Category Archives: Quantum Physics

In Quantum Physics, Everything Is Relative – The New York Times

The conceptual breakthrough initiated by Heisenberg (who was mentored by Niels Bohr), and firmed up with contributions from Max Born, Wolfgang Pauli, Paul Dirac, Erwin Schrdinger and others, makes it clear that the world of the very small that of photons, electrons, atoms and molecules obeys rules that go against the grain of our everyday physical reality.

Take an electron that is emitted at Point A and is detected at Point B. One would assume that the electron follows a trajectory, the way a baseball does from a pitchers hand to a catchers mitt. To explain experimental observations, Heisenberg rejected the notion of a trajectory for the electron. The resulting quantum theory deals in probabilities. It lets you calculate the probability of finding the electron at Point B. It says nothing of the path the electron takes. In its most austere form, quantum theory even denies any reality to the electron until it is detected (leading some to posit that a conscious observer somehow creates reality).

Since the 1950s, scientists have tried to make quantum theory conform to the dictates of classical physics, including arguing for a hidden reality in which the electron does have a trajectory, or suggesting that the electron takes every possible path, but these paths are manifest in different worlds. Rovelli dismisses these attempts. The cost of these approaches is to postulate a world full of invisible things.

Instead, in Helgoland Rovelli explains his relational interpretation, in which an electron, say, has properties only when it interacts with something else. When its not interacting, the electron is devoid of physical properties: no position, no velocity, no trajectory. Even more radical is Rovellis claim that the electrons properties are real only for the object its interacting with and not for other objects. The world fractures into a play of points of view that do not admit of a univocal, global vision, Rovelli writes. Or, as he puts it, Facts are relative. Its a dramatic denunciation of physics as a discipline that provides an objective, third-person description of reality.

This perspective blurs the distinction between mental and physical phenomena. Both are products of interactions between parts of the physical world, Rovelli says. In arguing that the mind is itself the outcome of a complex web of interactions, Rovelli takes on dualists who distinguish between the mental and the physical and nave materialists who say that everything begins with particles of matter with well-defined properties.

Link:

In Quantum Physics, Everything Is Relative - The New York Times

The Mystery at the Heart of Physics That Only Math Can Solve – Quanta Magazine

Over the past century, quantum field theory has proved to be the single most sweeping and successful physical theory ever invented. It is an umbrella term that encompasses many specific quantum field theories the way shape covers specific examples like the square and the circle. The most prominent of these theories is known as the Standard Model, and it is this framework of physics that has been so successful.

It can explain at a fundamental level literally every single experiment that weve ever done, said David Tong, a physicist at the University of Cambridge.

But quantum field theory, or QFT, is indisputably incomplete. Neither physicists nor mathematicians know exactly what makes a quantum field theory a quantum field theory. They have glimpses of the full picture, but they cant yet make it out.

There are various indications that there could be a better way of thinking about QFT, said Nathan Seiberg, a physicist at the Institute for Advanced Study. It feels like its an animal you can touch from many places, but you dont quite see the whole animal.

Mathematics, which requires internal consistency and attention to every last detail, is the language that might make QFT whole. If mathematics can learn how to describe QFT with the same rigor with which it characterizes well-established mathematical objects, a more complete picture of the physical world will likely come along for the ride.

If you really understood quantum field theory in a proper mathematical way, this would give us answers to many open physics problems, perhaps even including the quantization of gravity, said Robbert Dijkgraaf, director of the Institute for Advanced Study (and a regular columnist for Quanta).

Nor is this a one-way street. For millennia, the physical world has been mathematics greatest muse. The ancient Greeks invented trigonometry to study the motion of the stars. Mathematics turned it into a discipline with definitions and rules that students now learn without any reference to the topics celestial origins. Almost 2,000 years later, Isaac Newton wanted to understand Keplers laws of planetary motion and attempted to find a rigorous way of thinking about infinitesimal change. This impulse (along with revelations from Gottfried Leibniz) birthed the field of calculus, which mathematics appropriated and improved and today could hardly exist without.

Now mathematicians want to do the same for QFT, taking the ideas, objects and techniques that physicists have developed to study fundamental particles and incorporating them into the main body of mathematics. This means defining the basic traits of QFT so that future mathematicians wont have to think about the physical context in which the theory first arose.

The rewards are likely to be great: Mathematics grows when it finds new objects to explore and new structures that capture some of the most important relationships between numbers, equations and shapes. QFT offers both.

Physics itself, as a structure, is extremely deep and often a better way to think about mathematical things were already interested in. Its just a better way to organize them, said David Ben-Zvi, a mathematician at the University of Texas, Austin.

For 40 years at least, QFT has tempted mathematicians with ideas to pursue. In recent years, theyve finally begun to understand some of the basic objects in QFT itself abstracting them from the world of particle physics and turning them into mathematical objects in their own right.

Yet its still early days in the effort.

We wont know until we get there, but its certainly my expectation that were just seeing the tip of the iceberg, said Greg Moore, a physicist at Rutgers University. If mathematicians really understood [QFT], that would lead to profound advances in mathematics.

Its common to think of the universe as being built from fundamental particles: electrons, quarks, photons and the like. But physics long ago moved beyond this view. Instead of particles, physicists now talk about things called quantum fields as the real warp and woof of reality.

These fields stretch across the space-time of the universe. They come in many varieties and fluctuate like a rolling ocean. As the fields ripple and interact with each other, particles emerge out of them and then vanish back into them, like the fleeting crests of a wave.

Particles are not objects that are there forever, said Tong. Its a dance of fields.

To understand quantum fields, its easiest to start with an ordinary, or classical, field. Imagine, for example, measuring the temperature at every point on Earths surface. Combining the infinitely many points at which you can make these measurements forms a geometric object, called a field, that packages together all this temperature information.

In general, fields emerge whenever you have some quantity that can be measured uniquely at infinitely fine resolution across a space. Youre sort of able to ask independent questions about each point of space-time, like, whats the electric field here versus over there, said Davide Gaiotto, a physicist at the Perimeter Institutefor Theoretical Physics in Waterloo, Canada.

Quantum fields come about when youre observing quantum phenomena, like the energy of an electron, at every point in space and time. But quantum fields are fundamentally different from classical ones.

While the temperature at a point on Earth is what it is, regardless of whether you measure it, electrons have no definite position until the moment you observe them. Prior to that, their positions can only be described probabilistically, by assigning values to every point in a quantum field that captures the likelihood youll find an electron there versus somewhere else. Prior to observation, electrons essentially exist nowhere and everywhere.

Most things in physics arent just objects; theyre something that lives in every point in space and time, said Dijkgraaf.

A quantum field theory comes with a set of rules called correlation functions that explain how measurements at one point in a field relate to or correlate with measurements taken at another point.

Each quantum field theory describes physics in a specific number of dimensions. Two-dimensional quantum field theories are often useful for describing the behavior of materials, like insulators; six-dimensional quantum field theories are especially relevant to string theory; and four-dimensional quantum field theories describe physics in our actual four-dimensional universe. The Standard Model is one of these; its the single most important quantum field theory because its the one that best describes the universe.

There are 12 known fundamental particles that make up the universe. Each has its own unique quantum field. To these 12 particle fields the Standard Model adds four force fields, representing the four fundamental forces: gravity, electromagnetism, the strong nuclear force and the weak nuclear force. It combines these 16 fields in a single equation that describes how they interact with each other. Through these interactions, fundamental particles are understood as fluctuations of their respective quantum fields, and the physical world emerges before our eyes.

It might sound strange, but physicists realized in the 1930s that physics based on fields, rather than particles, resolved some of their most pressing inconsistencies, ranging from issues regarding causality to the fact that particles dont live forever. It also explained what otherwise appeared to be an improbable consistency in the physical world.

All particles of the same type everywhere in the universe are the same, said Tong. If we go to the Large Hadron Collider and make a freshly minted proton, its exactly the same as one thats been traveling for 10 billion years. That deserves some explanation. QFT provides it: All protons are just fluctuations in the same underlying proton field (or, if you could look more closely, the underlying quark fields).

But the explanatory power of QFT comes at a high mathematical cost.

Quantum field theories are by far the most complicated objects in mathematics, to the point where mathematicians have no idea how to make sense of them, said Tong. Quantum field theory is mathematics that has not yet been invented by mathematicians.

What makes it so complicated for mathematicians? In a word, infinity.

When you measure a quantum field at a point, the result isnt a few numbers like coordinates and temperature. Instead, its a matrix, which is an array of numbers. And not just any matrix a big one, called an operator, with infinitely many columns and rows. This reflects how a quantum field envelops all the possibilities of a particle emerging from the field.

There are infinitely many positions that a particle can have, and this leads to the fact that the matrix that describes the measurement of position, of momentum, also has to be infinite-dimensional, said Kasia Rejzner of the University of York.

And when theories produce infinities, it calls their physical relevance into question, because infinity exists as a concept, not as anything experiments can ever measure. It also makes the theories hard to work with mathematically.

We dont like having a framework that spells out infinity. Thats why you start realizing you need a better mathematical understanding of whats going on, said Alejandra Castro, a physicist at the University of Amsterdam.

The problems with infinity get worse when physicists start thinking about how two quantum fields interact, as they might, for instance, when particle collisions are modeled at the Large Hadron Collider outside Geneva. In classical mechanics this type of calculation is easy: To model what happens when two billiard balls collide, just use the numbers specifying the momentum of each ball at the point of collision.

When two quantum fields interact, youd like to do a similar thing: multiply the infinite-dimensional operator for one field by the infinite-dimensional operator for the other at exactly the point in space-time where they meet. But this calculation multiplying two infinite-dimensional objects that are infinitely close together is difficult.

This is where things go terribly wrong, said Rejzner.

Physicists and mathematicians cant calculate using infinities, but they have developed workarounds ways of approximating quantities that dodge the problem. These workarounds yield approximate predictions, which are good enough, because experiments arent infinitely precise either.

We can do experiments and measure things to 13 decimal places and they agree to all 13 decimal places. Its the most astonishing thing in all of science, said Tong.

One workaround starts by imagining that you have a quantum field in which nothing is happening. In this setting called a free theory because its free of interactions you dont have to worry about multiplying infinite-dimensional matrices because nothings in motion and nothing ever collides. Its a situation thats easy to describe in full mathematical detail, though that description isnt worth a whole lot.

Its totally boring, because youve described a lonely field with nothing to interact with, so its a bit of an academic exercise, said Rejzner.

But you can make it more interesting. Physicists dial up the interactions, trying to maintain mathematical control of the picture as they make the interactions stronger.

This approach is called perturbative QFT, in the sense that you allow for small changes, or perturbations, in a free field. You can apply the perturbative perspective to quantum field theories that are similar to a free theory. Its also extremely useful for verifying experiments. You get amazing accuracy, amazing experimental agreement, said Rejzner.

But if you keep making the interactions stronger, the perturbative approach eventually overheats. Instead of producing increasingly accurate calculations that approach the real physical universe, it becomes less and less accurate. This suggests that while the perturbation method is a useful guide for experiments, ultimately its not the right way to try and describe the universe: Its practically useful, but theoretically shaky.

We do not know how to add everything up and get something sensible, said Gaiotto.

Another approximation scheme tries to sneak up on a full-fledged quantum field theory by other means. In theory, a quantum field contains infinitely fine-grained information. To cook up these fields, physicists start with a grid, or lattice, and restrict measurements to places where the lines of the lattice cross each other. So instead of being able to measure the quantum field everywhere, at first you can only measure it at select places a fixed distance apart.

From there, physicists enhance the resolution of the lattice, drawing the threads closer together to create a finer and finer weave. As it tightens, the number of points at which you can take measurements increases, approaching the idealized notion of a field where you can take measurements everywhere.

The distance between the points becomes very small, and such a thing becomes a continuous field, said Seiberg. In mathematical terms, they say the continuum quantum field is the limit of the tightening lattice.

Mathematicians are accustomed to working with limits and know how to establish that certain ones really exist. For example, theyve proved that the limit of the infinite sequence $latex frac{1}{2}$ +$latex frac{1}{4}$ +$latex frac{1}{8}$ +$latex frac{1}{16}$ is 1. Physicists would like to prove that quantum fields are the limit of this lattice procedure. They just dont know how.

Its not so clear how to take that limit and what it means mathematically, said Moore.

Physicists dont doubt that the tightening lattice is moving toward the idealized notion of a quantum field. The close fit between the predictions of QFT and experimental results strongly suggests thats the case.

There is no question that all these limits really exist, because the success of quantum field theory has been really stunning, said Seiberg. But having strong evidence that something is correct and proving conclusively that it is are two different things.

Its a degree of imprecision thats out of step with the other great physical theories that QFT aspires to supersede. Isaac Newtons laws of motion, quantum mechanics, Albert Einsteins theories of special and general relativity theyre all just pieces of the bigger story QFT wants to tell, but unlike QFT, they can all be written down in exact mathematical terms.

Quantum field theory emerged as an almost universal language of physical phenomena, but its in bad math shape, said Dijkgraaf. And for some physicists, thats a reason for pause.

If the full house is resting on this core concept that itself isnt understood in a mathematical way, why are you so confident this is describing the world? That sharpens the whole issue, said Dijkgraaf.

Even in this incomplete state, QFT has prompted a number of important mathematical discoveries. The general pattern of interaction has been that physicists using QFT stumble onto surprising calculations that mathematicians then try to explain.

Its an idea-generating machine, said Tong.

At a basic level, physical phenomena have a tight relationship with geometry. To take a simple example, if you set a ball in motion on a smooth surface, its trajectory will illuminate the shortest path between any two points, a property known as a geodesic. In this way, physical phenomena can detect geometric features of a shape.

Now replace the billiard ball with an electron. The electron exists probabilistically everywhere on a surface. By studying the quantum field that captures those probabilities, you can learn something about the overall nature of that surface (or manifold, to use the mathematicians term), like how many holes it has. Thats a fundamental question that mathematicians working in geometry, and the related field of topology, want to answer.

One particle even sitting there, doing nothing, will start to know about the topology of a manifold, said Tong.

In the late 1970s, physicists and mathematicians began applying this perspective to solve basic questions in geometry. By the early 1990s, Seiberg and his collaborator Edward Witten figured out how to use it to create a new mathematical tool now called the Seiberg-Witten invariants that turns quantum phenomena into an index for purely mathematical traits of a shape: Count the number of times quantum particles behave in a certain way, and youve effectively counted the number of holes in a shape.

Witten showed that quantum field theory gives completely unexpected but completely precise insights into geometrical questions, making intractable problems soluble, said Graeme Segal, a mathematician at the University of Oxford.

Another example of this exchange also occurred in the early 1990s, when physicists were doing calculations related to string theory. They performed them in two different geometric spaces based on fundamentally different mathematical rules and kept producing long sets of numbers that matched each other exactly. Mathematicians picked up the thread and elaborated it into a whole new field of inquiry, called mirror symmetry, that investigates the concurrence and many others like it.

Physics would come up with these amazing predictions, and mathematicians would try to prove them by our own means, said Ben-Zvi. The predictions were strange and wonderful, and they turned out to be pretty much always correct.

But while QFT has been successful at generating leads for mathematics to follow, its core ideas still exist almost entirely outside of mathematics. Quantum field theories are not objects that mathematicians understand well enough to use the way they can use polynomials, groups, manifolds and other pillars of the discipline (many of which also originated in physics).

For physicists, this distant relationship with math is a sign that theres a lot more they need to understand about the theory they birthed. Every other idea thats been used in physics over the past centuries had its natural place in mathematics, said Seiberg. This is clearly not the case with quantum field theory.

And for mathematicians, it seems as if the relationship between QFT and math should be deeper than the occasional interaction. Thats because quantum field theories contain many symmetries, or underlying structures, that dictate how points in different parts of a field relate to each other. These symmetries have a physical significance they embody how quantities like energy are conserved as quantum fields evolve over time. But theyre also mathematically interesting objects in their own right.

A mathematician might care about a certain symmetry, and we can put it in a physical context. It creates this beautiful bridge between these two fields, said Castro.

Mathematicians already use symmetries and other aspects of geometry to investigate everything from solutions to different types of equations to the distribution of prime numbers. Often, geometry encodes answers to questions about numbers. QFT offers mathematicians a rich new type of geometric object to play with if they can get their hands on it directly, theres no telling what theyll be able to do.

Were to some extent playing with QFT, said Dan Freed, a mathematician at the University of Texas, Austin. Weve been using QFT as an outside stimulus, but it would be nice if it were an inside stimulus.

Mathematics does not admit new subjects lightly. Many basic concepts went through long trials before they settled into their proper, canonical places in the field.

Take the real numbers all the infinitely many tick marks on the number line. It took math nearly 2,000 years of practice to agree on a way of defining them. Finally, in the 1850s, mathematicians settled on a precise three-word statement describing the real numbers as a complete ordered field. Theyre complete because they contain no gaps, theyre ordered because theres always a way of determining whether one real number is greater or less than another, and they form a field, which to mathematicians means they follow the rules of arithmetic.

Those three words are historically hard fought, said Freed.

In order to turn QFT into an inside stimulus a tool they can use for their own purposes mathematicians would like to give the same treatment to QFT they gave to the real numbers: a sharp list of characteristics that any specific quantum field theory needs to satisfy.

A lot of the work of translating parts of QFT into mathematics has come from a mathematician named Kevin Costello at the Perimeter Institute. In 2016 he coauthored a textbook that puts perturbative QFT on firm mathematical footing, including formalizing how to work with the infinite quantities that crop up as you increase the number of interactions. The work follows an earlier effort from the 2000s called algebraic quantum field theory that sought similar ends, and which Rejzner reviewed in a 2016 book. So now, while perturbative QFT still doesnt really describe the universe, mathematicians know how to deal with the physically non-sensical infinities it produces.

His contributions are extremely ingenious and insightful. He put [perturbative] theory in a nice new framework that is suitable for rigorous mathematics, said Moore.

Costello explains he wrote the book out of a desire to make perturbative quantum field theory more coherent. I just found certain physicists methods unmotivated and ad hoc. I wanted something more self-contained that a mathematician could go work with, he said.

By specifying exactly how perturbation theory works, Costello has created a basis upon which physicists and mathematicians can construct novel quantum field theories that satisfy the dictates of his perturbation approach. Its been quickly embraced by others in the field.

He certainly has a lot of young people working in that framework. [His book] has had its influence, said Freed.

Costello has also been working on defining just what a quantum field theory is. In stripped-down form, a quantum field theory requires a geometric space in which you can make observations at every point, combined with correlation functions that express how observations at different points relate to each other. Costellos work describes the properties a collection of correlation functions needs to have in order to serve as a workable basis for a quantum field theory.

The most familiar quantum field theories, like the Standard Model, contain additional features that may not be present in all quantum field theories. Quantum field theories that lack these features likely describe other, still undiscovered properties that could help physicists explain physical phenomena the Standard Model cant account for. If your idea of a quantum field theory is fixed too closely to the versions we already know about, youll have a hard time even envisioning the other, necessary possibilities.

There is a big lamppost under which you can find theories of fields [like the Standard Model], and around it is a big darkness of [quantum field theories] we dont know how to define, but we know theyre there, said Gaiotto.

Costello has illuminated some of that dark space with his definitions of quantum fields. From these definitions, hes discovered two surprising new quantum field theories. Neither describes our four-dimensional universe, but they do satisfy the core demands of a geometric space equipped with correlation functions. Their discovery through pure thought is similar to how the first shapes you might discover are ones present in the physical world, but once you have a general definition of a shape, you can think your way to examples with no physical relevance at all.

And if mathematics can determine the full space of possibilities for quantum field theories all the many different possibilities for satisfying a general definition involving correlation functions physicists can use that to find their way to the specific theories that explain the important physical questions they care most about.

I want to know the space of all QFTs because I want to know what quantum gravity is, said Castro.

Theres a long way to go. So far, all of the quantum field theories that have been described in full mathematical terms rely on various simplifications, which make them easier to work with mathematically.

One way to simplify the problem, going back decades, is to study simpler two-dimensional QFTs rather than four-dimensional ones. A team in France recently nailed down all the mathematical details of a prominent two-dimensional QFT.

Other simplifications assume quantum fields are symmetrical in ways that dont match physical reality, but that make them more tractable from a mathematical perspective. These include supersymmetric and topological QFTs.

The next, and much more difficult, step will be to remove the crutches and provide a mathematical description of a quantum field theory that better suits the physical world physicists most want to describe: the four-dimensional, continuous universe in which all interactions are possible at once.

This is [a] very embarrassing thing that we dont have a single quantum field theory we can describe in four dimensions, nonperturbatively, said Rejzner. Its a hard problem, and apparently it needs more than one or two generations of mathematicians and physicists to solve it.

But that doesnt stop mathematicians and physicists from eyeing it greedily. For mathematicians, QFT is as rich a type of object as they could hope for. Defining the characteristic properties shared by all quantum field theories will almost certainly require merging two of the pillars of mathematics: analysis, which explains how to control infinities, and geometry, which provides a language for talking about symmetry.

Its a fascinating problem just in math itself, because it combines two great ideas, said Dijkgraaf.

If mathematicians can understand QFT, theres no telling what mathematical discoveries await in its unlocking. Mathematicians defined the characteristic properties of other objects, like manifolds and groups, long ago, and those objects now permeate virtually every corner of mathematics. When they were first defined, it would have been impossible to anticipate all their mathematical ramifications. QFT holds at least as much promise for math.

I like to say the physicists dont necessarily know everything, but the physics does, said Ben-Zvi. If you ask it the right questions, it already has the phenomena mathematicians are looking for.

And for physicists, a complete mathematical description of QFT is the flip side of their fields overriding goal: a complete description of physical reality.

I feel there is one intellectual structure that covers all of it, and maybe it will encompass all of physics, said Seiberg.

Now mathematicians just have to uncover it.

See the article here:

The Mystery at the Heart of Physics That Only Math Can Solve - Quanta Magazine

Alumna Sheds Light on Mysterious World of Theoretical Physics – UKNow

LEXINGTON, Ky. (June 10, 2021) In theoretical physics, a significant outstanding challenge is the mathematical description of the collective motion of electrons in synthetic materials. Despite nearly a century of research, the subtle laws of quantum mechanics in this regime remain poorly understood.

But a University of Kentucky alumna is leading the field in the right direction.

Nisheeta Desai, a 2020 UK graduate and now postdoctoral fellow at the Tata Institute of Fundamental Research, in collaboration with her mentor Ribhu Kaul, in the UK Department of Physics and Astronomy, has developed a theory that sheds new light on these mysteries. Their work, which recently published in Nature Physics, shows how the quantum motion of a synthetic material can be controlled by external magnetic fields. Such magnets may be key to realizing new quantum technologies.

In our work, we study interactions between a large number of particles and their effecton properties of the material, Desai said. We devise models of electronic spins in atoms interacting with each other. The spin is a quantum mechanical property of an electron and interactions between different spins affect the properties of the material on a large scale. For example, when spins in neighboring atoms tend to align parallelly with each other, it gives rise to magnetism.

Desai and her team, which included experimental groups from Estonia, Princeton and Johns Hopkins University, used a synthetic material called cobalt niobate in their study which exhibits magnetism along with significant quantum effects. By using a modern time-domain spectroscopy experimental technique (which historically played a crucial role in the development of quantum mechanics by allowing the observations of quantized energy levels of atoms) and sophisticated theoretical simulations of quantum matter, the team found that a very simple model explains many of the essential features of the experiment.

The agreement between results from our computational simulations and those from the experiment is remarkable, she said.

Progress in thetheory of quantum materialscould lead to unfathomable new technological revolutions, including the mass production of quantum computers, of which there are only a handful of machines in the world currently.

The models of interacting spins can be used to explain natural phenomena such as magnetism and destruction of magnetic order due to quantum effects, Desai said.Studies of such models can shed light on phases of materials that cannot be explained using purely classical physics.

Originally from Mumbai, India, Desai joined the graduate program at UK in 2014. During that time, she was awarded the Keith B. MacAdam Graduate Excellence Fellowship, the departments most prestigious award. In addition to the Nature Physics article,Desai has also published as first author in Physical Review Letters, one of the most prestigious journals in the field of physics, among many other publications.

"Nisheetadidexceptionally well in hercareer as a Ph.D. student at UK. She has also developed independent collaborations with various scientists across the world during her time here and is well on her way to a successful career as a scientist, said Kaul. This research would not have been possible without the exceptional atmosphere in our department. The combination of world-class physicists and a collegial supportive environment is somethingvery special to UK. I feel very lucky to be part of this department."

Desai says her six years at UK contributed greatly to both her personal and professional growth.

I found the environment in the department to be very pleasantand stimulating, she said. Theculture in the condensed matter theory groupwas instrumental in my development as a researcher. I metmanywonderful and inspiring people here (including my husband!) and gotto work on veryinteresting problems.

Through her achievements and success, Kaul and his colleagues consider Desai a role model to the next generation of women Ph.D. students in their department. While women are underrepresented in physics, Desai says she is optimistic about the future.

When I taught undergraduates at UK as a TA, I saw a clear mentalblock forthe subject, especially among female students, she said. It is hard to ignore unconscious biases in society, especially when there are relatively few female role modelsin physics. Nevertheless, it is impossible to overlook thesignificant contributionswomen have made to physics historically despite all the barriers theyfaced.

Her advice to women, or any student startingout their careers in physics research: focus on one thing at a time, and do it well.

It is easy to get discouraged if you try to do something very difficult all at once, she said. It is also important to remember that the process of scientific enquiry is a humbling one and it requires you to constantly challenge your biases and assumptions in the face of new evidence. It is a lifelong process of learning that progressivelymakes you more objective, open minded and rational.

When it comes to her own career, Desai says she is inspired to know she is a small part of humankinds noble pursuit of knowledge.

When I witness the accomplishments of other people in my field, especially my peers, I get motivated to try my best and contribute my bit towardexpanding the vast body of knowledge, she said. I like to think I am making the world a little better every day in this way.

Research reported in this publication was supported by theNational Science Foundationunder Award Number1611161.The opinions, findings, and conclusions or recommendations expressed are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

See original here:

Alumna Sheds Light on Mysterious World of Theoretical Physics - UKNow

Subatomic Particle Seen Changing to Antiparticle and Back for the First Time in Extraordinary Experiment – SciTechDaily

A team of physicists, including the University of Warwick, have proved that a subatomic particle can switch into its antiparticle alter-ego and back again, in a new discovery just revealed last week.

This new result shows for the first time that charm mesons can oscillate between the two states.

An extraordinarily precise measurement made by UK researchers using the LHCb experiment at CERN has provided the first evidence that charm mesons can change into their antiparticleand back again.

For more than 10 years, scientists have known that charm mesons, subatomic particles that contain a quark and an antiquark, can travel as a mixture of their particle and antiparticle states, a phenomenon called mixing. However, this new result shows for the first time that they can oscillate between the two states.

Armed with this new evidence, scientists can try to tackle some of the biggest questions in physics around how particles behave outside of the Standard Model. One being, whether these transitions are caused by unknown particles not predicted by the guiding theory.

The Large Hadron Collider tunnel. Credit: CERN

The research, submitted today to Physical Review Letters and available onarXiv, received funding from the Science and Technology Facilities Council (STFC).

Being one and the other

In the strange world of quantum physics, the charm meson can be itself and its antiparticle at once. This state, known as quantum superposition, results in two particles each with their own mass a heavier and lighter version of the particle. This superposition allows the charm meson to oscillate into its antiparticle and back again.

Using data collected during the second run of the Large Hadron Collider, researchers from the University of Oxford measured a difference in mass between the two particles of 0.00000000000000000000000000000000000001 grams or in scientific notation 110-38g. A measurement of this precision and certainty is only possible when the phenomenon is observed many times, and this is only possible due so many charm mesons being produced in LHC collisions.

As the measurement is extremely precise, the research team ensured the analysis method was even more so. To do this, the team used a novel technique originally developed by colleagues at the University of Warwick.

The LHCb experiment at CERN. Credit: CERN

There are only four types of particle in the Standard Model, the theory that explains particle physics, that can turn into their antiparticle. The mixing phenomenon was first observed in Strange mesons in the 1960s and in beauty mesons in the 1980s. Until now, the only other one of the four particles that has been seen to oscillate this way is the strange-beauty meson, a measurement made in 2006.

Professor Guy Wilkinson at University of Oxford, whose group contributed to the analysis, said:

What makes this discovery of oscillation in the charm meson particle so impressive is that, unlike the beauty mesons, the oscillation is very slow and therefore extremely difficult to measure within the time that it takes the meson to decay. This result shows the oscillations are so slow that the vast majority of particles will decay before they have a chance to oscillate. However, we are able to confirm this as a discovery because LHCb has collected so much data.

Professor Tim Gershon at University of Warwick, developer of the analytical technique used to make the measurement, said:

Charm meson particles are produced in protonproton collisions and they travel on average only a few millimeters before transforming, or decaying, into other particles. By comparing the charm meson particles that decay after traveling a short distance with those that travel a little further, we have been able to measure the key quantity that controls the speed of the charm meson oscillation into anti-charm meson the difference in mass between the heavier and lighter versions of charm meson.

This discovery of charm meson oscillation opens up a new and exciting phase of physics exploration; researchers now want to understand the oscillation process itself, potentially a major step forward in solving the mystery of matter-antimatter asymmetry. A key area to explore is whether the rate of particle-antiparticle transitions is the same as that of antiparticle-particle transitions, and specifically whether the transitions are influenced/caused by unknown particles not predicted by the Standard Model.

Dr. Mark Williams at University of Edinburgh, who convened the LHCb Charm Physics Group within which the research was performed, said:

Tiny measurements like this can tell you big things about the Universe that you didnt expect.

The result, 110-38g, crosses the five sigma level of statistical significance that is required to claim a discovery in particle physics.

Reference: Observation of the mass difference between neutral charm-meson eigenstates by LHCb collaboration: R. Aaij, C. Abelln Beteta, T. Ackernley, B. Adeva, M. Adinolfi, H. Afsharnia, C.A. Aidala, S. Aiola, Z. Ajaltouni, S. Akar, J. Albrecht, F. Alessio, M. Alexander, A. Alfonso Albero, Z. Aliouche, G. Alkhazov, P. Alvarez Cartelle, S. Amato, Y. Amhis, L. An, L. Anderlini, A. Andreianov, M. Andreotti, F. Archilli, A. Artamonov, M. Artuso, K. Arzymatov, E. Aslanides, M. Atzeni, B. Audurier, S. Bachmann, M. Bachmayer, J.J. Back, P. Baladron Rodriguez, V. Balagura, W. Baldini, J. Baptista Leite, R.J. Barlow, S. Barsuk, W. Barter, M. Bartolini, F. Baryshnikov, J.M. Basels, G. Bassi, B. Batsukh, A. Battig, A. Bay, M. Becker, F. Bedeschi, I. Bediaga, A. Beiter, V. Belavin, S. Belin, V. Bellee, K. Belous, I. Belov, I. Belyaev, G. Bencivenni, E. Ben-Haim, A. Berezhnoy, R. Bernet, D. Berninghoff, H.C. Bernstein, C. Bertella, A. Bertolin, C. Betancourt, F. Betti, Ia. Bezshyiko, S. Bhasin, J. Bhom, L. Bian, M.S. Bieker, S. Bifani, P. Billoir, M. Birch, F.C.R. Bishop, A. Bitadze, A. Bizzeti, M. Bjrn, M.P. Blago, T. Blake, F. Blanc, S. Blusk, D. Bobulska, J.A. Boelhauve, O. Boente Garcia, T. Boettcher, A. Boldyrev, A. Bondar, N. Bondar, S. Borghi, M. Borisyak, M. Borsato, J.T. Borsuk, S.A. Bouchiba, T.J.V. Bowcock, A. Boyer, C. Bozzi, M.J. Bradley et al., Submitted, Physical Review Letters.arXiv: 2106.03744

More:

Subatomic Particle Seen Changing to Antiparticle and Back for the First Time in Extraordinary Experiment - SciTechDaily

Some Scientists Believe the Universe Is Conscious – Popular Mechanics

In upcoming research, scientists will attempt to show the universe has consciousness. Yes, really. No matter the outcome, well soon learn more about what it means to be consciousand which objects around us might have a mind of their own.

What will that mean for how we treat objects and the world around us? Buckle in, because things are about to get weird.

The basic definition of consciousness intentionally leaves a lot of questions unanswered. Its the normal mental condition of the waking state of humans, characterized by the experience of perceptions, thoughts, feelings, awareness of the external world, and often in humans (but not necessarily in other animals) self-awareness, according to the Oxford Dictionary of Psychology.

Scientists simply dont have one unified theory of what consciousness is. We also dont know where it comes from, or what its made of.

However, one loophole of this knowledge gap is that we cant exhaustively say other organisms, and even inanimate objects, dont have consciousness. Humans relate to animals and can imagine, say, dogs and cats have some amount of consciousness because we see their facial expressions and how they appear to make decisions. But just because we dont relate to rocks, the ocean, or the night sky, that isnt the same as proving those things dont have consciousness.

This is where a philosophical stance called panpsychism comes into play, writes All About Spaces David Crookes:

Its also where physics enters the picture. Some scientists have posited that the thing we think of as consciousness is made of micro-scale quantum physics events and other spooky actions at a distance, somehow fluttering inside our brains and generating conscious thoughts.

One of the leading minds in physics, 2020 Nobel laureate and black hole pioneer Roger Penrose, has written extensively about quantum mechanics as a suspected vehicle of consciousness. In 1989, he wrote a book called The Emperors New Mind, in which he claimed that human consciousness is non-algorithmic and a product of quantum effects.

Lets quickly break down that statement. What does it mean for human consciousness to be algorithmic? Well, an algorithm is simply a series of predictable steps to reach an outcome, and in the study of philosophy, this idea plays a big part in questions about free will versus determinism.

Are our brains simply cranking out math-like processes that can be telescoped in advance? Or is something wild happening that allows us true free will, meaning the ability to make meaningfully different decisions that affect our lives?

Within philosophy itself, the study of free will dates back at least centuries. But the overlap with physics is much newer. And what Penrose claimed in The Emperors New Mind is that consciousness isnt strictly causal because, on the tiniest level, its a product of unpredictable quantum phenomena that dont conform to classical physics.

So, where does all that background information leave us? If youre scratching your head or having some uncomfortable thoughts, youre not alone. But these questions are essential to people who study philosophy and science, because the answers could change how we understand the entire universe around us. Whether or not humans do or dont have free will has huge moral implications, for example. How do you punish criminals who could never have done differently?

In physics, scientists could learn key things from a study of consciousness as a quantum effect. This is where we rejoin todays researchers: Johannes Kleiner, mathematician and theoretical physicist at the Munich Center For Mathematical Philosophy, and Sean Tull, mathematician at the University of Oxford.

Kleiner and Tull are following Penroses example, in both his 1989 book and a 2014 paper where he detailed his belief that our brains microprocesses can be used to model things about the whole universe. The resulting theory is called integrated information theory (IIT), and its an abstract, highly mathematical form of the philosophy weve been reviewing.

In IIT, consciousness is everywhere, but it accumulates in places where its needed to help glue together different related systems. This means the human body is jam-packed with a ton of systems that must interrelate, so theres a lot of consciousness (or phi, as the quantity is known in IIT) that can be calculated. Think about all the parts of the brain that work together to, for example, form a picture and sense memory of an apple in your minds eye.

The revolutionary thing in IIT isnt related to the human brainits that consciousness isnt biological at all, but rather is simply this value, phi, that can be calculated if you know a lot about the complexity of what youre studying.

If your brain has almost countless interrelated systems, then the entire universe must have virtually infinite ones. And if thats where consciousness accumulates, then the universe must have a lot of phi.

Hey, we told you this was going to get weird.

The theory consists of a very complicated algorithm that, when applied to a detailed mathematical description of a physical system, provides information about whether the system is conscious or not, and what it is conscious of, Kleiner told All About Space. If there is an isolated pair of particles floating around somewhere in space, they will have some rudimentary form of consciousness if they interact in the correct way.

Kleiner and Tull are working on turning IIT into this complex mathematical algorithmsetting down the standard that can then be used to examine how conscious things operate.

Think about the classic philosophical comment, I think, therefore I am, then imagine two geniuses turning that into a workable formula where you substitute in a hundred different number values and end up with your specific I am answer.

The next step is to actually crunch the numbers, and then to grapple with the moral implications of a hypothetically conscious universe. Its an exciting time to be a philosopheror a philosophers calculator.

This content is created and maintained by a third party, and imported onto this page to help users provide their email addresses. You may be able to find more information about this and similar content at piano.io

More here:

Some Scientists Believe the Universe Is Conscious - Popular Mechanics

How Do You Explain Quantum Computing To Your Dog (And Other Important People in Your Life)? – Medium

Image credit: Russell Huffman

By Ryan F. Mandelbaum and Olivia Lanes

What is Quantum Computing? Most of this blogs readers are already excited about this technology after all, weve spent many hours reading textbooks and documentation trying to figure out how to write programs for real quantum chips. But many of our friends, family members, and people we randomly encounter still scratch their heads when they hear the words quantum and computer put together. We think its high time that they learn about quantum computing, too.

Partially inspired by Talia Gershons awesome WIRED video where she explains quantum computing at five different difficulty levels, we came up with some stock quantum computing explanations you can use to start spreading your excitement for quantum computing to other people in your life (or, if youre new here, use to understand quantum yourself). While were excited about this technology, we tried our best to sidestep the hype; quantum computers are exciting enough on their own, and theres no need to exaggerate how far along they are, what they can do today, or what we hope theyll do in the future.

But, no matter who youre trying to explain quantum to, theres a core understanding we think everyone should have. A quantum computer is similar to a classical computer in a lot of ways. Just like a classical computer, you store information using some physical system. You have to initialize that system, then perform some sort of operations on it (in other words, run a program), and then extract the information. It differs from classical computing in two key elements, however:

These core counterintuitive ideas underlie the fundamental operations of quantum computing. Once you understand these two pieces, the rest is a matter of how deep youd like to learn, and how quantum algorithms might provide benefits to you, your life, or the industry you work in. You should also get started using Qiskit.

Each of these explanations are based mainly on our experiences and opinions, and you might have your own tricks to help get quantum computing across feel free to tell us about them, what worked, and what didnt in the comments!

Some problems are really hard for todays computers to tackle, like designing drugs, running machine learning algorithms, and solving certain kinds of math equations. But the ability to solve those problems could help humankind tackle some of its biggest challenges. Well, quantum computers represent a new kind of computing system under development today that solves problems using an architecture that follows the most fundamental laws of nature and we hope theyll one day be able to to solve these hard problems. You can even try them out for yourself.

Hey, you know what a computer is but do you know how it works? Well basically, it thinks of everything, the YouTube videos you watch, the letters on the screen, everything, in a special kind of code. Programs and apps are basically just instructions that change the code around, leading to the results you see on the screen. But theres only so many different kinds of things that a regular computer can do with that code. A quantum computer works similarly to a regular computer, but its code looks a little different, and it can do even more things to those codes than your parents computers can. Quantum computers are really new, so theyre not better than a regular computer juuust yet but we think that one day they might be able to solve some of the biggest challenges in the world. Maybe it will even help you do your homework faster or something.

What do I do for work? Well *cracks knuckles*

So, there are some problems that people would like to solve that take even the best supercomputers a ridiculously long amount of time to run problems like simulating chemistry or breaking big numbers into smaller factors. Quantum computers might be able to tackle these problems by relying on a different set of physical laws than your computer does. Your computer is really just lots of electrical switches, called bits, that represents everything using binary code. In other words, the language your computer speaks encodes everything as long strings of 0s or 1s, while programs are mathematical operations that can change zeros to ones and vice versa. However, at even at the most fundamental level, a quantum computers code and its corresponding hardware looks differently. Quantum bits, or qubits, dont have to be binary during the calculation; they can actually exist in well-defined combinations of 0 and 1.

Its kind of like, if I was a qubit, instead of having mashed potatoes OR asparagus, I can have a third of a helping of mashed potatoes and two thirds of a helping of asparagus so long as it adds up to a whole side dish. However, once the problem ends, the quantum computers can only give answers in binary code, with some probability determining the outcome. Its like, if someone wanted to know which side dish I had, they check by closing their eyes, shoving their fork onto my plate, and reporting only the first side dish they taste, with the probabilities determined by how much of each side I had on my plate when they went in for a bite. Qubits also interact differently from regular bits. Lets say that Olivia and Ryan are both at dinner, and you only know that between them theyve eaten a helping of potatoes and a helping of asparagus, and not whose dish has what sides on it. But even if they havent spoken since dinner started, if you did the same eyes-closed fork jab you did on my plate, the sides they picked will be more correlated than the usual rules of random guessing would allow.

A direct consequence of this quantum dinner behavior is that there exist different types of algorithms for quantum computers. In fact, due to the quantum nature of the processor, scientists have already shown that at least theoretically, some quantum algorithms can be run exponentially faster than their classical counterparts. Provided that we can build the hardware, all these sorts of near-impossible problems may one day have solutions within arms reach. Anyway, thats what I do at work. Can you pass the gravy?

Editor Note: While thankfully we havent encountered a large contingency of quantum computing conspiracies, hype and tabloid coverage has led to some worrying interpretations of what quantum can and cant do some indeed bordering on conspiracy-minded thinking. But according to at least one expert, the best way to speak with conspiracy theorists isnt with facts but with empathy.

Oh, youre worried about quantum computers? Whys that? I was actually really interested in learning more about them, too, and I didnt understand them at first. What have you learned so far? Huh, thats interesting. So far, Ive learned that some research labs are working on a new kind of computer that can solve certain problems that classical computers cant. I was definitely really interested in the science behind it. See, theyre more or less just computer processors that rely on a system of bits to solve problems. However, these quantum bits can perform a richer set of mathematical operations than classical bits, which makes them better at solving certain problems. What did you read that they could do? Portals and new dimensions, huh? Thats really interesting, but no, I did some research on my own and what the media doesnt want you to know is that these computers are more business-y than science fiction-y they might one day be revolutionary for chemistry, machine learning, and other topics. But the media also doesnt want you to know that these computers are still really early in their development like, they forget their information quickly and theres a lot of work to do before theyre something to worry about. There are actually services that let you try them out and program them on your own. Now tell me more about the UFO you saw

Quantum computers are a new kind of computer processor that one day might augment your current computing resources to tackle certain challenges difficult for todays classical computers alone. Quantum processors work in tandem with classical computers as part of a cloud-based computing workflow, providing value by performing mathematical operations challenging for classical processors. While theres no device capable of executing a killer app yet, research has demonstrated that the enhanced capabilities of quantum systems could accelerate the research and development process, and provide value to certain industries in the coming years chemical and materials design, drug development, finance, and machine learning, for example. In one report, Boston Consulting Group predicted that productivity gains by end users of quantum computing, both in cost savings and revenue generation opportunities, could equal $450 billion or more annually. Many Fortune-500 companies have already begun to research and develop domain-specific thought leadership in quantum computing so as to be prepared when the field matures.

Quantum processors are kind of like a GPU in the sense that theyre designed to handle specific tasks that the CPU isnt well-suited to handle. But unlike a GPU, quantum computers work using a different kind of hardware architecture, one that allows them to perform a richer array of logical operations than just Boolean logic. These hardware requirements lead to bulky systems, so todays developers hoping to exploit quantum resources run their code over the cloud, employing both classical and quantum processing power where necessary for their program.

Quantum computers are a nascent technology, so programming them today is can be a lot like writing code in assembly language, stringing individual quantum bits together into circuits using quantum logic gates. These circuits are similar to classical computers in that their programs begin by initializing the qubits into a string of zeroes and ones, then perform operations, then return an output. However, quantum gates can also produce superpositions of strings, creating well-defined combinations of bitstrings (though you can only end up with one of these bitstrings, determined by the rules of probability, at the end of the calculation). Further operations produce entanglement and interference, linking certain qubits together and changing those probability distributions such that certain bitstrings become more likely and certain bitstrings become less likely when you measure the final result.

Given how recently quantum programming languages arose, developers have organized into open source communities like Qiskit where they maintain the code used to access quantum computers. As part of that, theyre designing and implementing quantum algorithms that can run on these devices, and creating modules designed to harness the potential power of quantum computers without having to continually program individual bits kind of like building a higher-level programming language on top of the assembly language with which we access quantum computers today. You can learn more by getting started with Qiskit here!

Quantum mechanics might be confusing, but it can still be incredibly useful, even if youre not a physicist. A computer based on the laws of quantum physics might help solve problems in chemistry, machine learning, or even solving partial differential equations.

Objects following the rules of quantum mechanics can enter states called superpostions. If an objects state is in a superposition of 0 and 1, that means that the object is in a linear combination of both values simultaneously until a measurement forces the object into one state or the other, with the probability of measuring either state based on the coefficients of each state in the linear combination. These objects can also become entangled, meaning you cannot describe one object mathematically on its own; when we perform experiments on entangled particles, we find that their properties are more correlated than classical physics would otherwise allow. We use these principles to construct sets of quantum bits, or qubits. I cant know each qubit value individually I can only create these linear combinations from states that include both qubits. But if I measure one qubit and force it to choose, lets say it ends up measuring 1, then the other qubit will take on a value highly correlated with the first value more correlated than random chance alone would allow. We use these ideas to generate interference, where certain combinations of qubit values become more likely and certain ones become less likely.

In a classical computer, computational spaces add together, because bits can exist in only one state or the other, 0 or 1. In a quantum computer, the computational space grows exponentially as you add more bits (2^n where n is the number of bits) so its easy to understand how they can become powerful computational tools. Furthermore, there are certain problems that are hard for classical computers to compute. Because quantum computers themselves rely on quantum physics, they are better able to simulate quantum mechanical phenomena, like chemical interactions and bonds. Though the devices are noisy and error prone today, researchers hope that quantum computers will be able to utilize the properties of entanglement and interference to run some algorithms faster than a classical computer can, making solutions to these hard problems finally feasible. Together, these benefits might one day allow scientists to perform various elements of their jobs faster.

Macroscopic quantum effects have long been observed in superconducting circuits. However, it wasnt until theoretical developments showing that flux and voltage can be quantized circuit QED that this idea was applied to quantum information processing.

A superconducting transmon qubit is essentially a quantized anharmonic oscillator. The circuits macro state can be described by the quantized energy levels; the ground state (0), the excited state (1), or even higher order excited states as well (2, 3, 4, etc.). But because the circuit is anharmonic the energy transitions between states 0 and 1 is different than 1 and 2, so we can isolate the bottom levels with a microwave pulse at that frequency to create a quantum bit for information processing.

In order to read-out and control the state of a transmon, we couple the qubit to either a 2D or 3D resonator (the physics is the same). The qubit and the resonator interact in such a way that when we probe the resonator with a standing microwave tone, the resonant frequency will actually shift depending on if the qubit is in the ground or excited state. This is how we can read out and interact with the qubits that make up a quantum computer.

Coupling these qubit-cavity systems together in an array and allowing them to talk to other another with 2-qubit gates (essentially more finely tuned microwave pulses) creates a quantum processor. Running specific gates in a specific order on this processor can create quantum algorithms. By leveraging the processors quantum properties of entanglement, superposition and interference, some quantum algorithms can theoretically be run significantly faster than their classical counterparts. Once we have reached the point where applying these algorithms has become useful and advantageous, we will have achieved what we call the era of quantum advantage.

Whispers: Hey there, pup, listen. I told my boss I would be able to teach you quantum computing, but you barely understand how your doggy door works. So heres what Im gonna do. Im gonna train you how to give me your left paw when I say initialize. Then youre gonna give me your right paw when I say X-gate. Then when I say Hadamard gate, youre going to hop on your hind legs and give me both paws. When I say CNOT, youre going to roll over, and when I say measure, youre going to bark. If you do this for me Ill cut some salami up into your dinner tonight.

Hey, Boss! Yeah! I finally figured out how to explain quantum computing to the dog! Yep, Ill write it all down in the blog post tonight. Wanna see?

Get started using Qiskit here!

Read the original:

How Do You Explain Quantum Computing To Your Dog (And Other Important People in Your Life)? - Medium

CU the site of one of the last government-commissioned reports on UFOs. What does it say? – CU Boulder Today

Later this month, U.S. intelligence agencies are expected to present to Congress a highly anticipated unclassified report detailing what they know about unidentified flying objects (UFOs).

According to unnamed officials reported to have been briefed on its contents, the task forcedid not find evidence that the unexplained aerial phenomena (likened to UFOs) that Navy pilots have witnessed in recent years are alien spacecrafts. But the report does not definitively say they aren't.

One of the last government-commissioned reports on UFOs was conducted right here at CU Boulder and resides in the archives at University Libraries. Edward Condon, a former professor of physics and astrophysics, was given $300,000 to produce a thousand-page report named The Scientific Study of Unidentified Flying Objects,or the Condon Report, as it became known.

Heather Bowden, head of Rare and Distinctive Collections, has preserved and reviewed the Condon Reportand spoke with CU Boulder Today about what it found.

Head of Rare and Distinctive Collections Heather Bowden

Edward U. Condon (190274), a former professor of physics and astrophysics and fellow of the Joint Institute of Laboratory Astrophysics (JILA), was a prominent theoretical physicist who made substantial contributions in academia, industry and government. He had a major impact in the development of scientific fields such as quantum mechanics, nuclear science and electronicsbut was most known for his report on UFOs.

The Condon Report was commissioned by the United States Air Force in the mid-1960s with the aim of producing an unbiased scientific investigation into the possibility that unidentified flying objects may be of extraterrestrial origin. The decision to conduct the study came from a March 1966 report from an ad hoc committee of the Air Force Scientific Advisory Board tasked with reviewing this issue.

The collection contains documents, journals, research papers, international newsletters, film reels of suspected sightings and books gathered during Condon's commissioned study.

In the first section, Condon reported, Our general conclusion is that nothing has come from the study of UFOs in the past 21 years that has added to science knowledge, meaning the researchers involved in the project did not find conclusive evidence there have been sightings of UFOs that were crafted by remote galactic or intergalactic civilizations.

The 2021 government-commissioned UFO report came to a similar conclusion, according to unnamed sources cited in articles from The New York Times and CNN, but did not rule out the possibility that alien life exists.

How studying UFOs could lead to new scientific breakthroughs

This month, a Pentagon task force will release a long-awaited report digging into a topic typically relegated to science fiction movies and tabloids: unidentified flying objects. Professor Carol Cleland talks about the report and why scientists should take weird and mysterious observations seriously.

Im always most fascinated by the handwritten materials and scraps of notes that accompany published pieces like the report, because it lends a human element to something that could otherwise be considered clinical and dry.I also think the film reels would be fascinating to watch.

Students can access materials from the collection when Norlin Library reopens this fall by contacting rad@colorado.edu to schedule an appointment in the Rare and Distinctive Collections (RaD) Reading Room. Students can also check out additional UFO-related University Libraries resources online.

View post:

CU the site of one of the last government-commissioned reports on UFOs. What does it say? - CU Boulder Today

British innovation will be key to success of merger dubbed the ‘Apple of quantum computing’ – Sky News

Quantum computing is one of those technologies that, like artificial intelligence, has been attracting the interest of investors for some time - even though few can actually explain what it involves.

The technology, put very simply, involves harnessing quantum physics - the branch of the science that seeks to describe and explain how and why objects behave and move in the way that they do - to store data or perform computations to a vastly more efficient degree than traditional computers.

Quantum computers are said to be able to operate millions of times faster than existing ones.

A number of governments around the world are pumping capital into the sector in the hope of establishing a lead in the field. They include Germany which, in June last year, announced a 2bn (1.7bn) investment into two new quantum computers.

China, meanwhile, is setting up a national laboratory for quantum information sciences.

But the technology has also been the topic of much debate in investment circles.

Supporters believe it has the potential to transform many industries and sectors, including genetic medicine, pharmacology, financial services and materials development.

Sceptics argue that its vast potential may take many years, if ever, to be realised.

Wednesday, however, brought news of a deal that suggests quantum computing may indeed be on the verge of a breakthrough that could see it being applied more widely across business and industry.

Cambridge Quantum Computing, a British business founded in 2014, announced it is to combine with the quantum solutions arm of the US industrial giant Honeywell.

The pair said the combined business would be "extremely well-positioned to lead the quantum computing industry by offering advanced, fully integrated hardware and software solutions at an unprecedented pace, scale and level of performance to large high-growth markets worldwide".

Honeywell will be the majority shareholder of the new company, with CQ's shareholders, including Ilyas Khan, its founder and chief executive, owning just over 45% of the business.

Mr Khan said that he believed a breakthrough in the quantum computing had already arrived.

He told Sky News: "I think the tipping point was probably in the last 18 months. China, the United States, the United Kingdom, of course, have major programmes and lots of countries and companies have said that they face an existential risk if they don't get quantum computing right.

"In terms of applications, things that we will use on a day to day basis, I think a good analogy is mobile phones - at the end of the 1980s, before they arrived, nobody really knew that they're going to use them and of course, when they did arrive, the markets and their usage exploded.

"I would imagine that later on this year things like cyber security, for example, will be offering unhackable keys using the quantum computer, and it will begin to be more and more useful. Maybe the more esoteric uses are probably a couple of years away, machine learning, for example, [or] material discovery."

He said the combined business would be a "global powerhouse" capable of creating and commercialising quantum solutions that address "some of humanity's greatest challenges".

British tech start-ups are often accused of selling out too early but Mr Khan, who will lead the combined business, could not be described as such.

He added: "The UK is the leader in quantum and this is the first time since the Second World War that a major technology initiative is not being driven by Silicon Valley. We are a software and an algorithm provider and the merger creates an integrated business.

"[It will be] what I would describe as an Anglo American, actually a global business. The characterisation of a sell-out, I think, is probably not one I would agree with."

Honeywell will be investing between $270m (190m) and $300m (211m) in the new venture and Mr Khan said this money would be invested, predominantly, in people.

At the start of its life, the enlarged business will be employing around 350 people, of whom 200 are scientists - more than half of them boasting doctorates in disciplines such as chemistry, physics and maths.

Mr Khan went on: "This is a business where we are in scaling and growth mode - so it's primarily people. We will probably grow quite rapidly as far as the numbers are concerned, both in the United Kingdom, and in the United States, and then a reasonable amount of that capital will be in continuing to increase the capacity of the quantum computers. We have the world's best performing computer right now - and we will be deploying that for customer usage over the course of the next few years."

Hinting at a forthcoming stock market flotation of the business, Mr Khan said there would also be a fund-raising at some point in the near future, in which outside investors would be able to buy a stake in the business.

He declined to say what valuation had been put on Cambridge Quantum under the transaction but said some numbers would be released "over the course of the next week or two".

Mr Khan went on: "This is something which is obviously something that I'm very proud of. It's a British winner. The United Kingdom is the leader in this. We are the world's leader and, of course, consequently very valuable."

That reluctance to talk specific numbers is, perhaps, understandable.

Barron's, the influential US financial publication, has already suggested that the enlarged business could be the 'Apple of quantum computing' because the deal brings together Honeywell's expertise in quantum hardware with Cambridge Quantum's expertise in software and algorithms - emulating the way Apple straddles hardware, operating systems, and software applications. Honeywell itself has said that quantum computing will one day be a trillion dollar-a-year industry.

The deal marks another twist in what has been an inspiring story.

Born in Haslingden, in Lancashire, Mr Khan's father was a bus driver and he was brought up in what he told the Lancashire Telegraph in 2009 was a "two up, two down terrace". Educated at Haslingden Grammar School and University of London School of Oriental and African Studies, he want into banking on graduating, spending 20 years of his career in Hong Kong.

He first came to public attention when, in 2009, he rescued Accrington Stanley FC and later served as its chairman for three years. He has reportedly sunk more than 2m of his own money into the club over a 20-year period.

On returning to the UK he joined the University of Cambridge's Judge Business School and chairman of the Stephen Hawking Foundation and it was a comment from the late Professor Hawking, a friend, who prompted him to start Cambridge Quantum.

He told The Quantum Daily last year: "The prompt really came from a comment that Stephen made to me in a meeting that we were attending and Stephen said 'this is for real'. This really opened my eyes."

It is just possible that those investors still sceptical about quantum computing may well have had their eyes opened, too, following this deal.

Read the original post:

British innovation will be key to success of merger dubbed the 'Apple of quantum computing' - Sky News

What is an Electron: Its Discovery, Nature and Everything Else | IE – Interesting Engineering

An electron is a stable and negatively charged subatomic particle that also acts as the carrier of electricity. Each electron carries one unit of negative charge (1.602 x 10-19coulomb) and has a mass of just about 1/1836th of a proton.Electrons are found both not permanently attached to atoms andwithin the nucleus.

Quantum mechanics states that electrons can not be distinguished on the basis of any intrinsic property, so all electrons have thesamemass, thesameelectric charge, and thesamespin, so they can freely interchange their positions within a system without causing a noticeable change.

The possibility of electrons was predicted by Richard Laming (1838-1851), and other scientists.Irish physicistG. Johnstone Stoney(1874) coined the term electron in 1891, to refer to the unit of charge in his experiments. In 1897, English physicist Joseph John Thomson discovered electrons while conducting experiments with cathode-ray tubes. He called electrons "corpuscles".

Thomsondirected cathode rays between two parallelaluminumplates to the end of a tube, where they could be observed as luminescence on the glass. When the top aluminum plate was negative, the rays moved down; when the top plate was positive, the rays moved up. This deflection was proportional to the difference in potential between the plates, demonstrating that cathode rays were negatively charged particles.

From this,Thomson made the following hypotheses:

Today, we know that the third hypothesis is not accurate, but this discovery of the electron revolutionized physics and paved the way for developments concerning electricity, gravitation, electromagnetism, thermal conductivity, and many other areas. For his work, Thomson was awarded the 1906 Nobel Prize in Physics.

Prior to Thomson, scientists such as Richard Fleming had previously predicted the possible existence of electrons. The ancient Greeks are said to have discovered that when amber is rubbed with fur, it attracts small objects. The Greek word for amber,elektronwas used for the force that caused this attraction.

Protons and electrons have equal, but opposite charges. Electrons are attracted to positively charged particles, such as protons. Whether or not a substance has a net electric charge is determined by the balance between the number of electrons and the positive charge of atomic nuclei. If there are more electrons than positive charges, a material is said to be negatively charged. If there is an excess of protons, the object is considered to be positively charged. If the number of electrons and protons is balanced, a material is said to be electrically neutral.

The radius of an electron is approximately 2 x 10-10cm.Neutrons and protons, together known as nucleons, form 99.9% of the total atomic massof an atom, and as compared to these particles, electrons have negligible mass value, therefore, the mass of electrons is not considered when the mass number of an atom is calculated.

The symbol for an electron is e and for proton is p+ but, interestingly, protons are not the true antiparticles to electrons. The antiparticle of the electron is the positron, whichhas an electric charge of +1 e, a spin of 1/2 (the same as the electron), and has the same mass as an electron.

Positronsare not found in nature but are formed during the decay of nuclides that have an excess of protons in their nucleus. When decaying takes place, these radionuclides emit apositronand a neutrino.

For any element, the atomic mass number is the total number of protons and neutrons in the nucleus. It is measured in the atomic mass units (amu).

Atomic Mass Number = (Number of Protons) + (Number of Neutrons)

Whereas, the atomic number is the number of protons only. For example, the atomic number of carbon is six, therefore, carbon has six protons in its nucleus and six electrons in the energy orbits surrounding the nucleus.

Electrons are described as surrounding the nucleus of an atom in shells. These are not actual structures but are regions of probability.

Atomic Number = Number of Protons

However, in the case of charged atoms also known as ions, the number of protons and electrons differ and depends on the charge on the atom. The number of neutrons for an atom can be easily calculated by subtracting the number of protons from the total atomic mass number.

Number of Neutrons = Atomic Mass Number - Number of Protons

The nature of the electric charge on any substance is defined by the number of protons and electrons in its nuclei. If the number of protons exceeds the number of electrons, then the substance is positively charged. Where there are more electrons than protons, the substance is said to have an overall negative charge. Any substance is said to be balanced or electrically neutral when the number of protons and electrons is equal.

French physicist Louis De Broglie proposed the wave nature of electrons in his 1924 Ph.D. thesis. He stated that if light and radiation can show dual behavior, then the matter can also exist as both particle and wave.

De Broglie was influenced byAlbert Einsteins theory of relativity and the photoelectric effect. Twenty years earlier, Einstein has proposedthe idea that matter on the atomic scale might exhibit the properties of a wave and a particle.This idea of the dual nature of light was just beginning to gain scientific acceptance when de Broglie extended the idea to include matter.

According to De Broglies hypothesis, any moving object, whether macroscopic or microscopic has its own wavelength, and this wavelength is inversely proportional to the size of the object.

In the years that followed, the American physicists, Clinton Davisson and Lester Germer conducted electron diffraction experiments that further confirmed the dual nature of matter given by De Broglie. In 1929, De Broglie received the Nobel Prize in Physics for his exceptional contribution to quantum physics.

Continued here:

What is an Electron: Its Discovery, Nature and Everything Else | IE - Interesting Engineering

Was Einstein wrong? Why some astrophysicists are questioning the theory of space-time – Space.com

As in history, revolutions are the lifeblood of science. Bubbling undercurrents of disquiet boil over until a new regime emerges to seize power. Then everyone's attention turns to toppling their new ruler. The king is dead, long live the king.

This has happened many times in the history of physics and astronomy. First, we thought Earth was at the center of the solar system an idea that stood for over 1,000 years. Then Copernicus stuck his neck out to say that the whole system would be a lot simpler if we are just another planet orbiting the sun. Despite much initial opposition, the old geocentric picture eventually buckled under the weight of evidence from the newly invented telescope.

Then Newton came along to explain that gravity is why the planets orbit the sun. He said all objects with mass have a gravitational attraction towards each other. According to his ideas we orbit the sun because it is pulling on us, the moon orbits Earth because we are pulling on it. Newton ruled for two-and-a-half centuries before Albert Einstein turned up in 1915 to usurp him with his General Theory of Relativity. This new picture neatly explained inconsistencies in Mercury's orbit, and was famously confirmed by observations of a solar eclipse off the coast of Africa in 1919.

All About Space

This article is brought to you byAll About Space.

All About Spacemagazine takes you on an awe-inspiring journey through our solar system and beyond, from the amazing technology and spacecraft that enables humanity to venture into orbit, to the complexities of space science.

Instead of a pull, Einstein saw gravity as the result of curved space. He said that all objects in the universe sit in a smooth, four-dimensional fabric called space-time. Massive objects such as the sun warp the space-time around them, and so Earth's orbit is simply the result of our planet following this curvature. To us that looks like a Newtonian gravitational pull. This space-time picture has now been on the throne for over 100 years, and has so far vanquished all pretenders to its crown. The discovery of gravitational waves in 2015 was a decisive victory, but, like its predecessors, it too might be about to fall. That's because it is fundamentally incompatible with the other big beast in the physics zoo: Quantum theory.

The quantum world is notoriously weird. Single particles can be in two places at once, for example. Only by making an observation do we force it to 'choose'. Before an observation we can only assign probabilities to the likely outcomes. In the 1930s, Erwin Schrdinger devised a famous way to expose how perverse this idea is. He imagined a cat in a sealed box accompanied by a vial of poison attached to a hammer. The hammer is hooked up to a device that measures the quantum state of a particle. Whether or not the hammer smashes the vial and kills the cat hinges on that measurement, but quantum physics says that until such a measurement is made, the particle is simultaneously in both states, which means the vial is both broken and unbroken and the cat is alive and dead.

Such a picture cannot be reconciled with a smooth, continuous fabric of space-time. "A gravitational field cannot be in two places at once," said Sabine Hossenfelder, a theoretical physicist at the Frankfurt Institute for Advanced Studies. According to Einstein, space-time is warped by matter and energy, but quantum physics says matter and energy exist in multiple states simultaneously they can be both here and over there. "So where is the gravitational field?" asks Hossenfelder. "Nobody has an answer to that question. It's kind of embarrassing," she said.

Try and use general relativity and quantum theory together, and it doesn't work. "Above a certain energy, you get probabilities that are larger than one," said Hossenfelder. One is the highest probability possible it means an outcome is certain. You can't be more certain than certain. Equally, calculations sometimes give you the answer infinity, which has no real physical meaning. The two theories are therefore mathematically inconsistent. So, like many monarchs throughout history, physicists are seeking a marriage between rival factions to secure peace. They're searching for a theory of quantum gravity the ultimate diplomatic exercise in getting these two rivals to share the throne. This has seen theorists turn to some outlandish possibilities.

Arguably the most famous is string theory. It's the idea that sub-atomic particles such as electrons and quarks are made from tiny vibrating strings. Just as you can play strings on a musical instrument to create different notes, string theorists argue that different combinations of strings create different particles. The attraction of the theory is that it can reconcile general relativity and quantum physics, at least on paper. However, to pull that particular rabbit out of the hat, the strings have to vibrate across eleven dimensions seven more than the four in Einstein's space-time fabric. As yet there is no experimental evidence that these extra dimensions really exist. "It might be interesting mathematics, but whether it describes the space-time in which we live, we don't really know until there is an experiment," said Jorma Louko from the University of Nottingham.

Partly inspired by string theory's perceived failings, other physicists have turned to an alternative called Loop Quantum Gravity (LQG). They can get the two theories to play nicely if they do away with one of the central tenets of general relativity: That space-time is a smooth, continuous fabric. Instead, they argue, space-time is made up of a series of interwoven loops that it has structure at the smallest size scales. This is a bit like a length of cloth. At first glance it looks like one smooth fabric. Look closely, however, and you'll see it is really made of a network of stitches. Alternatively, think of it like a photograph on a computer screen: Zoom in, and you'll see it is really made of individual pixels.

The trouble is that when LQG physicists say small, they mean really small. These defects in space-time would only be apparent on the level of the Planck scale around a trillionth of a trillionth of a trillionth of a meter. That's so tiny that there would be more loops in a cubic centimeter of space than cubic centimeters in the entire observable universe. "If space-time only differs on the Planck scale then this would be difficult to test in any particle accelerator," says Louko. You'd need an atom smasher a 1,000-trillion-times more powerful than the Large Hadron Collider (LHC) at CERN. How, then, can you detect space-time defects that small? The answer is to look across a large area of space.

Light arriving here from the furthest reaches of the universe has traveled through billions of light years of space-time along the way. While the effect of each space-time defect would be tiny, over those distances interactions with multiple defects might well add up to a potentially observable effect. For the last decade, astronomers have been using light from far-off Gamma Ray Bursts to look for evidence in support of LQG. These cosmic flashes are the result of massive stars collapsing at the ends of their lives, and there is something about these distant detonations we currently cannot explain. "Their spectrum has a systematic distortion to it," said Hossenfelder, but no one knows if that is something that happens on the way here or if it's something to do with the source of the bursts themselves. The jury is still out.

To make progress, we might have to go a step further than saying space-time isn't the smooth, continuous fabric Einstein suggested. According to Einstein, space-time is like a stage that remains in place whether actors are treading its boards or not even if there were no stars or planets dancing around, space-time would still be there. However, physicists Laurent Freidel, Robert Leigh, and Djordje Minic think that this picture is holding us back. They believe space-time doesn't exist independently of the objects in it. Space-time is defined by the way objects interact. That would make space-time an artifact of the quantum world itself, not something to be combined with it. "It may sound kooky," said Minic, "but it is a very precise way of approaching the problem."

The attraction of this theory called modular space-time is that it might help solve another long-standing problem in theoretical physics regarding something called locality, and a notorious phenomenon in quantum physics called entanglement. Physicists can set up a situation whereby they bring two particles together and link their quantum properties. They then separate them by a large distance and find they are still linked. Change the properties of one and the other will change instantly, as if information has traveled from one to the other faster than the speed of light in direct violation of relativity. Einstein was so perturbed by this phenomenon that he called it 'spooky action at a distance'.

Modular space-time theory can accommodate such behavior by redefining what it means to be separated. If space-time emerges from the quantum world, then being closer in a quantum sense is more fundamental than being close in a physical sense. "Different observers would have different notions of locality," said Minic, it depends on the context. It's a bit like our relationships with other people. We can feel closer to a loved one far away than the stranger who lives down the street. "You can have these non-local connections as long as they are fairly small," said Hossenfelder.

Freidel, Leigh, and Minic have been working on their idea for the last five years, and they believe they are slowly making progress. "We want to be conservative and take things step-by-step," said Minic, "but it is tantalizing and exciting". It's certainly a novel approach, one that looks to "gravitationalize" the quantum world rather than quantizing gravity as in LQG. Yet as with any scientific theory, it needs to be tested. At the moment the trio are working on how to fit time into their model.

This may all sound incredibly esoteric, something only academics should care about, but it could have a more profound effect on our everyday lives. "We sit in space, we travel through time, and if something changes in our understanding of space-time this will impact not only on our understanding of gravity, but of quantum theory in general," said Hossenfelder. "All our present devices only work because of quantum theory. If we understand the quantum structure of space-time better that will have an impact on future technologies maybe not in 50 or 100 years, but maybe in 200," she said.

The current monarch is getting long in tooth, and a new pretender is long overdue, but we can't decide which of the many options is the most likely to succeed. When we do, the resulting revolution could bear fruit not just for theoretical physics, but for all.

Follow this link:

Was Einstein wrong? Why some astrophysicists are questioning the theory of space-time - Space.com