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Category Archives: Quantum Physics

A Discovery That Long Eluded Physicists: Superconductivity to the Edge – SciTechDaily

Posted: May 9, 2020 at 12:41 pm

Researchers at Princeton have discovered superconducting currents traveling along the outer edges of a superconductor with topological properties, suggesting a route to topological superconductivity that could be useful in future quantum computers. The superconductivity is represented by the black center of the diagram indicating no resistance to the current flow. The jagged pattern indicates the oscillation of the superconductivity which varies with the strength of an applied magnetic field. Credit: Stephan Kim, Princeton University

Princeton researchers detect a supercurrent a current flowing without energy loss at the edge of a superconductor with a topological twist.

A discovery that long eluded physicists has been detected in a laboratory at Princeton. A team of physicists detected superconducting currents the flow of electrons without wasting energy along the exterior edge of a superconducting material. The finding was published May 1 in the journal Science.

The superconductor that the researchers studied is also a topological semi-metal, a material that comes with its own unusual electronic properties. The finding suggests ways to unlock a new era of topological superconductivity that could have value for quantum computing.

To our knowledge, this is the first observation of an edge supercurrent in any superconductor, said Nai Phuan Ong, Princetons Eugene Higgins Professor of Physics and the senior author on the study.

Our motivating question was, what happens when the interior of the material is not an insulator but a superconductor? Ong said. What novel features arise when superconductivity occurs in a topological material?

Although conventional superconductors already enjoy widespread usage in magnetic resonance imaging (MRI) and long-distance transmission lines, new types of superconductivity could unleash the ability to move beyond the limitations of our familiar technologies.

Researchers at Princeton and elsewhere have been exploring the connections between superconductivity and topological insulators materials whose non-conformist electronic behaviors were the subject of the 2016 Nobel Prize in Physics for F. Duncan Haldane, Princetons Sherman Fairchild University Professor of Physics.

Topological insulators are crystals that have an insulating interior and a conducting surface, like a brownie wrapped in tin foil. In conducting materials, electrons can hop from atom to atom, allowing electric current to flow. Insulators are materials in which the electrons are stuck and cannot move. Yet curiously, topological insulators allow the movement of electrons on their surface but not in their interior.

To explore superconductivity in topological materials, the researchers turned to a crystalline material called molybdenum ditelluride, which has topological properties and is also a superconductor once the temperature dips below a frigid 100 milliKelvin, which is -459 degrees Fahrenheit.

Most of the experiments done so far have involved trying to inject superconductivity into topological materials by putting the one material in close proximity to the other, said Stephan Kim, a graduate student in electrical engineering, who conducted many of the experiments. What is different about our measurement is we did not inject superconductivity and yet we were able to show the signatures of edge states.

The team first grew crystals in the laboratory and then cooled them down to a temperature where superconductivity occurs. They then applied a weak magnetic field while measuring the current flow through the crystal. They observed that a quantity called the critical current displays oscillations, which appear as a saw-tooth pattern, as the magnetic field is increased.

Both the height of the oscillations and the frequency of the oscillations fit with predictions of how these fluctuations arise from the quantum behavior of electrons confined to the edges of the materials.

When we finished the data analysis for the first sample, I looked at my computer screen and could not believe my eyes, the oscillations we observed were just so beautiful and yet so mysterious, said Wudi Wang, who as first author led the study and earned his Ph.D. in physics from Princeton in 2019. Its like a puzzle that started to reveal itself and is waiting to be solved. Later, as we collected more data from different samples, I was surprisedat how perfectly the data fit together.

Researchers have long known that superconductivity arises when electrons, which normally move about randomly, bind into twos to form Cooper pairs, which in a sense dance to the same beat. A rough analogy is a billion couples executing the same tightly scripted dance choreography, Ong said.

The script the electrons are following is called the superconductors wave function, which may be regarded roughly as a ribbon stretched along the length of the superconducting wire, Ong said. A slight twist of the wave function compels all Cooper pairs in a long wire to move with the same velocity as a superfluid in other words acting like a single collection rather than like individual particles that flows without producing heating.

If there are no twists along the ribbon, Ong said, the Cooper pairs are stationary and no current flows. If the researchers expose the superconductor to a weak magnetic field, this adds an additional contribution to the twisting that the researchers call the magnetic flux, which, for very small particles such as electrons, follows the rules of quantum mechanics.

The researchers anticipated that these two contributors to the number of twists, the superfluid velocity and the magnetic flux, work together to maintain the number of twists as an exact integer, a whole number such as 2, 3 or 4 rather than a 3.2 or a 3.7. They predicted that as the magnetic flux increases smoothly, the superfluid velocity would increase in a saw-tooth pattern as the superfluid velocity adjusts to cancel the extra .2 or add .3 to get an exact number of twists.

The team measured the superfluid current as they varied the magnetic flux and found that indeed the saw-tooth pattern was visible.

In molybdenum ditelluride and other so-called Weyl semimetals, this Cooper-pairing of electrons in the bulk appears to induce a similar pairing on the edges.

The researchers noted that the reason why the edge supercurrent remains independent of the bulk supercurrent is currently not well understood. Ong compared the electrons moving collectively, also called condensates, to puddles of liquid.

From classical expectations, one would expect two fluid puddles that are in direct contact to merge into one, Ong said. Yet the experiment shows that the edge condensates remain distinct from that in the bulk of the crystal.

The research team speculates that the mechanism that keeps the two condensates from mixing is the topological protection inherited from the protected edge states in molybdenum ditelluride. The group hopes to apply the same experimental technique to search for edge supercurrents in other unconventional superconductors.

There are probably scores of them out there, Ong said.

Reference: Evidence for an edge supercurrent in the Weyl superconductor MoTe2 by Wudi Wang, Stephan Kim, Minhao Liu, F. A. Cevallos, Robert. J. Cava and Nai Phuan Ong, 1 May 2020, Science.DOI: 10.1126/science.aaw9270

Funding: The research was supported by the U.S. Army Research Office (W911NF-16-1-0116). The dilution refrigerator experiments were supported by the U.S. Department of Energy (DE- SC0017863). N.P.O. and R.J.C. acknowledge support from the Gordon and Betty Moore Foundations Emergent Phenomena in Quantum Systems Initiative through grants GBMF4539 (N.P.O.) and GBMF-4412 (R.J.C.). The growth and characterization of crystals were performed by F.A.C. and R.J.C., with support from the National Science Foundation (NSF MRSEC grant DMR 1420541).

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Why Self-Awareness and Communication Are Key for Self-Taught Players and Luthiers – Premier Guitar

Posted: at 12:41 pm

With his signature guitar built by our columnist at the ready, Japanese artist Jinmo publicly celebrates each time he completes a deadline with a different pipe and the words, Banzai! Im free!

Its hard to believe, but this is my100th column for Premier Guitar. So, this month, Id like to allow myself to get a bit more personal and talk a little about what it means to be on this side of the desk. When I first started writing this column, it had a huge impact on my workflow by adding two additional deadlines to my already busy monthly schedule: an early one to decide on the topic for the month, and the submission deadline for PG. Im sure every colleague at PG knows the feeling of panic when searching for a subject and then collecting all the needed information with a deadline looming. I was certain I couldnt manage it for more than six months before needing a break. Well, here we are approaching nine years.

Its no secret that Im not an expert when it comes to vintage stuff, but often, historical contexts play an important role in why things have developed in a specific direction. The amount of information out there is vast, and its easy to overlook or misinterpret certain details when researching decades of developments and products. I feel pretty safe when it comes to physics, but Im also aware of the massive amount of collective expertise among PG readers regarding many topics. Luckily, I havent causedor dont know ofany remarkable shit storms so far!

Were all learning. Autodidacticism is self-learningself-taught education without the guidance of masters such as teachers and professors, or institutions like schools and universities. Interestingly, the number of autodidacts among musicians and luthiers is huge. But what does this mean for our expertise and skills?

Luckily, making and hearing music has such a high emotional value that a relatively small amount of self-taught playing skills can create rock-star fame. Similarly, simply knowing how to work with wood can result in a good instrument, but, in both cases, its more by accident than on purpose.

Its worth reminding self-learners about the dangers of knowledge gaps and the resulting risk of failing to correctly connect the dots.

Some argue that self-teaching is the ideal and only way of keeping a free mind, and that it often results in outsider art. However, self-learning can easily turn into cherry picking while quietly skipping all the difficult, unpleasant, and toilsome parts. Its worth reminding self-learners about the dangers of knowledge gaps and the resulting risk of failing to correctly connect the dots.

Its like a friend who wants to study quantum mechanics, but insists on skipping all classic physics. (As if there is any sort of real understanding in quantum mechanics anyway!) Or the one who likes to study astrophysics without the basic ballistics and equations of motion in gravity fields. Its pretty obvious that this kind of learning will end in dilettantism. As applicable to music, this is exactly what created the outsider genre, synonymous with self-taught, untrained, naive, and primitive.

Somehow, we are all doing self-teaching in certain areas of our lives, but there is a line before it becomes involuntarily comical due to a lack of self-awareness, incompetence to judge your own standing, and a lack of communication. Communicating with others is like getting your knowledge tested. A good example would be a luthier and marketing expert talking about physics and the acoustical outcome of their instruments, or me writing columns about vintage instruments.

Nobody can reach an expert level in all areas, so at least be aware of that, especially once you have professional ambitions as a musician or a luthier. Otherwise, proclamations like we use roasted maple for the neck, as the resonances are hardened in a marketing video, or there is no F# on a bass by a self-taught bassist can easily backfire.

Im here in hopes of helping to raise your knowledge about all things bass, and I look forward to continuing to do so. Thank you for your continued reading and commenting!

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Devs: Here’s the real science behind the quantum computing TV show – New Scientist News

Posted: May 4, 2020 at 11:00 pm

By Rowan Hooper

BBC/FX Networks

TVDevsBBC iPlayer and FX on Hulu

Halfway through episode two of Devs, there is a scene that caused me first to gasp, and then to swear out loud. A genuine WTF moment. If this is what I think it is, I thought, it is breathtakingly audacious. And so it turns out. The show is intelligent, beautiful and ambitious, and to aid in your viewing pleasure, this spoiler-free review introduces some of the cool science it explores.

Alex Garlands eight-part seriesopens with protagonists Lilyand Sergei, who live in a gorgeous apartment in San Francisco. Like their real-world counterparts, people who work atFacebook orGoogle, the pair take the shuttle bus to work.

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They work at Amaya, a powerful but secretive technology company hidden among the redwoods. Looming over the trees is a massive, creepy statue of a girl: the Amaya the company is named for.

We see the company tag line asLily and Sergei get off the bus: Your quantum future. Is it just athrow-away tag, or should we think about what that line means more precisely?

Sergei, we learn, works on artificial intelligence algorithms. At the start of the show, he gets some time with the boss, Forest, todemonstrate the project he has been working on. He has managed to model the behaviour of a nematode worm. His team has simulated the worm by recreating all 302 of its neurons and digitally wiring them up. This is basically the WormBot project, an attempt to recreate a life form completely in digital code. The complete map of the connections between the 302 neurons of the nematode waspublished in 2019.

We dont yet have the processing power to recreate theseconnections dynamically in a computer, but when we do, it will be interesting to consider if the resulting digital worm, a complete replica of an organic creature, should be considered alive.

We dont know if Sergeis simulation is alive, but it is so good, he can accurately predict the behaviour of the organic original, a real worm it is apparently simulating, up to 10 seconds in thefuture. This is what I like about Garlands stuff: the show has only just started and we have already got some really deep questions about scientific research that is actually happening.

Sergei then invokes the many-worlds interpretation of quantum mechanics conceived by Hugh Everett. Although Forest dismisses this idea, it is worth getting yourhead around it because the show comes back to it. Adherents say that the maths of quantum physics means the universe isrepeatedly splitting into different versions, creating a vast multiverse of possible outcomes.

At the core of Amaya is the ultrasecretive section where thedevelopers work. No one outside the devs team knows what it is developing, but we suspect it must be something with quantum computers. I wondered whether the devssection is trying to do with the 86 billion neurons of thehuman brain what Sergei has been doing with the 302 neurons of the nematode.

We start to find out when Sergei is selected for a role in devs. He must first pass a vetting process (he is asked if he is religious, a question that makes sense later) and then he is granted access to the devs compound sealed by alead Faraday cage, gold mesh andan unbroken vacuum.

Inside is a quantum computer more powerful than any currently in existence. How many qubits does it run, asks Sergei, looking inawe at the thing (it is beautiful, abit like the machines being developed by Google and IBM). Anumber that it is meaningless to state, says Forest. As a reference point, the best quantum computers currently manage around 50 qubits, or quantum bits. We can only assume that Forest has solved the problem ofdecoherence when external interference such as heat or electromagnetic fields cause qubits to lose their quantum properties and created a quantum computer with fantasticprocessing power.

So what are the devs using it for? Sergei is asked to guess, and then left to work it out for himself from gazing at the code. He figures it out before we do. Then comes that WTF moment. To say any more will give away the surprise. Yet as someone remarks, the world is deterministic, but with this machine we are gaining magical powers. Devs has its flaws, but it is energising and exciting to see TV this thoughtful: it cast a spell on me.

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Raytheon Technologies CEO and CFO to present at the BofA Securities 2020 Transportation and Industrials Conference – PRNewswire

Posted: at 11:00 pm

WALTHAM, Mass., May 4, 2020 /PRNewswire/ -- Raytheon Technologies (NYSE: RTX) Chief Executive Officer Greg Hayes and Chief Financial Officer Toby O'Brien will speak at the Bank of America Securities 2020 Transportation and Industrials Conference on Tuesday, May 12 at 9:20 a.m. Eastern Time. The presentation will be broadcast live at http://www.rtx.com and will be archived on the website afterward.

About Raytheon TechnologiesRaytheon Technologies Corporation is an aerospace and defense company that provides advanced systems and services for commercial, military and government customers worldwide. With 195,000 employees and four industry-leading businesses Collins Aerospace Systems, Pratt & Whitney, Raytheon Intelligence & Space and Raytheon Missiles & Defense the company delivers solutions thatpush the boundaries in avionics, cybersecurity, directed energy, electric propulsion, hypersonics, and quantum physics. The company, formed in 2020 through the combination of Raytheon Company and the United Technologies Corporation aerospace businesses, is headquartered in Waltham, Massachusetts.

Media Contact Michele Quintaglie C: 860.493.4364 [emailprotected]

Investor Contact Kelsey DeBriyn C: 781.522.5141 [emailprotected]

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https://www.rtx.com

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Raytheon Technologies CEO and CFO to present at the BofA Securities 2020 Transportation and Industrials Conference - PRNewswire

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When quantum computing and AI collide – Raconteur

Posted: at 11:00 pm

Machine-learning and quantum computing are two technologies that have incredible potential in their own right. Now researchers are bringing them together. The main goal is to achieve a so-called quantum advantage, where complex algorithms can be calculated significantly faster than with the best classical computer. This would be a game-changer in the field of AI.

Such a breakthrough could lead to new drug discoveries, advances in chemistry, as well as better data science, weather predictions and natural-language processing. We could be as little as three years away from achieving a quantum advantage in AI if the largest players in the quantum computing space meet their goals, says Ilyas Khan, chief executive of Cambridge Quantum Computing.

This comes after Google announced late last year that it had achieved quantum supremacy, claiming their quantum computer had cracked a problem that would take even the fastest conventional machine thousands of years to solve.

Developing quantum machine-learning algorithms could allow us to solve complex problems much more quickly. To realise the full potential of quantum computing for AI, we need to increase the number of qubits that make up these systems, says Dr Jay Gambetta, vice president of quantum computing at IBM Research.

Quantum devices exploit the strange properties of quantum physics and mechanics to speed up calculations. Classical computers store data in bits, as zeros or ones. Quantum computers use qubits, where data can exist in two different states simultaneously. This gives them more computational fire power. Were talking up to a million times faster than some classical computers.

And when you add a single qubit, you double the quantum computers processing power. To meet Moores Law [the number of transistors on a computer chip is doubled about every two years while the cost falls], you would need to add a single qubit every year, says Peter Chapman, chief executive of IonQ.

Our goal is to double the number of qubits every year. We expect quantum computers to be able to routinely solve problems that supercomputers cannot, within two years.

Already industrial behemoths, such as IBM, Honeywell, Google, Microsoft and Amazon, are active in the quantum computing sector. Their investments will have a major impact on acceleratingdevelopments.

We expect algorithm development to accelerate considerably. The quantum community has recognised economic opportunities in solving complex optimisation problems that permeate many aspects of the business world. These range from how do you assemble a Boeing 777 with millions of parts in the correct order? to challenges in resource distribution, explains Dr David Awschalom, professor of quantum information at the University of Chicago.

The quantum community has recognised economic opportunities in solving complex optimisation problems that permeate many aspects of the business world

Many of the computational tasks that underlie machine-learning, used currently for everything from image recognition to spam detection, have the correct form to allow a quantum speed up. Not only would this lead to faster calculations and more resource-efficient algorithms, it could also allow AI to tackle problems that are currently unfeasible because of their complexity and size.

Quantum computers arent a panacea for all humankinds informatic problems. They are best suited to very specific tasks, where there are a huge number of variables and permutations, such as calculating the best delivery route for rubbish trucks or the optimal path through traffic congestion. Mitsubishi in Japan and Volkswagen in Germany have deployed quantum computing with AI to explore solutions to these issues.

There will come a time when quantum AI could be used to help us with meaningful tasks from industrial scheduling to logistics. Financial optimisation for portfolio management could also be routinely handled by quantum computers.

This sounds like it might have limited use, but it turns out that many business problems can be expressed as an optimisation problem. This includes machine-learning problems, says Chapman.

Within a few short years we will enter the start of the quantum era. Its important for people to be excited about quantum computing; it allows government funding to increase and aids in recruitment. We need to continue to push the technology and also to support early adopters to explore how they can apply quantum computing to their businesses.

However, its still early days. The next decade is a more accurate time frame in terms of seeing quantum computing and AI coalesce and really make a difference. The need to scale to larger and more complex problems with real-world impact is one area of innovation, as is creating quantum computers that have greater precision and performance.

The limitation of quantum technology, particularly when it comes to AI, is summarised by the term decoherence. This is caused by vibrations, changes in temperature, noise and interfacing with the external environment. This causes computers to lose their quantum state and prevents them from completing computational tasks in a timely manner or at all, says Khan.

The industrys immediate priority has shifted from sheer processing power, measured by qubits, to performance, better measured by quantum volume. Rightly so the industry is channelling its energy into reducing errors to break down this major barrier and unlock the true power of machine-learning.

Over time it is the ease of access to these computers that will lead to impactful business applications and the development of successful quantum machine-learning. IBM has opened its doors to its quantum computers via the cloud since 2016 for anyone to test ideas. In the process it has fostered a vibrant community with more than 200,000 users from over 100 organisations.

The more developers and companies that get involved in first solving optimisation problems related to AI and then over time building quantum machine-learning and AI development, the sooner well see even more scalable and robust applications with business value, explains Murray Thom, vice president of software at D-Wave Systems.

Most importantly, we need a greater number of smart people identifying and developing applications. That way we will be able to overcome limitations much faster, and expand the tools and platform so they are easier to use. Bringing in more startups and forward-thinking enterprise organisations to step into quantum computing and identify potential applications for their fields is also crucial.

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Wolfram Physics Project Seeks Theory Of Everything; Is It Revelation Or Overstatement? – Hackaday

Posted: at 11:00 pm

Stephen Wolfram, inventor of the Wolfram computational language and the Mathematica software, announced that he may have found a path to the holy grail of physics: A fundamental theory of everything. Even with the subjunctive, this is certainly a powerful statement that should be met with some skepticism.

What is considered a fundamental theory of physics? In our current understanding, there are four fundamental forces in nature: the electromagnetic force, the weak force, the strong force, and gravity. Currently, the description of these forces is divided into two parts: General Relativity (GR), describing the nature of gravity that dominates physics on astronomical scales. Quantum Field Theory (QFT) describes the other three forces and explains all of particle physics.

An overview of particle physics by Headbomb [CC-BY-SA 3.0]Up to now, it has not been possible to unify both General Relativity and Quantum Field Theory since they are formulated within different mathematical frameworks. In particular, treating gravity within the formalism of QFT leads to infinite terms that cannot be canceled out within the generally accepted framework of renormalization. The two most popular attempts to deliver a quantum mechanical description of gravity are String Theory and the lesser know Quantum Loop Gravity. The former would be considered a fundamental theory that describes all forces in nature while the latter limits itself to the description of gravity.

Apart from the incompatibility of QFT and GR there are still several unsolved problems in particle physics like the nature of dark matter and dark energy or the origin of neutrino masses. While these phenomena tell us that the current Standard Model of particle physics is incomplete they might still be explainable within the current frameworks of QFT and GR. Of course, a fundamental theory also has to come up with a natural explanation for these outstanding issues.

Stephen Wolfram is best known for his work in computer science but he actually started his career in physics. He received his PhD in theoretical particle physics at the age of 20 and was the youngest person in history to receive the prestigious McArthur grant. However, he soon left physics to pursue his research into cellular automata which lead to the development of the Wolfram code. After founding his company Wolfram Research he continued to develop the Wolfram computational language which is the basis for the Wolfram Mathematica software. On the one hand, it becomes obvious that Wolfram is a very gifted man, on the other hand, people have sometimes criticized him for being an egomaniac as his brand naming convention subtly suggests.

In 2002, Stephen Wolfram published his 1200-page mammoth book A New Kind of Sciencewhere he applied his research on cellular automata to physics. The main thesis of the book is that simple programs, in particular the Rule 110 cellular automaton, can generate very complex systems through repetitive application of a simple rule. It further claims that these systems can describe all of the physical world and that the Universe itself is computational. The book got controversial reviews, while some found that it contains a cornucopia of ideas others criticized it as arrogant and overstated. Among the most famous critics were Ray Kurzweil and Nobel laureate Steven Weinberg. It was the latter who wrote that:

Wolfram [] cant resist trying to apply his experience with digital computer programs to the laws of nature. [] he concludes that the universe itself would then be an automaton, like a giant computer. Its possible, but I cant see any motivation for these speculations, except that this is the sort of system that Wolfram and others have become used to in their work on computers. So might a carpenter, looking at the moon, suppose that it is made of wood.

The Wolfram Physics Project is a continuation of the ideas formulated in A New Kind of Science and was born out of a collaboration with two young physicists who attended Wolframs summer school. The main idea has not changed, i.e. that the Universe in all its complexity can be described through a computer algorithm that works by iteratively applying a simple rule. Wolfram recognizes that cellular automata may have been too simple to produce this kind of complexity instead he now focuses on hypergraphs.

In mathematics, a graph consists of a set of elements that are related in pairs. When the order of the elements is taken into account this is called a directed graph. The most simple example of a (directed) graph can be represented as a diagram and one can then apply a rule to this graph as follows:

The rule states that wherever a relation that matches {x,y} appears, it should be replaced by {{x ,y},{y,z}}, wherez is a new element. Applying this rule to the graph yields:

By applying this rule iteratively one ends up with more and more complicated graphs as shown in the example here. One can also add complexity by allowing self-loops, rules involving copies of the same relation, or rules depending on multiple relations. When allowing relations between more than two elements, this moves from graphs to hypergraphs.

How is this related to physics? Wolfram surmises that the Universe can be represented by an evolving hypergraph where a position in space is defined by a node and time basically corresponds to the progressive updates. This introduces new physical concepts, e.g. that space and time are discrete, rather than continuous. In this model, the quest for a fundamental theory corresponds to finding the right initial condition and underlying rule. Wolfram and his colleagues think they have already identified the right class of rules and constructed models that reproduce some basic principles of general relativity and quantum mechanics.

A fundamental problem of the model is what Wolfram calls computational irreducibility, meaning that to calculate any state of the hypergraph one has to go through all iterations starting from the initial condition. This would make it virtually impossible to run the computation long enough in order to test a model by comparing it to our current physical Universe.

Wolfram thinks that some basic principles, e.g. the dimensionality of space, can be deduced from the rules itself. Wolfram also points out that although the generated model universes can be tested against observations the framework itself is not amenable to experimental falsification. It is generally true that fundamental physics has long decoupled from the scientific method of postulating hypotheses based on experimental observations. String theory has also been criticized for not making any testable predictions. However, String theory historically developed from nuclear physics while Wolfram does not give any motivation for choosing evolving hypergraphs for his framework. However, some physicists are thinking in similar directions like Nobel laureate Gerard tHooft who has recently published a cellular automaton interpretation of quantum mechanics. In addition, Wolframs colleague, Jonathan Gorard, points out that their approach is a generalization of spin networks used in Loop Quantum Gravity.

On his website, Wolfram invites other people to participate in the project although it is somehow vague how this will work. In general, they need people to work out the potential observable predictions of their model and the relation to other fundamental theories. If you want to dive into the topic in depth there is a 448-page technical introduction on the website and they have also recently started a series of livestreams where they plan to release 400 hours of video material.

Wolframs model certainly contains many valuable ideas and cannot be simply disregarded as crackpottery. Still, most mainstream physicists will probably be skeptical about the general idea of a discrete computational Universe. The fact that Wolfram tends to overstate his findings and publishes through his own media channels instead of going through peer-reviewed physics journals does not earn him any extra credibility.

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The Cool Parts Show Reveals 3D Printing Reality and Potential – Modern Machine Shop

Posted: at 11:00 pm

Did you know that there are FDA-registered companies using metal 3D printing to make titanium spine cages? That you can already buy customized products like shoe insoles and glasses frames made through 3D printing? That 3D printed vacuum chambers can support quantum physics research?Or that the Ford Mustang Shelby GT500 contains a 3D printed bracket?

Its all true!

Over at Additive Manufacturing (a sister publication to Modern Machine Shop), weve built an entire YouTube showaround applications like these for industrial 3D printing technology. Each episode of our series The Cool Parts Show focuses on a unique, unusual or otherwise remarkable 3D-printed part. Think beyond models or rapid prototyping everyitem featured is a realpart in production today,or a proof-of-concept that soon could be. The goal is to provide a realistic picture of 3D printings capabilities and usefulness today, as well as a sneak peek at where it could go in the future.

Additive ManufacturingandModern Machine Shop Editor-in-Chief Peter Zelinskiis my cohost on the show. In each episode, we explore the details that went into making the part, as well as how it fits into larger themes like the Internet of Things, mass customization and sustainability. We strive to make every episode interesting and approachablewhether youre an AM pro or just curious about 3D printing.

There are two complete seasons of The Cool Parts Show out now, including episodes about all the cool parts mentioned above. Find them at thecoolpartsshow.com or on our YouTube channel; the full playlist is also embedded below.

Filming for Season 3 is already in progress, but in the more immediate future well be releasing some special coverage related to COVID-19.Were checking in with past subjects of the show to find out how they are adapting. Aspecial episode is also in the works on what might be the biggest production story for additive manufacturing that weve seen, pandemic or otherwise: testing swabs.

If you want to be notified about new episodes, subscribe to our channel on YouTube or to the weekly AM Update e-newsletter. Stay tuned!

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Caves elected to membership in the National Academy of Sciences – UNM Newsroom

Posted: at 11:00 pm

The National Academy of Sciences (NAS) has announced the election of University of New Mexico Distinguished Professor Emeritus and Research Professor of Physics and Astronomy Carlton Caves as a member. This prestigious honor is one of the highest accorded to scientists and is given in recognition of distinguished and continuing achievement in original research.

Caves is UNMs fifth selection to the prestigious group since its inception in 1863. He is one of 120 new members and becomes part of a select group of more than 2,400 active members in the NAS. Approximately 190 of those selected have received Nobel prizes. The election of new members is by current members based on outstanding achievement and commitment to service.

"What a well-deserved honor this is for Dr. Caves the culmination of a long and distinguished career, as well as a professional acknowledgement of his groundbreaking research, innovation, and service," said UNM President Garnett S. Stokes. "Membership in the National Academy of Sciences is one of the highest honors conferred on scientists, and we salute Dr. Caves for his remarkable accomplishment. We're proud of him, and of the cutting edge research he's conducted here at UNM."

UNM Distinguished Professor Emeritus and Research Professor of Physics and Astronomy Carlton Caves elected to National Academy of Sciences.

Caves conducts research in the burgeoning field of quantum information theory and quantum computation and has been a pioneer in the field for nearly 40 years. Related areas include the theory of open quantum systems and decoherence, nonlinear dynamics and quantum chaos and theoretical quantum optics.

Quantum Information Science(QIS) is an emerging field with vast potential to revolutionize advances in fields ofscienceand engineering involvingcomputation, communication, precision measurement and fundamentalquantum science.

I am a theoretical physicist, and my election to the Academy is, generally, recognition of a sustained series of contributions to quantum metrology, the science of making the best possible measurements in the presence of quantum uncertainties, and, specifically, acknowledgmentof an idea I had in 1981 for making interferometers more sensitive, said Caves.

"Carlton Caves has made extraordinary contributions to both the theory and practical application of ideas in quantum information and quantum optics, said UNM Provost and Executive Vice President for Academic Affairs James Holloway.His election to the National Academy of Sciences is a career-capping honor in a long list of honors and awards he has received for his work.

For a US scientist, this election is considered perhaps the most prominent national honor. Professor Caves is still actively working and publishing, and contributing to the frontiers of human knowledge. Congratulations to Professor Caves!

Caves is the founding directorof UNMs Center for Quantum Information and Control (CQuIC), a research center co-located at The University of New Mexico in Albuquerque and the University of Arizona in Tucson. Research at CQuIC is focused on the control of complex quantum systems with an aim to make quantum systems march to scientist orders, instead of doing what comes naturally.

CQuICsresearch is organized asquantum information and computation,quantum control and measurement,quantum metrology, andquantum optics and communication, with extensive theoretical and experimental research programs in all these areas.

Caves current research is focused on various topics drawn from quantum information science and quantum metrology, and he works on these topics with colleagues at UNM and around the world. Just at present, he is working with two postdocs at UNMs Center for Quantum Information and Control.

Caves and Rafael Alexander are investigating a technique, called quantum illumination, for detecting a faint target against a bright background using fundamental quantum effects, Additionally, he and Christopher Jackson are developing a general theory of the classical limit of quantum systems, which goes under the name of generalized coherent states.

After nearly 40 years of technical development, the idea of using squeezed light in interferometric gravitational-wave detectors was implemented in the LIGO and VIRGO gravitational-wave detectors a little over a year ago, and it made them measurably better, said Caves. When an idea tops off a $1 billion investment, it does attract attention, he added.

The National Academy of Sciences is a private nonprofit institution that provides expert advice on the most pressing challenges and the world. It was founded when President Abraham Lincoln signed a congressional charter forming the NAS as an independent adviser on scientific matters.

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Caves elected to membership in the National Academy of Sciences - UNM Newsroom

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Week of May 6 – Style Weekly

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ARIES (March 21-April 19)According to Aries author and mythologist Joseph Campbell, The quest for fire occurred not because anyone knew what the practical uses for fire would be, but because it was fascinating. He was referring to our early human ancestors, and how they stumbled upon a valuable addition to their culture because they were curious about a powerful phenomenon, not because they knew it would ultimately be so valuable. I invite you to be guided by a similar principle in the coming weeks, Aries. Unforeseen benefits may emerge during your investigation into flows and bursts that captivate your imagination.

TAURUS (April 20-May 20)The future belongs to those who see possibilities before they become obvious, says businessperson and entrepreneur John Sculley. You Tauruses arent renowned for such foresight. Its more likely to belong to Aries and Sagittarius people. Your tribe is more likely to specialize in doing the good work that turns others bright visions into practical realities. But this Year of the Coronavirus could be an exception to the general rule. In the past three months as well as in the next six months, many of you Bulls have been and will continue to be catching glimpses of interesting possibilities before they become obvious. Give yourself credit for this knack. Be alert for what it reveals.

GEMINI (May 21-June 20)For 148 uninterrupted years, American militias and the American army waged a series of wars against the native peoples who lived on the continent before Europeans came. There were more than 70 conflicts that lasted from 1776 until 1924. If there is any long-term struggle or strife that even mildly resembles that situation in your own personal life, our Global Healing Crisis is a favorable time to call a truce and cultivate peace. Start now! Its a ripe and propitious time to end hostilities that have gone on too long.

CANCER (June 21-July 22)Novelist Marcel Proust was a sensitive, dreamy, emotional, self-protective, creative Cancerian. That may explain why he wasnt a good soldier. During his service in the French army, he was ranked 73rd in a squad of 74. On the other hand, his majestically intricate seven-volume novel In Search of Lost Time is a masterpieceone of the 20th centurys most influential literary works. In evaluating his success as a human being, should we emphasize his poor military performance and downplay his literary output? Of course not! Likewise, Cancerian, in the coming weeks Id like to see you devote vigorous energy to appreciating what you do best and no energy at all to worrying about your inadequacies.

LEO (July 23-Aug. 22)Fortune resists half-hearted prayers, wrote the poet Ovid more than 2,000 years ago. I will add that Fortune also resists poorly formulated intentions, feeble vows, and sketchy plansespecially now, during an historical turning point when the world is undergoing massive transformations. Luckily, I dont see those lapses being problems for you in the coming weeks, Leo. According to my analysis, youre primed to be clear and precise. Your willpower should be working with lucid grace. Youll have an enhanced ability to assess your assets and make smart plans for how to use them.

VIRGO (Aug. 23-Sept. 22)Last year the Baltimore Museum of Art announced it would acquire works exclusively from women artists in 2020. A male art critic complained, Thats unfair to male artists. Heres my reply: Among major permanent art collections in the U.S. and Europe, the work of women makes up five percent of the total. So what the Baltimore Museum did is a righteous attempt to rectify the existing excess. Its a just and fair way to address an unhealthy imbalance. In accordance with current omens and necessities, Virgo, I encourage you to perform a comparable correction in your personal sphere.

LIBRA (Sept. 23-Oct. 22)In the course of my life, Ive met many sharp thinkers with advanced degrees from fine universitieswho are nonetheless stunted in their emotional intelligence. They may quote Shakespeare and discourse on quantum physics and explain the difference between the philosophies of Kant and Hegel, and yet have less skill in understanding the inner workings of human beings or in creating vibrant intimate relationships. Yet most of these folks are not extreme outliers. Ive found that virtually all of us are smarter in our heads than we are in our hearts. The good news, Libra, is that our current Global Healing Crisis is an excellent time for you to play catch up. Do what poet Lawrence Ferlinghetti suggests: Make your mind learn its way around the heart.

SCORPIO (Oct. 23-Nov. 21)Aphorist Aaron Haspel writes, The less you are contradicted, the stupider you become. The more powerful you become, the less you are contradicted. Lets discuss how this counsel might be useful to you in the coming weeks. First of all, I suspect you will be countered and challenged more than usual, which will offer you rich opportunities to become smarter. Secondly, I believe you will become more powerful as long as you dont try to stop or discourage the influences that contradict you. In other words, youll grow your personal authority and influence to the degree that you welcome opinions and perspectives that are not identical to yours.

SAGITTARIUS (Nov. 22-Dec. 21)Its always too early to quit, wrote author Norman Vincent Peale. We should put his words into perspective, though. He preached the power of positive thinking. He was relentless in his insistence that we can and should transcend discouragement and disappointment. So we should consider the possibility that he was overly enthusiastic in his implication that we should NEVER give up. What do you think, Sagittarius? Im guessing this will be an important question for you to consider in the coming weeks. It may be time to re-evaluate your previous thoughts on the matter and come up with a fresh perspective. For example, maybe its right to give up on one project if it enables you to persevere in another.

CAPRICORN (Dec. 22-Jan. 19)The 16-century mystic nun Saint Teresa of Avila was renowned for being overcome with rapture during her spiritual devotions. At times she experienced such profound bliss through her union with God that she levitated off the ground. Any real ecstasy is a sign you are moving in the right direction, she wrote. I hope that you will be periodically moving in that direction yourself during the coming weeks, Capricorn. Although it may seem odd advice to receive during our Global Healing Crisis, I really believe you should make appointments with euphoria, delight, and enchantment.

AQUARIUS (Jan. 20-Feb. 18)Grammy-winning musician and composer Pharrell Williams has expertise in the creative process. If someone asks me what inspires me, he testifies, I always say, That which is missing. According to my understanding of the astrological omens, you would benefit from making that your motto in the coming weeks. Our Global Healing Crisis is a favorable time to discover whats absent or empty or blank about your life, and then learn all you can from exploring it. I think youll be glad to be shown what you didnt consciously realize was lost, omitted, or lacking.

PISCES (Feb. 19-March 20)I am doing my best to not become a museum of myself, declares poet Natalie Diaz. I think she means that she wants to avoid defining herself entirely by her past. She is exploring tricks that will help her keep from relying so much on her old accomplishments that she neglects to keep growing. Her goal is to be free of her history, not to be weighed down and limited by it. These would be worthy goals for you to work on in the coming weeks, Pisces. What would your first step be?

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Week of May 6 - Style Weekly

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Nuclear Weapons Denied: How Hitler Failed to Even Get Close to the Bomb – The National Interest Online

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Key Point: The Germans made many errors in their quest for the bomb. Also, their evil andfoolish prejudice against minorities meant that they ignored and prosecuted many of their brilliant scientists.

The most nightmarish of World War II alternative history scenarios is the one in which Nazi Germany acquires atomic weapons. In fact, by the spring of 1945, when Americas massive nuclear program was reaching its culmination, the Nazi atomic program consisted of one experimental reactor in a cave in southern Germany, operated by scientists who lacked a clear conception of how to build an atomic weapon.

Even if the German scientists had known what they were doing, they still lacked suitable radioactive material to produce a weapon. One of World War IIs most remarkable and controversial stories is just how the Nazi atomic program came to this sorry pass.

The potential power of atomic energy is a corollary of Einsteins famous Theory of Relativity equation, E = MC2. Simply put, the equation means that all matter is energy. To determine the energy contained in any bit of matter, one need only multiply its mass times the square of the speed of light. As the speed of light is somewhere in excess of 186,000 miles per second, the resulting number is correspondingly huge.

Early in the 20th century, physicists realized that if it was possible to release the atomic energy in a piece of matter, say a brick, they could create a doomsday weapon. Fortunately, the atoms in bricks, and in almost all ordinary matter, are quite stable and not likely to erupt in an atomic chain reaction. However, by the mid-1930s, experiments with the unstable element uranium revealed the potential to tap into its store of nuclear energy and create machines of awesome power.

Nazi Germanys Rejection of Jewish Physics

Theoretically, by the 1930s Germany had a jump on the rest of the world in atomic research. Many of the worlds top nuclear physicists were German or Austrian, or worked closely with German or Austrian colleagues. It was a German scientist, Otto Hahn, who first split the atom in 1938. Although Hahn later tried to claim all the credit for his experiment, at the time he did not actually know what he had done.

It was Lise Meitner, an Austrian Jewish colleague, who realized the significance of Hahns discovery and described the processes involved. Meitner realized that Hahn, by bombarding a small sample of uranium with neutrons, had literally broken some uranium atoms apart, releasing powerful atomic energy. Incredibly, in accord with Nazi policy, Hahn and other German academics had recently driven Meitner from her post at the Kaiser Wilhelm Institute for Chemistry near Berlin to refuge in Sweden. Meitner was a brilliant scientist, but evidently socially and politically inept enough that she continued to assist Hahn despite his treatment of her and Nazi Germanys policies toward Jews in general.

Although Meitner continued to assist her former colleagues in Nazi Germany for a time, most Jewish scientists were not so lucky or nave. By the late 1930s almost all of Germany and Austrias Jewish physicists, along with many others who rejected Nazism, had fled, mostly to Britain or America. Einstein was by far the most famous among them, but only one of a great many.

Nazi academics began to take over Germanys great educational institutions, hungrily seizing positions and offices previously held by Jews, foreigners, or anti-Nazi German academics. Some of these newcomers were marginal teachers and scientists, envious of successes by those they considered racially or ideologically inferior. Many disdained theoretical physics and Einsteins relativity theories.

These men and the Nazi hierarchy regarded Einsteins relativity theories and their progeny as Jewish physics. For them, the only valid physics was Deutsche or Volkish physics, by which they apparently meant a classical experimental physics that could somehow ignore the realities Einstein described. Nonetheless, not all of Germanys scientists disdained Jewish physics, and as war loomed and then broke out, even high-ranking Nazis came to appreciate the tantalizing prospect of an atomic super weapon.

Werner Heisenberg: Germanys Top Physicist

In the late 1930s, the most famous physicist in Germany (Einstein having left Germany for New Jersey) was Werner Heisenberg. Heisenberg was internationally renowned for his work in quantum mechanics and the Uncertainty Principle that usually bore his name. He was a brilliant theorist and mathematician and prided himself on his practical abilities as a physicist, although in fact these were suspect. For a time he was Germanys youngest full professor.

In 1932, Heisenberg was awarded the Nobel Prize for Physics for his work on the Uncertainty Principle, although the prize committee slighted several other physicists who arguably deserved as much credit as the charismatic Heisenberg. In 1937, Heisenberg was appointed to a senior professorship at Leipzig University.

While not a card-carrying Nazi, Heisenberg was a loyal and patriotic German. Like many German academics and professional soldiers of his time, he considered himself above politics, and so was willing to serve whatever government ruled Germany, even Hitlers. He was the logical choice to lead the countrys atomic weapons program.

However, in July 1937, just months before Hahn split the atom, Heisenberg came under attack in an article that appeared in Das Schwarze Korps, an SS magazine. The instigator behind the article was Johannes Stark, a rabidly anti-Semitic experimentalist who resented Heisenbergs success and his association with Jewish physicists, a practical necessity in Heisenbergs field. The article accused Heisenberg of being a part of a white Jewish establishment that sought to keep true Germans from positions of importance, promoted Einsteins relativity theory, and by implication sought to undermine the Nazi Party.

Such an attack was serious business in Nazi Germany and threatened internment in a concentration camp or worse. Heisenberg sought the assistance of friends and associates within the establishment, including Nazi Party members, to clear his name. Heisenbergs mother, who had been an acquaintance of Heinrich Himmlers father, passed on a personal letter from the physicist to the SS Reichsfhrer. After a thorough investigation by the SS, which included a terrifying interview at its Berlin headquarters, Himmler personally exonerated Heisenberg, effectively inoculating him from charges of treason until the end of the war.

In his letter clearing Heisenberg, Himmler permitted him to continue with his work, but with the proviso that Heisenberg could only apply relativity theory and the work of Jewish scientists without acknowledging them. Relieved, Heisenberg readily agreed to the conditions and began working in earnest on the German atomic project.

Heavy Water Reactor Project

While Germany began state-sponsored atomic research several years before the Allies, its efforts did not go unnoticed. Because so many physicists were driven from the Reich, Allied governments were quickly able to form a relatively clear picture of German efforts. Americas program was sparked in part by Einsteins warning to President Franklin D. Roosevelt concerning possible German successes.

By 1941, the Germans were operating two experimental reactor projects, but German success had in fact been limited. Heisenbergs team in particular made certain engineering decisions that put the German program almost immediately at risk.

Very basically, a nuclear reactor operates by inducing a chain reaction in masses of Uranium 238 within the reactor. To initiate a reaction, the flow of neutrons around the radioactive isotope must be moderated by another substance, such as graphite or deuterium (heavy water). The Germans chose to use heavy water, which is rare in nature and difficult to manufacture.

In 1940, the Germans captured a heavy water plant in Vermok, a Norwegian town 100 miles north of Oslo. British intelligence had learned the basic outline of the German reactor project and realized that the Norwegian heavy water supply was a weak link. By mid-1942, the Norwegian factory was producing up to 10,000 pounds of heavy water per year for Heisenbergs teams in Leipzig and Berlin. An initial raid on the plant by British paratroopers ended in disaster when the gliders carrying the troops crashed far from the target.

The British were concerned enough about the plant to mount another operation. The second raid was more subtle than the first. A daring team of Norwegian commandos infiltrated the plant and blew up the water tanks. Later, British submarines interdicted further shipments. The loss of so much heavy water set the German project back but did not derail it. That, the Germans unwittingly did themselves.

The Challenges of U-235 Enrichment

Despite the continuing attacks on the heavy water supply line, by 1941 German scientists had come to several broad theoretical conclusions that mirrored American conceptions of how to build an atomic device: (1) an enriched uranium fission device, (2) a plutonium-based fission device, or (3) a reactor bomb. While the United States would build successful atomic reactors and both uranium and plutonium bombs by the end of the war, the German scientists never approached a working conception for actual production of a successful atomic machine.

The American bomb that exploded over Hiroshima was a uranium fission device. The key to manufacturing such a bomb was producing sufficient quantities of highly enriched Uranium 235, an isotope that exists naturally only in tiny quantities within the much more abundant Uranium 238. Extracting U-235 from U-238 cannot be done chemically and requires a time-consuming and expensive gaseous diffusion process.

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