Well, they’ve done it: at 2028 GMT, 29 November 2009 the Large Hadron Collider officially became the most powerful particle accelerator ever built by humans. One of the proton beams in the LHC was powered up to 1.05 teraelectron volts (TeV) at that time, and three hours later both of the beams were powered to 1.18 TeV. This breaks the previous record held by the Fermilab accelerator in Chicago, which has held the record of .98 TeV since 2001.
Despite the initial problems that the largest scientific instrument ever built had this past year, things seem to be progressing smoothly. Last week, the proton-proton beams were collided for the first time. This latest record accelerated the protons to 0.9997 times the speed of light.
No new collisions were seen at this latest milestone, as it is just part of the process of powering up the beams to the projected 7 TeV needed for the first experiments of next year. Each beam will be powered up to 3.5 TeV to smash protons in order to re-create the conditions that existed near the time of the Big Bang, and help physicists understand the fundamental nature of matter. The 7 TeV goal should be reached by the end of December, and the first collisions at the amazing energies of the LHC will occur in early 2010.
Director-General of CERN Rolf Heuer said the recent progress has been fantastic. “However, we are continuing to take it step by step, and there is still a lot to do before we start physics in 2010,” he said. “I’m keeping my champagne on ice until then.”
The LHC, is a 27 km (17 mile) long circular tunnel composed of super-cooled, superconducting magnets that runs underneath the town of Geneva, Switzerland. By colliding protons together at such energetic speeds, some fundamental questions about what matter is made of, and what the conditions were like around the earliest times of our Universe may be answered.
You can follow further advancements of the LHC at CERN’s site, on Twitter or right here at Universe Today!
Screens showing two beams in the LHC. Credit: CERN
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Two beams circulated simultaneously inside the Large Hadron Collider for the first time today, allowing for the first proton-proton collisions to take place. “It’s a great achievement to have come this far in so short a time,” said CERN Director General Rolf Heuer. “But we need to keep a sense of perspective – there’s still much to do before we can start the LHC physics program.”
The beams crossed at points where various detectors are stationed. The beams were made to cross at point 1, where the ATLAS all purpose detector is located, then at point five at the CMS (Compact Muon Solenoid) detector. Later, beams crossed at points 2 and 8, where the ALICE (heavy ion detector) and the LHCb (looking for heavy particles containing a bottom quark) are positioned.
The first collisions are allowing operators to test the synchronization of the beams.
“This is great news, the start of a fantastic era of physics and hopefully discoveries after 20 years’ work by the international community to build a machine and detectors of unprecedented complexity and performance,” said ATLAS spokesperson, Fabiola Gianotti at a press conference today.
“The events so far mark the start of the second half of this incredible voyage of discovery of the secrets of nature,” said CMS spokesperson Tejinder Virdee.
“It was standing room only in the ALICE control room and cheers erupted with the first collisions” said ALICE spokesperson Jurgen Schukraft. “This is simply tremendous.”
“The tracks we’re seeing are beautiful,” said LHCb spokesperson Andrei Golutvin, “we’re all ready for serious data taking in a few days time.”
The first collisions come just three days after the LHC restart. Since the start-up this weekend, the operators have been circulating beams around the ring alternately in one direction and then the other at the injection energy of 450 GeV (gigaelectron volts). The beam lifetime has gradually been increased to 10 hours, and today beams have been circulating simultaneously in both directions, still at the injection energy.
Next on the schedule is an intense commissioning phase aimed at increasing the beam intensity and accelerating the beams. If everything goes as planned, everyone at CERN hopes to obtain good quantities of collision data for all the experiments’ calibrations by Christmas, when the LHC should reach 1.2 TeV (terraelectron volts) per beam.
Today, CERN announced that the LHCb experiment had revealed the existence of two new baryon subatomic particles. Credit: CERN/LHC/GridPP
The Large Hadron Collider (LHC) could be re-started on this Saturday morning CERN officials said. Engineers are preparing to send a beam of sub-atomic particles around the 27km-long circular tunnel, which has been shut down since an accident in September 2008. Scientists hope to create conditions similar to those present moments after the Big Bang in search of the elusive Higgs particle to shed light on fundamental questions about the universe.
The massive “Big Bang Machine” as it’s been called is located on the French-Swiss border and is operated by the European Organization for Nuclear Research (CERN)
1,200 superconducting magnets arranged end-to-end in the underground tunnel bend proton beams in opposite directions around the main “ring” at close to the speed of light.
At allotted points around the tunnel, the proton beams cross paths, smashing into one another. Physicists hope to see new sub-atomic particles in the debris of these collisions.
The LHC had only recently been turned when on Sept. 19, 2008 a magnet problem called a “quench” caused a ton of liquid helium to leak into the tunnel.
Liquid helium is used to cool the LHC to an operating temperature of 1.9 kelvin (-271C; -456F).
Low-energy collisions are expected a week or two after full beam. High energy collisions will take place starting in early 2010.
Vitaly Ginzburg, a Russian physicist and Nobel laureate, died yesterday of cardiac arrest. He was 93 years old. Ginzburg shared the 2003 Nobel Prize in physics for his work on superconductors, but contributed to many other fields of study, including quantum theory, astrophysics, radio-astronomy and diffusion of cosmic radiation in the Earth’s atmosphere. In addition, he is known for his contributions to the development of the Russian hydrogen bomb in the 1950s, for which he received the Stalin Prize.
Ginzburg was born in 1916, before the Bolshevik Revolution, to a Jewish family in Moscow. He lived through the hardships of his childhood to enter Moscow State University in 1933, where he took up the study of physics, he wrote in his autobiography for the 2003 Nobel Prize.
Ginzburg went on to work on the hydrogen bomb during the 1950s, for which he credits his escape from Stalinist purges and anti-Semitism of the period. He became a member of the Soviet Academy of Sciences in 1953. Ginzburg later bcame editor of a leading scientific magazine on theoretical physics, Uspekhi Fizicheskikh Nauk and the head of the P.N. Lebedev Physical Institute, Moscow, Russia.
Ginzburg shared the 2003 Nobel Prize in physics with Alexei A. Abrikosov and Anthony J. Leggett for their work in the field of superconductivity, the ability of materials to conduct electricity with little or no resistance. Ginzburg also authored a book on the subject, titled On Superconductivity and Superfluidity.
His position on his role of the development of the H-bomb for Stalinist Russia is best left in his own words. Ginzburg said just last week in an interview with Physics World :
We thought at the time that we were working to prevent a monopoly on the atomic bomb – Hitler’s monopoly if he got the bomb before Stalin. The thought of what would happen if Stalin had a monopoly on atomic weapons somehow never entered my head. Scary thought. Stalin would seek to subjugate the entire world. I admit this may betray stupidity, but this stupidity was, back then, a common way of thinking in the Soviet Union.
Ginzburg will be buried Wednesday in the Novodevichye Cemetery in Moscow. To read more about Ginzburg and his long life and incredible list of achievements, see this video interview on the Nobel Prize site, and read his autobiography.
Today, CERN announced that the LHCb experiment had revealed the existence of two new baryon subatomic particles. Credit: CERN/LHC/GridPP
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Yes, this headline appears to be true. A bird dropping a piece of bread onto outdoor machinery has been blamed for a technical fault at the Large Hadron Collider (LHC) this week which saw significant overheating on parts of the accelerator. The LHC was not operational at the time of the incident, but the spike produced so much heat that had the beam been on, automatic safety detectors would have shut down the machine. This would put the LHC out of action for a few days while it was restarted, but there would be no repeat of the catastrophic damage suffered last September. That’s when an electrical connection in the circuit itself failed violently, causing a massive liquid-helium leak and subsequent damage along hundreds of meters of magnets.
Hmm. The idea of a time-traveling Higgs boson coming back to prevent its own discovery is seeming less and less far fetched!
Yes, this theory was recently proposed by a pair of physicists, who suggested the hypothesized Higgs boson, which physicists hope to produce with the collider, might be so abhorrent to nature that its creation would ripple backward through time and stop the collider before it could make the discovery, like a time traveler who goes back in time to kill his grandfather.
This most recent incident won’t delay the reactivation of the facility later this month, but exposes yet another vulnerability of the what might be the most complex machine ever built.
What accelerates cosmic rays to nearly the speed of light? Astronomer have pondered that question for nearly 100 years, and now new evidence supports a theory held for two decades that cosmic rays likely are powered by exploding stars and stellar winds. “This discovery has been predicted for almost 20 years, but until now no instrument was sensitive enough to see it,” said Wystan Benbow, an astrophysicist at the Smithsonian Astrophysical Observatory who coordinated this project for the Very Energetic Radiation Imaging Telescope Array System (VERITAS) collaboration.
Nearly 100 years ago, scientists detected the first signs of cosmic rays, which are actually not rays or beams but subatomic particles (mostly protons) that zip through space at nearly the speed of light. The most energetic cosmic rays hit with the punch of a 98-mph fastball, even though they are smaller than an atom. Astronomers questioned what natural force could accelerate particles to such a speed.
The rarest cosmic rays carry over 100 billion times as much energy as generated by any particle accelerator on Earth. Astronomers have devised ingenious methods for detecting cosmic rays that hit Earth’s atmosphere. However, detecting cosmic rays from a distance requires much more effort. This representative-color figure shows the very-high-energy gamma-ray emission observed by VERITAS coming from the Cigar Galaxy, also known as Messier 82. The black star is the location of the active starburst region. The emission from M82 is effectively point-like for VERITAS, and the white circle indicates the size of a simulated point source. The entire galaxy would be contained within the circle. Credit: CfA/V.A. Acciari
VERITAS has found new evidence for cosmic rays in the “Cigar Galaxy,” also known as Messier 82 (M82), which is located 12 million light-years from Earth in the direction of the constellation Ursa Major, which strongly support the long-held theory that supernovae and stellar winds from massive stars are the dominant accelerators of cosmic-ray particles.
Galaxies with high levels of star formation like M82, also known as “starburst” galaxies, have large numbers of supernovae and massive stars. If the theory holds, then starburst galaxies should contain more cosmic rays than normal galaxies. The VERITAS discovery confirms that expectation, indicating that the cosmic-ray density in M82 is approximately 500 times the average density in our Galaxy, the Milky Way.
“This discovery provides fundamental insight into the origin of cosmic rays,” said Rene Ong, a professor of physics at the University of California, Los Angeles, and the spokesperson for the VERITAS collaboration.
Using gamma rays to infer cosmic rays
VERITAS could not detect M82’s cosmic rays directly because they are trapped within the Cigar Galaxy. Instead, VERITAS looked for clues to the presence of cosmic rays: gamma rays. Gamma rays are the most energetic form of light, far more powerful than ultraviolet light or even X-rays. When cosmic rays interact with interstellar gas and radiation within M82, they produce gamma rays, which can then escape their home galaxy and reach Earthbound detectors.
It took two years of dedicated data collection to tease out the faint signal coming from M82.
“We knew that the detection of M82 would have important scientific implications. As a result, we scheduled an exceptionally long exposure immediately after the experiment became fully operational” said Benbow. “The data needed to be meticulously analyzed to extract the gamma-ray signal, which is over a million times smaller than the background noise. Although the signal is only a tiny fraction of the data, we made many checks for possible bias and we are confident that the signal is genuine.”
“The detection of M82 indicates that the universe is full of natural particle accelerators, and as ground-based gamma-ray observatories continue to improve, further discoveries are inevitable.” said Martin Pohl, a professor of physics at Iowa State University who helped lead the study. A next-generation VHE gamma-ray observatory, the Advanced Gamma-ray Imaging System (AGIS), is already under development.
VERITAS is operated by a collaboration of more than 100 scientists from 22 different institutions in the United States, Ireland, England and Canada. Click here for more information on VERITAS.
Lead image caption: A composite of multi-wavelength images of the active galaxy M82 from Hubble, Chandra, and Spitzer. Credit: NASA, ESA, CXC, and JPL-Caltech
The first ion beam entering point 2 of the LHC, just before the ALICE detector (23 October 2009). Credit: CERN
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The Large Hadron Collider reached an important milestone last weekend as a beam of ions was injected into the clockwise beam pipe. This is the first time particles have been inside the collider since September, 2008 when physicists were forced to shut down the system because of a massive failure. According to a CERN press release, lead ions were placed in the clockwise beam pipe on Friday October 23, but did not travel along the whole circumference of the LHC. CERN officials still hope for a restart in 2009, with the first circulating beam likely to be injected in mid-November, and the first high energy collisions occurring around mid-December.
CERN said that later last Friday the first beam of protons followed the same route — and then on Saturday protons were sent through the LHCb detector.
They reported all settings and parameters showed a perfect functioning of the machine. In the coming weeks, physicists hope to have the first circulating beam. Then hunt for the elusive Higgs particle will recommence.
Here is an interview with CERN director general Rolf-Dieter Heuer about the switch-on of the LHC.
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We all have things that keep us up at night, as we try to solve the problems in our lives. But just think of the poor physicists: They are trying to solve the problems of the Universe! At a recent physics conference at the Perimeter Institute for Theoretical Physics in Waterloo, Canada, a panel of scientists were asked what questions in physics kept them awake at night. Here are their answers:
Sean Carroll, Caltech
Why are the laws of physics the way they are?
Katherine Freese, University of Michigan
What is the universe made of?
Leo Kadanoff, University of Chicago
How does complexity develop in the universe?
Lawrence Krauss, Arizona State University
Have we come to the limits of our knowledge?
David Tong, Cambridge University
How will we ever know if string theory is correct?
Neil Turok, Director, Perimeter Institute
What happened at the singularity of the Big Bang?
Andrew White, University of Queensland
What is life?
Anton Zeilinger, University of Vienna
How far are we along the road of scientific discovery?
Gino Segrè from the University of Pennslyvania
He is concerned about the world not having enough young physicists to answer all those big questions that keep the rest of the panel awake.
Charged Coupled Devices (CCD) for Ultra-Violet and Visible Detection. Credit: NASA
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Well, actually, the people who invented the first successful imaging technology using a digital sensor, called a CCD (Charge-Coupled Device), have been awarded the Nobel Prize in Physics. In 1969 Willard S. Boyle and George E. Smith came up with the idea “from their own heads,” Smith said, and CCDs revolutionized photography, as light could now be captured electronically instead of on film, and became an irreplaceable tool in astronomy, providing new possibilities to visualize the previously unseen. The device also made it possible for amateur astronomers to rival the professionals in terms of quality astrophotography. CCD technology is also used in many medical applications, e.g. imaging the inside of the human body, both for diagnostics and for microsurgery. Sharing the prize with Boyle and Smith is Charles K. Kao, who in 1966 made a discovery that led to a breakthrough in fiber optics.
Both achievements helped shape the foundations of today’s networked societies.
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Einstein’s general theory of relativity describes gravity in terms of the geometry of both space and time. Far from a source of gravity, such as a star like our sun, space is “flat” and clocks tick at their normal rate. Closer to a source of gravity, however, clocks slow down and space is curved. But measuring this curvature of space is difficult. However, scientists have now used a continent-wide array of radio telescopes to make an extremely precise measurement of the curvature of space caused by the Sun’s gravity. This new technique promises to contribute greatly in studying quantum 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 3,333 (corrected by NRAO and updated here on 9/03/09 — see this link provided by Ned Wright of UCLA for more information on deflection and delay of light). 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. Sun's Path in Sky in Front of Quasars, 2005. Credit: NRAO
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 Lanyi of NASA’s Jet Propulsion Laboratory. They reported their findings in the July 10 issue of the Astrophysical Journal.
