 |
|
Quantum goes massive
July 16, 2009An astrophysics experiment in America has demonstrated how fundamental research in one subject area can have a profound effect on work in another as the instruments used for the Laser Interferometer Gravitational-Wave Observatory (LIGO) pave the way for quantum experiments on a macroscopic scale.
The work is reported in a research article published today, Thursday, 16 July, in New Journal of Physics (co-owned by the Institute of Physics and German Physical Society). It can be found at http://stacks.iop.org/NJP/11/073032.
LIGO is a huge experiment, funded mainly by the U.S. National Science Foundation and involving more than 600 astrophysicists worldwide, undertaken to detect gravitational waves and thereby help us monitor space through another valuable set of lenses - gravitational radiation.
By measuring tiny motions of test masses caused by passing gravitational waves, LIGO expects to directly detect this radiation, thought to stem from exotic phenomena in space such as the collisions of neutron stars and black holes, and supernovae.
Laser light is used to monitor relative displacements of interferometer mirrors, which are suspended as pendulums to act as quasi-free test masses. Since the effect of gravitational waves is expected to be very small, LIGO detectors are sensitive enough to measure displacements smaller than one-thousandth the size of a proton for mirrors that are 4 km apart.
In different frequency bands, the sensitivity of the LIGO instruments are limited by noise arising from the quantum nature of the laser light, or by thermal noise arising from the thermal energy of the mirrors. Observing quantum mechanical behaviour of the LIGO mirrors requires reducing the thermal noise, which may be achieved by cooling the interferometer mirrors with techniques similar to laser cooling of atoms. However, the temperature must be brought extremely close to absolute zero (0 Kelvin, or about -273 degrees Celsius).
While absolute zero is impossible to achieve, scientists working on LIGO have used both a frictionless damping force and a magnetic restoring force to cool the mirror oscillator to about 1 millionth of a degree above absolute zero. The frictionless damping force removes energy from the mirror while the restoring force increases the frequency of the oscillator in order to avoid disturbances caused by local ground motion.
While the effort to detect gravitational waves is ongoing, the researchers have now used the LIGO apparatus to observe the oscillations of a 2.7 kg pendulum mode at a level close to its quantum ground state. The results suggest that it should be possible for quantum physicists to use the apparatus to observe quantum mechanical behaviour, such as quantum entanglement, at mass scales previously thought impractical.
While there is still work to go in strengthening the laser and reducing excess noise in the detectors, LIGO scientists Thomas Corbitt and Nergis Mavalvala of the Massachusetts Institute of Technology echo the optimism of the research article, which concludes that "the present work, reaching Microkelvin temperatures, provides evidence that interferometric gravitational wave detectors, designed as sensitive probes of general relativity and astrophysical phenomena, can also become sensitive probes of macroscopic quantum mechanics."
Institute of Physics
By measuring tiny motions of test masses caused by passing gravitational waves, LIGO expects to directly detect this radiation, thought to stem from exotic phenomena in space such as the collisions of neutron stars and black holes, and supernovae.
Laser light is used to monitor relative displacements of interferometer mirrors, which are suspended as pendulums to act as quasi-free test masses. Since the effect of gravitational waves is expected to be very small, LIGO detectors are sensitive enough to measure displacements smaller than one-thousandth the size of a proton for mirrors that are 4 km apart.
In different frequency bands, the sensitivity of the LIGO instruments are limited by noise arising from the quantum nature of the laser light, or by thermal noise arising from the thermal energy of the mirrors. Observing quantum mechanical behaviour of the LIGO mirrors requires reducing the thermal noise, which may be achieved by cooling the interferometer mirrors with techniques similar to laser cooling of atoms. However, the temperature must be brought extremely close to absolute zero (0 Kelvin, or about -273 degrees Celsius).
While absolute zero is impossible to achieve, scientists working on LIGO have used both a frictionless damping force and a magnetic restoring force to cool the mirror oscillator to about 1 millionth of a degree above absolute zero. The frictionless damping force removes energy from the mirror while the restoring force increases the frequency of the oscillator in order to avoid disturbances caused by local ground motion.
While the effort to detect gravitational waves is ongoing, the researchers have now used the LIGO apparatus to observe the oscillations of a 2.7 kg pendulum mode at a level close to its quantum ground state. The results suggest that it should be possible for quantum physicists to use the apparatus to observe quantum mechanical behaviour, such as quantum entanglement, at mass scales previously thought impractical.
While there is still work to go in strengthening the laser and reducing excess noise in the detectors, LIGO scientists Thomas Corbitt and Nergis Mavalvala of the Massachusetts Institute of Technology echo the optimism of the research article, which concludes that "the present work, reaching Microkelvin temperatures, provides evidence that interferometric gravitational wave detectors, designed as sensitive probes of general relativity and astrophysical phenomena, can also become sensitive probes of macroscopic quantum mechanics."
Institute of Physics
Quantum Current Events and Quantum News RSSUCSB physicists move 1 step closer to quantum computing
Physicists at UC Santa Barbara have made an important advance in electrically controlling quantum states of electrons, a step that could help in the development of quantum computing.
MIT: Better way to harness waste heat
New MIT research points the way to a technology that might make it possible to harvest much of the wasted heat produced by everything from computer processor chips to car engines to electric powerplants, and turn it into usable electricity.
New study confirms exotic electric properties of graphene
First, it was the soccer-ball-shaped molecules dubbed buckyballs. Then it was the cylindrically shaped nanotubes. Now, the hottest new material in physics and nanotechnology is graphene: a remarkably flat molecule made of carbon atoms arranged in hexagonal rings much like molecular chicken wire.
Rice ties in race for atomic-scale breakthrough
Everybody loves a race to the wire, even when the result is a tie. The great irony is the ultraprecise clocks that could result from this competition could probably break any tie.
Small nanoparticles bring big improvement to medical imaging
If you're watching the complex processes in a living cell, it is easy to miss something important-especially if you are watching changes that take a long time to unfold and require high-spatial-resolution imaging.
JQI researchers create entangled photons from quantum dots
To exploit the quantum world to the fullest, a key commodity is entanglement-the spooky, distance-defying link that can form between objects such as atoms even when they are completely shielded from one another.
NIST demonstrates 'universal' programmable quantum processor
Physicists at the National Institute of Standards and Technology (NIST) have demonstrated the first "universal" programmable quantum information processor able to run any program allowed by quantum mechanics-the rules governing the submicroscopic world-using two quantum bits (qubits) of information.
Working together to design robust silicon chips
Designers of high-speed silicon chips have often had to compromise on performance levels for their integrated circuit designs because of physical weaknesses appearing during design verification or even in production.
In touch with molecules
The performance of modern electronics increases steadily on a fast pace thanks to the ongoing miniaturization of the utilized components.
First Bose-Einstein condensation of strontium
In an international first, scientists from the Institute of Quantum Optics and Quantum Information (IQOQI) produced a Bose-Einstein condensate of the alkaline-earth element strontium, thus narrowly winning an international competition between many first-rate scientific groups
More Quantum Current Events and Quantum News Articles
 |
Quantum: A Guide for the Perplexed by Dr. Jim Al-Khalili (Author) In this lively look at quantum science, a physicist takes you on an entertaining and enlightening journey through the basics of subatomic physics. Along the way he examines the paradox of quantum mechanics—beautifully mathematical in theory but confoundingly unpredictable in the real world. Marvel at the Dual Slit experiment as a tiny atom passes through 2 separate openings at the same time. Ponder the peculiar communication of quantum particles, which can remain in touch no matter how far apart. Join the genius jewel thief as he carries out a quantum measurement on a diamond without ever touching the object in question. With its clean, colorful layout and conversational tone, this text will hook you into the conundrum that is quantum mechanics. “Takes readers on a... |
![Quantum of Solace [Blu-ray]](http://ecx.images-amazon.com/images/I/51lWnAopXtL._SL160_.jpg) |
Quantum of Solace [Blu-ray] Starring: Daniel Craig, Jesper Christensen, Judi Dench, Lucrezia Lante Della Rovere, Tim Pigott-Smith Directed By: Marc Forster Also With: Roberto Schaefer (Cinematographer), David Arnold (Composer) Studio: Tcfhe/mgm Release Date: 03/24/2009 Run time: 107 minutes Rating: Pg13 |
 |
Quantum Enigma: Physics Encounters Consciousness by Bruce Rosenblum (Author), Fred Kuttner (Author) In trying to understand the atom, physicists built quantum mechanics and found, to their embarrassment, that their theory intimately connects consciousness with the physical world. Quantum Enigma explores what that implies and why some founders of the theory became the foremost objectors to it. Authors Bruce Rosenblum and Fred Kuttner explain all of this in non-technical terms with help from some fanciful stories and anecdotes about the theory's developers. They present the quantum mystery honestly, with an emphasis on 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 controversial. Every interpretation of quantum physics encounters... |
 |
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"... |
 |
Quantum of Solace Starring: Daniel Craig, Jesper Christensen, Judi Dench, Lucrezia Lante Della Rovere, Tim Pigott-Smith Directed By: Marc Forster Also With: Roberto Schaefer (Cinematographer), David Arnold (Composer) Studio: Tcfhe/mgm Release Date: 03/24/2009 Run time: 107 minutes Rating: Pg13 |
 |
Quantum Physics: A Beginner's Guide by Alastair I. M. 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:... |
 |
Quantum: Einstein, Bohr, and the Great Debate about the Nature of Reality by Manjit Kumar (Author) “One of the best guides yet to the central conundrums of modern physics.”—John Banville Quantum 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 ignited the greatest intellectual... |
 |
Quantum of Solace (Two-Disc Special Edition) Starring: Daniel Craig, Jesper Christensen, Judi Dench, Lucrezia Lante Della Rovere, Tim Pigott-Smith Directed By: Marc Forster Also With: Roberto Schaefer (Cinematographer), David Arnold (Composer) Studio: Tcfhe/mgm Release Date: 03/24/2009 Run time: 107 minutes Rating: Pg13 |
 |
Quantum Q Flash T5dR Digital Flash Head by Quantum Flashtube QF30 Reflector Diffuser Coiled Sync Cord 1/4in. -20 Mounting Thumbscrew Earphone. |
 |
Quantum Wellness: A Practical and Spiritual Guide to Health and Happiness by Kathy Freston (Author) From the New York Times bestselling author comes the ultimate guide to complete well-beingÑan instructive book on how to reach our highest level of health and contentment through small, focused changes. Featuring a foreword by #1 New York Times bestselling author Dr. Mehmet C. Oz, Quantum Wellness will forever change the way readers approach healthy living. |
| © 2009 BrightSurf.com |