Category Archives: Quantum Physics
Quantum material research connecting physicists in Hong Kong, Beijing and Shanghai facilitates discovery of better materials that benefit our society…
A joint research team from the University of Hong Kong (HKU), Institute of Physics at Chinese Academy of Science, Songshan Lake Materials Laboratory, Beihang University in Beijing and Fudan University in Shanghai, has provided a successful example of modern era quantum material research. By means of the state-of-art quantum many-body simulations, performed on the worlds fastest supercomputers (Tianhe-I and Tianhe-III protype at National Supercomputer Center in Tianjin and Tianhe-II at National Supercomputer Center in Guangzhou), they achieved accurate model calculations for a rare-earth magnet TmMgGaO4 (TMGO). They found that the material, under the correct temperature regime, could realise the the long-sought-after two-dimensional topological Kosterlitz-Thouless (KT) phase, which completed the pursuit of identifying the KT physics in quantum magnetic materials for half a century. The research work has been published in Nature Communications.
Quantum materials are becoming the cornerstone of the continuous prosperity of human society. From the next-generation AI computing chips that go beyond Moores law (the law is the observation that the number of transistors in a dense integrated circuit doubles about every two years, our PCs and smartphones are all based on the success of it. Nevertheless, as the size of the transistors are becoming smaller to the scale of nanometer, the behaviour of electrons are subject to quantum mechanics, Moores law is expected to breakdown very soon), to the high speed Maglev train and the topological unit for quantum computers, investigations along these directions all belong to the arena of quantum material research.
However, such research is by no means easy. The difficulty lies in the fact that scientists have to solve the millions of thousands of the electrons in the material in a quantum mechanical way (hence quantum materials are also called quantum many-body systems), this is far beyond the time of paper and pencil, and requires instead modern quantum many-body computational techniques and advanced analysis. Thanks to the fast development of the supercomputing platforms all over the world, scientists and engineers are now making great use of these computation facilities and advanced mathematical tools to discover better materials to benefit our society.
The research is inspired by the KT phase theory avocated by J Michael Kosterlitz, David J Thouless and F Duncan M Haldane, laureates of the Nobel Prize in Phyiscs 2016. They were awarded for their theoretical discoveries of topological phase and phase transitions of matter. Topology is a new way of classifying and predicting the properties of materials in condensed matter physics, and is now becoming the main stream of quantum material research and industry, with broad potential applications in quantum computing, lossless transmission of signals for information technology, etc. Back in the 1970s, Kosterlitz and Thouless had predicted the existence of topological phase, hence named after them as the KT phase, in quantum magnetic materials. However, although such phenomena have been found in superfluids and superconductors, KT phase has yet been realised in bulk magnetic material.
The joint team is led by Dr Zi Yang Meng from HKU, Dr Wei Li from Beihang Univeristy and Professor Yang Qi from Fudan University. Their joint effort has revealed the comprehensive properties of the material TMGO. For example, in Figure 2, by self-adjustable tensor network calculation, they computed the properties of the model system at different temperatures, magnetic field, and by comparing with the corresponding experimental results of the material, they identified the correct microscopic model parameters. With the correct microscopic model on hand, they then performed quantum Monte Carlo simulation and obtained the neutron scattering magnetic spectra at different temperatures (neutron scattering is the established detection method for material structure and their magnetic properties, the closest such facility to Hong Kong is the China Spallation Neutron Source in Dongguan, Guangdong). As shown in Figure 3, the magnetic spectra with its unique signature at the M point is the dynamical fingerprint of the topological KT phase that has been proposed more than half-a-century ago.
This research work provides the missing piece of topological KT phenomena in the bulk magnetic materials, and has completed the half-a-century pursuit which eventually leads to the Nobel Physics Prize of 2016. Since the topological phase of matter is the main theme of condensed matter and quantum material research nowadays, it is expected that this work will inspire many follow-up theoretical and experimental researches, and in fact, promising results for further identification of the topological properties in quantum magnet have been obtained among the joint team and our collaborators, said Dr Meng.
Dr Meng added: The joint team research across Hong Kong, Beijing and Shanghai also sets up the protocol of modern quantum material research, such protocol will certainly lead to more profound and impactful discoveries in quantum materials. The computation power of our smartphone nowadays is more powerful than the supercomputers 20 years ago, one can optimistically foresee that with the correct quantum material as the building block, personal devices in 20 years time can certainly be more powerful than the fastest supercomputers right now, with minimal energy cost of everyday battery.
Read more from the original source:
Exploring the Quantum Field, From the Suns Core to the Big Bang at MIT – SciTechDaily
Theoretical physicist William Detmold unlocks the mysteries of quarks, gluons, and their strong interactions at the subatomic level.
How do protons fuse to power the sun? What happens to neutrinos inside a collapsing star after a supernova? How did atomic nuclei form from protons and neutrons in the first few minutes after the Big Bang?
Simulating these mysterious processes requires some extremely complex calculations, sophisticated algorithms, and a vast amount of supercomputing power.
Theoretical physicist William Detmold marshals these tools to look into the quantum realm. Improved calculations of these processes enable us to learn about fundamental properties of the universe, he says. Of the visible universe, most mass is made of protons. Understanding the structure of the proton and its properties seems pretty important to me.
Researchers at the Large Hadron Collider (LHC), the worlds largest particle accelerator, investigate those properties by smashing particles together and poring over the subatomic wreckage for clues to what makes up and binds together matter.
Detmold, an associate professor in the Department of Physics and a member of the Center for Theoretical Physics and the Laboratory for Nuclear Science, starts instead from first principles namely, the theory of the Standard Model of particle physics.
With all of us stuck at home or in remote locations, Im not sure that anyone is feeling particularly inspired right now, but this pandemic will eventually end, and sometimes getting lost in the intricacies of Maxwells equations gives a nice break from what is going on in the world, says theoretical physicist William Detmold. Credit: Jared Charney
The Standard Model describes three of the four fundamental forces of particle physics (with the exception of gravity) and all of the known subatomic particles.
The theory has succeeded in predicting the results of experiments time and time again, including, perhaps most famously, the 2011 confirmation by LHC researchers of the existence of the Higgs boson.
A core focus of Detmolds research is on confronting experimental data from experiments such as the LHC. After devising calculations, running them on multiple supercomputers, and sifting through the enormous quantity of statistics they crank out a process that can take from six months to several years Detmold and his team then take all that data and do a lot of analysis to extract key physics quantities for example, the mass of the proton, as a numerical value with an uncertainty range.
My driving concern in this regard is how will this analysis impact experimental results, Detmold says. In some cases, we do these calculations in order to interpret experiments done at the LHC, and ask: Is the Standard Model describing whats going on there?
Detmold has made important advances in solving the complex equations of quantum chromodynamics (QCD), a quantum field theory that describes the strong interactions inside of a proton, between quarks (the smallest known constituent of matter) and gluons (the forces that bind them together).
He has performed some of the first QCD calculations of certain particle decays reactions. They have, for the most part, aligned very closely with results from the LHC.
There are no really stark discrepancies between the Standard Model and LHC results, but there are some interesting tensions, he says. My work has been looking at some of those tensions.
Detmolds interest in quantum physics dates to his schoolboy days, growing up in Adelaide, Australia. I remember reading a bunch of popular science books as a young kid, he recalls, and being very intrigued about quarks, gluons, and other fundamental particles, and wanting to get into the mathematical tools to work with them.
He would go on to earn both his bachelors degree and PhD from the University of Adelaide. As an undergraduate studying mathematics, he encountered a professor who opened his eyes to the mysteries of quantum mechanics. It was probably the most exciting class Ive had. And I get to teach that now.
MIT theoretical physicist William Detmold. Credit: Jared Charney
Hes been teaching that introductory course on quantum mechanics at MIT for a few years now, and he has become adept at spotting those students who are similarly seized by the subject. In every class there are students you can see the enthusiasm dripping off the page as they write their problem sets. Its exciting to interact with them.
While he cant always bring the full complexity of his research into those conversations, he tries to infuse them with the spirit of his enterprise: how to ask the questions that might yield new insights into the deep structures of the universe.
You can frame things in ways to inspire students to go into research and push themselves to learn more, he says. A lot of teaching is about motivating students to go and find out more themselves, not just information transmission. And hopefully I inspire my students the way my professor inspired me.
He adds: With all of us stuck at home or in remote locations, Im not sure that anyone is feeling particularly inspired right now, but this pandemic will eventually end, and sometimes getting lost in the intricacies of Maxwells equations gives a nice break from what is going on in the world.
When he isnt teaching or analyzing supercomputer data, Detmold is often helping to plan better experiments.
The Electron-Ion Collider, a facility planned for construction over the next decade at Brookhaven National Lab on Long Island, aims to advance understanding of the internal structure of the proton. Some of Detmolds calculations are aimed at providing a qualitative picture of the structure of gluons inside the proton, to help the projects designers know what to look for, in terms of orders of magnitude for detecting certain quantities.
We can make predictions for what well be seeing if you design it in a certain way, he says.
Detmold has also become something of an expert at orchestrating complex supercomputing projects. That entails figuring out how to run a huge number of calculations in an efficient way, given the limited availability of supercomputing power and time.
He and his lab members have developed algorithms and software infrastructure to run these calculations on massive supercomputers, some of which have different types of processing units that make data management complicated. Its a research project in its own right, how to perform those calculations in a way thats efficient.
Indeed, Detmold spends time working on how improve methods for getting to the answer. New algorithms, he says, are a key to advancing computation to tackle new problems, calculating nuclear structures and reactions in the context of the Standard Model.
Lets say theres a quantity we want to compute, but with the tools we have at the moment it takes 10,000 years of running a massive supercomputer, he says. Coming up with a new way to calculate something that actually makes it possible to do thats exciting.
But fundamental mysteries are still at the center of Detmolds work. As quarks and gluons get farther apart from each other, the strength of their interactions increases. To understand whats happening in these low-energy states, he has advanced the use of a computational technique known as lattice quantum chromodynamics (LQCD), which places the quantum fields of the quarks and gluons on a discretized grid of points to represent space-time.
In 2017, Detmold and colleagues made the first-ever LQCD calculations of the rate of proton-proton fusion the process by which two protons fuse together to form a deuteron.
This process kicks off the nuclear reactions that power the sun. Its also exceedingly difficult to study through experiments. If you try to smash together two protons, their electric charges mean they dont want to be near each other, says Detmold.
It shows where this field can go, he says of his teams breakthrough. Its one of the simplest nuclear reactions, but it opens the doorway to saying we can address these directly from the Standard Model. Were trying to build upon this work and calculate related reactions.
Another recent project involved using LQCD to study the formation of nuclei in the universe its earliest moments. As well as looking at these processes for the actual universe, hes performed computations that change certain parameters the masses of quarks and how strongly they interact in order to predict how the reactions of Big Bang nucleosynthesis might have happened and how much they might have affected the evolution of the universe.
These calculations can tell you how likely it is to end up producing universes like the one we see, Detmold says.
Link:
Exploring the Quantum Field, From the Suns Core to the Big Bang at MIT - SciTechDaily
10 of the best non-fiction science books to read right now – New Scientist
By Simon Ings
by Lee Smolin
Allen Lane
It is easy to state the basic problem of quantum mechanics as a theory of reality, wrote Lee Smolinin an essay last year for New Scientist: it doesnt tell us what is happening in reality.
Advertisement
Like the small boy in Hans Christian Andersons fairy tale, Lee Smolin, a theoretical physicist at the Perimeter Institute in Waterloo, Canada, delights in pointing out that the emperors of contemporary quantum physics wear surprisingly few intellectual clothes. Their theories are messy. No findings could possibly falsify them. And they dont even explain observable reality. Smolin declared war on string theorists, in particular, in 2006 with The Trouble With Physics, and theres rigor, as well as sincerity, to his ongoing critique. Theory should offer a reasonable explanation of how the world works, not replace it with a solipsistic mathematical theory, however ornate. In falling in love with our mathematics, we have come adrift from the real.
Einstein hated quantum theory. So did Louis de Broglie, who first predicted the wave-like aspects of matter. So did Erwin Schrdinger, whose collapsing wave functions gifted us that notorious undead cat metaphor. Roger Penrose and Gerard t Hooft cant stand it. It satisfies no one but who will cast the first stone? Critics say Smolin is tilting at windmills. Champions say hes got quantum itself on the run.
by Jennifer Doudna and Samuel Sternberg
The Bodley Head
I began to feel a bit like Doctor Frankenstein, writes Jennifer Doudna, in a book that our reviewer Adam Rutherford likened to James Watsons classic DNA discovery story The Double Helix. Had I created a monster?
With three years hindsight, we can safely say that monster doesnt even begin to describe the scale and enormity of Doudnas scientific achievement. She was the scientist who directed and led the effort to harness the genome-editing systems that occur naturally in bacteria.
If that doesnt mean much, perhaps the acronym will: CRISPR allows us to cut and paste genetic information. Identifying a gene, working out what it did and then modifying it to do something else, or do something better, was a miraculous enough ability, acquired a bit over a decade ago, and it kept researchers and ethicists awake wondering what the consequences of this work would be for humanity and the planet. Back then, though, the whole process could take months, even years. With CRISPR, we can perform the same process in days.
Doudna and her colleague Samuel Sternberg write very well about the hard graft of research, and capture the thrill of discovery. Best of all, though, they never take their eyes off the main prize: explaining how we can use CRISPR for good to tackle disease, for example, and manage the genie that they and others have released.
by Stuart Kauffman
Oxford University Press
Stuart Kauffman is a polymath. Originally a medical graduate, he is also trained in biochemistry, genetics, physics and philosophy, a recipient of a MacArthur Fellowship and a Wiener Medal. And he can write. In this extraordinary, and extraordinarily readable re-evaluation of his lifes work, Kaufmann explains how life arises: how molecular machines can organise into bounded systems that construct and assemble their own working parts. Evolving by natural selection, these protocells then create new niches into which further novel creatures can emerge. The diversity we see is self-constructing, self-propagating and its development is impossible to predict.
Kaufmann avoids empty philosophising. But the implications of his work are daunting. In a universe containing an estimated 100 billion solar systems, evolving life could be everywhere. Amid such ceaseless creativity, says Kaufmann, we cannot predict how the universe will evolve. Physics is insufficient to guide us through a biological universe. He argues that biology is a weak tool, barely able to comprehend the evolutionary journey of single species on a single planet. Something more, something new an entirely new science of systems may yet be awaiting discovery.
by Anne Harrington
W. W. Norton & Company
Unlike other doctors, psychiatrists cannot peer into a microscope and see the biological cause of the illnesses they treat. Theyre stuck in the premodern era, using the outward manifestations of a disease to devise diagnoses and treatments, rather in the way doctors used to treat vague diseases like ague and dropsy with bloodletting and mustard plasters.
In Mind Fixers, historian of neuroscience Anne Harrington explains what happened when ambitious 20th-century scientists, frustrated by their primitive discipline, started to claim too much for their work. Early in the 20th century, psychiatry threw off the woolly, patient-centered approaches of psychotherapy. Researchers fully expected that scientific study would reveal the true, biological causes of mental suffering. But it didnt happen.
Some people do respond well to the one-size-fits-all pharmacological and surgical procedures modern psychiatry has developed. In every case, though, the treatment comes first, often by accident, and explanations for its efficacy are either specious or absent.
The history of psychiatry is no catalogue of heroic discovery. It is the cautionary tale of what happens when the world doesnt unpack the way our sense of reason expects it to. The brain is the most complex object we know of in the universe. Psychiatrists chipping away at it with their little picks of objective study are not at all misguided, but, says Harrington, in this often shocking but admirably fair and level-headed history, they cannot expect instant results.
University of Chicago Press
by Lee Alan Dugatkin and Lyudmila Trut
University of Chicago Press
Do you like charming memoirs about peoples relationships with endearing animals? Do you like expansive, dramatic accounts of evolution in action? Do you like hard-nosed, laboratory-based studies of animal development? Then youll love this book, which contrives to combine all three approaches in its account of some groundbreaking studies in animal domestication, begun in the Soviet Union by co-author Lyudmila Trut and her boss Dmitri Belyaev in 1959.
In those days, genetics was labelled a fascist pseudoscience; its study could cost you your job, and even get you internally exiled. But Belyaev, under the noses of the authorities, embarked on a lifelong programme to understand the evolutionary relationship between friendliness, intelligence and physical signs of domestication like curly tails. The natural evolution of dogs from wolves took around 15,000 years, but it took Belyaev and Trut less than a decade to breed puppy-like tame foxes with floppy ears, piebald spots and curly tails.
To date, 56 generations of such foxes have been bred. It is even possible to adopt a tame fox theyre expensive, though the money is used to sustain the research project.
Generation by generation, they are helping us understand the molecular and evolutionary mechanisms behind domestication. It seems that most domestic animals have prolonged infancies, and that this developmental quirk leads to changes in hormones and behaviour.
Trut, in collaboration with Lee Alan Dugatkin, a US evolutionary biologist, captures both the charm of her lifes work and the brutality of all those Siberian winters in a book full of delights both intellectual and human.
by Shoshana Zuboff
PublicAffairs
In 1988 Shoshana Zuboff, a professor at Harvard Business School, published In the Age of the Smart Machine, a study of the impact of computerisation on organisations that gave us a glimpse, as her subtitle would have it, on the future of work and power.
Just over three decades later, she returns with a bigger (660 page), more precise and indeed much more frightening case for how our commercial systems have exploited that technology to create an entirely new and unfamiliar (and indeed, deliberately hidden) form of capitalism one that (in common with any power grab left unchecked by civic discourse or law-making) is robbing us of our freedom.
Surveillance capitalism, Zuboff explains, works by providing free services that we all cheerfully use and depend upon. These services monitor our behaviours and feed that data through algorithms to make prediction products that anticipate what you will do now, soon and later. This has monetary value since many companies are willing to lay bets on our future behaviour.
Westerners tut at Chinas Social Credit System, which acts as an artificially intelligent judge and jury over a constantly monitored population, but the commercial logics of Google, Experian, Facebook and the rest are hardly different, and the political cultures of democracy and one-party dictatorship are rapidly becoming indistinguishable.
The Age of Surveillance Capitalism is a crash course in the kinds of conversations we should have been having 20 years ago.
by Frans De Waal
W. W. Norton & Company
In April 2016, the biologist Jan van Hooff visited the Royal Burgers Zoo in Arnhem, the Netherlands, to say goodbye to Mama, a chimpanzee matriarch he had met and befriended 40 years before. Mama, now 58, was dying, and hardly able to move. But she recognised van Hoof, now 79, and at the sight of her old friend, she grinned from ear to ear and hauled herself up for a hug.
That hug, and the rest of that tearful, happy encounter, has been watched more than 10 million times on YouTube.
Humans arent the only species with the capacity for emotion. Considering how much animals act like us, share our physiological reactions, have the same facial expressions, and possess the same sort of brains, De Waal writes in Mamas Last Hug, wouldnt it be strange indeed if their internal experiences were radically different?
Mamas story and others like it from dogs adopting the injuries of their companions to rats helping fellow rats in distress will convince the reader that instead of tiptoeing around the emotions, its time for us to squarely face the degree to which all animals are driven by them.
by Jo Dunkley
Pelican
If youre new to astronomy, or simply want one slim, straightforward book to tell you how the cosmos works, then Jo Dunkley, a professor of physics and astrophysical sciences at Princeton University, has written the book for you. In her day job, Dunkley unpicks the origin and evolution of the universe. Here, she proves herself as adept at communication as she is at research, providing the sort of no-nonsense, cleanly written, non-technical account of whats out there beyond Earth, and why it behaves the way it does, that Patrick Moore provided for an earlier generation.
And it turns out the cosmos is far wilder than Moore and his peers could possibly have imagined. Did you know, for instance, that each of the multiple images of a distant object produced by gravitational lensing captures the object at a different moment in time? Or that we have two methods of measuring the rate that space is growing, and the age of the universe and that they dont agree? Dunkleys account is full of delightful details, wrinkles and unsolved mysteries. This book is a good start, for a reader new to astronomy, and for a researcher who could well become the public face of her discipline in the coming years.
Columbia University Press
by Donald Prothero
Columbia University Press
Books organised as a series of numbered vignettes are a dime-a-dozen these days, but now and again an author comes along who uses the format to bring their field to life as never before. Each of Donald Protheros 25 fossils is a complex puzzle, unfolding over generations, as palaeontologists repeatedly assembled, took apart and reassembled the fiendishly complex four-dimensional puzzle of dinosaur evolution.
How are scattered bones assembled to make a creature no one has seen before? How are dinosaurs of different ages recognised as belonging to one species? How do we know what dinosaurs looked like anyway, when the soft parts vanish during fossilisation? Why was the idea that birds are descended from dinosaurs so controversial for so long?
On the way, well learn why the brontosaurus never actually existed, and how the triceratopss three horns refused, for the longest time, to fit correctly on its head. From the desk of a seasoned and much celebrated California-based palaeontologist, this a story of imagination, rivalry, mistake and often not-so-quiet genius. Historical greats loom large. Theres Richard Owen brilliant, indefatigable, vain, arrogant, envious and vindictive and William Buckland, a notorious eccentric whose ambition was to plate up and eat every living thing. And as Prothero reveals, the field today is full of wonder and novelty, and hardly less colourful.
by Gaia Vince
Basic Books
The former news editor of Nature marshals the evidence of recent decades (genetic, anthropological, palaeontological, archaeological the list is long) to reveal whats special about the human species. Readers of Richard Wrangham (Catching Fire, 2009), mid-period Richard Dawkins (Climbing Mount Improbable, 1996), Sue Savage-Rumbaugh (Kanzi: The Ape at the Brink of the Human Mind, 1994) or, indeed, any of the popular volumes that have spoken to our place in the living world over the past 20 years, will have no trouble recognising where the riffs in Vinces medley hail from. But there is entertainment, and insight, in the synthesis she provides.
The qualities we once thought made us unique grammar, altruism, fire-starting, tool use, warfare, the pursuit of beauty, emotion itself are shared by many other species, who hone them to their own needs. Still, there must be some reason why those qualities, in combination, have given rise to contemporary Homo sapiens, a species that exploits 40 per cent of the planets total primary production.
In Vinces explanation, cooking and storytelling dominate. She is far too smart to be triumphalist: from far enough away, what human civilisation most resembles is a slime mould, in which single cells coalesce for group action, protecting the centre while exposing those on the margin to harm.
But why adopt so cold a perspective? Vince would rather we delighted in being ourselves, on a busy and various planet, and, for all our oddness, not so lonely after all.
More on these topics:
See the original post here:
10 of the best non-fiction science books to read right now - New Scientist
Letter reveals the quirky side of Albert Einstein – Chile News | Breaking News, Views, Analysis – The Santiago Times
German-Swiss-American mathematical physicist Albert Einstein (1879- 1955).By Hanan Greenwood
A letter up for auction in Israel shows a lighter side to world-renowned theoretical physicist Albert Einstein, who developed the theory of relativity, one of the two pillars of modern physics alongside quantum mechanics.
Letters from Einsteins estate are usually sold for hefty sums of money. The most recent offering, on the block at Winners Auctions, a Jerusalem-based agency specializing in manuscripts, ancient Hebrew books, historic documents, rare maps, and more, shows the quirkier side of the famous scientist, and jokes about the many attempts to interview him.
Einstein was famously some would say infamously averse to giving interviews.
According to the auction house, the letter was written to the chairman of the Association of Orthodox Jewish Scientists Dr. Elmer L. Offenbacher in 1953.
Offenbacher planned to write an article about Einsteins connection to Judaism, He sought to interview Einstein for the article, but the latter was not excited about the idea and wrote in response:
Dear Mr. Offenbacher, I thank you for your letter. I should say, May the Jewish devil get you if there were such a one. But seriously I am not able to fulfill your wish because, in principle, I never assist in something which would lead to the publication of things about my own person.
It is embarrassing enough for me that such nonsense has attached itself to my person.
You will certainly understand, if you make a little effort to put yourself in my situation, Einstein concluded his response.
Offenbacher eventually published the article in 1955, in Jewish Life.
See the original post here:
Louis Broglie and the Idea of Wave-Particle Duality – Interesting Engineering
In the early 1900s, a French physicist came up with a new idea to explain the theory of atomic structures. That physicist was a man by the name of Louis de Broglie.
Broglie hypothesized that particles could take on the properties of waves. Broglie's theory turned out to be correct and was confirmed a few years later in one of the most famous light experiments of all time, the double-slit experiment.
By confirming the theory that particles could act as waves simultaneously, physicists had discovered that electron streams act the same way as light.
Electrons, negatively charged electronic particles, can act as both waves and particles. This is known as wave-particle duality.
Wave-particle duality doesn't have a massive impact on electrons as a whole, but it does help physicists understand many of the strange behaviors that electrons present.
The concept of wave-particle duality is one that is central to quantum mechanics. It helps physicists fill in the gap to what can't easily be understood by traditional physics interpretations.
RELATED: SCIENTISTS CONFIRM SUBATOMIC PARTICLE PATTERNS USING LARGE HADRON COLLIDER OPEN DATA
The idea of wave-particle duality dates all the way back to the 1600s when Isaac Newton and Christian Huygens were proposing various theories about the properties of light. Einstein also heavily worked on the concept and of course, Louis de Broglie pioneered the theory in his time.
Today, it's thoroughly established that all objects have natures relating to both waves and particles. However, while this may be the case technically, we can't really observe the effects of this concept unless we look at very small scales, such as atoms.
In 1924, Broglie developed his theory of electron waves, which was the idea that matter might have the properties of waves on the atomic scale, rooted in Einstein's earlier theories. The duality of light was first starting to develop but it was Broglie that took this idea and extended it to all of matter. Broglie pioneered the idea of the duality of matter through wave-particle duality.
With everything having both wave and particle natures, the next thing we need to ponder is how light behaves.
In the spirit of wave-particle duality, light is technically both a particle and a wave. However, light is also not a wave or a particle. Light is conceptually an entirely new complex existence.
Think about it this way. If you hold a cylinder up in the air letting a shadow cast down, you'll be presented with two different shapes. Hold it one way and you'll be presented with a rectangle. Hold it another and you'll be presented with a circle. If you examine the shapes of the shadows individually, you'll be left with technically accurate but wholly incomplete views of the original object. A cylinder is neither a circle nor a rectangle but it's also both. This is in the same manner that light is neither a particle nor a wave but is also technically both.
Thinking a little deeper about the flaw in the shadows' representations of the cylinder, they're incomplete because they're not working in the same dimensions. A cylinder is a 3D object that can't fully be explained by 2-dimensional shadows.
RELATED: 9 AMAZING FACTS ABOUT PARTICLE ACCELERATORS AND HOW THEY WORK THAT WILL BLOW YOUR MIND
When we examine light on a quantum scale, this metaphor rings even truer.
Saying that light is a particle is a condensed representation of what it really is. Saying that light is a wave is an oversimplified explanation of what light is.
When we observe light, we see this complex and confusing duality play out.
Light is like waves in that it can be diffracted, refracted, reflected, and interfered with.
As De Broglie was working to flesh out his theory of particle-wave duality, he leaned heavily on Einstein's theory of the photoelectric effect. This theory encompasses the emission of electrons from an object when hit with types of electromagnetic radiation, like light.
Light can be observed as a particle, known as photons. These particles, when of enough energy, are strong enough to knock electrons from substances.
Electrons also release kinetic energy when they are released from an object. Upon experimentation, though, scientists saw that brighter lights didn't affect the overall kinetic energy of the electrons. This is to say that traditionally, waves with greater intensity have greater energy. Since energy is proportional to amplitude, it would've been expected that the brighter the light shone on an object, the more kinetic energy released by the electrons, however, this is the case.
Scientists discovered that the frequency of lights, rather, is what changes the level of kinetic energy in the equation. This means that certain objects don't emit electrons under certain frequencies, having a threshold known asV0.
RELATED: THIS TINY PARTICLE ACCELERATOR RECYCLES ENERGY WITH TERAHERTZ WAVES
But what does all of this mean? Since the energy of waves and the overall energy of light do not correlate, this means that light is a particle that contains the properties of waves.
All of this can be a little confusing, however, so watching a video with visuals on the topic is likely the next best way to understand what we're discussing.
To further understand the properties of light as a particle and a wave, as well as understand the duality of particles and waves, take a look at this video below depicting the famous double-slit experiment.
Read the rest here:
Louis Broglie and the Idea of Wave-Particle Duality - Interesting Engineering
Scientists Discover Quantum Matter for the First Time in Space – Beebom
Nearly a century ago, Indian mathematician, Satyendra Nath Bose, and German theoretical physicist, Albert Einstein predicted the existence of an exotic particle that is responsible for the unending expansion of the universe. This came to be known as the Bose-Einstein condensates (BECs). Now, for the first time, astronauts onboard the International Space Station have found the particle out in space, orbiting the earth. And scientists think that this could lead to some major discoveries in the future.
Now, BECs are quite fragile particles and that makes it pretty hard to retain the element for a longer time. This is because they are formed when bosonic atoms (ones that have an equal number of neutrons and protons) are brought down 0 Kelvin (~273.15-degree Celcius).
Once the element is formed, scientists use magnetic traps to confine the element. However, Earths high gravitational pullrestricts the shape of possible magnetic traps in such a way that a deep trap is needed to confine a BEC, according to the report. So, without the appropriate magnetic trap, the BEC interacts with the external world, the temperature rises and as a result, the atom disseminates before scientists could study it. On Earth, this happens in milliseconds.
However, a team of NASA scientists working in the International Space Station (ISS) recently revealed the first results from BEC experiments done in the space station that show unexpected results. According to David Aveline, the leader of the research project, the team found rubidium BECs orbiting the earth. They then used similar magnetic traps to confine the BEC and surprisingly, the element sustained for a whole second before dissipating. This gave the scientists a much longer time to study the matter than they get here on Earth.Image: Nature Journal
According to the scientists, this was possible due to the low-gravitational force (microgravity) in the space station. So, this leads the researchers to believe that microgravity plays a huge role in studying the BECs and this discovery could lead to some monumental breakthrough in quantum physics.
If you are interested to find out more about the subject, then you can read the research paper published by the NASA scientists on Nature journal.
Originally posted here:
Scientists Discover Quantum Matter for the First Time in Space - Beebom
Physicists May Have Solved Long-Standing Mystery of Matter and Antimatter – SciTechDaily
An element that could hold the key to the long-standing mystery around why there is much more matter than antimatter in our Universe has been discovered by a University of the West of Scotland (UWS)-led team of physicists.
The UWS and University of Strathclyde academics have discovered, in research published in the journal Nature Physics, that one of the isotopes of the element thorium possesses the most pear-shaped nucleus yet to be discovered. Nuclei similar to thorium-228 may now be able to be used to perform new tests to try find the answer to the mystery surrounding matter and antimatter.
UWSs Dr. David ODonnell, who led the project, said: Our research shows that, with good ideas, world-leading nuclear physics experiments can be performed in university laboratories.
This work augments the experiments which nuclear physicists at UWS are leading at large experimental facilities around the world. Being able to perform experiments like this one provides excellent training for our students. Dr. David ODonnell, UWS project leader
Physics explains that the Universe is composed of fundamental particles such as the electrons which are found in every atom. The Standard Model, the best theory physicists have to describe the sub-atomic properties of all the matter in the Universe, predicts that each fundamental particle can have a similar antiparticle. Collectively the antiparticles, which are almost identical to their matter counterparts except they carry opposite charge, are known as antimatter.
According to the Standard Model, matter and antimatter should have been created in equal quantities at the time of the Big Bang yet our Universe is made almost entirely of matter.
Thorium-228. Credit: Dr. David ODonnell, UWS
In theory, an electric dipole moment (EDM) could allow matter and antimatter to decay at different rates, providing an explanation for the asymmetry in matter and antimatter in our universe.
Pear-shaped nuclei have been proposed as ideal physical systems in which to look for the existence of an EDM in a fundamental particle such as an electron. The pear shape means that the nucleus generates an EDM by having the protons and neutrons distributed non-uniformly throughout the nuclear volume.
The research team was made up of Dr. ODonnell, Dr. Michael Bowry, Dr. Bondili Sreenivasa Nara Singh, Professor Marcus Scheck, Professor John F Smith and Dr. Pietro Spagnoletti from UWSs School of Computing, Engineering and Physical Sciences; and the University of Strathclydes Professor Dino Jaroszynski, and PhD students Majid Chishti and Giorgio Battaglia.
Professor Dino Jaroszynski, Director of the Scottish Centre for the Application of Plasma-based Accelerators (SCAPA) at the University of Strathclyde, said: This collaborative effort, which draws on the expertise of a diverse group of scientists, is an excellent example of how working together can lead to a major breakthrough. It highlights the collaborative spirit within the Scottish physics community fostered by the Scottish University Physics Alliance (SUPA) and lays the groundwork for our collaborative experiments at SCAPA.
The experiments began with a sample of thorium-232, which has a half-life of 14 billion years, meaning it decays very slowly. The decay chain of this nucleus creates excited quantum mechanical states of the nucleus thorium-228. Such states decay within nanoseconds of being created, by emitting gamma rays.
Dr. ODonnell and his team used highly sensitive state-of-the-art scintillator detectors to detect these ultra-rare and fast decays. With careful configuration of detectors and signal-processing electronics, the research team have been able to precisely measure the lifetime of the excited quantum states, with an accuracy of two trillionths of a second. The shorter the lifetime of the quantum state the more pronounced the pear shape of the thorium-228 nucleus giving researchers a better chance of finding an EDM.
Reference: Direct measurement of the intrinsic electric dipole moment in pear-shaped thorium-228 by M. M. R. Chishti, D. ODonnell, G. Battaglia, M. Bowry, D. A. Jaroszynski, B. S. Nara Singh, M. Scheck, P. Spagnoletti and J. F. Smith, 18 May 2020, Nature Physics.DOI: 10.1038/s41567-020-0899-4
Read more from the original source:
Physicists May Have Solved Long-Standing Mystery of Matter and Antimatter - SciTechDaily
Duckworth on Education: The Feynman Technique – EMSWorld
Richard Feynman was one of the greatest educators of the twentieth century. He was also a Nobel Prize-winning physicist known for his unique approaches to communicating complex topics in simple terms without skipping important details. Feynman was a child prodigy in math who worked on the Manhattan Project in his early twenties, won the Nobel Prize for his work in quantum mechanics, and was the most well-known and highly sought-after professor of physics at Caltech. Albert Einstein attended Feynmans first talk as a graduate student. Bill Gates was so influenced by Feynmans skill as an educator that Gates called him the greatest teacher [hed] ever had.
Feynman was perhaps best known for his ability to assimilate explain complex concepts, especially in the undergraduate classes he taught. Feynman explained the key to this ability was his differentiation of two kinds of knowledge. He said, You can know the name of that bird in all the languages of the world, but when youre finished, youll know absolutely nothing whatever about the bird. Youll only know about humans in different places, and what they call the bird I learned very early the difference between knowing the name of something and knowing something.
This is where Feynmans concepts can be applied to EMS education. At the foundational level of Blooms Taxonomy, students have to memorize names and terms in order for higher levels of learning to occur. On the second level students may learn basic facts about anatomy and physiology, but in order for them to apply this information on a real emergency call, this information has to have meaning for them. This is the performance gap that Feynman had identified. There is a difference between knowing the name of a thing (memorization) and knowing a thing (understanding).
Students often focus on their immediate need, which is to know the name of a thing to pass an exam. It is critical that educators prompt students to make connections between knowing the name of something and knowing how they will apply their knowledge about it to provide effective patient care. For example, a student may know the fact that the coronary arteries connect at the base of the aorta. They may even know that the coronary arteries perfuse during diastole. But can they think critically about the relevance of this? How can they apply this information to improve patient care? Rather than lecturing students on facts to memorize, a good educator will help students understand that because the coronary arteries only fill during diastole, this means that during CPR, while chest compressions (systole) eject blood to the body, really effective chest recoil (diastole) is required to perfuse the coronary arteries.
Feynman went further, explaining how good educators can become great educators in four simple steps.
1. Choose Your Topic
This may be better thought of as choose your objective. Feynman emphasized that educators need to be focused for each lesson and clear on exactly what they want the students to learn. Therefore, choosing a topic of airway is not only too broad, it doesnt define what you want a student to be able to do. A clear objective is the key to preparing to teach, setting expectations for students, getting co-educators on the same page, and setting up fair and effective testing.
2. Teach It to a Child
Feynman didnt mean that you had to literally teach the topic to a child. He explained that educators need to consider teaching as if they want a curious five-year-old to use this knowledge. The goal is not to dumb-down the information. The goal is to distill what you communicate into the essential concepts. Again, focus on how the student can apply the information. This forces you, the educator, to test both your complete understanding of the concepts you want students to apply, as well as your communication skills.
Feynman emphasized the importance of writing down those key concepts in the way you would explain it to the curious five-year-old. This forces an educator to do more than feel they could explain a subject well because they know a subject well. Writing it down exposes knowledge and communication gaps and forces the educator to make important decisions about exactly what to leave out, exactly what to teach, and exactly how to teach it. In the words of Albert Einstein, If you cant explain it simply, you don't understand it well enough.
3. Review and Fill In
Step 2 will almost surely expose opportunities for educators to improve their lesson. Maybe they will notice an important gap in their understanding of the subject. Maybe theyll realize the way theyd planned on running the education relied on students understanding of a topic that hadnt yet been thoroughly covered. Or perhaps the original lesson conveyed more knowledge with little focus on how students should apply the knowledge to meet the desired objectives.
4. Organize and Simplify
With the educators knowledge and communication gaps identified and filled in with a laser-focus on the objectives, it is time to make a final pass at the lesson plan (even if the lesson plan is simply educator notes on the back of an envelope). The Feynman technique focuses on step two: being able to teach to a child. The risk of step threeis that the educator will add too much back to the lesson. This final step is to organize the lesson so that it makes sense, focusing on the fundamentals the students will need to perform the objectives. If the students have questions, this is where the educators deeper knowledge and subject matter expertise will shine, but this is not time to roll out the war stories or show off how much more the educator knows than the student. This step is exactly what it says on the label: organize and simplify.
Using this simple technique, Richard Feynman was able to teach the most complex concepts in quantum mechanics to students in undergraduate physics classes. The key for us, as EMS educators, is to know a topic well enough to explain it simply, and to do so in a way that our students learn not just the name of a thing, but how to use it to improve their patient care.
Go here to see the original:
Sussex Uni physicist creates the fifth state of matter whilst working from home – The Tab
A Sussex physicist has had a scientific breakthrough during lockdown.
A researcher from the quantum physics and technologies department at the University of Sussex has created the state of fifth form matter from her computer at home during lockdown.
Dr Amruta Gadge has successfully created a Bose-Einstein Condensate (BEC) a state of matter where atoms cooled to extreme temperatures clump together and act like one single object. This is thought to be the first time that a BEC has been created in remote conditions, which were made unavoidable due to the coronavirus pandemic.
Despite the closure of university research facilities, Dr Gadge was able to use her computer at home in her living room to control lasers and radio waves that would create the BEC. This development by Sussexs Quantum Systems & Devices research group will have applications in magnetic field research, as well as in medicine, Dr Gadge told The Argus.
This feat marks a step in the path towards operating quantum technology remotely, which could be extremely useful for accessing difficult environments, such as underground or in space.
Dr Gadge and the rest of the team celebrated the achievement in true lockdown style via a Zoom call.
Professer of experimental physics at Sussex University, Peter Krger, told The Argus, We are all extremely excited that we can continue to conduct our experiments remotely during lockdown, and any possible future lockdowns.
Go here to see the original:
Sussex Uni physicist creates the fifth state of matter whilst working from home - The Tab
Beware of ‘Theories of Everything’ – Scientific American
By 1931, Kurt Gdel had proven his second incompleteness theorem, which states that a formal logical system cannot prove itself consistent. This theorem throws cold water on the ultimate ability to prove theories of everything, which have become fashionable in theoretical physics. It implies that any scientific theory is incomplete.
Galileo Galilei went beyond the limitations of pure logic and argued that any physical theory claiming to describe reality must also make predictions that stand up to the scrutiny of experiments. He found experimentally, for example, that heavy objects do not accelerate faster than light objects under the influence of gravity, as previously thought. This result laid the foundation for Albert Einsteins later realization that gravity is not a force but the curvature of spacetime that all test objects respond to in the same way.
Galileos dictum, based on humility, established the bedrock of modern physics over the years. But a new culture of physicists appears to challenge its underlying role now. For example, the pioneer of the theory of cosmic inflation, Alan Guth, replied during a panel discussion to my question of whether inflation is falsifiable that this theory cannot be proven false. He argued that it is a mathematical framework, like gauge theories, that must be valid, and the role of experiments is merely to fix its flexible degrees of freedom. In other words, the theory is adjustable enough to fit any experimental data about the universe.
But if so, can inflation be regarded a physical theory that obeys Galileos dictum? How can a theory claim to explain the beginning of the universe if it cannot be proven false by some hypothetical experimental data? By now, we know of alternative origin stories for our universe, suggesting that it may have gone through a bounce from a previously contracting phase before the big bang or that it started from some special initial state associated with string theory. In two papers that I wrote recently with my Harvard colleague, Xingang Chen and collaborators, we identified an experimental test that revealed tentative evidence in the cosmic microwave background and could favor alternative scenarios over the model of inflation. In short, it subjects inflation to Galileos dictum.
This would hardly be the first time a mathematically ingenious theory failed to capture physical reality. After all, the geocentric Ptolemaic theory of epicycles was mathematically appealing and its framework was broad enough to describe the motion of all planets on the sky. But it was eventually disfavored relative to the heliocentric Newtonian theory of gravity because it required a large number of free parameters that had to be finely tuned individually for each planet.
Despite lessons from the history of science, the notion that some physical theories cannot be refuted, and must be intrinsically true based on abstract reasoning, is still gaining popularity. Additional examples include the hypothetical existence of the multiverse, the conjecture that reality is a computer simulation, applications of the AdS/CFT correspondence to the real worldwhich is not embedded in anti de-Sitter (AdS) space but instead in nearly de-Sitter space of a completely different geometry, or Stephen Wolframs new concept of a theory of everything. Following an inspiring colloquium that Wolfram just gave at Harvards Black Hole Initiative, one thought came to my mind: If this theory predicts the lowest mass possible for an elementary particle, we will be able to test it based on astrophysical data.
The real world is under no obligation to follow our blueprints, just because they are mathematically appealing or easier to formulate than some alternative. The best example is quantum mechanics, whose fundamental principles deviated qualitatively from classical physics but were forced upon us through experiments. After quantum theory was formulated, Albert Einstein debated Niels Bohr against its unexpected nonclassical interpretation, arguing in a 1926 Letter to Max Born that In any event, I am convinced that He [God] is not playing dice. Recent experiments have proven Einsteins intuition false.
Human culture is filled with myths. Science aims to correct preconceived theories by emphasizing the key role of experimental verification. The natural tendency of humans to blindly follow popular conjectures should be moderated, since it places blinders on our scientific vision and suppresses progress in understanding reality.
Mathematical beauty is admirable, but in attempting to figure out reality it should be downgraded to second place relative to evidence. Physics is a dialogue with natureaccomplished through experimental testing of our ideas, and not a monologue in which we formulate our theories of everything and rest on our laurels. We must stay humble, keeping in mind Gdels proof that all mathematical systems are logically incomplete and Galileos insight that most of them may have nothing to do with reality.
See original here: