



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: Coarsegraining makes it hard to see micromacro 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 ArticlesA little light interaction leaves quantum physicists beaming A team of physicists at the University of Toronto (U of T) have taken a step toward making the essential building block of quantum computers out of pure light. Drawing a line between quantum and classical world Quantum theory is one of the great achievements of 20th century science, yet physicists have struggled to find a clear boundary between our everyday world and what Albert Einstein called the "spooky" features of the quantum world, including cats that could be both alive and dead, and photons that can communicate with each other across space instantaneously. Seeing a supernova in a new light Type Ia supernovae are the "standard candles" astrophysicists use to chart distance in the Universe. But are these dazzling exploding stars truly all the same? To answer this, scientists must first understand what causes stars to explode and become supernovae. Scientists see ripples of a particleseparating wave in primordial plasma Scientists in the STAR collaboration at the Relativistic Heavy Ion Collider, a particle accelerator exploring nuclear physics and the building blocks of matter at the U.S. Department of Energy's Brookhaven National Laboratory, have new evidence for what's called a "chiral magnetic wave" rippling through the soup of quarkgluon plasma created in RHIC's energetic particle smashups. Squeezed quantum catsQuantum physics is full of fascinating phenomena. Take, for instance, the cat from the famous thought experiment by the physicist Erwin Schrodinger. Researchers find the 'key' to quantum network solution Scientists at the University of York's Centre for Quantum Technology have made an important step in establishing scalable and secure high rate quantum networks. Quantum physics  hot and cold at the same time Temperature is a very useful physical quantity. It allows us to make a simple statistical statement about the energy of particles swirling around on complicated paths without having to know the specific details of the system. A glass fiber that brings light to a standstill Light is an extremely useful tool for quantum communication, but it has one major disadvantage: it usually travels at the speed of light and cannot be kept in place. Super sensitive measurement of magnetic fieldsThere are electrical signals in the nervous system, the brain and throughout the human body and there are tiny magnetic fields associated with these signals that could be important for medical science. Scientists move closer to '2 for 1 deal' on solar cell efficiency The underlying mechanism behind an enigmatic process called "singlet exciton fission", which could enable the development of significantly more powerful solar cells, has been identified by scientists in a new study. More Quantum Physics Current Events and Quantum Physics News Articles

The Elegant Universe: Superstrings, Hidden Dimensions, and the Quest for the Ultimate Theory
by Brian Greene (Author)
The international bestseller that inspired a major Nova special and sparked a new understanding of the universe, now with a new preface and epilogue. Brian Greene, one of the world's leading string theorists, peels away layers of mystery to reveal a universe that consists of eleven dimensions, where the fabric of space tears and repairs itself, and all matter―from the smallest quarks to the most gargantuan supernovas―is generated by the vibrations of microscopically tiny loops of energy. The Elegant Universe makes some of the most sophisticated concepts ever contemplated accessible and thoroughly entertaining, bringing us closer than ever to understanding how the universe works.


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 stepbystep guide to quantum theory, right from the very basic principles to the most cuttingedge developments, such as superfast computers and unbreakable codes, which could soon become reality. Finally, Rae turns to the philosophical questions posed by quantum physics and asks: if...


Quantum Physics: Superstrings, Einstein & Bohr, Quantum Electrodynamics, Hidden Dimensions and Other Most Amazing Physics Theories  Ultimate Beginner's Guide
by Jared Hendricks (Author)
2nd Edition **BONUS** right after the conclution Ever wonder about how light moves? What does it mean to study the smallest particles known to man? How does science measure the smallest particles in the world, such as atoms, protons, neutrons and electrons? What is ether and how did it become a source of debate in the scientific community? Studying the smallest particles known to man can be exciting work. This study of the world on the molecular level, particularly matter and energy, is the realm of Quantum Physics. Scientists use mathematical equations to help them explain the behavior of matter and energy within the Universe. If you have a curiosity about the world of Quantum Physics, but thought the science textbooks would be too much to absorb, this book is for you. With an...


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 onethird 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 nontechnical 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...


ESquared: Nine DoItYourself Energy Experiments That Prove Your Thoughts Create Your Reality
by Pam Grout (Author)
Don’t face reality. Create reality! ESquared could best be described as a lab manual with simple experiments to prove once and for all that reality is malleable, that consciousness trumps matter, and that you shape your life with your mind. Rather than take it on faith, you are invited to conduct nine 48hour experiments to prove there really is a positive, loving, totally hip force in the universe. Yes, you read that right. It says prove. The experiments, each of which can be conducted with absolutely no money and very little time expenditure, demonstrate that spiritual principles are as dependable as gravity, as consistent as Newton’s laws of motion. For years, you’ve been hoping and praying that spiritual principles are true. Now, you can know. ...


Quantum Physics For Dummies
by Steven 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 Applications The Foundations of Quantum Physics Vector Notation Spin Scattering Theory, Angular Momentum, and more Your plainEnglish guide to understanding and working with the micro world Quantum physics — also called quantum mechanics or...


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 cuttingedge 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, easytouse 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.


The Quantum World: Quantum Physics for Everyone
by Kenneth W. Ford (Author), Diane Goldstein (Contributor)
As Kenneth W. Ford shows us in The Quantum World, the laws governing the very small and the very swift defy common sense and stretch our minds to the limit. Drawing on a deep familiarity with the discoveries of the twentieth century, Ford gives an appealing account of quantum physics that will help the serious reader make sense of a science that, for all its successes, remains mysterious. In order to make the book even more suitable for classroom use, the author, assisted by Diane Goldstein, has included a new section of Quantum Questions at the back of the book. A separate answer manual to these 300+ questions is available; visit The Quantum World website for ordering information. There is also a cloth edition of this book, which does not include the "Quantum Questions" included in...


Quantum Field Theory for the Gifted Amateur
by Tom Lancaster (Author), Stephen J. Blundell (Author)
Quantum field theory is arguably the most farreaching 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...


The Fabric of the Cosmos: Space, Time, and the Texture of Reality
by Brian Greene (Author)
From Brian Greene, one of the world’s leading physicists and author the Pulitzer Prize finalist The Elegant Universe, comes a grand tour of the universe that makes us look at reality in a completely different way.
Space and time form the very fabric of the cosmos. Yet they remain among the most mysterious of concepts. Is space an entity? Why does time have a direction? Could the universe exist without space and time? Can we travel to the past? Greene has set himself a daunting task: to explain nonintuitive, mathematical concepts like String Theory, the Heisenberg Uncertainty Principle, and Inflationary Cosmology with analogies drawn from common experience. From Newton’s unchanging realm in which space and time are absolute, to Einstein’s fluid conception of...

