Science Current Events | Science News | Brightsurf.com
 

Quantum cats are hard to see

December 19, 2011
International team of researchers explain the difficulty of detecting quantum effects

Are there parallel universes? And how will we know? This is one of many fascinations people hold about quantum physics. Researchers from the universities of Calgary and Waterloo in Canada and the University of Geneva in Switzerland have published a paper this week in Physical Review Letters explaining why we don't usually see the physical effects of quantum mechanics.

"Quantum physics works fantastically well on small scales but when it comes to larger scales, it is nearly impossible to count photons very well. We have demonstrated that this makes it hard to see these effects in our daily life," says Dr. Christoph Simon, who teaches in the Department of Physics and Astronomy at the University of Calgary and is one of the lead authors of the paper entitled: Coarse-graining makes it hard to see micro-macro entanglement.

It's well known that quantum systems are fragile. When a photon interacts with its environment, even just a tiny bit, the superposition is destroyed. Superposition is a fundamental principle of quantum physics that says that systems can exist in all their possible states simultaneously. But when measured, only the result of one of the states is given.

This effect is known as decoherence, and it has been studied intensively over the last few decades. The idea of decoherence as a thought experiment was raised by Erwin Schrödinger, one of the founding fathers of quantum physics, in his famous cat paradox: a cat in a box can be both dead and alive at the same time.

But, according to the authors of this study, it turns out that decoherence is not the only reason why quantum effects are hard to see. Seeing quantum effects requires extremely precise measurements. Simon and his team studied a concrete example for such a "cat" by using a particular quantum state involving a large number of photons.

"We show that in order to see the quantum nature of this state, one has to be able to count the number of photons in it perfectly," says Simon. "This becomes more and more difficult as the total number of photons is increased. Distinguishing one photon from two photons is within reach of current technology, but distinguishing a million photons from a million plus one is not."

University of Calgary


Related Quantum Physics Current Events and Quantum Physics News Articles


Entanglement made tangible
Quantum entanglement refers to the "pairing" of two subatomic particles in such a way that they form a whole quantum system.

Engineers show light can play seesaw at the nanoscale
University of Minnesota electrical engineering researchers have developed a unique nanoscale device that for the first time demonstrates mechanical transportation of light.

From light into matter, nothing seems to stop quantum teleportation
Physicists at the University of Geneva (UNIGE) have succeeded in teleporting the quantum state of a photon to a crystal over 25 kilometres of optical fibre.

Fluid mechanics suggests alternative to quantum orthodoxy
The central mystery of quantum mechanics is that small chunks of matter sometimes seem to behave like particles, sometimes like waves.

The sound of an atom has been captured
Researchers at Chalmers University of Technology are first to show the use of sound to communicate with an artificial atom.

Atomically thin material opens door for integrated nanophotonic circuits
A new combination of materials can efficiently guide electricity and light along the same tiny wire, a finding that could be a step towards building computer chips capable of transporting digital information at the speed of light.

Can our computers continue to get smaller and more powerful?
From their origins in the 1940s as sequestered, room-sized machines designed for military and scientific use, computers have made a rapid march into the mainstream, radically transforming industry, commerce, entertainment and governance while shrinking to become ubiquitous handheld portals to the world.

Diamonds are a Quantum Computer's Best Friend
The Quantum Computer is the Holy Grail of quantum technology. Its computing power would eclipse even the fastest classical computers we have today.

Mapping the optimal route between two quantum states: when a straight line is not the shortest distance
As a quantum state collapses from a quantum superposition to a classical state or a different superposition, it will follow a path known as a quantum trajectory.

Spin Diagnostics
Magnetic resonance imaging (MRI), which is the medical application of nuclear magnetic resonance spectroscopy, is a powerful diagnostic tool.
More Quantum Physics Current Events and Quantum Physics News Articles

Quantum Physics: A Beginner's Guide (Beginner's Guides)

Quantum Physics: A Beginner's Guide (Beginner's Guides)
by Alastair Rae (Author)


As Alastair Rae points out in his introduction, "quantum physics is not rocket science". It may have gained a reputation as the theory that no one really understands, but its practical applications are all around us in everyday life. If it were not for quantum physics, computers would not function, metals would not conduct electricity, and the power stations that heat our homes would not produce energy. Assuming no prior scientific or mathematical knowledge, this clear and concise introduction provides a step-by-step guide to quantum theory, right from the very basic principles to the most cutting-edge developments, such as super-fast computers and unbreakable codes, which could soon become reality. Finally, Rae turns to the philosophical questions posed by quantum physics and asks: if...

Quantum: Einstein, Bohr, and the Great Debate about the Nature of Reality

Quantum: Einstein, Bohr, and the Great Debate about the Nature of Reality
by Manjit Kumar (Author)


“A lucid account of quantum theory (and why you should care) combined with a gripping narrative.”—San Francisco ChronicleQuantum theory is weird. As Niels Bohr said, if you weren’t shocked by quantum theory, you didn’t really understand it. For most people, quantum theory is synonymous with mysterious, impenetrable science. And in fact for many years it was equally baffling for scientists themselves. In this tour de force of science history, Manjit Kumar gives a dramatic and superbly written account of this fundamental scientific revolution, focusing on the central conflict between Einstein and Bohr over the nature of reality and the soul of science. This revelatory book takes a close look at the golden age of physics, the brilliant young minds at its core—and how an idea...

Why Quantum Physicists Do Not Fail: Learn the Secrets of Achieving Almost Anything Your Heart Desires

Why Quantum Physicists Do Not Fail: Learn the Secrets of Achieving Almost Anything Your Heart Desires
by Greg Kuhn (Author)


Author Greg Kuhn is a professional educator and a futurist, specializing in framing new paradigms for 21st century living. Since 1993, he has written with his father, Clifford Kuhn, M.D., about health, wellness, and productivity. In Why Quantum Physicists Do Not Fail, Greg has unveiled all of his most cutting-edge research into the attainment of your goals and dreams through revolutionary new paradigms from the amazing science of quantum physics. Always entertaining, Greg reveals simple, easy-to-use techniques which you’ll not only master quickly, but also have fun using. Greg is also the author of the acclaimed book, Why Quantum Physicists Don’t Get Fat, which teaches you to finally lose your unwanted weight also using new paradigms from quantum physics.

Quantum Field Theory for the Gifted Amateur

Quantum Field Theory for the Gifted Amateur
by Tom Lancaster (Author), Stephen J. Blundell (Author)


Quantum field theory is arguably the most far-reaching and beautiful physical theory ever constructed, with aspects more stringently tested and verified to greater precision than any other theory in physics. Unfortunately, the subject has gained a notorious reputation for difficulty, with forbidding looking mathematics and a peculiar diagrammatic language described in an array of unforgiving, weighty textbooks aimed firmly at aspiring professionals. However, quantum field theory is too important, too beautiful, and too engaging to be restricted to the professionals. This book on quantum field theory is designed to be different. It is written by experimental physicists and aims to provide the interested amateur with a bridge from undergraduate physics to quantum field theory. The imagined...

Quantum Physics For Dummies

Quantum Physics For Dummies
by Steve Holzner (Author)


Quantum Physics For Dummies, Revised Edition helps make quantum physics understandable and accessible. From what quantum physics can do for the world to understanding hydrogen atoms, readers will get complete coverage of the subject, along with numerous examples to help them tackle the tough equations. Compatible with classroom text books and courses, Quantum Physics For Dummies, Revised Edition lets students study at their own paces and helps them prepare for graduate or professional exams. Coverage includes:The Schrodinger Equation and its ApplicationsThe Foundations of Quantum PhysicsVector NotationSpinScattering Theory, Angular Momentum, and moreYour plain-English guide to understanding and working with the micro worldQuantum physics — also called quantum mechanics or quantum field...

Introducing Quantum Theory: A Graphic Guide to Science's Most Puzzling Discovery

Introducing Quantum Theory: A Graphic Guide to Science's Most Puzzling Discovery
by J.P. McEvoy (Author), Oscar Zarate (Author)


Quantum theory is one of science's most thrilling, challenging and even mysterious areas. Scientists such as Planck, Einstein, Bohr, Heisenberg and Schrödinger uncovered bizarre paradoxes in the early 20th century that seemed to destroy the fundamental assumptions of 'classical physics' - the basic laws we are taught in school. Notoriously difficult, quantum theory is nonetheless an amazing and inspiring intellectual adventure, explained here with patience, wit and clarity.

Quantum Enigma: Physics Encounters Consciousness

Quantum Enigma: Physics Encounters Consciousness
by Bruce Rosenblum (Author), Fred Kuttner (Author)


In trying to understand the atom, physicists built quantum mechanics, the most successful theory in science and the basis of one-third of our economy. They found, to their embarrassment, that with their theory, physics encounters consciousness. Authors Bruce Rosenblum and Fred Kuttner explain all this in non-technical terms with help from some fanciful stories and anecdotes about the theory's developers. They present the quantum mystery honestly, emphasizing what is and what is not speculation. Quantum Enigma's description of the experimental quantum facts, and the quantum theory explaining them, is undisputed. Interpreting what it all means, however, is heatedly controversial. But every interpretation of quantum physics involves consciousness. Rosenblum and Kuttner therefore turn to...

Harnessing the Magic of the Universe

Harnessing the Magic of the Universe





There is magic at work each day creating everything we see around us.

What would you do with the power to take control of this magic and bend it to your will?

"Harnessing" is the first title in the "Magic of the Universe" series. This short guidebook will introduce you to Universal Magic--what it is, what it does and how it works in your life whether you know it or not. What's more, it gives you step-by-step instructions for how to make the Magic work exactly as you demand!

Author and Master Practitioner Joss Conlon shows you how to utilize the power of manifestation, taking control of Universal Magic to help you find happiness, create wealth, and make the life of your dreams a reality. The Conlon method is so simple!

The Quantum Moment: How Planck, Bohr, Einstein, and Heisenberg Taught Us to Love Uncertainty

The Quantum Moment: How Planck, Bohr, Einstein, and Heisenberg Taught Us to Love Uncertainty
by Robert P. Crease (Author), Alfred Scharff Goldhaber (Author)


The fascinating story of how quantum mechanics went mainstream. The discovery of the quantum—the idea, born in the early 1900s in a remote corner of physics, that energy comes in finite packets instead of infinitely divisible quantities—planted a rich set of metaphors in the popular imagination. Quantum imagery and language now bombard us like an endless stream of photons. Phrases such as multiverses, quantum leaps, alternate universes, the uncertainty principle, and Schrödinger's cat get reinvented continually in cartoons and movies, coffee mugs and T-shirts, and fiction and philosophy, reinterpreted by each new generation of artists and writers.Is a "quantum leap" big or small? How uncertain is the uncertainty principle? Is this barrage of quantum vocabulary pretentious and wacky,...

Quantum Mechanics: A Comprehensible Introduction for Students [New Edition with Readable Equations]

Quantum Mechanics: A Comprehensible Introduction for Students [New Edition with Readable Equations]
by Amazon Kindle Direct Publishing


Quantum mechanics is full of mysteries and paradoxes. It has even been regarded as the most difficult subject to understand. The main reason is that unlike classical mechanics, quantum mechanics provides no visualizable spatial-temporal images for the physical processes it describes. It is well understood that classical mechanics describes the continuous motion of particles in space and time. In quantum mechanics, however, it is still unclear how microscopic particles such as electrons move in space and time, and in fact, it is even unknown whether these microscopic particles are really particles or not.

Based on a penetrating analysis of the wave function and its evolution, this book presents a new, comprehensible formulation of quantum mechanics. It turns out that, like...

© 2014 BrightSurf.com