

That is, doing something of your own free will means that no one forced you to do it or threatened you with unpleasant consequences if you didnt do it.

But the phrase free will has another meaning, a meaning it doesnt have in everyday conversation. And most people seem to understand free will when its used with this meaning. Most people would say that they understood the following words, which were written by Paul-Henri Thiry, Baron dHolbach, an 18th-century French philosopher)

A mans life is a line that nature commands him to describe upon the surface of the earth, and he is never able to swerve from it, even for an instant. . . . he is constantly being modified by causes, whether visible or hidden, over which he has no control . . . Nevertheless, in despite of the chains by which he is bound, it is pretended he is an agent with free will.

Its evident that Holbach is not saying that its only under pressure that people ever sign contracts or allow themselves to be vaccinated. That is, hes not denying that we do things of our own free will. And yet most people would understand this passage. That sense seems to have something to do with the way our decisions are caused, so lets examine a decision.

In the writings of the mid-20th-century existentialist philosopher Jean-Paul Sartre there is a famous example of a young man in Nazi-occupied France who is torn between remaining at home and caring for his aged mother and leaving home to join the Resistance.

Suppose we are there, observing him as he desperately tries to decide which course of action he will pursue. If Holbach is right, then we should conclude that the following statement is true: Either he will stay and care for his mother and he is unable to join the Resistance or he will leave and join the Resistance and he is unable to stay and care for his mother.

This suggests the following definition of not having free will: A person lacks free if and only if:

. . . whenever that person is trying to decide between two courses of action, A and B, either that person is going to do A and is unable to do B or is going to do B and is unable to do A.

And this implies a definition of free will: A person has free will if and only if:

. . . sometimes, when that person is trying to decide between two courses of action, A and B, either the person is going to do A and is able to do B or is going to do B and is able to do A.

The belief of Holbach and his fellow pre-twentieth-century materialists that free will in this sense was ruled out by physics rested on two assumptions.

They assumed, first, that that physics had demonstrated the truth of determinismthe doctrine that the past and the laws of nature determine the future (and determine it even in the smallest detail).

The belief of Holbach and his fellow pre-twentieth-century materialists that free will in this sense was ruled out by physics rested on two assumptions.

Early in the nineteenth century, the great mathematician Pierre-Simon Laplace gave this statement of determinism:

We ought then to regard the present state of the universe as the effect of its anterior state and as the cause of the one which is to follow. Given for one instant an intelligence which could comprehend all the forces by which nature is animated and the respective situation of the beings who compose itan intelligence sufficiently vast to submit these data to analysisit would embrace in the same formula the movements of the greatest bodies of the universe and those of the lightest atom; for it, nothing would be uncertain and the future, as the past, would be present to its eyes.

Their other assumption was incompatibilism, the thesis that free will and determinism are incompatiblethat is, that determinism rules out free will. Those in any age who accept incompatibilism probably do so because of some version of the so-called Consequence Argument:

If determinism is true, what we do is always a consequence of the way things were long before we were born and the laws of physics; but the way things were before we were born is never up to us and its never up to us what the laws of physics are; therefore, if determinism is true, what we do is never up to us.

The physics known to Holbach and Laplace was indeed deterministic (a few very minor and highly technical points aside). The situation is different in todays physics.

Photo by Greg Jeanneau on Unsplash

In present-day physics, all phenomena in nature other than gravity are treated by a theory called the standard model. The standard model is a quantum field theory, which means that its over-all structure is provided by quantum mechanics. And there is general agreement that quantum mechanics is incompatible with Laplaces statement of determinism. There is, moreover, universal agreement that the success of the standard model at the very least means that physics does not endorse determinism. And if physics does not endorse determinism, we have no reason to accept determinism.

Should we then conclude that there is no reason to think that we lack free will, owing to the fact that there is no reason to accept determinism?

That would be a hasty conclusion. We have considered an argument that is supposed to show that human beings lack free will:

Physics tells us that determinism is true; Determinism is incompatible with free will; therefore, free will does not exist.

But even if the premise of this argumentthat physics testifies to the truth of determinismis false, all that its falsity shows is that one argument against free will has a false premise. Maybe there are other arguments against free willones that dont depend on determinism.

There are.

Some are based on experimental evidence about human beings, such as the controversial experiments conducted by the neuroscientist Benjamin Libet in the 1980s. Others depend the idea of near-determinism: All right, the proponents of these arguments say, maybe determinism is strictly speaking false. But there are things like computers whose behavior is so close to being deterministic that one could say that they were deterministic for all practical purposes. Quantum mechanics doesnt imply that we human beings arent as nearly deterministic as computers. And if determinism is incompatible with free will, doesnt it seem likely that near determinism is, too?

But the most troubling argument of this kind is an argument that is supposed to show that indeterminism is incompatible with free will. The idea behind this argument is that an act that is undetermined is an act that is due to chance.

For example, suppose that Sally has to choose between telling the truth and lying, and that she tells the truth, and that her decision was completely undetermined. Suppose that, simultaneously with her decision, fifty atom-for-atom absolutely perfect duplicates of Sally in duplicate immediate environments are making the same decision. (Since they are duplicates of Sally, their decisions are undetermined, too.) If you arranged these fifty women in a line, youd see something like this (L stand stands for woman who lies and T for woman who tells the truth):

LTTLTLTTTTTTTLTTLTLTLLLTLLLTTLTLTLTLTTLLTTLTLTTLLL

A random distribution!

Since the decision of each woman in the line was undetermined, theres no explanation of why her decision went one way and not the other. And what could be further from your having free will than your decisions being random events? If your decisions are indeterministic (the argument suggests) they might as well be the outcome of a little man in your brain tossing a coin!

So we have arguments for Determinism implies theres no free will (the Consequence Argument) and Indeterminism implies theres no free will. If both arguments are right, free will is impossible. What would it mean if there were no free will?

It would mean that we live in a world in which nothing that happens is ever anyones fault. It would mean that we live in a world full of terrible things and that no one is ever to blame for any of them. It would mean that the Atlantic slave trade and the Final Solution and the assassination of Martin Luther King were not anyones faultthat no one is to blame for those terrible events.

But lets focus our thoughts on a smaller, more easily visualizable, case than those great, world-historical tragedies.

You and your family plan to be out of town for a few weeks, and your friend Frank promises to feed Fluffy the family cat while youre away. You return and find that he never fed Fluffy and she has died of starvation. You say to him, Poor Fluffy is dead, and my children are crying themselves to sleep and little Sally is the one who found her dead and shes going to need therapy and its all your fault! Frank says that none of those things is his fault, because he was unable to feed Fluffy, owing to the fact that the day we left he was diagnosed with Yellow Fever and confined to his house by the state quarantine authority. All right, you say, but you could have arranged to have someone else feed her. No, he replies, his phone was the only means of contact with the outside world, and the phone company cut off his service because of a mistake in their billing office. (And so on, and so on. You continue the story.)

The point is, if Frank can convince you that there was nothing he could have done to prevent Fluffys death, then you should agree that that event and its consequences werent his fault. And this is a general principle. If you say that something is Alices fault or that Alice is to blame for it, that implies that Alice shouldnt have allowed it to happen. And that impliessince it did happenthat Alice should have done something different from what she did do. And that implies that Alice was able to do something different from what she did do. And to be able to do something different from what one does do is to have free will.

The bottom line is: if there is no free will, if no one is ever able to do anything but what he or she does do, nothing is anyones fault.

To me, the statement

Neither the Atlantic slave trade nor the Final Solution nor the assassination of Martin Luther King was anyones fault

is so obviously false that I can only conclude that we do have free willand that there is therefore something wrong with either the Consequence Argument or the fifty perfect duplicates argument. My own view is that the Consequence Argument is valid and sound and that theres some flaw in the duplicates argument. But I confess I do not know what that flaw is.

Editor's Note: The notion that free will is tough to prove is not something most theologically minded people (like myself) would prefer to hear. Nonetheless, we have posted Dr. van Inwagens essay in the spirit of free inquiry and to celebrate the investigation of truth.

Judaic tradition insists that humanity was gifted free will, that it is the hub around which all morality turns and that it is the capacity that most makes humanity Godly.

Free will is obviously an extremely complex and controversial subject, and rightly so, given the stakes outlined by Dr. van Inwagen. One can easily respect his struggle with the subject and his honesty in professing his personal belief in free will concurrently with his current inability to prove it philosophically. He rightly notes that the physics that seemed so settled and obvious in the 18th Century was radically overturned in the 20th in a way that directly impacted the free will debate. It seems likely that more scientific revolutions will take place in the future and that these too may spark new explorations of free will.

One additional observation is that though there may be people who claim to disbelieve free will, very few actually conduct their lives as if it wasn't real (not that they could help it). My subjective feeling is that in their heart of hearts, most people don't really think themselves incapable of making choices or that this deep-seated human faculty is simply an illusion.

Image credit by Burst on Unsplash

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Can Science Prove There's No Free Will? Can Anything? - aish.com - Aish

Overview

We are a newly established group at UCLA led by Prof. Clarice D. Aiello. Our mission is to establish the extent to which quantum mechanics accounts for biologically relevant phenomena, and can be manipulated to technological and therapeutic advantage.

Experiments suggest that nontrivial quantum mechanical effects involving spin might underlie biologically relevant phenomena as varied as magnetic field detection for animal navigation, metabolic regulation in cells and optimal electron transport in chiral biomolecules. We investigate such phenomena using high-tech tools borrowed from the fields of quantum sensing/computing, device physics, and atomic and molecular (AMO) physics. Current and near-future research directions include:

Optimal quantum control of spins in biological systems via optically-detected magnetic resonance performed under a single-molecule microscope, and subsequent correlation with microscopic cellular processes;

Detection and control of spin coherence and polarization in electrons traversing nanoscale chiral potentials (from complex engineered materials to DNA and proteins) using a scanning tunneling microscope with spin-resonance capabilities.

At this time, we seek postdoctoral candidates with training in AMO, spin or solid-state physics (including but not restricted to: ultracold atoms, trapped ions, superconducting qubits, NV centers). Nanofabrication skills and experience in developing experimental control software are a plus.

Postdoctoral scholars are expected to conduct research in small teams, and mentor trainees. In particular, accepted candidates will have an invaluable opportunity to help shape our young lab. Formal teaching opportunities and pursuing the nationally recognized CIRTL certification at UCLA are possibilities. Clarice is invested in working with accepted candidates to develop a plan towards their own career goals.

Diversity and inclusion

We encourage applications from members of underrepresented groups with respect to gender, race and ethnicity, religion, sexual orientation, disability status, age, socioeconomic background, care-taking status, and other axes of diversity.

Compensation

Pay is non-negotiable and at a NIH+7 level, well above-average for a postdoctoral appointment in the United States (scholarships will be topped up to this amount). Postdoctoral contracts are 1-year long, with the possibility of extension upon mutual agreement.

All team members are encouraged and expected to apply for fellowships.

Timeline

While flexible, preferred start dates are between September 2021 and March 2022. The positions will remain open until filled.

Application

Applicants should send an email to Clarice (cla@ucla.edu): 1. briefly detailing their research experience, interests and career plans; 2. with an up-to-date CV as attachment.

Additional info

We encourage you to follow us on Twitter (@ClariceDAiello, @QuBiT_UCLA) and LinkedIn (ClariceDAiello, Quantum Biology Tech (QuBiT) Lab @UCLA)!

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Postdoctoral researcher at the Quantum Biology Tech (QuBiT) Lab at UCLA; AMO/spin/solid-state physic job with UNIVERSITY OF CALIFORNIA | 288634 -...

Credit: Scientific American Space & Physics, April/May 2022Advertisement

In physics, some hypotheses can take more than a lifetime to confirmas happened in 2019, when researchers saw the first image of a black hole, a cosmological phenomenon whose existence was theorized by Albert Einstein a full century before but never observed directly. Other ideas in physics have endured decades of debate, without resolution or further clarity. In this issue, reporter Davide Castelvecchi profiles the fascinating history of a landmark experiment from 1922 that recorded the quantum spin of an elementary particle, the interpretation of which is still ongoing (see Hundred Years Ago a Quantum Experiment Explained Why We Dont Fall through Our Chairs).

Elsewhere in this issue, columnist John Horgan contemplates what a radical new quantum theory means for our perception of reality (see Does Quantum Mechanics Reveal That Life Is but a Dream?). He writes that quantum researchers share a notable trait with artists who try to turn the chaos of things into a meaningful narrative. I would take his idea further and say that finding sense among lifes challenges is an inherent part of all human experience.

This article was originally published with the title "Humans and the Quantum Experience" in SA Space & Physics 5, 2, (April 2022)

Andrea Gawrylewski is the collections editor at Scientific American.Follow Andrea Gawrylewski on TwitterCredit: Nick Higgins

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