ScienceDaily (Sep. 2, 2009) — Scientists using a continent-wide array of radio telescopes have made an extremely precise measurement of the curvature of space caused by the Sun's gravity, and their technique promises a major contribution to a frontier area of basic physics.
"Measuring the curvature of space caused by gravity is one of the most sensitive ways to learn how Einstein's theory of General Relativity relates to quantum physics. Uniting gravity theory with quantum theory is a major goal of 21st-Century physics, and these astronomical measurements are a key to understanding the relationship between the two," said Sergei Kopeikin of the University of Missouri.
Kopeikin and his colleagues used the National Science Foundation's Very Long Baseline Array (VLBA) radio-telescope system to measure the bending of light caused by the Sun's gravity to within one part in 30,000. With further observations, the scientists say their precision technique can make the most accurate measure ever of this phenomenon.
Bending of starlight by gravity was predicted by Albert Einstein when he published his theory of General Relativity in 1916. According to relativity theory, the strong gravity of a massive object such as the Sun produces curvature in the nearby space, which alters the path of light or radio waves passing near the object. The phenomenon was first observed during a solar eclipse in 1919.
Though numerous measurements of the effect have been made over the intervening 90 years, the problem of merging General Relativity and quantum theory has required ever more accurate observations. Physicists describe the space curvature and gravitational light-bending as a parameter called "gamma." Einstein's theory holds that gamma should equal exactly 1.0.
"Even a value that differs by one part in a million from 1.0 would have major ramifications for the goal of uniting gravity theory and quantum theory, and thus in predicting the phenomena in high-gravity regions near black holes," Kopeikin said.
To make extremely precise measurements, the scientists turned to the VLBA, a continent-wide system of radio telescopes ranging from Hawaii to the Virgin Islands. The VLBA offers the power to make the most accurate position measurements in the sky and the most detailed images of any astronomical instrument available.
The researchers made their observations as the Sun passed nearly in front of four distant quasars -- faraway galaxies with supermassive black holes at their cores -- in October of 2005. The Sun's gravity caused slight changes in the apparent positions of the quasars because it deflected the radio waves coming from the more-distant objects.
The result was a measured value of gamma of 0.9998 +/- 0.0003, in excellent agreement with Einstein's prediction of 1.0.
"With more observations like ours, in addition to complementary measurements such as those made with NASA's Cassini spacecraft, we can improve the accuracy of this measurement by at least a factor of four, to provide the best measurement ever of gamma," said Edward Fomalont of the National Radio Astronomy Observatory (NRAO). "Since gamma is a fundamental parameter of gravitational theories, its measurement using different observational methods is crucial to obtain a value that is supported by the physics community," Fomalont added.
Kopeikin and Fomalont worked with John Benson of the NRAO and Gabor Lanyl of NASA's Jet Propulsion Laboratory. They reported their findings in the July 10 issue of the Astrophysical Journal.
The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.
--------------------------------------------------------------------------------
Adapted from materials provided by National Radio Astronomy Observatory.
Sunday, November 8, 2009
Einstein's 'Spooky Physics' Gets More Entangled
By Clara Moskowitz, LiveScience Staff Writer
03 June 2009 01:00 pm ET
Quantum entanglement is just spooky — even Einstein thought so. As if particles (as in particle physics) have telepathic empathy.
The theory of quantum mechanics predicts that two or more particles can become "entangled" so that even after they are separated in space, when an action is performed on one particle, the other particle responds immediately. Scientists still don't know how the particles send these instantaneous messages to each other, but somehow, once they are entwined, they retain a fundamental connection.
This bizarre idea riled Einstein so much he called it "spooky action at a distance."
A new study found that this eerie quantum link can apply even to situations that resemble the larger, everyday world. Scientists entangled two pairs of vibrating particles separated in space, so that when one pair was forced to change its movement, the other pair did as well.
"We've entangled something that has never been entangled before, and it's the kind of physical, oscillating system you see in the classical world, just much smaller," said John Jost, a physics graduate student at the University of Colorado at Boulder, and a guest researcher at the National Institute of Standards and Technology. Jost and team describe their findings in the June 4 issue of the journal Nature.
Previous experiments have entangled the internal properties of particles, such as spin states, but this is the first time scientists have entangled the particles' pattern of motion.
The breakthrough could help researchers build quantum computers, which could theoretically make calculations much faster than existing technology.
"Apart from adding another toy to the quantum mechanic’s playground, this is an important tool for further developments in quantum-state engineering," wrote physicist Rainer Blatt of the Austrian Academy of Sciences in a separate essay in the June 4 issue of Nature. Blatt was not involved in the new study.
To achieve this feat of entanglement, Jost and colleagues set up two pairs of ions (atoms with one electron removed, so that they have a positive charge). Each pair included one beryllium and one magnesium ion, vibrating back and forth toward and away from each other as if they were connected by an invisible spring.
Using electric fields and lasers, the researchers herded the ions into separate pairs and then entangled their motion. Then they separated the pairs by 240 micrometers (millionths of a meter), which is actually quite a span for an atom. Even at this distance, when the researchers changed the motion of one pair — stopped or started the vibrations — the other responded immediately, stopping or starting in kind.
The experiment proved that this kind of everyday springy motion is entangle-able, and blurred the boundary between the quantum world and the regular macroscopic world we live in, where normal objects don't behave like that.
As for why this entanglement, or any entanglement, is possible, physicists aren't so sure.
"It’s a very difficult question," Jost told LiveScience. "I would just have to say that it stems from the laws and rules of quantum mechanics. There are a lot of people trying to understand what it means."
•Top 10 Unexplained Phenomena
•How Quantum Physics Could Power the Future
•The Greatest Mysteries in Science
03 June 2009 01:00 pm ET
Quantum entanglement is just spooky — even Einstein thought so. As if particles (as in particle physics) have telepathic empathy.
The theory of quantum mechanics predicts that two or more particles can become "entangled" so that even after they are separated in space, when an action is performed on one particle, the other particle responds immediately. Scientists still don't know how the particles send these instantaneous messages to each other, but somehow, once they are entwined, they retain a fundamental connection.
This bizarre idea riled Einstein so much he called it "spooky action at a distance."
A new study found that this eerie quantum link can apply even to situations that resemble the larger, everyday world. Scientists entangled two pairs of vibrating particles separated in space, so that when one pair was forced to change its movement, the other pair did as well.
"We've entangled something that has never been entangled before, and it's the kind of physical, oscillating system you see in the classical world, just much smaller," said John Jost, a physics graduate student at the University of Colorado at Boulder, and a guest researcher at the National Institute of Standards and Technology. Jost and team describe their findings in the June 4 issue of the journal Nature.
Previous experiments have entangled the internal properties of particles, such as spin states, but this is the first time scientists have entangled the particles' pattern of motion.
The breakthrough could help researchers build quantum computers, which could theoretically make calculations much faster than existing technology.
"Apart from adding another toy to the quantum mechanic’s playground, this is an important tool for further developments in quantum-state engineering," wrote physicist Rainer Blatt of the Austrian Academy of Sciences in a separate essay in the June 4 issue of Nature. Blatt was not involved in the new study.
To achieve this feat of entanglement, Jost and colleagues set up two pairs of ions (atoms with one electron removed, so that they have a positive charge). Each pair included one beryllium and one magnesium ion, vibrating back and forth toward and away from each other as if they were connected by an invisible spring.
Using electric fields and lasers, the researchers herded the ions into separate pairs and then entangled their motion. Then they separated the pairs by 240 micrometers (millionths of a meter), which is actually quite a span for an atom. Even at this distance, when the researchers changed the motion of one pair — stopped or started the vibrations — the other responded immediately, stopping or starting in kind.
The experiment proved that this kind of everyday springy motion is entangle-able, and blurred the boundary between the quantum world and the regular macroscopic world we live in, where normal objects don't behave like that.
As for why this entanglement, or any entanglement, is possible, physicists aren't so sure.
"It’s a very difficult question," Jost told LiveScience. "I would just have to say that it stems from the laws and rules of quantum mechanics. There are a lot of people trying to understand what it means."
•Top 10 Unexplained Phenomena
•How Quantum Physics Could Power the Future
•The Greatest Mysteries in Science
Thursday, September 3, 2009
EINSTEIN NEWS: Astronomers snap most distant black hole in universe, which is 1bn times bigger than the Sun
By Claire Bates
Last updated 03rd September 2009
MailOnline
Astronomers have discovered a supermassive black hole near the edge of the known universe. It lies within a galaxy the size of the Milky Way, which is 12.8billion light-years from Earth. The light from this galaxy has travelled for most of the universe's 13.7billion-year lifespan to reach us.
Most scientists believe the universe is rapidly expanding following a catastrophic event known as the Big Bang.
Light from distant objects is therefore stretched and shifted to longer wavelengths. This process, known as the redshift, is used to calculate huge distances in space.
Study leader Dr Goto said: 'It is surprising that such a giant galaxy existed when the universe was only one-sixteenth of its present age, and that it hosted a black hole one billion times more massive than the sun.
'The galaxy and black hole must have formed very rapidly in the early universe.'
Scientists hope the new images will explain how galaxies and black holes have managed to evolve together.
Black holes cannot be seen directly because they are so dense that light cannot escape from their gravitational pull.
However, matter falling into a black hole heats up from friction as it swirls around the event horizon of the black hole at great speeds. The hot material radiates strongly in ultraviolet and visible light. Until now, studying host galaxies in the distant universe has been extremely difficult because the blinding bright light from the vicinity of the black hole makes it more difficult to see the already faint light from the host galaxy.
Black holes cannot be seen directly because they are so dense that light cannot escape from their gravitational pull. To see the supermassive black hole, the team of scientists used new red-sensitive charge-coupled devices (CCDs) installed in the Suprime-Cam camera on the Subaru telescope on Mauna Kea.
CCDs are used in many light detecting gadgets from photocopiers to bar-code readers. In astronomy they are used to collect analogue information (such as light or an electrical charge from a distant object) and convert it into digital information that can be analyzed by computer software.
Professor Satoshi Miyazaki of the National Astronomical Observatory of Japan (NAOJ) is a lead investigator for the creation of the new CCDs and a collaborator on this project. He said: 'The improved sensitivity of the new CCDs has brought an exciting
discovery as its very first result.'
A careful analysis of the colours revealed that 40 per cent of light around 9100Angstrom is from the host galaxy itself and 60 per cent is from the surrounding ionized nebulae illuminated by the black hole.
Yousuke Utsumi, a member of the project team, said: 'We have witnessed a supermassive black hole and its host galaxy forming together. This discovery has opened a new window for investigating galaxy-black hole co-evolution at the dawn of the universe.'
Unlike smaller black holes, which form when a large star dies, the origin of the supermassive black holes remains an unsolved problem. A currently favored model requires several intermediate black holes to merge. The host galaxy discovered in this work provides a reservoir of such intermediate black holes.
The research will be published in the online version of the journal Monthly Notices of the Royal Astronomical Society this month.
Last updated 03rd September 2009
MailOnline
Astronomers have discovered a supermassive black hole near the edge of the known universe. It lies within a galaxy the size of the Milky Way, which is 12.8billion light-years from Earth. The light from this galaxy has travelled for most of the universe's 13.7billion-year lifespan to reach us.
Most scientists believe the universe is rapidly expanding following a catastrophic event known as the Big Bang.
Light from distant objects is therefore stretched and shifted to longer wavelengths. This process, known as the redshift, is used to calculate huge distances in space.
Study leader Dr Goto said: 'It is surprising that such a giant galaxy existed when the universe was only one-sixteenth of its present age, and that it hosted a black hole one billion times more massive than the sun.
'The galaxy and black hole must have formed very rapidly in the early universe.'
Scientists hope the new images will explain how galaxies and black holes have managed to evolve together.
Black holes cannot be seen directly because they are so dense that light cannot escape from their gravitational pull.
However, matter falling into a black hole heats up from friction as it swirls around the event horizon of the black hole at great speeds. The hot material radiates strongly in ultraviolet and visible light. Until now, studying host galaxies in the distant universe has been extremely difficult because the blinding bright light from the vicinity of the black hole makes it more difficult to see the already faint light from the host galaxy.
Black holes cannot be seen directly because they are so dense that light cannot escape from their gravitational pull. To see the supermassive black hole, the team of scientists used new red-sensitive charge-coupled devices (CCDs) installed in the Suprime-Cam camera on the Subaru telescope on Mauna Kea.
CCDs are used in many light detecting gadgets from photocopiers to bar-code readers. In astronomy they are used to collect analogue information (such as light or an electrical charge from a distant object) and convert it into digital information that can be analyzed by computer software.
Professor Satoshi Miyazaki of the National Astronomical Observatory of Japan (NAOJ) is a lead investigator for the creation of the new CCDs and a collaborator on this project. He said: 'The improved sensitivity of the new CCDs has brought an exciting
discovery as its very first result.'
A careful analysis of the colours revealed that 40 per cent of light around 9100Angstrom is from the host galaxy itself and 60 per cent is from the surrounding ionized nebulae illuminated by the black hole.
Yousuke Utsumi, a member of the project team, said: 'We have witnessed a supermassive black hole and its host galaxy forming together. This discovery has opened a new window for investigating galaxy-black hole co-evolution at the dawn of the universe.'
Unlike smaller black holes, which form when a large star dies, the origin of the supermassive black holes remains an unsolved problem. A currently favored model requires several intermediate black holes to merge. The host galaxy discovered in this work provides a reservoir of such intermediate black holes.
The research will be published in the online version of the journal Monthly Notices of the Royal Astronomical Society this month.
Tuesday, August 18, 2009
Stan Lee Reflects On 'Friendly' Relationship With Michael Jackson
Pair met 'a number of times' in the 1990s to discuss buying Marvel Comics.
By Rick Marshall
For MTV Movies Blog
July 29, 2009
SAN DIEGO — It's no secret that Michael Jackson was a comic book fan — just take a look at some of the items from his personal collection. But what many people don't realize is that the recently deceased pop icon was almost a comic book publisher too.
Last month, MTV's comic book movie blog Splash Page recalled how close Jackson came to buying Marvel Comics in the late 1990s alongside Stan Lee, the famous co-creator of Spider-Man, the X-Men, Fantastic Four and countless other superheroes.
During last weekend's Comic-Con, Lee said the relationship he developed with Jackson over the course of their business dealings extended well beyond professional courtesy. In fact, as various videos popping up around the Internet lately seem to attest, it wouldn't be out of line to call Jackson a fan of Lee and his creations.
"We had met a number of times," Lee told MTV News. "In fact, [Jackson] came to my house once with his son, and I remember my wife took care of his son for about an hour while Michael and I were talking.
"He was quite a good father," he added. "He was very solicitous, and he cared very much for the boy."
While their plan to buy Marvel never progressed past "the discussion phase," Lee said, the pair grew fairly close. At one point, Lee even made a trip to Jackson's home to discuss, of all things, Spider-Man.
"I had been to his place in Neverland," Lee said. "He wanted to do Spider-Man. I'm not sure whether he just wanted to produce it or wanted to play the role...our conversation never got that far along.
"He thought I'd be the one who could get him the rights [to make a Spider-Man movie], and I told him I couldn't," Lee continued. "He would have to go to the Marvel company. But we did become friendly...and he was a great guy."
By Rick Marshall
For MTV Movies Blog
July 29, 2009
SAN DIEGO — It's no secret that Michael Jackson was a comic book fan — just take a look at some of the items from his personal collection. But what many people don't realize is that the recently deceased pop icon was almost a comic book publisher too.
Last month, MTV's comic book movie blog Splash Page recalled how close Jackson came to buying Marvel Comics in the late 1990s alongside Stan Lee, the famous co-creator of Spider-Man, the X-Men, Fantastic Four and countless other superheroes.
During last weekend's Comic-Con, Lee said the relationship he developed with Jackson over the course of their business dealings extended well beyond professional courtesy. In fact, as various videos popping up around the Internet lately seem to attest, it wouldn't be out of line to call Jackson a fan of Lee and his creations.
"We had met a number of times," Lee told MTV News. "In fact, [Jackson] came to my house once with his son, and I remember my wife took care of his son for about an hour while Michael and I were talking.
"He was quite a good father," he added. "He was very solicitous, and he cared very much for the boy."
While their plan to buy Marvel never progressed past "the discussion phase," Lee said, the pair grew fairly close. At one point, Lee even made a trip to Jackson's home to discuss, of all things, Spider-Man.
"I had been to his place in Neverland," Lee said. "He wanted to do Spider-Man. I'm not sure whether he just wanted to produce it or wanted to play the role...our conversation never got that far along.
"He thought I'd be the one who could get him the rights [to make a Spider-Man movie], and I told him I couldn't," Lee continued. "He would have to go to the Marvel company. But we did become friendly...and he was a great guy."
Thursday, August 6, 2009
10 Lessons Every Student Can Learn From Einstein
Posted by Site Administrator in Education
Aug 5th, 2009
Online College.org
Albert Einstein was one of the greatest scientists to ever live. Einstein’s physics theories are still confounding scientists more than half a century after his death. In addition to his grand technical accomplishments, the kindly German doctor was also a philosopher and ethicist of the highest order. More than simply a scientist, Einstein’s legacy provides insight into a number of fields. Here are the ten lessons every student can learn from Albert Einstein, pulled directly from his quotes and sayings.
1."Imagination is more important than knowledge.": Without the ability to dream or imagine Einstein never would have been remembered as a famous scientist. In fact Einstein even used imagination as a scientific tool by developing theories through thought experiments conducted entirely in the mind.
2."Do not worry about your difficulties in Mathematics. I can assure you mine are still greater.": Not all Einstein’s breakthroughs came easily and despite his renowned intellect, he often claimed deficiencies as a mathematician. Though many claim he failed math as kid, this endearing story is sadly not true.
3."The only real valuable thing is intuition.": Einstein understood the value of instinct and intuition when tackling problems. While knowledge and information are necessary, trusting your first reaction is often best.
4."Anyone who has never made a mistake has never tried anything new.": Falling flat on ones face is an essential part of the human experience. Failure allows time and hindsight to explore mistakes and review other courses of action.
5."The only thing that interferes with my learning is my education.": Learning is a lifelong process that frequently relies more on interests and passions then official curricula. Students that follow their interests end up successful and fulfilled.
6."I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones.": Despite having contributed heavily to the atomic bomb, Einstein deplored its use and lobbied American presidents to limit the weapons’ proliferation.
7."We can’t solve problems by using the same kind of thinking we used when we created them.": Finding solutions means finding different routes of failure. Success can only be achieved with focused effort and well thought out solutions.
8."The important thing is not to stop questioning. Curiosity has its own reason for existing.": Questions are good. They shape all academic disciplines and lead to more knowledge. Unfortunately, asking questions is an easy habit to break. Einstein constantly reminded people to indulge their curiosity.
9."Whoever undertakes to set himself up as a judge of Truth and Knowledge is shipwrecked by the laughter of the gods.": For all his genius and success, Einstein was aware he would never discover all the answers. This humility and down to earth sensibility has made Einstein an icon of human thought for generations.
10."Not everything that counts can be counted, and not everything that can be counted counts.": This sign hung in Einstein’s Princeton University office as a reminder of the truly important things in life: love and happiness.
Aug 5th, 2009
Online College.org
Albert Einstein was one of the greatest scientists to ever live. Einstein’s physics theories are still confounding scientists more than half a century after his death. In addition to his grand technical accomplishments, the kindly German doctor was also a philosopher and ethicist of the highest order. More than simply a scientist, Einstein’s legacy provides insight into a number of fields. Here are the ten lessons every student can learn from Albert Einstein, pulled directly from his quotes and sayings.
1."Imagination is more important than knowledge.": Without the ability to dream or imagine Einstein never would have been remembered as a famous scientist. In fact Einstein even used imagination as a scientific tool by developing theories through thought experiments conducted entirely in the mind.
2."Do not worry about your difficulties in Mathematics. I can assure you mine are still greater.": Not all Einstein’s breakthroughs came easily and despite his renowned intellect, he often claimed deficiencies as a mathematician. Though many claim he failed math as kid, this endearing story is sadly not true.
3."The only real valuable thing is intuition.": Einstein understood the value of instinct and intuition when tackling problems. While knowledge and information are necessary, trusting your first reaction is often best.
4."Anyone who has never made a mistake has never tried anything new.": Falling flat on ones face is an essential part of the human experience. Failure allows time and hindsight to explore mistakes and review other courses of action.
5."The only thing that interferes with my learning is my education.": Learning is a lifelong process that frequently relies more on interests and passions then official curricula. Students that follow their interests end up successful and fulfilled.
6."I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones.": Despite having contributed heavily to the atomic bomb, Einstein deplored its use and lobbied American presidents to limit the weapons’ proliferation.
7."We can’t solve problems by using the same kind of thinking we used when we created them.": Finding solutions means finding different routes of failure. Success can only be achieved with focused effort and well thought out solutions.
8."The important thing is not to stop questioning. Curiosity has its own reason for existing.": Questions are good. They shape all academic disciplines and lead to more knowledge. Unfortunately, asking questions is an easy habit to break. Einstein constantly reminded people to indulge their curiosity.
9."Whoever undertakes to set himself up as a judge of Truth and Knowledge is shipwrecked by the laughter of the gods.": For all his genius and success, Einstein was aware he would never discover all the answers. This humility and down to earth sensibility has made Einstein an icon of human thought for generations.
10."Not everything that counts can be counted, and not everything that can be counted counts.": This sign hung in Einstein’s Princeton University office as a reminder of the truly important things in life: love and happiness.
Sunday, July 19, 2009
Quantum Goes Massive: Profound Effect Of Astrophysics Experiment On Future Quantum Experiments
ScienceDaily (July 18, 2009) — An 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.
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."
--------------------------------------------------------------------------------
Journal reference:
1.B Abbott et al. Observation of a kilogram-scale oscillator near its quantum ground state. New J. Phys., 11 073032 (13pp) DOI: 10.1088/1367-2630/11/7/073032
Adapted from materials provided by the Institute of Physics.
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."
--------------------------------------------------------------------------------
Journal reference:
1.B Abbott et al. Observation of a kilogram-scale oscillator near its quantum ground state. New J. Phys., 11 073032 (13pp) DOI: 10.1088/1367-2630/11/7/073032
Adapted from materials provided by the Institute of Physics.
Spider-Man Reaches #600, Hero Initiative Gets Birthday Present!
Posted: Friday, July 10, 2009
Posted By: Kevin Powers
Marvel Comics’ Amazing Spider-Man has been around long enough to reach its milestone 600th issue! And to celebrate, San Francisco’s Comic Outpost is holding a Spider-Man anniversary party on the date of the book’s release, Wednesday, July 22. The party takes place at Comic Outpost, 2381 Ocean Ave. in San Francisco.
Comic Outpost has constructed a massive wall displaying ALL 600 issues of Amazing Spider-Man, dating back to issue #1 from 1963. Fans will be able to view the massive Spidey collection, and enter raffles for books signed and sketched by legendary Spider-Man artist John Romita Sr., a signed-and-numbered copy of Stan’s Soapbox: The Collection, which collects all of Stan Lee’s legendary “Soapbox” columns, and more. The highlight of the raffle will be a genuine chainsaw prop from the Doctor Octopus emergency room scene in the Spider-Man 2 movie. All proceeds from the event will benefit Hero Initiative, the charity dedicated to helping older comic creators in medical or financial need.
“Way back in the early ’70s, my mother bought me my first comic, Marvel Team-Up #42, featuring Spider-Man and Vision. From that point I was hooked!” said Comic Outpost owner Gary Buechler. “Through the years, I’ve put together a full run of Amazing Spider-Man and it's a kick to be able to display it in my own store! It’s an honor and a duty to help give back to all of the creators who brought me and so much joy and have allowed me to actually make a living. It is the least I could do.”
“I’m very proud of my years of work on Spider-Man, and always pleasantly surprised to see that people remember it fondly still today,” said Hero Initiative Board member John Romita Sr. “My thanks to the crew at Comic Outpost. This should be a great event I wish I could attend, and should raise some much-needed funds for Hero!”
Posted By: Kevin Powers
Marvel Comics’ Amazing Spider-Man has been around long enough to reach its milestone 600th issue! And to celebrate, San Francisco’s Comic Outpost is holding a Spider-Man anniversary party on the date of the book’s release, Wednesday, July 22. The party takes place at Comic Outpost, 2381 Ocean Ave. in San Francisco.
Comic Outpost has constructed a massive wall displaying ALL 600 issues of Amazing Spider-Man, dating back to issue #1 from 1963. Fans will be able to view the massive Spidey collection, and enter raffles for books signed and sketched by legendary Spider-Man artist John Romita Sr., a signed-and-numbered copy of Stan’s Soapbox: The Collection, which collects all of Stan Lee’s legendary “Soapbox” columns, and more. The highlight of the raffle will be a genuine chainsaw prop from the Doctor Octopus emergency room scene in the Spider-Man 2 movie. All proceeds from the event will benefit Hero Initiative, the charity dedicated to helping older comic creators in medical or financial need.
“Way back in the early ’70s, my mother bought me my first comic, Marvel Team-Up #42, featuring Spider-Man and Vision. From that point I was hooked!” said Comic Outpost owner Gary Buechler. “Through the years, I’ve put together a full run of Amazing Spider-Man and it's a kick to be able to display it in my own store! It’s an honor and a duty to help give back to all of the creators who brought me and so much joy and have allowed me to actually make a living. It is the least I could do.”
“I’m very proud of my years of work on Spider-Man, and always pleasantly surprised to see that people remember it fondly still today,” said Hero Initiative Board member John Romita Sr. “My thanks to the crew at Comic Outpost. This should be a great event I wish I could attend, and should raise some much-needed funds for Hero!”
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