Category Archives: Quantum Physics

"IEEE is now at the center of a global conversation to understand the power and promise of quantum computing." Travis Humble, Oak Ridge National Lab

IEEE Quantum Weekis recognized as a leading venue for presenting high-quality original research, ground-breaking innovations, and insights in quantum computing and engineering. Throughparticipation from the international quantum community,QCE21 offers an extensive conference program withworld-class keynote speakers, technical paper presentations,innovative posters, excitingexhibits, technical briefings, workforce-building tutorials, community-building workshops,stimulating panels,and Birds-of-Feather sessions.

Stay informed of all QCE21 updates - sign up for QCE21 conference alerts.

Participation opportunities are available for a limited time. Authorsare invited to submit contributionsfor technical papers, tutorials, workshops, panels, posters, and Birds-of-a-Feather sessions. Papers accepted by QCE21 will be submitted to the IEEE Xplore Digital Library, and the best papers will be invited to the journalsIEEE Transactions on Quantum Engineering (TQE)andACM Transactions on Quantum Computing (TQC). The submission schedule is available at QCE21 Submission Deadlines.

The high standards for QCE21 were set by the tremendous success of the inaugural QCE20.Over 800 people from 45 countries and 225 companies attended the premier event that delivered 270+ hours of programming on quantum computing and engineering.

The second annual Quantum Week will virtually connect a wide range of leading quantum professionals, researchers, educators, entrepreneurs, champions and enthusiasts to exchange and share their experiences, challenges, research results, innovations, applications, and enthusiasm, on all aspects of quantum computing, engineering and technologies. The IEEE Quantum Week schedule will take place during Mountain Daylight Time (MDT).

Visit IEEE QCE21for all event news including sponsorship and exhibitor opportunities.

QCE 21 is co-sponsored by the IEEE Computer Society, IEEE Communications Society, IEEE Council of Superconductivity, IEEE Future Directions Committee, and IEEE Photonics Society.

About the IEEE Computer Society

The IEEE Computer Societyis the world's home for computer science, engineering, and technology. A global leader in providing access to computer science research, analysis, and information, the IEEE Computer Society offers a comprehensive array of unmatched products, services, and opportunities for individuals at all stages of their professional career. Known as the premier organization that empowers the people who drive technology, the IEEE Computer Society offers international conferences, peer-reviewed publications, a unique digital library, and training programs.

About the IEEE Communications Society

TheIEEE Communications Societypromotes technological innovation and fosters creation and sharing of information among the global technical community. The Society provides services to members for their technical and professional advancement and forums for technical exchanges among professionals in academia, industry, and public institutions.

About the IEEE Council on Superconductivity

TheIEEE Council on Superconductivityand its activities and programs cover the science and technology of superconductors and their applications, including materials and their applications for electronics, magnetics, and power systems, where the superconductor properties are central to the application.

About the IEEE Future Directions Quantum Initiative

IEEE Quantumis an IEEE Future Directions initiative launched in 2019 that serves as IEEE's leading community for all projects and activities on quantum technologies. IEEE Quantum is supported by leadership and representation across IEEE Societies and OUs. The initiative addresses the current landscape of quantum technologies, identifies challenges and opportunities, leverages and collaborates with existing initiatives, and engages the quantum community at large.

About the IEEE Photonics Society

TheIEEE Photonics Societyforms the hub of a vibrant technical community of more than 100,000 professionals dedicated to transforming breakthroughs in quantum physics into the devices, systems, and products to revolutionize our daily lives. From ubiquitous and inexpensive global communications via fiber optics, to lasers for medical and other applications, to flat-screen displays, to photovoltaic devices for solar energy, to LEDs for energy-efficient illumination, there are myriad examples of the Society's impact on the world around us.

SOURCE IEEE Computer Society

http://www.computer.org

Read more:

Quantum Week 2021 Unveils the Latest in Quantum Computing and Engineering - PRNewswire

The UC Davis Center for Quantum Mathematics and Physics, or QMAP, finally has its permanent home on the two upper floors of the Physical Sciences and Engineering Library. Next, the first and lower floors of the standalone building will be renovated for the campuss growing research programs, including those associated with data sciences and artificial intelligence.

By co-locating these initiatives, the hope is to facilitate cross-campus and interdisciplinary collaboration among them, Provost and Executive Vice Chancellor Mary Croughan wrote in a March 18 letter to the Council of Deans and Vice Chancellors, members of the Academic Senatre and Academic Federation, and all students. In order to best respond to emerging interdisciplinary research needs in the future, the space is planned to be flexible enough to evolve as programs grow and shift.

QMAP construction began in 2018, coupled with extensive retrofitting of the entire building for seismic and fire safety. The Physical Sciences and Engineering Library, or PSEL, stayed open on the first and lower floors until it too vacated the building due to the construction.

By the summer of 2019, all library collections and circulation functions had been integrated with other campus libraries. I am grateful to the library staff for their commitment to addressing the collections needs of various disciplines that previously relied on this space, the provost wrote. In addition, the campus added 300 new study seats at Shields Library more than were displaced at PSEL to mitigate the loss of study space for our students at PSEL.

While there are no plans for the building to resume operations as a library facility, the UC Davis Library will retain a footprint for a satellite DataLab collaborative office.

Meanwhile, the QMAP floors are ready for occupancy, said Tracy Ligtenberg, assistant dean for executive administration in the College of Letters and Science. While a few faculty have moved in, it is not operating as we would expect due to the COVID restrictions, she said.

Distinguished Professor Andreas Albrecht, Department of Physics and Astronomy. expects more activity this spring and certainly by summer and fall, according to Ligtenberg. The research group is excited to move in and start collaborating, she said.

The provost said she had appointed a committee to oversee completion of the building systems and renovation of the first floor and lower level. She listed some of the programs in line for space in PSEL: the TETRAPODS Institute for Data Science; the Center for Data Science and Artificial Intelligence Research, or CeDAR; and the AI Institute for Next Generation Food Systems. Study and office space for other emerging AI or data science programs and for the new data science major may also be included as plans develop. Read about the new data science major.

The PSEL Renovation 2020 Project Implementation Committee includes representatives from the College of Letters and Science, Office of Research, library and TETRAPODS, along with the relevant campus units for planning, facilities and construction management.

More here:

QMAP Will Have Data Science and AI as Downstairs Neighbors - UC Davis

If theres one misconception people have about black holes, its that nothing ever escapes them. As physicist Stephen Hawking and colleagues showed back in the 1970s, black holes actually emit a faint glow of light.

Theres a funny consequence to this glow: It carries energy away from the black hole. Eventually this drip, drip, drip of radiation drains a black hole completely and causes it to disappear. All that remains is the light.

In the 1970s, scientists calculations suggested that this light contained almost no information. Black holes seemed to be destroyers not just of the objects that sank into them but also of any information about what those objects had been in the first place.

The problem is: According to quantum mechanics, thats impossible.

A core tenet of quantum mechanics, the study of particle behavior on the subatomic level, is this: If you know the current state of any system, then you know everything there is to know about its past and its future.

Somehow, black holes seemed to be destroying information that, according to quantum physics, cannot be destroyed. This problem, today known as the black hole information paradox, has befuddled physicists for decades.

But over the last several years, theoretical physicists have identified key pieces that Hawkings original calculation overlooked. Calculations completed in 2019 gave scientists insight into how that information might stick around.

Those developments could mean more than just solving the information paradoxthey could also provide clues that could help finally solve the mystery of how gravity works at the subatomic level, says MIT physicist Netta Engelhardt, whose work with Institute for Advanced Study physicist Ahmed Almheiri, along withsimilar work by University ofCalifornia, Berkeley physicistGeoffPenington and colleauges, pointed the way toward the latest results. The research was supported in part by the US Department of Energys Office of Science.

This, she says, is where we need to look to understand quantum gravity better.

In the 1990s, the first hint arrived that black holes might not be the information-destroyers theyd been made out to be.

Physicist Don Page, a former student of Hawkings, imagined a black hole that absorbed quantum-mechanical waves and then radiated them back out in a scrambled form. Unlike Hawking, he followed quantum theory in assuming that the combined systemof the black hole, the incoming waves and the outgoing radiationwas closed, so that whatever information was in the system to begin with would be preserved.

In Pages calculation, radiationboth contains information and is correlated with what remains behind in theblack holeand therefore is also correlated with the radiation the black holeemits later on.

Pages keyresultis whats now called the Page curve, which describes the amount of information connectedto a black hole and itsradiation. This curve increases slowly overtime, reachinga maximum about halfway through the processwhen all of theinformation that hasemerged is as correlated as can be with all of theinformation that remainsand eventually decliningback down to zerowhen theblackhole vanishes, and the pairing is no more.

The Page curve tantalized physicists almost as much as theoriginal information paradox. It showed that while physicists should still expect Hawkings calculation to hold for quite a long time, it has to go wrong eventually, and before you would expect it to, based on other calculations, saysPenington, the UC Berkeley physicist.

Still, many physicists wondered whether Page could really beright. The Hawking calculation seemed veryrobust, Penington says. To get something like the Page curve in a real black hole, itseemed like youd need something very radical.

For the last several decades, the challenge has been to calculate the Page curve in the full gloryor perhaps full brutalityof Einsteins general theory of relativity, finally taking gravity into account.

And now physicists have done just that.

The result relies on the replica trick, a mathematical method for calculating entropy. In computing the entropy of a black hole and its radiation, physicists need to add up contributions from many different configurations of that system. That turns out to be practically impossible to do directlyif limited to one black hole.

If, on the other hand, they consider two copies of a black hole, each existing in a separate universe, and the radiation that both emit, the entropy is relatively easy to compute, says Almheiri, the IAS physicist. From this calculation physicists can infer what information would exist between a single black hole and its radiation.Within the context of the replica trick, information in the interior of one black hole can flow into the interior of the other, and this information flow becomes more important over time.

Back in the regular universe, the finding makes precise an idea that had been suggested a few times in the last decade: The entropy in the connection between Hawking radiation outside the black hole and whats left inside can actually affect the interior structure of the black hole.As Almheiri puts it, there's an operation you can perform on the radiation outside that would create a cat inside.

Of course, no one actually knows what they would have to do to the radiation outside an actual, real-world black hole to make a cat inside it. Nor do the latest calculations reveal exactly what radiation black holes produce or how thats connected to what falls into them in the first place.

But most everyone agrees, it is significant progress. To Almheiri, the paradox is not as severe as it once was.

Whats more, examining exactly how the quantum calculations work in a wider range of circumstances could reveal something new about how a full quantum theory of gravity could work, Engelhardt says.

And even if it doesnt, the possibility of resolving the information paradox is enticing. When Engelhardt and her collaborators first started studying it, she says, I barely slept, it was so exciting. For the first time in a really long time, were making progress.

Read the original post:

Has the black hole information paradox evaporated? - Symmetry magazine

Even for scientists who have dedicated their lives to understanding gravity, the forces relentless downward pull is sometimes a drag. Consider, for instance, the researchers who study Bose-Einstein condensates (BECs) as precise probes of fundamental physics. BECs emerge when a dilute gas of atoms is cooled close to absolute zero and begins behaving as a single, strange chunk of quantum mattersimilar to how wriggling water molecules transform into a block of ice once they are chilled. These odd assemblages magnify otherwise hidden quantum-mechanical effects such as the wavelike nature of matter, making them visible at macroscales. Yet sometimes gravitys pernicious influence can get in the way.

Earthbound escapes from gravitys hold involve subjecting BECs to free fall, usually for short spates inside tall drop towers or airplanes flying in parabolic arcs. But the best approach is arguably to leave Earth behind, placing BECs in rockets to experience longer periods of weightless free fall in outer space. Recently, a team of physicists supported by Germanys space agency reported on doing just that. In Nature Communications this past February, they published the results of a 2017 experiment that manufactured BECs on a millimeter-sized chip in a suborbital sounding rocket almost 300 kilometers above the planets surface. The BECs then crashed together in the microgravity conditions, allowing the physicists to study the collisions in exquisite detail. Their mission, MAIUS-1, was the first to successfully collide BECs in space, and it points the way toward new space-based tests of fundamental physics.

When two BECs collide, instead of bouncing off one another like atoms usually do, they interact as waves. When their peaks line up, they form an even taller wave. If the peak of one matter wave overlaps with the trough of another, they cancel each other out, leaving behind empty space. An encounter between two misaligned condensates results in a wave-interference pattern: alternating bright stripes where the two waves enhanced each other and dark stripes where they annihilated each other. Creating and studying these patterns in matter is called atom interferometry.

Onboard the MAIUS-1 rocket, a carefully choreographed system of lasers split the ultracold atoms into multiple matter waves before letting them collide. Images captured inside the rocket, and analyzed once the spacecraft returned to Earth, showed a detailed striped interference pattern that emerged from slight differences in the shapes and positions of each BECs peaks and troughs. By studying such details, the researchers could tell whether, prior to crashing, the matter waves had been changed by interacting with light or any other forces in their surroundings.

Atoms are sensitive to all of it, says Naceur Gaaloul, a physicist at Leibniz University Hannover in Germany and co-author on the study. The stripe pattern produced by colliding BECs, Gaaloul says, is a bit like an archeological dig: it helps scientists determine the precise precrash history of the matter waves and pinpoint anything that could have moved their peaks and troughs.

Gravitys pull complicates all of this because it makes BECs fall while they move toward each other, resulting in vanishingly brief clashes and blurred interference patterns. The microgravity conditions of space remove these limitations.

According to Maike D. Lachmann, a physicist at Leibniz University Hannover and the studys lead author, escaping gravity has always been her teams motivation. The whole thing started in a collaboration, which was aiming to do experiments in a drop-tower facility, she recalls. But the long-term goal was always going to space. Dropping ultracold atoms from a nearly 150-meter-high tower bought scientists several seconds of microgravity. The MAIUS-1 rocket bumped that up to nearly six minutes.

Microgravity is just really where you want to be, says Cass Sackett, a physicist at the University of Virginia, who was not involved with the study. I expect that as time goes on, we will see atom interferometers in space that are better than anything thats been on the ground. In fact, in 2018 NASA launched an ultracold atom experiment into space. The space agencys Cold Atom Laboratory (CAL) has been cooling atoms onboard the International Space Station (ISS) ever since.

CALs ability to create quantum states in microgravity for scientists to play with captivated many physicists, including Sackett. Anita Sengupta, an aerospace engineer who served as CALs project manager during the first five years of its development and was not part of the new study, echoes this sentiment. My personal motivation behind the mission was to engineer a facility to explore the fundamental physics of the BEC, to open a new doorway into the quantum world, she says. Researchers using CAL have recently performed atom interferometry experiments similar to the work of the MAIUS-1 team as well, Sengupta adds.

Regardless of the specific space-based platform being used, one common research goal for atom interferometry is to test the fundamental principle that bodies of all compositions fall at the same rate under the influence of gravity. According to Lachmann, conducting the MAIUS-1 matter wave interference experiment multiple times using batches of elementally different atoms would test this idea to unprecedented levels of precision. In the unlikely event gravity moved one set of atoms more than the other, their two stripe patterns would be visibly different.

The extreme precision offered by atom interferometry also ushers in the small possibility that signatures of exotic forces, perhaps those associated with some models of dark energy, could be spotted through the technique.

A more immediate and practical application for devices such as the MAIUS-1 chip could emerge in celestial navigation. Because BEC interference patterns are so sensitive to even the smallest fluctuations in gravity, they can be used to map out details of gravitational fields. Similar to how maps of underwater currents help ships navigate, these gravitational-field maps could be useful for fine-tuning a spacecrafts deep-space maneuvers.

During its mission, the MAIUS-1 team already achieved several technological advances. The scientists experiment fit on a single ruggedized chip rather than being laid out on a large table like the arrangement in most terrestrial laboratoriesbecause it had to survive the rockets bumpy flight through Earths atmosphere. Also, the researchers could not communicate with the rocket after it launched, so autonomous systems cooled, manipulated and imaged the atoms. In the future, they want to equip the rocket with commonly used navigation sensors and compare those sensors performance to that of their chip.

For now, NASA and MAIUS-1 scientists are collaborating on developing upgrades for future installation on CAL onboard the ISS that will offer more options for microgravity experiments, including using atoms that have magnetic spins or that interact with one another strongly. Combining their experiences of trying to wrestle atoms away from gravitys pull, researchers hope to put fundamental physics under an even more powerful magnifying glass in outer space.

Read more here:

Ultracold Quantum Collisions Have Been Achieved in Space for the First Time - Scientific American

When she entered the field of particle physics in the early 2000s, Lindley Winslow was swept into the center of a massive experiment to measure the invisible.

Scientists were finalizing the Kamioka Liquid Scintillator Antineutrino Detector, or KamLAND, a building-sized particle detector built within a cavernous mine deep inside the Japanese Alps. The experiment was designed to detect neutrinos subatomic particles that pass by the billions through ordinary matter.

Neutrinos are produced anywhere particles interact and decay, from the Big Bang to the death of stars in supernovae. They rarely interact with matter and are therefore pristine messengers from the environments that create them.

By 2000, scientists had observed neutrinos from various sources, including the sun, and hypothesized that the particles were morphing into different flavors by oscillating. KamLAND was designed to observe the oscillation, as a function of distance and energy, in neutrinos generated by Japans nearby nuclear reactors.

Winslow joined the KamLAND effort the summer before graduate school and spent months in Japan, helping to prepare the detector for operation and then collecting data.

I learned to drive a manual transmission on reinforced land cruisers into the mine, past a waterfall, and down a long tunnel, where we then had to hike up a steep hill to the top of the detector, Winslow says.

In 2002, the experiment detected neutrino oscillations for the first time.

It was one of those moments in science where you know something that no one else in the world does, recalls Winslow, who was part of the scientific collaboration that received the Breakthrough Prize in Fundamental Physics in 2016 for the discovery.

The experience was pivotal in shaping Winslows career path. In 2020, she received tenure as associate professor of physics at MIT, where she continues to search for neutrinos, with KamLAND and other particle-detecting experiments that she has had a hand in designing.

I like the challenge of measuring things that are very, very hard to measure, Winslow says. The motivation comes from trying to discover the smallest building blocks and how they affect the universe we live in.

Measuring the impossible

Winslow grew up in Chadds Ford, Pennsylvania, where she explored the nearby forests and streams, and also learned to ride horses, even riding competitively in high school.

She set her sights west for college, with the intention of studying astronomy, and was accepted to the University of California at Berkeley, where she happily spent the next decade, earning first an undergraduate degree in physics and astronomy, then a masters and PhD in physics.

Midway through college, Winslow learned of particle physics and the large experiments to detect elusive particles. A search for an undergraduate research project introduced her to the Cryogenic Dark Matter Search, or CDMS, an experiment that was run beneath the Stanford University campus. CDMS was designed to detect weakly interacting massive particles, or WIMPS hypothetical particles that are thought to comprise dark matter in detectors wrapped in ultrapure copper. For her first research project, Winslow helped analyze copper samples for the experiments next generation.

I liked seeing how all these pieces worked together, from sourcing the copper to figuring out how to build an experiment to basically measure the impossible, Winslow says.

Her later work with KamLAND, facilitated by her quantum mechanics professor and eventual thesis advisor, further inspired her to design experiments to search for neutrinos and other fundamental particles.

Little particles, big questions

After completing her PhD, Winslow took a postdoc position with Janet Conrad, professor of physics at MIT. In Conrads group, Winslow had freedom to explore ideas beyond the labs primary projects. One day, after watching a video about nanocrystals, Conrad wondered whether the atomic-scale materials might be useful in particle detection.

I remember her saying, These nanocrystals are really cool. What can we do with them? Go! And I went and thought about it, Winslow says.

She soon came back with an idea: What if nanocrystals made from interesting isotopes could be dissolved in liquid scintillator to also realize more sensitive neutrino detection? Conrad thought it was a good idea and helped Winslow seek out grants to get the project going.

In 2010, Winslow was awarded the LOral for Women in Science Fellowship and a grant that she put toward the nanocrystal experiment, which she named NuDot, for the quantum dots (a type of nanocrystal) that she planned to work into a detector. When she finished her postdoc, she accepted a faculty position at the University of California at Los Angeles, where she continued laying plans for NuDot.

A cold bargain

Winslow spent two years at UCLA, during a time when the search for neutrinos circled around a new target: neutrinoless double-beta decay, a hypothetical process that, if observed, would prove that the neutrino is also its own antiparticle, which would help to explain why the universe has more matter than antimatter.

At MIT, physics professor and department head Peter Fisher was looking to hire someone to explore double-beta decay. He offered the job to Winslow, who negotiated in return.

I told him what I wanted was a dilution refrigerator, Winslow recalls. The base price for one these is not small, and its asking a lot in particle physics. But he was like, done!

Winslow joined the MIT faculty in 2015, setting her lab up with a new dilution refrigerator that would allow her to cool macroscopic crystals to millikelvin temperatures to look for heat signatures from double-beta decay and other interesting particles. Today she is continuing to work on NuDot and the new generation of KamLAND, and is also a key member of CUORE, a massive underground experiment in Italy with a much larger dilution refrigerator, designed to observe neutrinoless double-beta decay.

Winslow has also made her mark on Hollywood. In 2016, while settling in at MIT, a colleague at UCLA recommended her as a consultant to the remake of the film Ghostbusters. The set design department was looking for ideas for how to stage the lab of one of the movies characters, a particle physicist. I had just inherited a lab with a huge amount of junk that needed to be cleared out gigantic crates filled with old scientific equipment, some of which had started to rust, Winslow says. [The producers] came to my lab and said, This is perfect! And in the end it was a really fun collaboration.

In 2018, her work took a surprising turn when she was approached by theorist Benjamin Safdi, then at MIT, who with MIT physicist Jesse Thaler and former graduate student Yonatan Kahn PhD 15 had devised a thought experiment named ABRACADABRA, to detect another hypothetical particle, the axion, by simulating a magnetar a type of neutron star with intense magnetic fields that should make any interacting axions briefly detectable. Safdi heard of Winslows refrigerator and wondered whether she could engineer a detector inside it to test the idea.

It was an example of the wonderfulness that is MIT, recalls Winslow, who jumped at the opportunity to design an entirely new experiment. In its first successful run, the ABRACADABRA detector reported no evidence of axions. The team is now designing larger versions, with greater sensitivity, to add to Winslows stable of growing detectors.

Thats all part of my groups vision for the next 25 years: building big experiments that might detect little particles, to answer big questions, Winslow says.

Read the original post:

Measuring the invisible - MIT News

During a physics class I took in college, the professor introduced the unit on thermodynamics with a quote from Albert Einstein, who said that it is the only physical theory of universal content which I am convinced . . . will never be overthrown. I was suitably impressed. Yet within about 10 minutes my enthusiasm flagged. Sure, the field might be eternal, but even Einsteins imprimatur couldnt glamorize the grubby details of heat exchange and energy conservation.

Such is the fate of thermodynamics. Its arguably the most successful scientific theory in history, sweeping and precise and revolutionary all at once. And virtually no one cares.

Einsteins Fridge: How the Difference Between Hot and Cold Explains the Universe, a wide-ranging book by the British documentary filmmaker Paul Sen, sets out to rectify that situation. Mr. Sen knows the challenge that awaits him. In the books very first sentence, he laments that thermodynamics is a dreadful name. It implies a bland focus on heat flow and, to me at least, conjures up images of Victorians in stuffy suits tinkering with steam engines. Its a far cry from the romance of relativity or the enigmatic koans of quantum mechanics. Mr. Sen nevertheless makes a strong case that thermodynamics is every bit as lively as those other fieldsand vastly more useful for understanding what makes the universe tick.

The history of thermodynamics flips the relationship between science and technology on its head. Nowadays, scientists emphasize the primacy of fundamental research. Only after you understand the basic science, they argue, can you hope to apply it outside the lab. Not so with thermodynamics. In case after casesteam engines, refrigerators, computer circuitsengineers and dedicated tinkerers began making impressive progress in the field before they had any real understanding of the underlying science.

This topsy-turvy history might explain, in part, the fields inability to charm the public. We love bold leaps that open up new vistas of thought; sweeping scientific breakthroughs are sexy. Tinkering isnt. And even after scientists jumped into thermodynamics, their understanding came fitfullya handful of men and women advancing piecemeal over a century. Contrast that to the theory of relativity and its lone, dreamy hero in Einstein. Or quantum mechanics, which had the feverish air of a revolution in the 1920s. However important, the history of thermodynamics is messy.

Read the original:

Einsteins Fridge Review: Heated Arguments - The Wall Street Journal

Ive been squabbling about realism lately, with myself as well as with others. I dont mean realism in the colloquial sense, meaning hardheadedness, or political realism, which assumes were all selfish jerks. (Hypothesis: political realists are jerks who project their jerkiness onto everyone else.)

No, I mean realism in the hifalutin philosophical sense, which assumes that the world has an objective, physical existence, independent of us, that we can discover through science. This position is sometimes called scientific realism or, by critics, naive realism.

Philosophers will probably object to my definition, but philosophers object to any definition. Thats what philosophers do. In this column Ill present a few thoughts on realism, in the hope that they help me reach a conclusion that satisfies me, if no one else.

REALISM AND THE END OF SCIENCE

When you present the realist position to nonphilosophers, they often react with some equivalent of: Duh, what idiot doubts that there is a real world out there and that science discovers it? Actually, many people object to realism, and some are quite clever.

Antirealism can take many different forms, including postmodernism, which denies that absolute truth is attainable and brackets scientific knowledge in scare quotes; idealism, which says mind is more fundamentalmore real! than matter; and the simulation hypothesis, the idea that were living in a virtual reality, like The Matrix. Although antirealist perspectives vary, most suggest that objective, physical reality is illusory or unknowable.

Realism is a central premise of my 1996 book The End of Science. Scientists have constructed a map of nature so accurate, so true, I contend, that it is unlikely to undergo significant revisions. We have discovered, not merely imagined, features of nature such as electrons, atoms, elements, DNA, bacteria, viruses, neurons, gravity and galaxies. These things are real; they exist whether or not we believe in them, and only fools and philosophers would dare to claim otherwise. I dismiss the claim of Thomas Kuhn, a pioneer of postmodernism, that science never gets a firm grip on reality and hence is always ripe for revolution.

QUANTUM UNCERTAINTY

Then, beginning last summer, I dove into quantum mechanics. This project has thrown me for a loop, forcing me to question my commitment to realism. Quantum mechanics accounts for countless experiments, and its applications have transformed our world. Many physicists think that quantum mechanics represents the final framework for physics. No matter how his field evolves, Steven Weinberg told me in 1995, I think well be stuck with quantum mechanics.

Experts cannot agree on what quantum mechanics tells us about the nature of matter, energy, space, time and mind. Some interpretations challenge the realist assumption that reality is strictly physical. I just finished the marvelous little book Q Is for Quantum, in which physicist Terry Rudolph boils quantum mechanics down to its odd mathematical essence. Quantum mechanics, Rudolph says, makes it hard to sustain the naive realistic belief that the universe has physical properties of some form independent of my concerns.

In The End of Science, I say that particle physics rests on the firm foundation of quantum mechanics. Firm foundation? Ha! The more I ponder quantum mechanics, the more physics resembles a house of cards. Floating on a raft. On a restless sea. Physics seems wobbly, ripe for revolution, for a paradigm shift that sends science veering off in unexpected directions.

ALL NUMBERS ARE IMAGINARY

My quantum experiment has also made me suspicious of mathematical models of reality. The Schrdinger equation, for example, employs so-called imaginary numbers, multiples of the square root of 1. My efforts to understand how imaginary numbers map onto the real world have led me, perversely, in the opposite direction. Instead of imaginary numbers becoming more real, real numbers, which fall on a line extending from positive to negative infinity, are becoming less real.

If the inclusion of imaginary numbers is worrying, philosopher R.I.G. Hughes writes in The Structure and Interpretation of Quantum Mechanics (recommended by Jim Holt, one of my quantum advisors), it is worth considering the sense in which a negative number, 6 say, is realor, come to that, the sense in which 6 itself is real. Hughes cites Bertrand Russells definition of mathematics as the subject in which we never know what we are talking about, nor whether what we are saying is true.

Physicists Gerard t Hooft and Sheldon Glashow make similar points in a recent online exchange, Confusions Regarding Quantum Mechanics. t Hooft calls real numbers artificial, manmade and arbitrary, suggesting that they give us a sense of false, unwarranted precision. Glashow points out that t Hooft is not the first to question the reality of real numbers. He cites mathematician Gregory Chaitin and physicist Nicolas Gisin, who have also suggested that real number might be an oxymoron.

These remarks undercut the realist claim that mathematical theories like quantum mechanics and general relativity work because they mirror nature. Perhaps we should view the theories as calculating devices that predict experimental outcomes but have an obscure relation to reality, whatever that is.

DOES MATTER COME FROM MIND?

No wonder, then, that some scientists and philosophers have challenged scientific realism and its corollary, materialism, which decrees that reality consists of matter. Quantum theorist John Wheeler proposes that we live in a participatory universe, in which our questions and observations define reality and even bring it into existence. QBism (pronounced like the art movement) suggests that quantum mechanics represents our subjective perception of the world. And your perception isnt necessarily the same as mine.

I recently participated in an online symposium with idealist critics of materialism, including philosopher Bernardo Kastrup and psychologist Donald Hoffman, authors, respectively, of Why Materialism Is Baloney (love that title) and The Case Against Reality. These authors contend that matter stems from mind rather than vice versa. Atheists like Richard Dawkins deride Deepak Chopra, the spirituality and health mogul, for insisting that reality consists of consciousness. Wouldnt it be funny if Chopra turned out to be right and Dawkins wrong?

Mystical experiences seem to corroborate mind-centric metaphysics. Many mystics come away from their visions convinced that our everyday material world, consisting of people and other things, is illusory, and that a cosmic consciousness transcending that of any individual lies at the bottom of things. My psychedelic experiences make me sympathetic toward this idealist view. One trip left me wondering whether our reality is actually virtual, the fever dream of an insane God.

REALISM AND WHAT REALLY MATTERS

And yet. Although my realism has been wobbling lately, I remain a realist. Before I explain why, I need to make a point that is subtle, perhaps incoherent. Here goes. There is something tendentious, question-begging and contradictory about the terms real, realism and reality. When you say, This is real or This is reality, you are implicitly saying, This is what matters. Ostensibly, you are making a claim about what is objectively real, and hence true. Actually, you are making a subjective value judgment.

Take, for example, What Is Real?, a terrific book on quantum mechanics by Adam Becker. That title reflects physicists judgment that their work represents knowledge-seeking at its most profound. Many physicists still believe that one day they will discover a complete, consistent account of the physical realm, which some call a theory of everything.

The absurdity of that phrase! If physicists ever find such a theory (a big if), it will tell us nothing about death, sex, love, fear, war, justice, beauty and other deep, defining features of the human condition. These matter more, and hence are far more real, than wave functions or dark energy. Pride and Prejudice and Ulyssesworks of fiction!tell us more about our messy, painful human reality than physics ever will. (And please dont send me links on quantum social science.)

But some antirealist perspectives, including the simulation hypothesis and my own psychedelic theology, are equally absurdand even, I would argue, immoral. When they suggest that our material world is an illusion, they trivialize human suffering and injustice, and they undermine our motives for making the world a better place.

Another insidious effect of antirealismand this is especially true of postmodernismstems from its claim that scientific knowledge reflects our subjective fears, desires and biases. There is some truth to this assertion, of course. Scientists lust for fame, glory and money can corrupt them. Moreover, as I emphasize in Mind-Body Problems, we cant escape our subjectivity when we try to understand ourselves. But taken too far, postmodernism can undercut efforts to analyze and solve all-too-real problems like climate change, economic inequality, militarism and the COVID-19 pandemic.

Filmmaker Errol Morris, who studied under Kuhn in the 1970s and ended up loathing him, contends that Kuhnian-style postmodernism makes it easier for politicians and other powerful figures to lie. Philosopher Timothy Williamson makes a similar point in In defence of realism. Imagine a future, Williamson writes, where a dictator or would-be dictator, accused of spreading falsehoods, can reply: You are relying on obsolescent realist ideas of truth and falsity; realism has been discredited in philosophy.

Philosopher Michael Strevens sticks up for scientific realism in his insightful new book The Knowledge Machine: How Irrationality Created Modern Science. The radical subjectivists, Strevens notes, can explain everything about the messy human business of scientific inquiry except what matters most: the great wave of progress that followed on the Scientific Revolution. Medical progress, technological progress, and progress in understanding how it all hangs together, how everything works. Immense, undeniable, life-changing progress.

Yes, thats the same argument I made in The End of Science, and that I continue to make to my postmodern pals. So, Id like to reiterate my support for a particular kind of realism, a pragmatic, ethical realism, which acknowledges sciences power as well as its fallibility and puts mortal, troubled humanity at the center of things. Like democracy, realism is flawed, but it beats the alternatives.

Postscript: My Stevens Institute colleagues Greg Morgan and Michael Steinmann, who are philosophers, and James McClellan, a historian of science, have labored mightily (and they probably think in vain) to make my realism less naive. Thanks guys!

Further Reading:

I mull over realism in my recent books Pay Attention: Sex, Death and Science and Mind-Body Problems.

Over the last year Ive discussed realism-related issues on my podcast Mind-Body Problems with a wide range of thinkers, including Michael Brooks, George Musser, Amanda Gefter, Adam Becker, Philip Goff, Jeffrey Kripal and Errol Morris.

This is an opinion and analysis article.

More:

I'm Agonizing over My Naive Realism - Scientific American

Schematic of the four-qubit quantum processor made using semiconductor manufacturing technology. Credit: Nico Hendrickx (QuTech)

The heart of any computer, its central processing unit, is built using semiconductor technology, which is capable of putting billions of transistors onto a single chip. Now, researchers from the group of Menno Veldhorst at QuTech, a collaboration between TU Delft and TNO, have shown that this technology can be used to build a two-dimensional array of qubits to function as a quantum processor. Their work, a crucial milestone for scalable quantum technology, was published today (March 24, 2021) in Nature.

Quantum computers have the potential to solve problems that are impossible to address with classical computers. Whereas current quantum devices hold tens of qubits the basic building block of quantum technology a future universal quantum computer capable of running any quantum algorithm will likely consist of millions to billions of qubits. Quantum dot qubits hold the promise to be a scalable approach as they can be defined using standard semiconductor manufacturing techniques. Veldhorst: By putting four such qubits in a two-by-two grid, demonstrating universal control over all qubits, and operating a quantum circuit that entangles all qubits, we have made an important step forward in realizing a scalable approach for quantum computation.

Electrons trapped in quantum dots, semiconductor structures of only a few tens of nanometres in size, have been studied for more than two decades as a platform for quantum information. Despite all promises, scaling beyond two-qubit logic has remained elusive. To break this barrier, the groups of Menno Veldhorst and Giordano Scappucci decided to take an entirely different approach and started to work with holes (i.e. missing electrons) in germanium. Using this approach, the same electrodes needed to define the qubits could also be used to control and entangle them. No large additional structures have to be added next to each qubit such that our qubits are almost identical to the transistors in a computer chip, says Nico Hendrickx, graduate student in the group of Menno Veldhorst and first author of the article. Furthermore, we have obtained excellent control and can couple qubits at will, allowing us to program one, two, three, and four-qubit gates, promising highly compact quantum circuits.

Menno Veldhorst and Nico Hendrickx standing next to the setup hosting the germanium quantum processor. Credit: Marieke de Lorijn (QuTech)

After successfully creating the first germanium quantum dot qubit in 2019, the number of qubits on their chips has doubled every year. Four qubits by no means makes a universal quantum computer, of course, Veldhorst says. But by putting the qubits in a two-by-two grid we now know how to control and couple qubits along different directions. Any realistic architecture for integrating large numbers of qubits requires them to be interconnected along two dimensions.

Demonstrating four-qubit logic in germanium defines the state-of-the-art for the field of quantum dots and marks an important step toward dense, and extended, two-dimensional semiconductor qubit grids. Next to its compatibility with advanced semiconductor manufacturing, germanium is also a highly versatile material. It has exciting physics properties such as spin-orbit coupling and it can make contact to materials like superconductors. Germanium is therefore considered as an excellent platform in several quantum technologies. Veldhorst: Now that we know how to manufacture germanium and operate an array of qubits, the germanium quantum information route can truly begin.

Reference: A four-qubit germanium quantum processor by N. W. Hendrickx, W. I. L. Lawrie, M. Russ, F. van Riggelen, S. L. de Snoo, R. N. Schouten, A. Sammak, G. Scappucci and M. Veldhorst, 24 March 2021, Nature.DOI: 10.1038/s41586-021-03332-6

Funding: The research is supported by NWO, the Dutch Research Council.

More:

Crucial Milestone for Scalable Quantum Technology: 2D Array of Semiconductor Qubits That Functions as a Quantum Processor - SciTechDaily

Glenn Jordans article about Mainers beta-testing Elon Musks Starlink service (To solve broadband problem in rural Maine, some look to stars, March 8) was a good exploration of that services potential.

One issue that was not covered is the concern that the proliferation of satellites needed to provide robust coverage will interfere with future astronomical research. Googling satellite broadband astronomy will bring up a host of articles about the threat that Musks projected 12,000 satellites may pose to science, to our enjoyment of the night sky and to nocturnal wildlife. Amazon also has plans for its own constellation, as do other companies here and abroad. Within a few years, there may be more satellites overhead than visible stars.

We may think of astronomy as an arcane field without practical applications, but science is all one. What we learn about distant galaxies and black holes informs the quantum physics that gives us smart phones and microwave ovens, as well as deepening our appreciation of the universes mystery. We need to be careful about how we proceed here.

Neil GallagherBrunswick

Invalid username/password.

Please check your email to confirm and complete your registration.

Use the form below to reset your password. When you've submitted your account email, we will send an email with a reset code.

Previous

Go here to see the original:

Letter to the Editor: Too many satellites could obscure the stars - pressherald.com

The Netflix films will compete with recession drama "Nomadland," which is playing in theaters and streaming on Walt Disney Co's Hulu. Disney scored 15 Oscar nominations overall, including three for animated Pixar movie "Soul" on the Disney+ streaming service.By Lisa RichwineLOS ANGELES: Netflix Inc on Monday landed 35 Academy Award nominations for 16 films, including "Mank" and "The Trial of the Chicago 7," leading a pack of streaming services that offered movies at home while the coronavirus pandemic shut theaters.

"Mank," a black-and-white drama about 1930s Hollywood, topped all films with 10 nods, including best picture, director, actor and supporting actress.

Companies launch multimillion-dollar campaigns for Oscar nominations and wins. The recognition provides bragging rights for use in marketing and help the winners attract top talent for future projects.

"We learned a lot of hard lessons last year, but a nice one was that people will find a way to go to the movies, even if they can only go as far as their living rooms," said Aaron Sorkin, director of historical drama "Trial of the Chicago 7."

Sorkin's film also was nominated for best picture, giving Netflix two shots at the film industry's top prize. The company began releasing original movies in 2015 but has never won best picture.

The Netflix films will compete with recession drama "Nomadland," which is playing in theaters and streaming on Walt Disney Co's Hulu. Disney scored 15 Oscar nominations overall, including three for animated Pixar movie "Soul" on the Disney+ streaming service.

Amazon.com's Amazon Studios earned a spot in the best picture race with "Sound of Metal," the story of a drummer who loses his hearing, and 12 nominations overall, a record for the company. "One Night in Miami" picked up three nominations.

IPhone maker Apple Inc received its first Oscar nominations for movies on Apple TV+. They included a best animated feature nod for "Wolfwalkers."

Read the original:

Netflix scores 35 Oscar nominations in year dominated by streaming - ETTelecom.com