Category Archives: Quantum Physics

The awardees, says the committee, have opened new perspectives in mathematical analysis and probability theory, which have had a great influence on a generation of mathematicians. They have also introduced powerful analysis techniques to solve longstanding math problems, some of them arising from fundamental questions in theoretical physics.

Charles Fefferman, a professor at Princeton University in the United States, is considered one of todays most versatile mathematicians, who has brought new insights to such seemingly disparate fields as the mathematical description of fluid dynamics, analysis of the laws of quantum mechanics or the properties of graphene and other two-dimensional materials.

The BBVA Foundation Frontiers of Knowledge Award in Information and Communication Technologies has gone in this fourteenth edition to Judea Pearl for bringing a modern foundation to artificial intelligence. The Professor of Computer Science at the University of California (UCLA), has made contributions that enable AI programs to use two of the key resources we humans use to interpret the world and arrive at decisions: probability and causality.

Le Gall, a professor at Universit Paris-Saclay, works in probability theory, and much of his research draws on physics models that attempt to explain the quantum world at the atomic scale and in the early universe, with the construction of a quantum theory of gravity.

Fefferman entered the University of Maryland, United States, at just 14 years of age and published his first mathematical paper the following year. In 1971, at the age of 22, he became Americas youngest full professor. In his long career, he has maintained strong links with Spain, particularly with the mathematics school of the Universidad Autnoma de Madrid.

Fefferman reckons that over his career he must have solved several dozen problems. Asked about his favorites, he picks the duality theorem, which connects problems from fields far removed from math, providing a functional tool that opens up new vistas in harmonic analysis. He likes it partly because it took the least time to resolve, just a couple of weeks, compared to others he has worked on for up to twenty years.

In an interview after hearing of the award, Fefferman explained that, for him, jumping between fields is second nature: I have the feeling that I dont pick the problems, they pick me. I hear about a problem and it is so fascinating that I cannot stop thinking about it. If it happens to be in a field I have not worked in before but I think I have a chance to get involved and maybe do something, then I try.

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Fefferman and Le Gall win Frontiers of Knowledge award for solving fundamental mathematical problems - BBVA

Avengers Endgame released on 26th April 2019 was about Avengers(those who survived the snap) reuniting together & doing the Time Heist with a motive to reverse Thanos snap in order to bring back the dusted ones. We will try to understand time travel theory along with the Avengers journey during time heist in Avengers Endgame through this article.

The Time Travel in Avengers: Endgame is based on a popular time travel theory in the field of quantum physics. Post Thanos snap the remaining Avengers(those who survived the snap) learnt that Thanos destroyed the stones after completing his mission this means that Avengers wont be able to use the Infinity Stones again & reverse his snap. They were a bit taken aback & disappointed, in rage Thor even chopped off Thanos head.

Five Years Later, at present (i.e.2023) It was because of a rat Scott Lang was able to get out of Quantum Realm(To understand more about the quantum realm & how did Scott ended up there you need to watch Ant-Man and the Wasp) as soon as he learnt exactly what happened (Thanos snap) when he was in the Quantum Realm he went to the Avengers compound, there he met Natasha & Steve, & explained them his experience of the quantum realm, he tries to explain that time moves differently in the quantum realm further explaining that he was in it for five years according to the world but it was just five hours for him. He then suggested that they can travel back to a different point of time using the quantum realm & try to reverse Thanos snap. But since the three of them didnt have the exact knowledge of quantum physics they thought to get help from Tony Stark, but Stark refused to help as doing time travel & changing the present would also risk his family, especially his daughter Morgans existence. So after Tonys refusal to help Natasha, Steve along with Scott approached Banner who was now a merged version of his intellect with Hulks physique. They tried the time travel experiment using Stotts Van which kind of didnt go well. Steve who was disappointed with the failure of the time travel experiment went out of the Avengers compound, just then Stark approaches him with time-space GPS, he also returns Steve his shield back indicating his reunion for the plan of time travel.

The remaining Avengers assemble at the Avengers compound, Banner & Rocket went to New Asgard to recruit Thor for Time Heist however theyre met with the now overweight, depressed, drunk Thor, On the other side Natasha goes to Tokyo to stop Clint Barton from the massacre he has been carrying on in vengeance after losing his family in the blip & tells him about their time heist plan, Stark along with Rocket builds the time machine & suits, they run a time travel test & Barton volunteers himself for it, it was successful. Now, they plan to travel back in time and retrieve the Infinity Stones from various points in history before Thanos collects them & does the snap.

Hulk,Ant-Man,Iron ManandCaptain Americawere sent back to theBattle of New Yorkin2012, where Hulk was sent to theNew York Sanctumto request theTime Stone from Doctor Strange, but there he met TheAncient One, initially she refused to give the Time Stone explaining that she could not give him theInfinity Stoneso Banner could alter his timeline and subsequently leave hers undefended without the stone, However when Banner told her about Doctor Strange giving up the Time stone voluntarily, trusting Stranges decision she agreed to give the Time stone to Banner, as he also promised that he would return the stones at the exact moment it was taken, erasing the dark splinter reality that will be created due to absence of the stones.

On the other side, Steve was able to acquire Lokis Scepter (it contained mind stone) from STRIKE by pretending to be associated with HYDRA, STRIKE (SpecialTacticalReserve forInternationalKeyEmergencies) was a counter-terrorist Special Mission Unit ofS.H.I.E.L.D., it included several of S.H.I.E.L.D.s best agents, however at the same time most members of the team were actually undercover HYDRA Agents, On the other side, Stark & Lang tried to steal the Tesseract, but failed as Loki got a hold of it & used it to teleport himself. So Stark and Rogers decided to go back further to Camp Lehigh to an alternate 1970 New Jersey, there they tried to grab the Tesseract and more Pym Particles for their further journey. Lang is left with the Scepter to return to the present day. Steve was able to get more Pym Particles but he sneaked into a cabin, to avoid Agent Jenkins as she had considered him andTony suspicious and reported them, soon he realized it was Peggy Carters cabin(his love) who was also S.H.I.E.L.D. director at that time he silently watches her from far & even Stark was able to get Tesseract but when he was about to leave from there he encountered Howard Stark (his father), Tony introduced himself with the name Howard Potts, they had a brief conversation & Tony was able to finally get a chance to give his father a hug & thank him.

Meanwhile, Thor & Rocket went in an alternate timeline 2013 in Asgard to remove Aether(Reality Stone) from Jane Fosters Body. While they were there Thor saw his mother Frigga & got emotional as after some time according to the original timeline Frigga is killed, Thor was trying to hide but Frigga caught him she also knew that he is from future, they had a conversation & she advised him to follow his own path. He tried to warn her about her upcoming fate (death) but she refused to hear him & accept her fate rather than changing it. Rocket arrives with Aether & Thor hugs his mother last time, but before leaving from there he summons his hammer Mjlnir, he is also relieved at the fact that he is still worthy of it & takes the hammer along with him.

Ronin, Natasha, Rhodes&Nebulawent to Morag with Benatar in the 2014 timeline, Rhodes & Nebula wait for Peter Quill as he would lead them to collect the Power Stone Orb from Morag, Rhodes knocks out Quill & they took the orb, but as they prepare to return to the present timelinetogether only Rhodes shrinks back into theQuantum Realm, Nebulas cybernetics glitch & she falls to the ground, she is left behind as affected by the connection with her alternate past self, due to this connection Thanos of the past timeline(2014) gets aware about his future(his snap & death) & also Avengers Time Heist plan. As soon as Nebula realized it she tries to inform other teammates but the alternate past Nebula captures Nebula of the present timeline & travels to the present time through the quantum realm.

Natasha & Ronin further went to Vormir in Benatar to get the Soul Stone, They are greeted by Red Skull, stating that he knows them Natasha, daughter of Ivan and Clint, son of Edith, and warns them about the sacrifice of a soul(loved one) is to be done in order to obtain soul stone. Both Clint & Natasha were ready to sacrifice their own life in order to save the other one, However at the end, Natasha jumped off the cliff by her own will despite of Clints attempt to stop her, he then wakes up with the soul stone in his hand in the pool of Vormir but cries in grief due to Natashas death.

After completing their mission to collect stones from different timelines they all return to the present time(2023) & the fellow Avengers learn about Natashas sacrifice they were shocked & sad to lose her but they also determined not to let her sacrifice go in vain & decided to move further with their plan & do the snap. Hulk wielded the Infinity Gauntlet & did the snap but the radiations of the Infinity Stones damaged his arm. Although their mission to bring back the dusted ones was successful. However, they hardly got time to celebrate their victory as Thanos(from the 2014 timeline) attacked them by teleporting himself along with his army with the help of Nebula. All the Avengers(including the dusted ones) assemble & give a tough fight to Thanos & his army(Battle of Earth), but Thanos acquires the gauntlet of Infinity stones & was about to do the snap once again but Tony tries to stop him, the Mad Titan knocks Tony aside & did the snap but nothing happens as Tony transferred the stones into his suit & does the snap wiping out Thanos & his army resulting in Avengers victory but Tony dies shortly after doing the snap due to the radiations of the Infinity Stones.

After winning the Battle of Earth & attending Tonys funeral Steve travels back in time through the Quantum Realm to return the Infinity stones as promised also Thors hammer Mjlnir, and returns the Infinity Stones to the exact moment it was taken, erasing the dark splinter reality that was being created due to their absence.

After returning the Stones he decided to remain in past & live his life along with Peggy Carter & return as an old person, he also brought the shield that he gave to Sam Wilson (Falcon) passing him the baton of Captain America.

Time travel theory in Endgame is a popular time travel theory in the field of quantum physics. So If Avengers tried to change something in past (like kill baby Thanos: as suggested by Rhodes), as explained by Banner (Professor Hulk)it wouldnt affect the present timeline it would just create a parallel timeline different from the original timeline where the snap is already done. So there was no use even if they stopped or killed Thanos as this wouldnt reverse his snap that already happened.

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Avengers Endgame Time Theory & Different Timelines Explained - THE MOVIE CULTURE - THE MOVIE CULTURE

About the Centre for Quantum Technologies

The Centre for Quantum Technologies (CQT) is a research centre of excellence in Singapore. It brings together physicists, computer scientists and engineers to do basic research on quantum physics and to build devices based on quantum phenomena. Experts in this new discipline of quantum technologies are applying their discoveries in computing, communications, and sensing.

CQT is hosted by the National University of Singapore and also has staff at Nanyang Technological University. With some 180 researchers and students, it offers a friendly and international work environment.

Learn more about CQT atwww.quantumlah.org

Job Description

Experimental researchin quantum optomechanics and quantum thermodynamics in optoelectronics nanostructures

Over the past two decades, the progress of semiconductor nanotechnologies as led to an exquisite degree of control of artificial hybrid optoelectronic elementary excitations known as exciton-polaritons. The unique features of these quasi-particles have the potential to put quantum optomechanics and thermodynamics into yet unexplored regimes of operations, characterized by a deeply nonequilibrium situations, and by larger optomechanical interactions, stronger light-matter interface, and ultrafast operations, at the expense of dealing with more complex many-body quantum states state-of-the art systems. The purpose of this research position is to setup and run an experimental platform dedicated to investigating new polaritonic nanostructures in this context. The impact of this work is expected to occur both at the fundamental level, and for the realization of quantum-enhanced functionalities (e.g. ultra-sensitive force sensors). This work requires theory and experiment to develop alongside, and will thus be carried out within a strong theory-experiment partnership.

Job Requirements

Covid-19 Message

At NUS, the health and safety of our staff and students are one of our utmost priorities, and COVID-vaccination supports our commitment to ensure the safety of our community and to make NUS as safe and welcoming as possible. Many of our roles require a significant amount of physical interactions with students/staff/public members. Even for job roles that may be performed remotely, there will be instances where on-campus presences are required.

In accordance with Singapore's legal requirements, unvaccinated workers will not be able to work on the NUS premises with effect from 15 January 2022. As such, job applicants will need to be fully COVID-19 vaccinated to secure successful employment with NUS.

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Visiting Associate Research Professor, Quantum Optomechanics, Centre for Quantum Technologies job with NATIONAL UNIVERSITY OF SINGAPORE | 283490 -...

THE MAN FROM THE FUTUREThe Visionary Life of John von NeumannBy Ananyo BhattacharyaIllustrated. 353 pages. W.W. Norton & Company. $30.

The mathematician John von Neumann was an undeniable genius whose many accomplishments included an essential role in the development of quantum mechanics, computing and the atom bomb. As the co-author of one of the first textbooks on game theory, he took a coolly analytical approach to a range of situations that included bluffing in poker and the prospect of nuclear annihilation. Still, von Neumann didnt let his deep understanding of physics and rational utility get in the way of something else that was clearly very important to him: a love of driving, along with what seemed to be a cheerful commitment to being terrible at it.

After leaving Europe in 1933 for a life of the mind at the Institute for Advanced Study in Princeton, N.J., von Neumann failed the driving test so many times that he had to bribe the examiner to get his license. Every year he found an excuse to buy a new car, preferably an enormous Cadillac. I was proceeding down the road, he would start to say to his incredulous friends when recalling another one of his accidents. The trees on the right were passing me in orderly fashion at 60 miles an hour. Suddenly one of them stepped in my path. Boom!

This is one of several vivid anecdotes recounted in Ananyo Bhattacharyas The Man From the Future, which bills itself as a biography of von Neumann but is more devoted to exploring the ideas and technological inquiries he inspired.

The mathematical contributions von Neumann made in the mid-20th century now appear more eerily prescient with every passing year, Bhattacharya writes, alluding to this books excellent title. His thinking is so pertinent to the challenges we face today that it is tempting to wonder if he was a time traveler, quietly seeding ideas that he knew would be needed to shape the Earths future.

When von Neumann was alive, before the full import of his influence could be gauged, his brilliance marked him not as a time traveler but as an alien one of the so-called Martians, the nickname for the Hungarian-Jewish emigrs, including Edward Teller, who worked on the secret atom bomb project at Los Alamos. Naturally, the intellectually omnivorous von Neumann came up with his own theories about the Hungarian phenomenon (the shorthand term for the scientific accomplishments of von Neumann and his countrymen), deciding that it had something to do with the Austro-Hungarian mixture of liberalism and feudalism that allowed Jews some avenues for success while keeping them away from the true levers of power. This provoked a feeling of extreme insecurity, von Neumann said, making him and his fellow Martians believe that they needed to produce the unusual or face extinction.

This was a dark and introspective assessment from someone who may have anticipated World War II in Europe but was also remembered as a cheerful man, an optimist who loved money and believed firmly in human progress, in the words of one of his lifelong friends. Bhattacharya, a science journalist who also holds a Ph.D. in physics, doesnt probe too deeply into these apparent contradictions. We get a brisk tour through the first three decades of von Neumanns life born in Budapest in 1903, he was a mathematical prodigy who lived a mostly privileged existence before we land in Princeton, where his real-world influence quickly took off.

Von Neumann came of age when mathematics wasnt considered a practical profession. He studied chemistry too, as a sop to his father, an investment banker banking being another field that, later on, would become in thrall to mathematics. After arriving in the United States, von Neumann spent nearly a quarter of a century at the Institute for Advanced Study, where his office neighbors included Albert Einstein and Kurt Gdel. From New Jersey von Neumann would travel the country, teaching and consulting, most consequentially at Los Alamos. Bhattacharya quotes from a report that von Neumann put together for the U.S. Navy, detailing how the angle of incidence could make a bombs detonation more destructive. The report may have been written for a military audience, but von Neumann seems so excited by his own reasoning that he resorts to exclamation points.

Bhattacharya shows how this unabashedly forthright treatment of morally fraught matters earned von Neumann a reputation for hawkishness, as did his support for the logic of preventive war. He advocated taking out the Soviet Unions nuclear arsenal with a surprise attack (If you say why not bomb them tomorrow, I say why not today?) a position that he later walked back. Yet Bhattacharya also says that von Neumann, as someone who was Central European to the core, believed that people would work together for their mutual benefit, which was embedded in his approach to game theory. So who was he? The hopeful Central European or the hard-nosed cold warrior?

He was, as Bhattacharya puts it, a complex character, and there are tantalizing glimmers of such human strangeness and complexity in this book. But The Man From the Future sometimes seems so focused on explicating that future narrating the fates of von Neumanns ideas long past his death, from cancer, in 1957 that the man himself recedes from view.

The skill with which Bhattacharya teases apart dense scientific concepts left me feeling ambivalent. On the one hand, what we do see of von Neumann hints at such a fascinating personality that I wanted to know more; on the other, maybe theres something to be said for fixating so intently on the cerebral output of someone whose daughter once observed, My fathers first love in life was thinking.

Besides, von Neumann, ever the restless pollinator, may have approved of his biographers approach: Busy with so many other things, he would whizz in, lecture for an hour or two on the links between information and entropy or circuits for logical reasoning, then whizz off again leaving the bewildered attendees to discuss the implications of whatever he had said for the rest of the afternoon.

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The Man From the Future Recounts the Life of a Restless Genius - The New York Times

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 ...

Applied mathematician David Orrell offers a look at the difference quantum mechanical thinking would make to economics. The author of Money, Magic, and How to Dismantle a Financial Bomb: Quantum Economics for the Real World (2022) received considerable criticism for an article he wrote four years ago, Economics is quantum, which he summarizes in a followup article, published this month:

The idea is that money is best understood as a quantum social technology, with quantum properties of its own. In financial transactions, for example, value can be modelled as a probabilistic wave function which collapses down to an exact number when money is exchanged. When you put your house up for sale, you might have a fuzzy idea of its worth, but the actual price is only determined when a deal is made. An idea that seems bizarre in physics makes perfect sense in economics. Financial contracts such as mortgages and other loans entangle the debtor and the creditor in a fashion that can be modelled using quantum mathematics. The debtor is treated as being in a superposed state, balanced somewhere between a propensity to honour the debt and a propensity to default. Methods from quantum cognition can handle those phenomena, such as mental interference between incompatible concepts, that first inspired quantum physicists.

And the argument that quantum effects dont scale up has no relevance to economics. The idea isnt that money inherits its quantum properties from subatomic properties, but that its properties can be modelled using quantum mathematics (the aim isnt to use more maths, just different maths where needed). For example, the creation of money can be expressed using a quantum circuit in a way that captures effects such as uncertainty, power relationships, and so on. The effects of this substance scale up all the time (its called the financial system), and, like dark matter, exert a huge pull over the economy that goes undetected by classical approaches.

What difference would seeing things from a quantum perspective make in practice?

A defining feature of quantum mechanics, after all, is that it looks hard, but the picture that it paints of reality is soft and fuzzy. In many respects it isnt a hard science, but a soft science. A wave equation, for example, looks hard when it is written out as a mathematical formula but it is an equation of a wave, which is soft.

Quantum mechanical thinking might make better sense of markets where social values intersect with economic ones. For example people will pay more for an elite label than for a functionally equivalent house brand. Some zip codes (and universities) cost more than others when the main offering seems to be the prestigious number or name.

The people who respond to such fuzzy signals are not necessarily acting irrationally, as a classical economics approach might suppose. They are often responding to genuine realities which, like quantum mechanics, are fuzzy. The realities often collapse into a single situation: An introduction to an influential neighbor in the elite zip code can change a life or a career. But no single, hard number can be assigned to the role of influence during the process.

That said, Orrell leans heavily on claims that quantum mechanics is somehow more female and that women have been deprived and neglected in classical economics. Many women may find this sort of thing the assumption that femaleness is a reliable marker for having a different attitude to economics off-putting. But his thoughts are well worth reading anyway.

Author and design theorist Eric Anderson offers a note of caution. He is concerned that we make a distinction between what intelligent agents do and what quantum mechanics can do: Quantum mechanics is a terrible explanation for intelligent decision-making. We might as well argue that a Beethoven sonata resulted from the collapse of probabilistic wave functions as the large number of possible notes eventually collapsed to the final notes when he put pen to page. Might there be some interesting analogies between quantum mathematical models and human activities? Perhaps. But we need to be careful to not fall into the trap of thinking that the quantum model is ever an actual explanation for real decision-making. He develops the point that intelligent agents collapse probabilities to achieve a particular outcome in a podcast, Probability & Design (June 6, 2015), 7:00 minute mark.

It appears that Orrell, whose specialty is scientific forecasting, is attempting to model a process rather than its origin.

You may also wish to read: How Erik Larson hit on a method for deciding who is influential. The author of The Myth of Artificial Intelligence decided to apply an algorithm to Wikipedia but it had to be very specific.

The difference between influence and official power. Do you wonder why some people are listened to and not others, regardless of the value of their ideas? Well, read on

and

As money slowly transitions from matter to information Lets look at a brief history of cryptocurrencies which is not quite what we might think. The mysterious Satoshi Nakamoto, founder of Bitcoin, did not invent new concepts in computer science or cryptography; he put them together in a way that worked.

Originally posted here:

What If Quantum Physics Were Applied To Economics? - Walter Bradley Center for Natural and Artificial Intelligence

Quantum mechanics the behavior of the Universe at the smallest of scales continues to surprise us, with scientists now having been able to successfully create a quantum object called a domain wall in laboratory settings.

For the first time, these walls can now be generated in the lab on demand, occurring when atoms stored at very cold temperatures a scenario known as a Bose-Einstein condensate group together in domains under certain conditions. The walls are the junctions between these domains.

The researchers creating these domain walls say they could end up shedding new light on many different areas of quantum mechanics, including quantum electronics, quantum memory, and the behavior of exotic quantum particles.

"It's kind of like a sand dune in the desert it's made up of sand, but the dune acts like an object that behaves differently from individual grains of sand," says physicist Kai-Xuan Yaofrom the University of Chicago.

There has been previous research into domain walls, but they've never been able to be created at will in the laboratory until now, giving scientists the ability to analyze them in new ways. It turns out they act as independent quantum objects, but not necessarily in the way that scientists would expect them to.

That unexpected behavior means domain walls join a class of objects called emergent phenomena, where particles that join together seem to follow a different set of physics laws than particles that are operating on their own.

One of the unusual observations made by the team is the way that domain walls react to electric fields, something which will need further study to untangle. For now, just being able to produce and manipulate these walls is an important step forward.

"We have a lot of experience in controlling atoms," says physicist Cheng Chinfrom the University of Chicago. "We know if you push atoms to the right, they will move right. But here, if you push the domain wall to the right, it moves left."

Part of the reason why the discovery is so important is that it could teach us more about how atoms behaved at the very beginning of the Universe's existence: Particles that were once clumped together eventually expanded to form stars and planets, and scientists would like to know exactly how that happened.

This domain wall discovery falls under the umbrella of what's known as dynamical gauge theory a way to test and compute the dynamics of quantum phenomena in the lab. These discoveries could explain how emergent phenomena operate in everything from materials to the early Universe.

As well as looking backwards though, the researchers are also looking forwards. Once more is understood about how domain walls can be controlled, it could open up opportunities for new quantum technologies.

"There may be applications for this phenomenon in terms of making programmable quantum material or quantum information processors," says Chin.

"It can be used to create a more robust way to store quantum information or enable new functions in materials. But before we can find that out, the first step is to understand how to control them."

The research has been published in Nature.

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Strange Quantum Object Successfully Created in The Lab For The First Time - ScienceAlert

Applications for the CAD software extend far beyond medicine and throughout the burgeoning field of synthetic biology, which involves redesigning organisms to give them new abilities. For example, we envision users designing solutions for biomanufacturing; it's possible that society could reduce its reliance on petroleum thanks to microorganisms that produce valuable chemicals and materials. And to aid the fight against climate change, users could design microorganisms that ingest and lock up carbon, thus reducing atmospheric carbon dioxide (the main driver of global warming).

Our consortium, GP-write, can be understood as a sequel to the Human Genome Project, in which scientists first learned how to "read" the entire genetic sequence of human beings. GP-write aims to take the next step in genetic literacy by enabling the routine "writing" of entire genomes, each with tens of thousands of different variations. As genome writing and editing becomes more accessible, biosafety is a top priority. We're building safeguards into our system from the start to ensure that the platform isn't used to craft dangerous or pathogenic sequences.

Need a quick refresher on genetic engineering? It starts with DNA, the double-stranded molecule that encodes the instructions for all life on our planet. DNA is composed of four types of nitrogen basesadenine (A), thymine (T), guanine (G), and cytosine (C)and the sequence of those bases determines the biological instructions in the DNA. Those bases pair up to create what look like the rungs of a long and twisted ladder. The human genome (meaning the entire DNA sequence in each human cell) is composed of approximately 3 billion base-pairs. Within the genome are sections of DNA called genes, many of which code for the production of proteins; there are more than 20,000 genes in the human genome.

The Human Genome Project, which produced the first draft of a human genome in 2000, took more than a decade and cost about $2.7 billion in total. Today, an individual's genome can be sequenced in a day for $600, with some predicting that the $100 genome is not far behind. The ease of genome sequencing has transformed both basic biological research and nearly all areas of medicine. For example, doctors have been able to precisely identify genomic variants that are correlated with certain types of cancer, helping them to establish screening regimens for early detection. However, the process of identifying and understanding variants that cause disease and developing targeted therapeutics is still in its infancy and remains a defining challenge.

Until now, genetic editing has been a matter of changing one or two genes within a massive genome; sophisticated techniques like CRISPR can create targeted edits, but at a small scale. And although many software packages exist to help with gene editing and synthesis, the scope of those software algorithms is limited to single or few gene edits. Our CAD program will be the first to enable editing and design at genome-scale, allowing users to change thousands of genes, and it will operate with a degree of abstraction and automation that allows designers to think about the big picture. As users create new genome variants and study the results in cells, each variant's traits and characteristics (called its phenotype) can be noted and added to the platform's libraries. Such a shared database could vastly speed up research on complex diseases.

What's more, current genomic design software requires human experts to predict the effect of edits. In a future version, GP-write's software will include predictions of phenotype to help scientists understand if their edits will have the desired effect. All the experimental data generated by users can feed into a machine-learning program, improving its predictions in a virtuous cycle. As more researchers leverage the CAD platform and share data (the open-source platform will be freely available to academia), its predictive power will be enhanced and refined.

Our first version of the CAD software will feature a user-friendly graphical interface enabling researchers to upload a species' genome, make thousands of edits throughout the genome, and output a file that can go directly to a DNA synthesis company for manufacture. The platform will also enable design sharing, an important feature in the collaborative efforts required for large-scale genome-writing initiatives.

There are clear parallels between CAD programs for electronic and genome design. To make a gadget with four transistors, you wouldn't need the help of a computer. But today's systems may have billions of transistors and other components, and designing them would be impossible without design-automation software. Likewise, designing just a snippet of DNA can be a manual process. But sophisticated genomic designwith thousands to tens of thousands of edits across a genomeis simply not feasible without something like the CAD program we're developing. Users must be able to input high-level directives that are executed across the genome in a matter of seconds.

Our CAD program will be the first to enable editing at genome-scale, with a degree of abstraction and automation that allows designers to think about the big picture.

A good CAD program for electronics includes certain design rules to prevent a user from spending a lot of time on a design, only to discover that it can't be built. For example, a good program won't let the user put down transistors in patterns that can't be manufactured or put in a logic that doesn't make sense. We want the same sort of design-for-manufacture rules for our genomic CAD program. Ultimately, our system will alert users if they're creating sequences that can't be manufactured by synthesis companies, which currently have limitations such as trouble with certain repetitive DNA sequences. It will also inform users if their biological logic is faulty; for example, if the gene sequence they added to code for the production of a protein won't work, because they've mistakenly included a "stop production" signal halfway through.

But other aspects of our enterprise seem unique. For one thing, our users may import huge files containing billions of base-pairs. The genome of the Polychaos dubium, a freshwater amoeboid, clocks in at 670 billion base-pairsthat's over 200 times larger than the human genome! As our CAD program will be hosted on the cloud and run on any Internet browser, we need to think about efficiency in the user experience. We don't want a user to click the "save" button and then wait ten minutes for results. We may employ the technique of lazy loading, in which the program only uploads the portion of the genome that the user is working on, or implement other tricks with caching.

Getting a DNA sequence into the CAD program is just the first step, because the sequence, on its own, doesn't tell you much. What's needed is another layer of annotation to indicate the structure and function of that sequence. For example, a gene that codes for the production of a protein is composed of three regions: the promoter that turns the gene on, the coding region that contains instructions for synthesizing RNA (the next step in protein production), and the termination sequence that indicates the end of the gene. Within the coding region, there are "exons," which are directly translated into the amino acids that make up proteins and "introns," intervening sequences of nucleotides that are removed during the process of gene expression. There are existing standards for this annotation that we want to improve on, so our standardized interface language will be readily interpretable by people all over the world.

The CAD program from GP-write will enable users to apply high-level directives to edit a genome, including inserting, deleting, modifying, and replacing certain parts of the sequence. GP-write

Once a user imports the genome, the editing engine will enable the user to make changes throughout the genome. Right now, we're exploring different ways to efficiently make these changes and keep track of them. One idea is an approach we call genome algebra, which is analogous to the algebra we all learned in school. In mathematics, if you want to get from the number 1 to the number 10, there are infinite ways to do it. You could add 1 million and then subtract almost all of it, or you could get there by repeatedly adding tiny amounts. In algebra, you have a set of operations, costs for each of those operations, and tools that help organize everything.

In genome algebra, we have four operations: we can insert, delete, invert, or edit sequences of nucleotides. The CAD program can execute these operations based on certain rules of genomics, without the user having to get into the details. Similar to the "PEMDAS rule" that defines the order of operations in arithmetic, the genome editing engine must order the user's operations correctly to get the desired outcome. The software could also compare sequences against each other, essentially checking their math to determine similarities and differences in the resulting genomes.

In a later version of the software, we'll also have algorithms that advise users on how best to create the genomes they have in mind. Some altered genomes can most efficiently be produced by creating the DNA sequence from scratch, while others are more suited to large-scale edits of an existing genome. Users will be able to input their design objectives and get recommendations on whether to use a synthesis or editing strategyor a combination of the two.

Users can import any genome (here, the E. coli bacteria genome), and create many edited versions; the CAD program will automatically annotate each version to show the changes made. GP-write

Our goal is to make the CAD program a "one-stop shop" for users, with the help of the members of our Industry Advisory Board: Agilent Technologies, a global leader in life sciences, diagnostics and applied chemical markets; the DNA synthesis companies Ansa Biotechnologies, DNA Script, and Twist Bioscience; and the gene editing automation companies Inscripta and Lattice Automation. (Lattice was founded by coauthor Douglas Densmore). We are also partnering with biofoudries such as the Edinburgh Genome Foundry that can take synthetic DNA fragments, assemble them, and validate them before the genome is sent to a lab for testing in cells.

Users can most readily benefit from our connections to DNA synthesis companies; when possible, we'll use these companies' APIs to allow CAD users to place orders and send their sequences off to be synthesized. (In the case of DNA Script, when a user places an order it would be quickly printed on the company's DNA printers; some dedicated users might even buy their own printers for more rapid turnaround.) In the future, we'd like to make the ordering step even more user-friendly by suggesting the company best suited to the manufacture of a particular sequence, or perhaps by creating a marketplace where the user can see prices from multiple manufacturers, the way people do on airfare sites.

We've recently added two new members to our Industrial Advisory Board, each of which brings interesting new capabilities to our users. Catalog Technologies is the first commercially viable platform to use synthetic DNA for massive digital storage and computation, and could eventually help users store vast amounts of genomic data generated on GP-write software. The other new board member is SOSV's IndieBio, the leader in biotech startup development. It will work with GP-write to select, fund, and launch companies advancing genome-writing science from IndieBio's New York office. Naturally, all those startups will have access to our CAD software.

We're motivated by a desire to make genome editing and synthesis more accessible than ever before. Imagine if high-school kids who don't have access to a wet lab could find their way to genetic research via a computer in their school library; this scenario could enable outreach to future genome design engineers and could lead to a more diverse workforce. Our CAD program could also entice people with engineering or computational backgroundsbut with no knowledge of biologyto contribute their skills to genetic research.

Because of this new level of accessibility, biosafety is a top priority. We're planning to build several different levels of safety checks into our system. There will be user authentication, so we'll know who's using our technology. We'll have biosecurity checks upon the import and export of any sequence, basing our "prohibited" list on the standards devised by the International Gene Synthesis Consortium (IGSC), and updated in accordance with their evolving database of pathogens and potentially dangerous sequences. In addition to hard checkpoints that prevent a user from moving forward with something dangerous, we may also develop a softer system of warnings.

Imagine if high-school kids who don't have access to a lab could find their way to genetic research via a computer in their school library.

We'll also keep a permanent record of redesigned genomes for tracing and tracking purposes. This record will serve as a unique identifier for each new genome and will enable proper attribution to further encourage sharing and collaboration. The goal is to create a broadly accessible resource for researchers, philanthropies, pharmaceutical companies, and funders to share their designs and lessons learned, helping all of them identify fruitful pathways for advancing R&D on genetic diseases and environmental health. We believe that the authentication of users and annotated tracking of their designs will serve two complementary goals: It will enhance biosecurity while also engendering a safer environment for collaborative exchange by creating a record for attribution.

One project that will put the CAD program to the test is a grand challenge adopted by GP-write, the Ultra-Safe Cell Project. This effort, led by coauthor Farren Isaacs and Harvard professor George Church, aims to create a human cell line that is resistant to viral infection. Such virus-resistant cells could be a huge boon to the biomanufacturing and pharmaceutical industry by enabling the production of more robust and stable products, potentially driving down the cost of biomanufacturing and passing along the savings to patients.

The Ultra-Safe Cell Project relies on a technique called recoding. To build proteins, cells use combinations of three DNA bases, called codons, to code for each amino acid building block. For example, the triplet 'GGC' represents the amino acid glycine, TTA represents leucine, GTC represents valine, and so on. Because there are 64 possible codons but only 20 amino acids, many of the codons are redundant. For example, four different codons can code for glycine: GGT, GGC, GGA, and GGG. If you replaced a redundant codon in all genes (or 'recode' the genes), the human cell could still make all of its proteins. But viruseswhose genes would still include the redundant codons and which rely on the host cell to replicatewould not be able to translate their genes into proteins. Think of a key that no longer fits into the lock; viruses trying to replicate would be unable to do so in the cells' machinery, rendering the recoded cells virus-resistant.

This concept of recoding for viral resistance has already been demonstrated. Isaacs, Church, and their colleagues reported in a 2013 paper in Science that, by removing all 321 instances of a single codon from the genome of the E. coli bacterium, they could impart resistance to viruses which use that codon. But the ultra-safe cell line requires edits on a much grander scale. We estimate that it would entail thousands to tens of thousands of edits across the human genome (for example, removing specific redundant codons from all 20,000 human genes). Such an ambitious undertaking can only be achieved with the help of the CAD program, which can automate much of the drudge work and let researchers focus on high-level design.

The famed physicist Richard Feynman once said, "What I cannot create, I do not understand." With our CAD program, we hope geneticists become creators who understand life on an entirely new level.

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Quantum Holograms Dont Even Need to See Their Subject - IEEE Spectrum

image:The Bs0 mesons oscillate between the material form composed of the strange quark s and the beautiful antiquark b bar, and the antimatterial form composed of the beautiful quark b and the strange antiquark s bar. (Source: IFJ PAN) view more

Credit: Source: IFJ PAN

We think of matter and antimatter as being as opposite as fire and water. There are, however, particles that can behave as representatives once of the world of matter, once the world of antimatter. An international group of scientists working onexperiments at the LHCb detector have reported their measurement of the extreme speed of oscillation of these sorts of particles between the two worlds.

Like a child on a swing, moving back and forth, there are particles that can change their properties many times with incredible speed, acting as representatives of the world of matter at one moment only to behave like antimatter in the next. Oscillations of particle properties between matter and antimatter are considered to be one of the most fascinating phenomena of quantum mechanics. Inthe case of the mesons known as Bs0, these oscillations have been measured with unprecedented accuracy. The results of this unusual measurement were reported by a group of scientists carrying out experiments in the LHCb detector at the Large Hadron Collider. An article describing their work has appeared in Nature Physics.

The first measurement of the Bs0 meson oscillation was carried out back in 2006, as part of the CDF experiment at the US Fermilab laboratory. We have now managed to improve the accuracy of the original measurement by as much as two orders of magnitude!, says Dr. Agnieszka Dziurda from the Institute of Nuclear Physics of the Polish Academy of Sciences (IFJ PAN) in Cracow. Dr.Dziurda leads the international team of physicists who carried out this research.

The constituents of matter that make up the visible Universe are mainly up and down quarks, electrons and electron neutrinos. Inside the Standard Model, a complex theoretical tool that describes the world on atomic and subatomic scales, these particles are grouped into one generation. It is known that two other generations exist. Both contain particles with similar properties to the first generation, only that they become more and more massive in subsequent generations.

In the Standard Model, every particle of matter has its counterpart in the form of an antiparticle that differs mainly in the sign of its electric charge (in the case of electrically neutral neutrinos, other quantum properties are important). Quarks do not like loneliness and always combine with others into particles. The simplest of these are mesons, i.e. pairs made up of a quark and an antiquark (not necessarily of the same kind).

Mesons may carry an electric charge, but they do not have to. Those devoid of electric charge, referred to as neutral, exhibit an intriguing feature they oscillate between matter and antimatter forms. We focused on analysing the oscillation frequencies of neutral mesons Bs0 containing athird-generation beauty quark b and a second-generation strange quark s, explains Dr. Dziurda.

As unstable particles, mesons decay quickly. It is no different with Bs0 mesons, whose life in the experiment in question ended after a single picosecond (that's a fraction of a second with 12 zeros after the decimal point). During this time Bs0 mesons covered a distance of about one centimetre and, as it turned out, they oscillated several times.

From a technical point of view, measuring a phenomenon of such high frequency proved to be extremely difficult. In particular, it required a deep understanding of the experimental techniques used in the detector, as these could have distorted the measurement. Only with this knowledge physicists were able to precisely reconstruct the trajectory of the recorded mesons and identify the particles into which it decayed.

Quantum mechanics predicts that the decay products of the Bs0 meson must be different depending on whether it was in a state of matter or antimatter at the time of the decay. Thus, only after recording and identifying the decay products of a given meson we could determine whether it decayed as a representative of the matter or antimatter world. Combining this knowledge with information about the nature of the particle at the time of its production allowed us to measure the oscillation frequency, explains Dr. Dziurda.

The data analysed concerned Bs0 mesons created in proton-proton collisions with a total energy of 13 teraelectronvolts, recorded at the LHCb detector between 2015 and 2018. Ultimately, the researchers were able to determine that Bs0 mesons oscillate between matter and antimatter three trillion times per second, which is 300 times faster than the oscillation of a typical atomic clock built using caesium.

The result obtained by physicists from the LHCb experiment is not an empty encyclopaedic curiosity from the exotic world of quanta, but a measurement of wider significance. On the one hand, it agrees with the predictions of quantum mechanics at a new level of accuracy and is its beautiful illustration. On the other hand, the measured oscillation frequency of Bs0 mesons significantly narrows the search areas for particles undescribed by the Standard Model, including those suggested by many theorists to explain the anomalies observed in recent years. Perhaps traces ofthis new physics can be detected when the upgraded LHCb detector resumes recording collisions in 2022.

The Henryk Niewodniczaski Institute of Nuclear Physics (IFJ PAN) is currently one of the largest research institutes of the Polish Academy of Sciences. A wide range of research carried out at IFJ PAN covers basic and applied studies, from particle physics and astrophysics, through hadron physics, high-, medium-, and low-energy nuclear physics, condensed matter physics (including materials engineering), to various applications of nuclear physics in interdisciplinary research, covering medical physics, dosimetry, radiation and environmental biology, environmental protection, and other related disciplines. The average yearly publication output of IFJ PAN includes over 600 scientific papers in high-impact international journals. Each year the Institute hosts about 20 international and national scientific conferences. One of the most important facilities of the Institute is the Cyclotron Centre Bronowice (CCB), which is an infrastructure unique in Central Europe, serving as a clinical and research centre in the field of medical and nuclear physics. In addition, IFJ PAN runs four accredited research and measurement laboratories. IFJ PAN is a member of the Marian Smoluchowski Krakw Research Consortium: "Matter-Energy-Future", which in the years 2012-2017 enjoyed the status of the Leading National Research Centre (KNOW) in physics. In 2017, the European Commission granted the Institute the HR Excellence in Research award. The Institute holds A+ category (the highest scientific category in Poland) in the field of sciences and engineering.

CONTACTS:

Dr. Agnieszka Dziurda

Institute of Nuclear Physics, Polish Academy of Sciences

tel.: +48 12 6628086

email: agnieszka.dziurda@ifj.edu.pl

SCIENTIFIC PUBLICATIONS:

Precise determination of the $B_s^0 - bar{B}_s^0$ oscillation frequency

LHCb Collaboration

Nature Physics, 2022

DOI: https://doi.org/10.1038/s41567-021-01394-x

LINKS:

http://www.ifj.edu.pl/

The website of the Institute of Nuclear Physics, Polish Academy of Sciences.

http://press.ifj.edu.pl/

Press releases of the Institute of Nuclear Physics, Polish Academy of Sciences.

IMAGES:

IFJ220209b_fot01s.jpg

HR: https://www.euvolution.com/prometheism-transhumanism-posthumanism/wp-content/uploads/2022/02/IFJ220209b_fot01.jpg

The Bs0 mesons oscillate between the material form composed of the strange quark s and the beautiful antiquark b bar, and the antimatterial form composed of the beautiful quark b and the strange antiquark s bar. (Source: IFJ PAN)

VIDEOS:

IFJ220209b_vid01.mp4

HR: http://press.ifj.edu.pl/news/2022/02/09/IFJ220209b_vid01.mp4

The Bs0 mesons oscillations. (Source: IFJ PAN)

6-Jan-2022

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From matter to antimatter, to and fro trillions of times a second - EurekAlert

Few science experiments are as strange and compelling as the double-slit experiment.

Few experiments, if any, in modern physics are capable of conveyingsuch a simple ideathat light and matter can act as both waves and discrete particles depending on whether they are being observedbut which is nonetheless one of the great mysteries of quantum mechanics.

It's the kind of experiment that despite its simplicity is difficult to wrap your mind around because what it shows is incredibly counter-intuitive.

But not only has the double-slit experiment been repeated countless times in physics labs around the world, but it has also even spawned many derivative experiments that further reinforce its ultimate result, that particles can be waves or discrete objects and that it is as if they "know" when you are watching them.

To understand what the double-slit experiment demonstrates, we need to lay out some key ideas from quantum mechanics.

In 1925,Werner Heisenberg presented his mentor, the eminent German physicist Max Born, with a paper to review that showed how the properties of subatomic particles, like position, momentum, and energy, could be measured.

Born saw that these properties could be represented through mathematical matrices, with definite figures and descriptions of individual particles, and this laid the foundation for the matrix description of quantum mechanics.

Meanwhile, in 1926,Edwin Schrdingerpublished his wave theory of quantum mechanics which showed that particles could be described by an equation that defined their waveform; that is, it determined that particles were actually waves.

This gave rise to the concept of wave-particle duality, which is one of the defining features of quantum mechanics. According to this concept, subatomic entities can be described as both waves and particles, and it is up to the observer to decide how to measure them.

That last part is important since it will determine how quantum entities will manifest. If you try to measure a particle's position, you will measure a particle's position, and it will cease to be a wave at all.

If you try to define its momentum, you will find that behaves like a wave and you can't know anything definitive about its position beyond the probability that it exists at any given point within that wave.

Essentially, you will measure it as a particle or a wave, and doing so decides what form it will take.

The double-slit experiment is one of the simplest demonstrations of this wave-particle duality as well as a central defining weirdness ofquantum mechanics, one that makes the observer an active participant in the fundamental behavior of particles.

The easiest way to describe the double-slit experiment is by using light. First, take a source of coherent light, such as a laser beam, that shines in a single wavelength, like purely blue visible light at 460nm, and aim it at a wall with two slits in it.The distance between the slits should be roughly the same as the light's wavelengthso that they will both sit inside that beam of light.

Behind that wall, place a screen that can detect and record the light that impacts it. If you fire the laser beam at the two slits, on the recording screen behind the wall you will see a stripey pattern like this:

This is probably not what you might have been expecting, and that's perfectly rational if you treat light as if it were a wave. If the light was a wave, then when the single wave of light from the laser hit both slits, each slit would become a new "source" of light on the other side of the wall, and so you would have a new wave originating from each slit producing two waves.

Where those two waves intersect causes something known as interference, and it can be either constructive or destructive. When the amplitude of the waves overlaps at either a peak or a trough, it acts to boost the wavelength in either direction by adding its energy together. This is constructive interference, and it produces these brighter bars in this pattern.

When the waves cancel each other out, as when a peak hits a trough, the effect neutralizes the wavelength and diminishes or even eliminates the light, producing the blacked-out spaces in between the blue bars.

But in the case of quantum entities like photons of light or electrons, they are also individual particles. So what happens when you shoot a single photon through the double slits?

One photon alone reacting to the screen might leave a tiny dot behind, which might not mean much in isolation, but if you shoot many single photons at the double slits, those tiny dots that the photon leaves behind on our screen actually show up in that same stripey interference pattern produced by the laser beam hitting the double slits.

In other words, the individual photon behaves as if it passed through both slits like it was a wave.

Now, here's where things get really weird.

We can set up a detector in front of one of the slits that can watch for photons and light up whenever it detects one passing through. When we do this, the detector will light up 50% of the time, and the pattern left behind on the screen changes, giving us something that looks like this:

And to make things even wilder, we can set up a detector behind the wall that only detects a photon after it has passed through the slit and we get the same result. That means that even if the photon passes through both slits as a wave, the moment it is detected, it is no longer a wave but a particle. And not just that, that second wave emerging from the other slit also collapses back into the particle that was detected passing through the other slit.

In practice, this means that somehow the universe "knows" that someone is watching and flips the metaphorical quantum coin to see which slit the particle passed through. The more individual photons you shoot through the double slit, the closer that photon detector comes to detecting photons 50% of the time, just as flipping a coin 10 times might give you heads 70% of the time while flipping it 100 times might give you tails 55% of the time, and flipping it 1 billion times gives you heads 50.0003% of the time.

This seems to show that not only is the universe watching the observer as well, but that the quantum states of entities passing through the double slits are governed by the laws of probability, making it impossible to ever predict with certainty what the quantum state of an entity will be.

The double-slit experiment actually predates quantum mechanics by a little more than acentury.

During the Scientific Revolution, the nature of light was a particularly contentious topic, with manylike Isaac Newton himselfarguing in favor of a corpuscular theory of light that held that light was transmitted through particles.

Others believed that light was a wave that was transmitted through "aether" or some other medium, the way sound travels through air and water, but Newton's reputation and a lack of an effective means to demonstrate the wave theory of light solidified the corpuscular view for just shy of a century after Newton published hisOpticks in 1704.

The definitive demonstration came from the British polymath Thomas Young, who presented a paper to the Royal Society of London in 1803 that described a pair of simple experiments that anyone could perform to see for themselves that light was in fact a wave.

First, Young established that a pair of waves were subject to interference when they overlapped, producing a distinctive interference pattern.

He initially demonstrated this interference pattern using a ripple tank of water, showing that such a pattern is characteristic of wave propagation.

Young then introduced the precursor to the modern double-slit experiment, though instead of using a laser beam to produce the required light source, Young used reflected sunlight striking two slits in a card as its target.

The resulting light diffraction showed the expected interference pattern, and the wave theory of light gained considerable support. It would take another decade and a half before further experimentation conclusively refuted corpuscles in favor of waves, but the double-slit experiment that Young developed proved to be a fatal blow to Newton's theory.

Young wasn't lying when he said, "The experiments I am about to relate...may be repeated with great ease, whenever the sun shines, and without any other apparatus than is at hand to everyone."

While it might be a stretch to say that you can use the double-slit experiment to demonstrate some of the more counterintuitive features of quantum mechanics (unless you have a photon detector handy and a laser that shoots individual photons), you can still use it to demonstrate the wave nature of light.

If you want to replicate Young's experiment, you only need as large a box as is practical with a hole cut in it a little smaller than an index card. Then, take an Exacto knife or similar blade for fine cutting work and cut two slits into a piece of cardboard larger than the hole in your box. The slits should be between 0.1mm and 0.4mm apart, as the closer together they are, the more distinct the interference pattern will be. It's better to create cards for this rather than cut directly into the box since you might need to make adjustments to the spacing of the slits.

Once you're satisfied with the spacing, affix the card with the double-slit in it over the hole and secure it in place with tape. Just make sure sunlight isn't leaking around the card.

You'll also need to create some eye-holes in the box so you can look inside without getting in the way of the light hitting the double-slit card, but once you figure that out, you're all set.

To accurately diffract sunlight using this box, you will need to have the sunlight more or less hitting the double-slit card dead on, so it might take some maneuvering to get it properly positioned.

Once it is, look through the eye holes and you can see the interference pattern forming on the inside wall, as well as different colors emerging as the different wavelengths interfering with each other change the color of the light being created.

If you wanted to try it out with something fancier, get yourself a laser pointer from an office supply store. Just like you'd do with a viewing box, create cards with slits in them, and when properly spaced, set up a shielded area for the card to rest on.

You'll want to make sure that only the light from the laser pointer is hitting the double-slit, so shield the card however you need to. Then, set the laser pointer on a surface level with the slits and shine the laser at them. On the wall behind the card, the interference pattern from the slits should be clearly visible.

If you don't want to go through all that trouble, you can also use Photoshop or similar software to recreate the effect.

First, create a template of evenly spaced concentric circles. Using different layers for each source, as well as a background later, position the center of the concentric rings near to one another. On a 1200 pixel wide canvas, a distance of 100 pixels between the two centers should do nicely.

Then, fill in the color of each concentric ring, alternating light and dark, with an opacity set to about 33%. You may need to hide one of the concentric circle layers while you work on the other. When you're done, reveal the two overlapping layers of circles and the interference pattern should jump out at you immediately, looking something like this:

Of course, if you want to dig into the quantum mechanics side of things, you'll need to work in a pretty advanced physics lab at a university or science institute, since photon detectors aren't the kind of thing you can pick up at the hobby store.

Still, if you're compelled to try the heavier stuff out for yourself, you wouldn't be the first person to get drawn into a career in physics because of the weirdness of quantum mechanics, and there are definitely worse ways to make a living.

Original post:

What is the double-slit experiment, and why is it so important? - Interesting Engineering