Category Archives: Quantum Physics
What’s happening at the Library: Books for the Future and Words for Every Day of the Year – Winchester Sun – Winchester Sun
By John Maruskin Almost the New Year. What will it bring? Librarians are not prognosticators, but they can offer resources that allow you to find your own direction, come to your own conclusions.
Heres a quartet of new books offering new perspectives on perennial questions from the origin of the Universe to the origins of words. They can be found in the New Nonfiction section at the front of the Library.
Fear of a Black Universe: An Outsiders Guide to the Future of Physics, by Stephon Alexander (call # 523.1 Alex). Stephon Alexander is a professor of physics at Brown University, the 2020 president of the National Society of Black Physicists, and an electronic jazz musician.In Fear of a Black Universe, he draws on ideas from relativity, quantum mechanics, and emergence to explore unconventional theories about the origins of the universe, life, and consciousness. He posits embracing perspectives of marginalized people will produce truly revolutionary insights in physics.
Abolition for the People: The Movement for a Future Without Policing and Prisons, edited by Colin Kaepernick (call # 364.6 Kaep). Over thirty essays from a diversity of voices presenting a vision of an abolitionist future in which communities can be safe, valued, and truly free.
A world, Kaepernick writes, grounded in love, justice, and accountability, a world grounded in safety and good health, a world grounded in meeting the needs of the people. He does not claim Abolition for the People will answer all social and political question. He hopes this book sparks questions that will open possibilities for a future in which everyone can thrive.
Rebugging the Planet: The Remarkable Things that Insects (and Other Invertebrates) Do-And Why We Need to
Love Them More, by Vicki Hird (call # 595.7 Hird). This book is about the benefits bugs provide for all life on Earth, including humans. Benefits like pollinating plants, feeding birds, defending crops and cleaning water systems.
Rebugging the Planet not only describes important ways insects keep life on Earth healthy, but also describes how individual home owners can contribute to sound local ecosystems by making their yardscapes more insect friendly.
The Cabinet of Linguistic Curiosities: A Yearbook of Forgotten Words, by Paul Anthony Jones (call #422.03 Jones). Offering a word a day along with astute etymologies and entertaining historical corollaries The Cabinet of Linguistic Curiosities provides joyful learning and great anecdotes for conversation.
For example, Muggle, the word for June 26, which entered contemporary parlance through Harry Potter books, meaning a person possessing no magical powers, has actually been in use since the 13th century as another name for fish tails, probably deriving from mugil, the Latin name for the grey mullet.
Theres a lot more where those books came from, The Clark County Public Library. Drop in.
Talk to a librarian. Enrich your perspectives in 2022.
Happy New Year.
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Nine Mathematical Equations that Changed the World – Greek Reporter
Gravity Probe B orbiting the Earth to measure space-time, a four-dimensional description of the universe including height, width, length, and time. Credit: NASA/Public Domain
Mathematical equations have been the greatest tool for mankind to explain the world around him and the key to advance our knowledge about the Universe. And the most important one of them all was created by of course an ancient Greek mathematician.
Galileo famously stated that the Universe is a grand book written in the language of mathematics.
The brightest minds in history have used mathematical equations to lay the foundation for the way we measure and understand our entire universe.
Thanks to those great minds which contributed to the writing of this grand book, all the giant scientific leaps humanity has made brought us to explore new planets, an idea that belonged to science fiction just a few decades ago.
The following mathematical equations are the ones that have shaped our World, according to Live Science:
Everything is a number was the motto of the Pythagorean School. Pythagoras, one of the greatest of all ancient Greek thinkers, was influenced by the Babylonians, who assigned numerical values to everything around them.
This ancient theorem first recorded circa 570 495 BC is a fundamental principle in Euclidean Geometry, and the basis for the definition of distance between two points.
The Pythagorean Theoremis summed up by the following statement: In a right triangle, the square of the hypotenuse is equal to the sum of the squares of the two perpendicular sides, is
It may sound like a simple equation, but the Greek philosophers theorem remains current 2,500 years later.
Newtons Law explains why the planets move the way they do, and how gravity works, both on Earth and throughout the Universe.
All objects attract each other with a force of gravitational attraction. Gravity is universal. This force is directly dependent upon the masses of both objects and inversely proportional to the square of the distance that separates their centers.
First published in The Principia in July of 1687, the Law of Universal Gravitation was the defacto reference equation for nearly 200 years until it was replaced by Einsteins Theory of General Relativity.
Einsteins most famous work is the generally accepted theory on the relationship between space and time.
The basic idea here is that instead of being an invisible force that attracts objects to one another, gravity is a curving or warping of space. The more massive an object is, the more it warps the space around it.
First proposed in 1905, the Theory of Relativity has both radically altered the course of physics, and deepened our knowledge of the Universes past, present, and future.
Upon the discovery of electricity, James Clerk Maxwell formulated equations that describe how electric and magnetic fields are generated and altered, both by each other and by charges and currents.
First published between 1861 and 1862, they are to classical electromagnetism what Newtons Laws of Motion and universal gravitation are to classical mechanics.
Maxwells equations paved the way for Einsteins special theory of relativity, which established the equivalence of mass and energy.
Rudolf Clausius law states that energy always flows from higher concentration to lower concentrations. It also states that whenever energy changes or moves, it becomes less useful.
In 1865 he introduced the concept of entropy. In 1870 he introduced the virial theorem which applied to heat.
Clausius theorems have led to the development of technologies like internal combustion engines, cryogenics, and electricity generation.
The total energy of the universe is constant; the total entropy is continually increasing, Clausius famously wrote.
John Napier is best known as the discoverer of logarithms. He also made common the use of the decimal point in arithmetic and mathematics.
Logarithms were introduced by Napier in the early 17th century as a way to simplify calculations. They answer the question, How many of X number do we multiply to get Y number?
Logarithms were adopted by early navigators, scientists and engineers. Today, scientific calculators and digital computers do this work for us.
This equation describes how the quantum state of a quantum system changes with time. It provides a way to calculate the wave function of a system and how it changes dynamically in time.
Developed by Austrian physicist Erwin Schrdinger in 1926, it governs the behavior of atoms and subatomic particles in quantum mechanics.
Schrdingers Equation underpins many modern computer-based gadgets andpaved the way for nuclear power, microchips, electron microscopes, and quantum computing.
In 1822, French baron Jean-Baptiste Joseph Fourier wrote down certain equations that have allowed researchers to break down complex and messy data into combinations of simple waves that are much easier to analyze.
The Fourier transform, as it is known, was a radical notion in its time, but later was appliedin many modern fields of science, including data processing, image analysis, optics, communication, astronomy and engineering.
In the 1920s, Russian physicist Alexander Friedmann used Einsteins theories of relativity to show that the characteristics of an expanding universe could be expressed from the Big Bang onward using two equations.
They combine the curvature of the cosmos, how much matter and energy it contains, and how fast it is expanding.
They also combines other constants such as the speed of light, the gravitational constant and The Hubble constant, which captures the accelerating expansion of the universe.
The Friedmann Equation now forms the backbone of contemporary cosmological theory, which is known as CDM (Lambda CDM, where CDM stands for cold dark matter) and accounts for all the known components of reality.
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Nine Mathematical Equations that Changed the World - Greek Reporter
Could an Overlooked Quantum Theory Help The Universe Make Sense Again? – ScienceAlert
Back in the 1920s, when the field of quantum physics was still in its infancy, a French scientist named Louis de Broglie had an intriguing idea.
In response to confusion over whether light and matter were fundamentally particles or waves, he suggested an alternative: what if both were true? What if the paths taken by quantum objects were guided by something that rose and fell like an ocean swell?
His hypothesis was the foundation of what would later become pilot wave theory, but it wasn't without its problems. So, like any beautiful idea that falters in the face of experiment, it swiftly became a relic of scientific history.
Today, the majority of physicists subscribe to what's referred to as the 'Copenhagen interpretation of quantum mechanics', which, generally speaking, doesn't give precise locations and momentums to particles until they're measured, and therefore observed.
Pilot wave theory, on the other hand, suggests that particles do have precise positions at all times, but in order for this to be the case, the world must also be strange in other ways which led to many physicists dismissing the idea.
Yet something about De Broglie's surfing particles makes it impossible to leave alone, and over the past century, the idea continues to increasingly pop up in modern physics.
For some, it's a concept that could finally help the Universe make sense from the tiniest quantum particles to the largest galaxies.
To better understand what a pilot wave is, it helps to first understand what it is not.
By the 1920s, physicists were baffled by highly accurate experiments on light and subatomic particles, and why their behavior seemed more like that of a wave than a particle.
The results were best explained by a new field of mathematics, one that incorporated probability theory with the mechanics of wave behavior.
To theoretical physicists like Danish theorist Niels Bohr and his German colleague Werner Heisenberg, who set the foundations of the Copenhagen interpretation, the most economical explanation was to treat probability as a fundamental part of nature. What behaved like a wave was an inherent uncertainty at work.
This isn't merely the kind of uncertainty a lack of knowledge brings. According to Bohr, it was as if the Universe was yet to make up its mind on where to put a particle, what direction it should be twisting, and what kind of momentum it might have. These properties, he maintained, can only be said to exist once an observation has been made.
Just what any of this means on an intuitive level is hard to say. Prior to quantum physics, the mathematics of probability were tools for predicting the roll of a dice, or the turning of a wheel. We can picture a stack of playing cards sitting upside down on a table, its hidden sequence locked in place. Mathematics merely puts our ignorance in order while reality exists with 100 percent certainty in the background.
Now, physicists were proposing a flavor of probability that wasn't about our naivety. And that isn't as easy to imagine.
De Broglie's idea of a hypothetical wave was meant to return some kind of physicality to the notion of probability. The scattered patterns of lines and dots observed in experiments are just as they seem consequences of waves rising and falling through a medium, little different to a ripple on a pond.
And somewhere on that wave is an actual particle. It has an actual position, but its destiny is in the hands of changes in the flow of the fluid that guides it.
On one level, this idea feels right. It's a metaphor we can relate to far more easily than one of a dithering Universe.
But experimentally, the time wasn't right for de Broglie's simple idea.
"Although de Broglie's view seems more reasonable, some of its initial problems led the scientific community to adopt Bohr's ideas," Paulo Castro, a science philosopher at the University of Lisbon in Portugal, told Science Alert.
Eminent Austrian physicist Wolfgang Pauli, one of the pioneers of quantum physics, pointed out at the time that de Broglie's model didn't explain observations being made on particle scattering, for example.
It also didn't adequately explain why particles that have interacted with one another in the past will have correlating characteristics when observed later, a phenomenon referred to as entanglement.
For around a quarter of a century, de Broglie's notion of particles riding waves of possibilities remained in the shadows of Bohr's and Heisenberg's fundamental uncertainty. Then in 1952, the American theoretical physicist David Bohm returned to the concept with his version, which he called a pilot wave.
Similar to de Broglie's suggestion, Bohm's pilot wave hypothesis combined particles and waves as a partnership that existed regardless of who was watching. Interfere with the wave, though, and its characteristics shift.
Unlike de Broglie's idea, this new proposal could account for the entangled fates of multiple particles separated by time and distance by invoking the presence of a quantum 'potential', which acted as a channel for information to be swapped between particles.
Now commonly referred to as the de Broglie-Bohm theory, pilot waves have come a long way in the decades since.
"The new main hypothesis is that the quantum wave encodes physical information, acting as a natural computation device involving possible states," says Castro.
"So, one can have whatever superposition of states encoded as physical information in the tridimensional wave. The particle changes its state to another by reading the proper information from the wave."
Philosophically speaking, a theory is only as good as the experimental results it can explain and the observations it can predict. No matter how appealing an idea feels, if it can't tell a more accurate story than its competitors, it's unlikely to win over many fans.
Pilot waves fall frustratingly short of contributing to a robust model of nature, explaining just enough about quantum physics in an intuitive way to continue to attract attention, but not quite enough to flip the script.
For example, in 2005 French researchers noticed oil droplets hopped in an odd fashion across a vibrating oil bath, interacting with the medium in a feedback loop that was rather reminiscent of de Broglie's wave-surfing particles. Critical to their observations was a certain quantization of the particle's movements, not unlike the strict measurements limiting the movements of electrons around an atom's nucleus.
The similarities between these macro scale waves and quantum ones were intriguing enough to hint at some kind of unifying mechanics that demanded further investigation.
Physicists at the Niels Bohr Institute in the University of Copenhagen later tested one of the quantum-like findings made on the oil drop analogy based on their interference patterns through a classic double slit experiment, and failed to replicate their results. However, they did detect an 'interesting' interference effect in the altered movements of the waves that could tell us more about waves of a quantum variety.
In a remarkable act of serendipity, Bohr's own grandson a fluid physicist named Tomas Bohr also weighed in on the debate, proposing a thought experiment that effectively rules out pilot waves.
While null results and thought experiments hardly disprove the basic tenets of today's version of de Broglie-Bohm's pilot waves, they reinforce the challenges advocates face in elevating their models to a true theory status.
"The wave quantum memory is a powerful concept, but of course, there is still a lot of work to be done," says Castro.
It's clear there's an aching void at the heart of physics, a gap begging for an intuitive explanation for why reality rides wave-like patterns of randomness.
It's possible the duality of waves and particles has no analogy in our daily experience. But the idea of a wave-like medium that acts as some kind of computational device for physics is just too tempting to leave alone.
For pilot wave theory to triumph, though, physicists will need to find a way to pluck a surfer from its quantum wave and show the two can exist independently. Experimentally, this could be achieved by emitting two particles and separating one from its ride by measuring it.
"Then we make this empty quantum wave interfere with the wave of the other particle, altering the second particle's behavior," says Castro. "We have presented this at the first International Conference on Advances in Pilot Wave Theory."
Practically speaking, the devices required to detect such an event would need to be extremely sensitive. This isn't outside of the bounds of feasibility, but it is a task patiently waiting for an opportunity. Empty pilot waves might even hold the key for solving practical problems in quantum computation by making the waves less prone to surrounding noise.
Future physicists could eventually land on observations that open us to a Universe that makes sense right down to its roots. Should experiments detect something, it'll be a solid indication that far from empty, the heart of physics beats with a pulse. Even when nobody's watching.
All Explainers are determined by fact checkers to be correct and relevant at the time of publishing. Text and images may be altered, removed, or added to as an editorial decision to keep information current.
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Could an Overlooked Quantum Theory Help The Universe Make Sense Again? - ScienceAlert
research highlights from 2021 – Purdue University News – Purdue News Service
From FDA approval on a Purdue-developed drug that helps surgeons find cancer lesions to self-aware algorithms that stop hackers to a new test for bovine respiratory disease, Purdues faculty helped to advance key research that improves our work, health and world. Enjoy a roundup of Purdue research news from 2021.
Pioneering imaging drug allowed surgeons to find cancer lesionsA pioneering new imaging drug developed by Purdue chemistry researcher Philip Low will help surgeons find additional cancer lesions. The drug, developed with support from Purdues Center for Cancer Research and the Purdue Institute for Drug Discovery, was approved by the FDA in November.Read more
Whitest paint could help combat global warming
Purdue mechanical engineering professorXiulinRuan created the worlds whitest paint, which could eventually reduce or even eliminate the need for air conditioning. Its unique concentration of barium sulfate particles with varying sizesenableit to reflect 98.1% of sunlight.Read more
Cracking the code of cellular defense
Imagine the day when any tissue or organ can be repaired or the replacements personalized to the patient. Through the NSF-funded EMBRIO Institute, Purdues Weldon School of Biomedical Engineering professor DavidUmulisbelieves we can use AI tosee how cells defend themselves or repair their damage with the help of biochemical and mechanical inputs and reactions.Read more
Self-aware algorithm to ward off hacking attempts
Purdue Universityprofessor of nuclear engineeringHany Abdel-Khalik has come up with a powerful response to hackers attempting to attack our most critical infrastructure. Abdel-Khalik, a CERIAS-affiliated researcher, is working to makethe computer models that run thesecyberphysicalsystems both self-aware and self-healing.Read more
Pen-side test for bovine respiratory disease may save cattle industry millions
Mohit Verma, assistant professor of agricultural and biological engineering, is leading research on a new on-site kit for testing bovine respiratory disease,which is the most common and costly disease affecting cattle in the world.The new testing kit will help save time, effort, and resources during treatment.Read more
Using remotesensing technologies and techniques in archaeology
An NSF-funded interdisciplinary research project, Remote Observation and Sensing Technologies and Techniques inArchaeo-Anthropology (ROSETTA),ledby Sorin Adam Matei, associate dean of research and graduate education in the College of Liberal Arts, combinesthe strengthsof ourremote sensing,computational,and socio-humanities scholarstobuild artificial intelligence-based framework for modeling complex urban constructions.Read more
Purdue co-leads on DOD-funded lead-free adoption project
A new consortium funded by the U.S. Department of Defense has selected Purdue University to co-lead a project toadvance adoption of lead-free electronics in defense systems. The project, for whichCarol Handwerker, Purdues Reinhardt Schuhmann Jr. Professor ofMaterials Engineering, is a principal investigator, will accelerate the transition to lead-free electronics in aerospace, defense, and other high-performance electronics.Read more
Canadian firm secures exclusive rights to Purdue's rare-earth element separation and purification tech
A Canadian firm, Medallion Resources, acquired the exclusive rights to Purdue University-developed rare-earth element separation and purification technologies. The flagship technology from Purdue is known as ligand-assisted displacement (LAD), developed by Purdue Chemical Engineering professor Linda Wang.Her LAD technology could enable the U.S. to more safely utilize critical resources from domestic sources and aligned nations.Read more
Purdue researchers develop responsive practices for K-6 students with high intensity needs
A team of interdisciplinary researchers at Purdue was awarded $1.6 million from the U.S. Department of Education to develop responsive practices for K-6 students with high intensity needs. TheIPE-SHINES project, led byRose Mason, associate professor of special education in the Department of Educational Studies, addresses a national need for highly skilled speech-language pathologists (SLPs) and board-certified behavior analysts (BCBAs).Read more
Marathon of crisis: Nurses mental health in forefront of new study
Purdue University College of Health and Human Sciences professor Karen Foils research project, Nurses Psychological Trauma and Cognitive Control in the COVID-19 Pandemic, sheds light on vital mental health topics such as depression, anxiety, PTSD, and drug and alcohol use during the height of the pandemic.Read more
Purdue planetary researcher plays key roles in Mars rovermission
Purdue planetary scientist Briony Horgan has several key leadership roles for the Mars rover mission.Horgans teamproduced one of the major results on the location that contributed to NASAs selection of Jezero Crater as the Mars landing site.She is on the roversMastcam-Z camera team the scientific eyes for Perseverance, and she is one of the tactical science leads working with NASA to plan the next days activities for the rover.Read more
Purdue spotlights quantum and work-life research with prestigious awards
Three Purdue professors advancing quantum science and work-life and work-life family research policy were chosento receive the university's most prestigious research and scholarship awards in 2021. The awardees were:
Ellen ErnstKossek,a leading social scientist whose work has shaped the field of work-life and work-family research policy in the U.S. and internationally.
Michael J. Manfra,a leading condensed matter experimentalist whose work has helped to define the field of quantum physics.
Yong Chen, a leading quantum researcher whose work is at the convergence of condensed matter physics and atomic, molecular, and optical physics. Read more
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research highlights from 2021 - Purdue University News - Purdue News Service
Neural’s best quantum computing and physics stories from 2021 – The Next Web
2021 will be remembered for a lot of things, but when its all said and done we think itll eventually get called the year quantum computing finally came into focus.
Thats not to say useful quantum computers have actually arrived yet. Theyre still somewhere between a couple years and a couple centuries away. Sorry for being so vague, but when youre dealing with quantum physics there arent yet many guarantees.
This is because physics is an incredibly complex and challenging field of study. And the difficulty gets cranked up exponentially when you start adding theoretical and quantum to the research.
Were talking about physics at the very edge of reason. Like, for example, imagining a quantum-powered artificial intelligence capable of taking on the Four Horseman of the Apocalypse.
That might sound pretty wacky, but this story explains why its not quite as out there as you might think.
But lets go even further. Lets go past the edge of reason and into the realm of the speculative science. Earlier this year we wondered what would happen if physicists could actually prove that reality as we know it isnt real.
Per that article:
Theoretically, if we could zoom in past the muons and leptons and keep going deeper and deeper, we could reach a point where all objects in the universe are indistinguishable from each other because, at the quantum level, everything that exists is just a sea of nearly-identical subparticulate entities.
This version of reality would render the concepts of space and time pointless. Time would only exist as a construct by which we give meaning to our own observations. And those observations would merely be the classical side-effects of existing in a quantum universe.
So, in the grand scheme of things, its possible that our reality is little more than a fleeting, purposeless arrangement of molecules. Everything that encompasses our entire universe may be nothing more than a brief hallucination caused by a quantum vibration.
Nothing makes you feel special like trying to conceive of yourself as a few seasoning particles in an infinite soup of gooey submolecules.
If having an existential quantum identity-crisis isnt your thing, we also covered a lot of cool stuff that doesnt require you to stop seeing yourself as an individual stack of materials.
Does anyone remember the time China said it had built a quantum computer a million times more powerful than Googles? We dont believe it. But thats the claim the researchersmade. You can read more about that here.
Oh, and that Google quantum system the Chinese researchers referenced? Yeah, it turns out it wasnt exactly the massive upgrade over classical supercomputers it was chalked up to be either.
But, of course, we forgive Google for its marketing faux pas. And thats because, hands down, the biggest story of the year for quantum computers was the time crystal breakthrough.
As we wrote at the time:
If Googles actually created time-crystals, it could accelerate the timeline for quantum computing breakthroughs from maybe never to maybe within a few decades.
At the far-fetched, super-optimistic end of things we could see the creation of a working warp drive in our lifetimes. Imagine taking a trip to Mars or the edge of our solar system, and being back home on Earth in time to catch the evening news.
And, even on the conservative end with more realistic expectations, its not hard to imagine quantum computing-based chemical and drug discovery leading to universally-effective cancer treatments.
Talk about a eureka moment!
But there were even bigger things in the world of quantum physics than just advancing computer technology.
Scientists from the University of Sussex determined that black holes emanate a specific kind of quantum pressure that could lend some credence to multiple universe theories.
Basically, we cant explain where the pressure comes from. Could this be blow back from white holes swallowing up energy and matter in a dark, doppelganger universe that exists parallel to our own? Nobody knows! You can read more here though.
Still there were even bigger philosophical questions in play over the course of 2021 when it came to interpreting physics research.
Are we incapable of finding evidence for God because were actually gods in our rights? That might sound like philosophy, but there are some pretty radical physics interpretations behind that assertion.
And, if we are gods, can we stop time? Turns out, whether were just squishy mortal meatbags or actual deities, we actually can!
Alright. If none of those stories impress you, weve saved this one for last. If being a god, inventing time crystals, or even stopping time doesnt float your boat, how about immortality? And not just regular boring immortality, butquantum immortality.
Its probably not probable, and adding the word quantum to something doesnt necessarily make it cooler, but anythings possible in an infinite universe. Plus, the underlying theories involving massive-scale entanglement are incredible read more here.
Seldom a day goes by where something incredible isnt happening in the world of physics research. But thats nothing compared to the magic weve yet to uncover out there in this fabulous universe we live in.
Luckily for you, Neural will be back in 2022 to help make sense of it all. Stick with us for the most compelling, wild, and deep reporting on the quantum world this side of the non-fiction realm.
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Neural's best quantum computing and physics stories from 2021 - The Next Web
Quantum physics requires imaginary numbers to explain reality – Science News Magazine
Imaginary numbers might seem like unicorns and goblins interesting but irrelevant to reality.
But for describing matter at its roots, imaginary numbers turn out to be essential. They seem to be woven into the fabric of quantum mechanics, the math describing the realm of molecules, atoms and subatomic particles. A theory obeying the rules of quantum physics needs imaginary numbers to describe the real world, two new experiments suggest.
Imaginary numbers result from taking the square root of a negative number. They often pop up in equations as a mathematical tool to make calculations easier. But everything we can actually measure about the world is described by real numbers, the normal, nonimaginary figures were used to (SN: 5/8/18). Thats true in quantum physics too. Although imaginary numbers appear in the inner workings of the theory, all possible measurements generate real numbers.
Quantum theorys prominent use of complex numbers sums of imaginary and real numbers was disconcerting to its founders, including physicist Erwin Schrdinger. From the early days of quantum theory, complex numbers were treated more as a mathematical convenience than a fundamental building block, says physicist Jingyun Fan of the Southern University of Science and Technology in Shenzhen, China.
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Some physicists have attempted to build quantum theory using real numbers only, avoiding the imaginary realm with versions called real quantum mechanics. But without an experimental test of such theories, the question remained whether imaginary numbers were truly necessary in quantum physics, or just a useful computational tool.
A type of experiment known as a Bell test resolved a different quantum quandary, proving that quantum mechanics really requires strange quantum linkages between particles called entanglement (SN: 8/28/15). We started thinking about whether an experiment of this sort could also refute real quantum mechanics, says theoretical physicist Miguel Navascus of the Institute for Quantum Optics and Quantum Information Vienna. He and colleagues laid out a plan for an experiment in a paper posted online at arXiv.org in January 2021 and published December 15 in Nature.
In this plan, researchers would send pairs of entangled particles from two different sources to three different people, named according to conventional physics lingo as Alice, Bob and Charlie. Alice receives one particle, and can measure it using various settings that she chooses. Charlie does the same. Bob receives two particles and performs a special type of measurement to entangle the particles that Alice and Charlie receive. A real quantum theory, with no imaginary numbers, would predict different results than standard quantum physics, allowing the experiment to distinguish which one is correct.
Fan and colleagues performed such an experiment using photons, or particles of light, they report in a paper to be published in Physical Review Letters. By studying how Alice, Charlie and Bobs results compare across many measurements, Fan, Navascus and colleagues show that the data could be described only by a quantum theory with complex numbers.
Another team of physicists conducted an experiment based on the same concept using a quantum computer made with superconductors, materials which conduct electricity without resistance. Those researchers, too, found that quantum physics requires complex numbers, they report in another paper to be published in Physical Review Letters. We are curious about why complex numbers are necessary and play a fundamental role in quantum mechanics, says quantum physicist Chao-Yang Lu of the University of Science and Technology of China in Hefei, a coauthor of the study.
But the results dont rule out all theories that eschew imaginary numbers, notes theoretical physicist Jerry Finkelstein of Lawrence Berkeley National Laboratory in California, who was not involved with the new studies. The study eliminated certain theories based on real numbers, namely those that still follow the conventions of quantum mechanics. Its still possible to explain the results without imaginary numbers by using a theory that breaks standard quantum rules. But those theories run into other conceptual issues, making them ugly, he says. But if youre willing to put up with the ugliness, then you can have a real quantum theory.
Despite the caveat, other physicists agree that the quandaries raised by the new findings are compelling. I find it intriguing when you ask questions about why is quantum mechanics the way it is, says physicist Krister Shalm of the National Institute of Standards and Technology in Boulder, Colo. Asking whether quantum theory could be simpler or if it contains anything unnecessary, these are very interesting and thought-provoking questions.
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Quantum physics requires imaginary numbers to explain reality - Science News Magazine
9 equations that changed the world – Livescience.com
Mathematical equations offer unique windows into the world. They make sense of reality and help us see things that haven't been previously noticed. So its no surprise that new developments in math have often gone hand in hand with advancements in our understanding of the universe. Here, we take a look at nine equations from history that have revolutionized how we look at everything from tiny particles to the vast cosmos.
One of the first major trigonometric rules that people learn in school is the relationship between the sides of a right triangle: the length of each of the two shorter sides squared and added together equals the length of the longest side squared. This is usually written as a^2 + b^2 = c^2, and it has been known for at least 3,700 years, since the time of the ancient Babylonians.
The Greek mathematician Pythagoras is credited with writing down the version of the equation used today, according to the University of St. Andrews in Scotland. Along with finding use in construction, navigation, mapmaking and other important processes, the Pythagorean theorem helped expand the very concept of numbers. In the fifth century B.C., the mathematician Hippasus of Metapontum noticed that an isosceles right triangle whose two base sides are 1 unit in length will have a hypotenuse that is the square root of 2, which is an irrational number. (Until that point, no one in recorded history had come across such numbers.) For his discovery, Hippasus is said to have been cast into the sea, because the followers of Pythagoras (including Hippasus) were so disturbed by the possibility of numbers that went on forever after a decimal point without repeating, according to an article from the University of Cambridge.
British luminary Sir Isaac Newton is credited with a large number of world-shattering findings. Among them is his second law of motion, which states that force is equal to the mass of an object times its acceleration, usually written asF=ma. An extension of this law, combined with Newton's other observations, led him, in 1687, to describe what is now called his law of universal gravitation. It is usually written as F= G (m1* m2) / r^2, where m1 and m2 are the masses of two objects and r is the distance between them. G is a fundamental constant whose value has to be discovered through experimentation. These concepts have been used to understand many physical systems since, including the motion of planets in the solar system and the means to travel between them using rockets.
Using Newton's relatively new laws, 18th-century scientists began analyzing everything around them. In 1743, French polymath Jean-Baptiste le Rond d'Alembert derived an equation describing the vibrations of an oscillating string or the movement of a wave, according to a paper published in 2020 in the journal Advances in Historical Studies. The equation can be written as follows:
1/v^2 * ^2y/t^2= ^2y/x^2
In this equation, v is the velocity of a wave, and the other parts describe the displacement of the wave in one direction. Extended to two or more dimensions, the wave equation allows researchers to predict the movement of water, seismic and sound waves and is the basis for things like the Schrdinger equationof quantum physics, which underpins many modern computer-based gadgets.
Even if you haven't heard of the French baron Jean-Baptiste Joseph Fourier, his work has affected your life. That's because the mathematical equations he wrote down in 1822 have allowed researchers to break down complex and messy data into combinations of simple waves that are much easier to analyze. The Fourier transform, as it's known, was a radical notion in its time, with many scientists refusing to believe that intricate systems could be reduced to such elegant simplicity, according to an article in Yale Scientific. But Fourier transforms are the workhorses in many modern fields of science, including data processing, image analysis, optics, communication, astronomy and engineering.
Electricity and magnetism were still new concepts in the 1800s, when scholars investigated how to capture and harness these strange forces. Scottish scientist James Clerk Maxwell greatly boosted our understanding of both phenomena in 1864, when he published a list of 20 equations describing how electricity and magnetism functioned and were interrelated. Later honed to four, Maxwell's equations are now taught to first-year physics students in college and provide a basis for everything electronic in our modern technological world.
No list of transformational equations could be complete without the most famous equation of all. First stated by Albert Einstein in 1905 as part of his groundbreaking theory of special relativity, E = mc^2 showed that matter and energy were two aspects of one thing. In the equation, Estands for energy,mrepresents mass andcis the constant speed of light. The notions contained within such a simple statement are still hard for many people to wrap their minds around, but without E = mc^2, we wouldn't understand how stars or the universe worked or know to build gigantic particle accelerators like the Large Hadron Collider to probe the nature of the subatomic world.
It seems like hubris to think you can create a set of equations that define the entire cosmos, but that's just what Russian physicist Alexander Friedmanndid in the 1920s. Using Einstein's theories of relativity, Freidmann showed that the characteristics of an expanding universe could be expressed from the Big Bang onward using two equations.
They combine all the important aspects of the cosmos, including its curvature, how much matter and energy it contains, and how fast it's expanding, as well as a number of important constants, like the speed of light, the gravitational constant and the Hubble constant, which captures the accelerating expansion of the universe. Einstein famously didn't like the idea of an expanding or contracting universe, which his theory of general relativity suggested would happen due to the effects of gravity. He tried to add a variable into the result denoted by the Greek letter lambda that acted counter to gravity to make the cosmos static. While he later called it his greatest mistake, decades afterwards the idea was dusted off and shown to exist in the form of the mysterious substance dark energy, which is driving an accelerated expansion of the universe.
Most people are familiar with the 0s and 1s that make up computer bits. But this critical concept wouldn't have become popular without the pioneering work of American mathematician and engineer Claude Shannon. In an important 1948 paper, Shannon laid out an equation showing the maximum efficiency at which information could be transmitted, often given as C = B * 2log(1+S/N). In the formula, C is the achievable capacity of a particular information channel, B is the bandwidth of the line, S is the average signal power and N is the average noise power. (The S over N gives the famous signal-to-noise ratio of the system.) The output of the equation is in units of bits per second. In the 1948 paper, Shannon credits the idea of the bit to mathematician John W. Tukey as a shorthand for the phrase binary digit.
Very simple things can sometimes generate unimaginably complex results. This truism might not seem all that radical, but it took until the mid-20th century for scientists to fully appreciate the idea's weight. When the field of chaos theory took off during that time, researchers began to get a handle on the ways that systems with just a few parts that fed back on themselves might produce random and unpredictable behavior. Australian physicist, mathematician and ecologist Robert May wrote a paper, published in the journal Nature in 1976, titled "Simple mathematical models with very complicated dynamics," which popularized the equation xn+1 = k * xn(1 xn).
Xn represents some quantity in a system at the present time that feeds back on itself through the part designated by (1 xn). K is a constant, and xn+1 shows the system at the next moment in time. Though quite straightforward, different values of k will produce wildly divergent results, including some with complex and chaotic behavior. May's map has been used to explain population dynamics in ecological systems and to generate random numbers for computer programming.
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Postdoctoral Fellow in Theoretical Quantum Physics job with UNIVERSITY OF OTAGO | 275372 – Times Higher Education (THE)
DODD-WALLS CENTRE & DEPARTMENT OF PHYSICS
About us/M mtou
The University of Otago is New Zealands oldest university, with its Physics Department a founding element of the University. The Dodd-Walls Centre is a national Centre of Research Excellence, providing opportunities for collaboration across world class experimental and theoretical quantum physics groups.
The Role/Te mahi
A Postdoctoral Research Fellow position in Theoretical Quantum Physics is available in the Dodd-Walls Centre at the Department of Physics. The position is in the group of the Centres Director, Professor David Hutchinson, and will support the research programme of the group.
The main research aims of the group involve the theoretical studies of ultracold atomic gases and, in particular, the effects of disorder upon properties of cold gases. A strong theoretical background in ultracold gases or condensed matter physics is strongly desirable, although candidates with backgrounds that complement Professor Hutchinsons other research interests will be considered.
PhD scholarships are also available within the group.
Further details/Proko
This position is fixed-term, full-time for two years.
Specific enquiries may be directed to Professor Hutchinson via the contact details on the Current Vacancies page at: Postdoctoral Fellow in Theoretical Quantum Physics
Application/Tono
To submit your application (Including CV and cover letter) please click the apply button. Applications quoting reference number 2101991 will close on Thursday, 27 January 2022.
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Swinging on the quantum level – EurekAlert
image:If two differently coloured lasers are used to excite a quantum system (shown schematically on the left), it can be excited via a swing up process. This corresponds to a spiral movement in the quantum system. view more
Credit: University of Mnster - AG Reiter
After the first quantum revolution the development of devices such as lasers and the atomic clock the second quantum revolution is currently in full swing. Experts from all over the world are developing fundamentally new technologies based on quantum physics. One key application is quantum communication, where information is written and sent in light. For many applications making use of quantum effects, the light has to be in a certain state namely a single photon state. But what is the best way of generating such single photon states? In the PRX Quantum journal, researchers from Mnster, Bayreuth and Berlin (Germany) have now proposed an entirely new way of preparing quantum systems in order to develop components for quantum technology.
In the experts view it is highly promising to use quantum systems for generating single photon states. One well-known example of such a quantum system is a quantum dot. This is a semiconductor structure, just a few nanometres in size. Quantum dots can be controlled using laser pulses. Although quantum dots have properties similar to those of atoms, they are embedded in a crystal matrix, which is often more practical for applications. Quantum dots are excellent for generating single photons, and that is something we are already doing in our labs almost every day, says Dr. Tobias Heindel, who runs an experimental lab for quantum communication at the Technical University of Berlin. But there is still much room for improvement, especially in transferring this technology from the lab to real applications, he adds.
One difficulty that has to be overcome is to separate the generated single photons from the exciting laser pulse. In their work, the researchers propose an entirely new method of solving this problem. The excitation exploits a swing-up process in the quantum system, explains Mnster Universitys Thomas Bracht, the lead author of the study. For this, we use one or more laser pulses which have frequencies which differ greatly from those in the system. This makes spectral filtering very easy.
Scientists define the swing-up process as a particular behaviour of the particles excited by the laser light in the quantum system the electrons or, to be more precise, electron-hole pairs (excitons). Here, laser light from two lasers is used which emit light pulses almost simultaneously. As a result of the interaction of the pulses with one another, a rapid modulation occurs, and in each modulation cycle, the particle is always excited a little, but then dips towards the ground state again. In this process, however, it does not fall back to its previous level, but is excited more strongly with each swing up until it reaches the maximum state. The advantage of this method is that the laser light does not have the same frequency as the light emitted by the excited particles. This means that photons generated from the quantum dot can be clearly assigned.
The team simulated this process in the quantum system, thus providing guidelines for experimental implementation. We also explain the physics of the swing-up process, which helps us to gain a better understanding of the dynamics in the quantum system, says associate professor Dr. Doris Reiter, who led the study.
In order to be able to use the photons in quantum communication, they have to possess certain properties. In addition, any preparation of the quantum system should not be negatively influenced by environmental processes or disruptive influences. In quantum dots, especially the interaction with the surrounding semiconductor material is often a big problem for such preparation schemes. Our numerical simulations show that the properties of the photons generated after the swing-up process are comparable with the results of established methods for generating single photons, which are less practical, adds Prof. Martin Axt, who heads the team of researchers from Bayreuth.
The study constitutes theoretical work. As a result of the collaboration between theoretical and experimental groups, however, the proposal is very close to realistic experimental laboratory conditions, and the authors are confident that an experimental implementation of the scheme will soon be possible. With their results, the researchers are taking a further step towards developing the quantum technologies of tomorrow.
Computational simulation/modeling
Not applicable
Swing-Up of Quantum Emitter Population Using Detuned Pulses
17-Dec-2021
Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.
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Growing Peppers on the ISS Is Just the Start of Space Farming – newsconcerns
The sensory experience of growing productive crops can also help mitigate the psychological effects of long-term space travel. Theres a certain emotional connection to food that doesnt come from a dehydrated space pantry. Spencer says the team cracked open the door of the APH every day to observe their vegetable companions with all the tenderness of home gardeners. When harvest day came, they batted their bounty around the ISS, taking selfies and delighting in watching the fruits pirouetting around the spacecraft. Even when the sharp heat of that first bite made them scrunch up their faces, the astronauts still reveled in the chilies, which they ate with fajita beef and rehydrated tomatoes and artichokes.
We were thinking no heat, so that [the peppers] wouldnt be dangerous, but maybe the astronauts need a little spice in their life, says Paul Bosland, who along with his colleagues at the Chile Pepper Institute genetically engineered the Espaola Improved chili pepper seeds grown in Plant Habitat-04. (They are the new extraterrestrial pride of New Mexico.)
Working with NASA, Bosland cultivated a variety that could accommodate both the nutritional needs of astronauts as well as the logistics of growing a plant in space. Boslands crosses are designed with Mars in mind: Bred to be early-maturing, compact, efficient under low light, resilient in low-pressure environments, and to pack three times the Vitamin C of an orange to prevent scurvy.
Every aspect of the plants growth cycle was mechanized. Seeds were planted along with a specially-developed fertilizer in a soil-less, arselite clay medium, and each quadrant was equipped with salt-absorbing wicks that protected the seedlings from scorching due to the saline residue of the fertilizer. Once they germinated, the astronauts thinned the plants until only four remained. The 180-plus sensors controlled every aspect of their growth conditions, including adjusting the colors of the lights to stunt their growth and keep them at a manageable two-foot height.
Despite the highly-controlled growing environment, microgravity affected the plants in some unforeseen ways. Without a gravitational tug, the flowers and their pollen-laden stamen grew facing upward. Ironically, that thwarted how the APH was supposed to pollinate themby using fans that pulsed soft bursts of air meant to mobilize pollen, the way a breeze would. Instead, astronauts had to fill in as knock-off bees, manually pollinating them one plant at a time.
Microgravity also posed challenges to watering. As demonstrated by the Canadian Space Agency, water behaves differently in microgravity than on Earth. Unable to fall, flow, or ascend, water creates an aqueous layer enveloping the surface of whatever it clings to. But clingy water can suffocate a plants roots; as Bosland notes, chili peppers dont like their feet wet.
This was one of the challenges APH engineer and Kennedy Space Center research scientist Oscar Monje had to solve. The system recycled water in a closed loop; the entire experiment used approximately the same amount of water as an office water cooler. Moisture sensors regulated the exact amount that adhered to a roots surface. Then any water unabsorbed by the plant would evaporate after humidity sensors created the arid environment peppers crave. Its not a technology thats ready to roll out on say, the moon or Mars. The APH uses a watering system thats not sustainable for crop production right now. But its good enough for conducting space biology experiments, Monje says.
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Growing Peppers on the ISS Is Just the Start of Space Farming - newsconcerns