Scientists may have caught their first glimpse of the elusive Higgs boson, which is thought to give mass to the basic building blocks of nature.
Researchers at the Large Hadron Collider at Cern, the European particle physics lab near Geneva, announced the findings at a conference on Friday.
The world's most powerful atom smasher hunts for signs of new physics by slamming subatomic particles together at nearly the speed of light in an 18-mile round tunnel beneath the French-Swiss border.
Speaking at the meeting, teams working on two of the collider's huge detectors, Atlas and CMS, independently reported unusual bumps in their data that could be the first hints of the particle.
Physicists stressed that it was too early to know whether the signals were due to the missing particle.
Bumps that look like new discoveries can be caused by statistical fluctuations in data, flaws in computer models and other glitches, they said.
"We cannot say anything today, but clearly it's intriguing," Fabiola Gianotti, spokeswoman for the 3,000-strong Atlas team, said. She said the picture would become clearer as the groups gathered more data and combined results in the next few months. The view was shared by Guido Tonelli, spokesman for the CMS group, said more data was needed to understand whether the bumps were due to "statistical fluctuations or possible hints of a signal".
The long-sought particle was first postulated in 1964 by Peter Higgs, a physicist at Edinburgh University, in a theory that described how fundamental particles gained mass from an invisible field that pervaded the cosmos.
The field has been compared to a snowfield that clings to particles and slows them down to different extents. Light particles pass through the field swiftly as if they have skis on, while heavy particles trudge through as though walking barefoot.
The boson was nicknamed the "God particle" in 1993 by the Nobel prize-winning physicist, Leon Lederman. The monicker is detested by Higgs. "I find it embarrassing because, though I'm not a believer myself, I think it is the kind of misuse of terminology which I think might offend some people," he said.
From previous work, the Higgs boson was thought to have a mass somewhere between 114 and 185GeV (gigaelectronvolts) – one GeV is roughly equivalent to the mass of a proton, a subatomic particle found in atomic nuclei.
The Atlas team reported a Higgs-like bump in their data between 120 and 140GeV. In a later session, the CMS group announced two bumps in the same region.
Matt Strassler, a theoretical physicist at Rutgers University in New Jersey, commented on his blog: "Exciting … but far too early to be sure this is anything interesting." He added: "This is certainly something we'll be watching."
Thursday 28 July 2011
Astronomers Find Largest, Oldest Mass of Water in Universe
Astronomers have discovered the largest and oldest mass of water ever detected in the universe — a gigantic, 12-billion-year-old cloud harboring 140 trillion times more water than all of Earth's oceans combined.
The cloud of water vapor surrounds a supermassive black hole called a quasar located 12 billion light-years from Earth. The discovery shows that water has been prevalent in the universe for nearly its entire existence, researchers said.
"Because the light we are seeing left this quasar more than 12 billion years ago, we are seeing water that was present only some 1.6 billion years after the beginning of the universe," said study co-author Alberto Bolatto, of the University of Maryland , in a statement. "This discovery pushes the detection of water one billion years closer to the Big Bang than any previous find
Studying a distant quasar
Quasars are the most luminous, most powerful and most energetic objects in the universe. They are powered by enormous black holes that suck in surrounding gas and dust and spew out huge amounts of energy.
The research team studied a particular quasar called APM 08279+5255, which harbors a black hole 20 billion times more massive than the sun and produces as much energy as one quadrillion suns.
The astronomers used two different telescopes, one in Hawaii and one in California , to detect and confirm the water vapor surrounding the quasar.
Scientists think water vapor was present even in the early universe. So finding this old cloud of the stuff doesn't come as a shock.
"It's another demonstration that water is pervasive throughout the universe, even at the very earliest times," said study lead author Matt Bradford of NASA's Jet Propulsion Laboratory in Pasadena, Calif.
However, the sheer size of the vapor cloud may surprise some scientists. APM 08279+5255 contains 4,000 times more water vapor than our own Milky Way galaxy, researchers said. That may be because much of the Milky Way's water is locked up in ice rather than vapor.
Learning about the quasar
The water vapor in the quasar is distributed around the massive black hole in a region spanning hundreds of light-years. The cloud has a temperature of minus 63 degrees Fahrenheit (minus 53 degrees Celsius), and it's 300 trillion times less dense than Earth's atmosphere.
That may sound chilly and tenuous, but it means the cloud is five times hotter and 10 to 100 times denser than what's typical in galaxies like the Milky Way, researchers said.
In addition to shedding light on the early universe, the huge vapor cloud also reveals some important information about the quasar, researchers said.
Measurements of the water vapor and of other molecules, such as carbon monoxide, suggest that there is enough gas to feed the black hole until it grows to about six times its size. Whether or not this will happen is unclear, researchers said, since some of the gas may end up condensing into stars or may be ejected from the quasar
The cloud of water vapor surrounds a supermassive black hole called a quasar located 12 billion light-years from Earth. The discovery shows that water has been prevalent in the universe for nearly its entire existence, researchers said.
"Because the light we are seeing left this quasar more than 12 billion years ago, we are seeing water that was present only some 1.6 billion years after the beginning of the universe," said study co-author Alberto Bolatto, of the University of Maryland , in a statement. "This discovery pushes the detection of water one billion years closer to the Big Bang than any previous find
Studying a distant quasar
Quasars are the most luminous, most powerful and most energetic objects in the universe. They are powered by enormous black holes that suck in surrounding gas and dust and spew out huge amounts of energy.
The research team studied a particular quasar called APM 08279+5255, which harbors a black hole 20 billion times more massive than the sun and produces as much energy as one quadrillion suns.
The astronomers used two different telescopes, one in Hawaii and one in California , to detect and confirm the water vapor surrounding the quasar.
Scientists think water vapor was present even in the early universe. So finding this old cloud of the stuff doesn't come as a shock.
"It's another demonstration that water is pervasive throughout the universe, even at the very earliest times," said study lead author Matt Bradford of NASA's Jet Propulsion Laboratory in Pasadena, Calif.
However, the sheer size of the vapor cloud may surprise some scientists. APM 08279+5255 contains 4,000 times more water vapor than our own Milky Way galaxy, researchers said. That may be because much of the Milky Way's water is locked up in ice rather than vapor.
Learning about the quasar
The water vapor in the quasar is distributed around the massive black hole in a region spanning hundreds of light-years. The cloud has a temperature of minus 63 degrees Fahrenheit (minus 53 degrees Celsius), and it's 300 trillion times less dense than Earth's atmosphere.
That may sound chilly and tenuous, but it means the cloud is five times hotter and 10 to 100 times denser than what's typical in galaxies like the Milky Way, researchers said.
In addition to shedding light on the early universe, the huge vapor cloud also reveals some important information about the quasar, researchers said.
Measurements of the water vapor and of other molecules, such as carbon monoxide, suggest that there is enough gas to feed the black hole until it grows to about six times its size. Whether or not this will happen is unclear, researchers said, since some of the gas may end up condensing into stars or may be ejected from the quasar
Friday 22 July 2011
Radioactive Decay Fuels Earth's Inner Fires
CREDIT: Lawrence Berkeley National Laboratory
Half of the extraordinary heat of the Earth that erupts on its surface volcanically and drives the titanic motions of the continents is due to radioactivity, scientists find.
This new discovery shows that the planet still retains an extraordinary amount of heat it had from its primordial days.
To better understand the sources of the Earth's heat, scientists studied antineutrinos, elementary particles that, like their neutrino counterparts, only rarely interact with normal matter. Using the Kamioka Liquid-scintillator Antineutrino Detector (KamLAND) located under a mountain in Japan, they analyzed geoneutrinos — ones emitted by decaying radioactive materials within the Earth — over the course of more than seven years.
The specific amount of energy an antineutrino packs on the rare occasions one does collide with normal matter can tell scientists about what material emitted it in the first place — for instance, radioactive material from within the Earth, as opposed to in nuclear reactors. If one also knows how rarely such an antineutrino interacts with normal matter, one can then estimate how many antineutrinos are being emitted and how much energy they are carrying in total.
The researchers found the decay of radioactive isotopes uranium-238 and thorium-232 together contributed 20 trillion watts to the amount of heat Earth radiates into space, about six times as much power as the United States consumes. U.S. power consumption in 2005 averaged about 3.34 trillion watts.
As huge as this value is, it only represents about half of the total heat leaving the planet. The researchers suggest the remainder of the heat comes from the cooling of the Earth since its birth.
Knowing what the sources of heat from Earth are "is a very important issue in geophysics," researcher Itaru Shimizu, an elementary particle physicist at Tohoku University in Miyagi, Japan, told OurAmazingPlanet.
For instance, the heat from Earth's primordial days is thought to be bound to the planet's core, while the heat from radioactive decay is thought to be distributed in the crust and mantle layers of the planet, greatly influencing currents in the mantle, "which drive plate tectonics and geophysical activity," Shimizu said.
Subscribe to:
Posts (Atom)