



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

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)
From quarks to computing, this fascinating introduction covers every element of the quantum world in clear and accessible language. Drawing on a wealth of expertise to explain just what a fascinating field quantum physics is, Rae points out that it is not simply a maze of technical jargon and philosophical ideas, but a reality which affects our daily lives.


Quantum Mechanics: The Theoretical Minimum
by Leonard Susskind (Author), Art Friedman (Author)
First he taught you classical mechanics. Now, physicist Leonard Susskind has teamed up with data engineer Art Friedman to present the theory and associated mathematics of the strange world of quantum mechanics.
In this followup to the New York Times bestselling The Theoretical Minimum, Susskind and Friedman provide a lively introduction to this famously difficult field, which attempts to understand the behavior of subatomic objects through mathematical abstractions. Unlike other popularizations that shy away from quantum mechanics' weirdness, Quantum Mechanics embraces the utter strangeness of quantum logic. The authors offer crystalclear explanations of the principles of quantum states, uncertainty and time dependence, entanglement, and particle and wave states, among...


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: 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...


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...


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...


Introduction to Quantum Mechanics
by David J. Griffiths (Author)
This bestselling undergraduate quantum mechanics textbook is now available in a reissued, affordable edition from Cambridge University Press. The text first teaches students how to do quantum mechanics, and then provides them with a more insightful discussion of what it means. The author avoids the temptation to include every possible relevant topic, instead presenting students with material that they can easily focus on in a complete treatment with few distractions and diversions. Fundamental principles are covered, quantum theory is presented, and special techniques are developed for attacking realistic problems. The innovative twopart coverage is entertaining and informative, organizing topics under basic theory and assembling an arsenal of approximation schemes with illustrative...


Fundamentals of Physics II: Electromagnetism, Optics, and Quantum Mechanics (The Open Yale Courses Series)
by R. Shankar (Author)
R. Shankar, a wellknown physicist and contagiously enthusiastic educator, was among the first to offer a course through the innovative Open Yale Course program. His popular online video lectures on introductory physics have been viewed over a million times. In this second book based on his online Yale course, Shankar explains essential concepts, including electromagnetism, optics, and quantum mechanics. The book begins at the simplest level, develops the basics, and reinforces fundamentals, ensuring a solid foundation in the principles and methods of physics. It provides an ideal introduction for collegelevel students of physics, chemistry, and engineering; for motivated AP Physics students; and for general readers interested in advances in the sciences.

