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| Neutrino Events-A compilation of some cool and unique neutrino events captured by the IceCube Neutrino Observatory. |
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| Neutrino Events-A compilation of some cool and unique neutrino events captured by the IceCube Neutrino Observatory. |
- Clues to the nature of dark matter could come from evidence that high-energy neutrinos are produced in the Sun. The neutrinos, according to certain dark matter theories, would result from particles called WIMPs (weakly interacting massive particles) becoming trapped by the Sun’s gravitational field and annihilating with each other. Now, the collaboration running the world’s largest neutrino telescope, the IceCube experiment at the South Pole, reports in Physical Review Letters its most comprehensive search to date for the predicted neutrinos. See: Synopsis: A Year-Long Search for Dark Matter
- We have performed a search for muon neutrinos from dark matter annihilation in the center of the Sun with the 79-string configuration of the IceCube neutrino telescope. For the first time, the DeepCore subarray is included in the analysis, lowering the energy threshold and extending the search to the austral summer. The 317 days of data collected between June 2010 and May 2011 are consistent with the expected background from atmospheric muons and neutrinos. Upper limits are set on the dark matter annihilation rate, with conversions to limits on spin-dependent and spin-independent scattering cross sections of weakly interacting massive particles (WIMPs) on protons, for WIMP masses in the range 20–5000 GeV/c2. These are the most stringent spin-dependent WIMP-proton cross section limits to date above 35 GeV/c2 for most WIMP models.See: Search for Dark Matter Annihilations in the Sun with the 79-String IceCube Detector
![]() | Exploring the Wonders of the UniverseThe newly-installed Alpha Magnetic Spectrometer-2 is visible at center of the International Space Station's starboard truss. The Alpha Magnetic Spectrometer, or AMS, is the largest scientific collaboration to use the orbital laboratory. This investigation is sponsored by the U.S. Department of Energy and made possible by funding from 16 nations. Led by Nobel Laureate Samuel Ting, more than 600 physicists from around the globe will be able to participate in the data generated from this particle physics detector. The mission of the AMS is, in part, to seek answers to the mysteries of antimatter, dark matter and cosmic ray propagation in the universe. Image Credit: NASA |
Future directions
The lack of observation of neutrinos in coincidence with GRBs implies, at face value, that the theoretical models need to be revisited. “Calculations embracing the concept that cosmic ray protons are the decay products of neutrons that escaped the magnetic confinement of the GRB fireball are supported by the research community and have been convincingly excluded by the present data,” says Francis Halzen, IceCube principle investigator and a professor of physics at the University of Wisconsin-Madison. "IceCube will continue to collect more data with a final, better calibrated and better understood detector in the coming years." Since April 2011, IceCube has collected neutrino data using the full detector array. With the larger detector, researchers can see more neutrinos, providing a “higher resolution” picture of the neutrino sky. See: Cosmic Rays: 100 years of mystery
“This result represents a coming-of-age of neutrino astronomy,” says Nathan Whitehorn from the University of Wisconsin-Madison, who led the recent GRB research with Peter Redl of the University of Maryland. “IceCube, while still under construction, was able to rule out 15 years of predictions and has begun to challenge one of only two major possibilities for the origin of the highest-energy cosmic rays, namely gamma-ray bursts and active galactic nuclei.”
Redl says, “While not finding a neutrino signal originating from GRBs was disappointing, this is the first neutrino astronomy result that is able to strongly constrain extra-galactic astrophysics models, and therefore marks the beginning of an exciting new era of neutrino astronomy.” The IceCube Collaboration’s report on the search appears in the April 19, 2012, issue of the journal Nature. See: Where Do the Highest-Energy Cosmic Rays Come From? Probably Not from Gamma-Ray Bursts
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Brookhaven National Laboratory
HOT A computer rendition of 4-trillion-degree Celsius quark-gluon plasma created in a demonstration of what scientists suspect shaped cosmic history. |
The IceCube project at the South Pole needed a new server cluster to reconstruct raw data, so it selected Dell PowerEdge servers for the HPC solution.
The IceCube Neutrino Observatory has just completed construction in Antarctica as of January 2011, and will help scientists search for elusive neutrinos that can help us map out the universe in new and exciting ways. I traveled to the South Pole in November and December 2009 to participate in this project, and reported back to classrooms across the US. This stop-motion animated video is an introduction to the IceCube Neutrino Observatory, answering basic questions such as: What is a neutrino? how can we detect them? How does IceCube work? See: Dell Powers IceCube Neutrino Observatory in Antartica
Thinking outside the box See: A physicist inthe cancer lab
Ackerman became interested in physics in middle school, reading popular science books about quantum mechanics and string theory. As an undergraduate at the Massachusetts Institute of Technology, she traveled to CERN, the European particle physics laboratory near Geneva, to work on one of the detectors at the Large Hadron Collider, the most powerful particle collider in the world. Then she spent a summer at SLAC working on BaBar, an experiment investigating the universe’s puzzling shortage of antimatter, before starting her graduate studies there in 2007.
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| A European Network For Astroparticle Physics in Europe |
In conclusion, we have a rich panorama of experiments that all make use of neutrinos as probes of exotic phenomena as well as processes which we have to measure better to gain understanding of fundamental physics as well as gather information about the universe. See:Vernon Barger: perspectives on neutrino physics May 22, 2008
| This image presents a beautiful composite of X-rays from Chandra (red, green, and blue) and optical data from Hubble (gold) of Cassiopeia A, the remains of a massive star that exploded in a supernova. Evidence for a bizarre state of matter has been found in the dense core of the star left behind, a so-called neutron star, based on cooling observed over a decade of Chandra observations. The artist's illustration in the inset shows a cut-out of the interior of the neutron star where densities increase from the crust (orange) to the core (red) and finally to the region where the "superfluid" exists (inner red ball). X-ray: NASA/CXC/UNAM/Ioffe/D. Page, P. Shternin et al.; Optical: NASA/STScI; Illustration: NASA/CXC/M. WeissSee Also:Superfluid and superconductor discovered in star's core |
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| Illustration of Cassiopeia A Neutron Star This is an artist's impression of the neutron star at the center of the Cassiopeia A supernova remnant. The different colored layers in the cutout region show the crust (orange), the higher density core (red) and the part of the core where the neutrons are thought to be in a superfluid state (inner red ball). The blue rays emanating from the center of the star represent the copious numbers of neutrinos that are created as the core temperature falls below a critical level and a superfluid is formed. (Credit: Illustration: NASA/CXC/M.Weiss) |
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| X-ray and Optical Images of Cassiopeia A Two independent research teams studied the supernova remnant Cassiopeia A, the remains of a massive star, 11,000 light years away that would have appeared to explode about 330 years as observed from Earth. Chandra data are shown in red, green and blue along with optical data from Hubble in gold. The Chandra data revealed a rapid decline in the temperature of the ultra-dense neutron star that remained after the supernova. The data showed that it had cooled by about 4% over a ten-year period, indicating that a superfluid is forming in its core. (Credit: X-ray: NASA/CXC/UNAM/Ioffe/D.Page,P.Shternin et al; Optical: NASA/STScI) |
TAUWER is a proposed astroparticle experiment to detect ultrahigh energy TAU neutrinos, using detector towers arrayed on a mountainside looking down into a valley. This test is to study the possibility of replacing Hamamatsu miniature PMTs with SiPMs for readout by determining the response of scintillation detectors with SiPM readout to low energy electrons, 2 GeV or lower, as the beam will provide. The detector itself is a compact package, previously used in a parasitic test beam run on December 15, 2010, to compare the relative timing of the signals from three counters for Minimized Ionized Particles.
The experiment will take some electron data with 1.5 cm of Pb in front of counter 2 or counter 3, and without the Pb for calibration purposes. The three scintillators are 0.7, 1.4, and 0.7 cm thick, each 19 x 19 cm square. Each has a single SiPM readout, seen in the picture. The SiPM operating voltage is 34 volts. This is introduced by BNC cables from power supplies in the electronics area. The red and white wires adapt the BNC cable to separate power and ground leads for the center counter. The SiPM signals are taken on RG174 cables to a local waveform digitizer (DRS4) adjacent to the optical box. The DRS4 is controlled by a PC located in the beam enclosure, operated remotely from the control room.
Name of Experiment:TAUWER Test
When a neutrino collides with a water molecule deep in Antarctica’s ice, the particle it produces radiates a blue light called Cerenkov radiation, which IceCube will detect (Steve Yunck/NSF)Exploring our dark universe is often the domain of extreme physics. Traces of dark matter particles are searched for by huge neutrino telescopes located underwater or under Antarctic ice, by scientists at powerful particle colliders, and deep underground. Clues to mysterious dark energy will be investigated using big telescopes on Earth and experiments that will be launched into space.
But an experiment doesn’t have to be exotic to explore the unexplained. At the International Conference on High Energy Physics, which ended today in Paris, scientists unveiled the first results from the GammeV-CHASE experiment, which used 30 hours’ worth of data from a 10-meter-long experiment to place the world’s best limits on the existence of dark energy particles.
CHASE, which stands for Chameleon Afterglow Search, was constructed at Fermilab to search for hypothetical particles called chameleons. Physicists theorize that these particles may be responsible for the dark energy that is causing the accelerating expansion of our universe.
“One of the reasons I felt strongly about doing this experiment is that it was a good example of a laboratory experiment to test dark energy models,” says CHASE scientist Jason Steffen, who presented the results at ICHEP. “Astronomical surveys are important as well, but they’re not going to tell us everything.” CHASE was a successor to Fermilab’s GammeV experiment, which searched for chameleon particles and another hypothetical particle called the axion.

A new cutting edge experiment aims to discover how exactly cosmic rays and the Sun may influence the formation of low level clouds, and possibly climate change.
More than two centuries ago, the British Astronomer Royal William Herschel noted a correlation between sunspots an indicator of solar activity and the price of wheat in England. He suggested that when there were few sunspots, prices rose.
However, up until recently, there was little to back up this hypothesis. Today, inside an unassuming some would say decrepit:looking building at Cern, the Cloud (Cosmics Leaving OUtdoor Droplets) experiment might help explain how the Sun affects the climate.
Robert Betts Laughlin (born November 1, 1950) is a professor of Physics and Applied Physics at Stanford University who, together with Horst L. Störmer and Daniel C. Tsui, was awarded the 1998 Nobel Prize in physics for his explanation of the fractional quantum Hall effect.The natural world is regulated both by fundamental laws and by powerful principles of organization that flow out of them which are also transcendent, in that they would continue to hold even if the fundamentals were changed slightly. This is, of course, an ancient idea, but one that has now been experimentally demonstrated by the stupendously accurate reproducibility of certain measurements - in extreme cases parts in a trillion. This accuracy, which cannot be deduced from underlying microscopics, proves that matter acting collectively can generate physical law spontaneously.
Physicists have always argued about which kind of law is more important - fundamental or emergent - but they should stop. The evidence is mounting that ALL physical law is emergent, notably and especially behavior associated with the quantum mechanics of the vacuum. This observation has profound implications for those of us concerned about the future of science. We live not at the end of discovery but at the end of Reductionism, a time in which the false ideology of the human mastery of all things through microscopics is being swept away by events and reason. This is not to say that microscopic law is wrong or has no purpose, but only that it is rendered irrelevant in many circumstances by its children and its children's children, the higher organizational laws of the world.

The Suzuki Foundation has published some of the most recent and most exhaustive research on mountain pine beetle epidemics in BC, but it appears the provincial government is only interested in receiving information from an industry perspective, he added.
“We actually were asked by the Premier’s office to attend tomorrow’s symposium, but when we received the agenda early this week we saw we weren’t on it. When I called to inquire, I was told we could observe from the audience but not present our report called Salvaging Solutions.
“I am absolutely flabbergasted and in fact insulted. In 25 years of attending such forums, as a Member of Parliament and for 10 years at the Suzuki Foundation, I have never been invited by a senior government official to travel 400 kilometres so that I can be window dressing. You have to wonder who on Earth is running Premier Campbell’s office and if they are really interested in gathering all of the best information on this issue.”
Photo by Lorraine Maclauchlan, Ministry of Forests, Southern Interior Forest Region
An International Facility to Study the Highest Energy Cosmic Rays See:Pierre Auger Observatory
One day, some bright, enterprising physicist, perhaps inspired by this article, will complete the theory, open the doorway, and use the power of pure thought to determine if string theory is a theory of everything, anything, or nothing.See: Window On the Universe
Only time will tell if Einstein was correct when he said, "But the creative principle resides in mathematics. In a certain sense, therefore, I hold it true that pure thought can grasp reality, as the ancients dreamed."Michio Kaku

We observed muon components in the detected air showers and studied their characteristics. Generally speaking, more muons in a shower cascade favors heavier primary hadrons and measurement of muons is one of the methods used to infer the chemical composition of the energetic cosmic rays. Our recent measurement indicates no systematic change in the mass composition from a predominantly heavy to a light composition above 3 x 1017eV claimed by the Fly's Eye group.
Omega=the actual density to the critical density
If we triangulate Omega, the universe in which we are in, Omegam(mass)+ Omega(a vacuum), what position geometrically, would our universe hold from the coordinates given?

That's not all. The fact that space-time itself is accelerating - that is, the expansion of the universe is speeding up - also creates a horizon. Just as we could learn that an elephant lurked inside a black hole by decoding the Hawking radiation, perhaps we might learn what's beyond our cosmic horizon by decoding its emissions. How? According to Susskind, the cosmic microwave background that surrounds us might be even more important than we think. Cosmologists study this radiation because its variations tell us about the infant moments of time, but Susskind speculates that it could be a kind of Hawking radiation coming from our universe's edge. If that's the case, it might tell us something about the elephants on the other side of the universe.

Although a 1916 paper by Ludwig Flamm from the University of Vienna [4] is sometimes cited as giving the first hint of a wormhole, "you definitely need hindsight to detect it," says Matt Visser of Victoria University in Wellington, New Zealand. Einstein and Rosen were the first to take the idea seriously and to try to accomplish some physics with it, he adds. The original goal may have faded, but the Einstein-Rosen bridge still pops up occasionally as a handy solution to the pesky problem of intergalactic travel.
So "open doorways" and ideas of "tunneling" are always interesting in terms of how we might look at an area like GR in cosmology? Look for way in which such instances make them self known.
Are they applicable to the very nature of quantum perceptions that such probabilities could have emerged through them? Held to "time travel scenarios" and grabbed the history of what had already preceded us in past tense, could have been brought again forward for inspection?
Another deep quantum mystery for which physicists have no answer has to do with "tunneling" -- the bizarre ability of particles to sometimes penetrate impenetrable barriers. This effect is not only well demonstrated; it is the basis of tunnel diodes and similar devices vital to modern electronic systems.
Tunneling is based on the fact that quantum theory is statistical in nature and deals with probabilities rather than specific predictions; there is no way to know in advance when a single radioactive atom will decay, for example.
The probabilistic nature of quantum events means that if a stream of particles encounters an obstacle, most of the particles will be stopped in their tracks but a few, conveyed by probability alone, will magically appear on the other side of the barrier. The process is called "tunneling," although the word in itself explains nothing.
Chiao's group at Berkeley, Dr. Aephraim M. Steinberg at the University of Toronto and others are investigating the strange properties of tunneling, which was one of the subjects explored last month by scientists attending the Nobel Symposium on quantum physics in Sweden.
"We find," Chiao said, "that a barrier placed in the path of a tunneling particle does not slow it down. In fact, we detect particles on the other side of the barrier that have made the trip in less time than it would take the particle to traverse an equal distance without a barrier -- in other words, the tunneling speed apparently greatly exceeds the speed of light. Moreover, if you increase the thickness of the barrier the tunneling speed increases, as high as you please.
"This is another great mystery of quantum mechanics."

A Bose-Einstein condensate (such as superfluid liquid helium) forms for reasons that only can be explained by quantum mechanics. Bose condensates form at low temperature
The muon will travel faster than light in the ice (but of course still slower than the speed of light in vacuum), thereby producing a shock wave of light, called Cerenkov radiation. This light is detected by the photomultipliers, and the trace of the neutrinos can be reconstructed with an accuracy of a couple of degrees. Thus the direction of the incoming neutrino and hence the location of the neutrino source can be pinpointed. A simulation of a muon travelling through AMANDA is shown here (1.5 MB).
What are the main goals of the LHC?-The LHC will also help us to solve the mystery of antimatter. Matter and antimatter must have been produced in the same amounts at the time of the Big Bang. From what we have observed so far, our Universe is made of only matter. Why? The LHC could provide an answer.
It was once thought that antimatter was a perfect 'reflection' of matter - that if you replaced matter with antimatter and looked at the result in a mirror, you would not be able to tell the difference. We now know that the reflection is imperfect, and this could have led to the matter-antimatter imbalance in our Universe.
The strongest limits on the amount of antimatter in our Universe come from the analysis of the diffuse cosmic gamma-rays arriving on Earth and the density fluctuations of the cosmic background radiation. If one asumes that after the Big Bang, the Universe separated somehow into different domains where either matter or antimatter was dominant, then at the boundaries there should be annihilations, producing cosmic gamma rays. In both cases the limit proposed by current theories is practically equivalent to saying that there is no antimatter in our Universe.
Of course this information is based on 2003 data but the jest of the idea here is that in order to go to a "fast forward" the conditions had to exist previously that did not included "sterile neutrinos" and were a result of this "cross over."




...the creative principle resides in mathematics. In a certain sense therefore, I hold it true that pure thought can grasp reality, as the ancients dreamed.Albert Einstein

As we know from Einstein’s theory of special relativity, nothing can travel faster than c, the velocity of light in a vacuum. The speed of the light that we see generally travels with a slower velocity c/n where n is the refractive index of the medium through which we view the light (in air at sea level, n is approximately 1.00029 whereas in water n is 1.33). Highly energetic, charged particles (which are only constrained to travel slower than c) tend to radiate photons when they pass through a medium and, consequently, can suddenly find themselves in the embarrassing position of actually travelling faster than the light they produce!
The result of this can be illustrated by considering a moving particle which emits pulses of light that expand like ripples on a pond, as shown in the Figure (right). By the time the particle is at the position indicated by the purple spot, the spherical shell of light emitted when the particle was in the blue position will have expanded to the radius indicated by the open blue circle. Likewise, the light emitted when the particle was in the green position will have expanded to the radius indicated by the open green circle, and so on. Notice that these ripples overlap with each other to form an enhanced cone of light indicated by the dotted lines. This is analogous to the idea that leads to a sonic boom when planes such as Concorde travel faster than the speed of sound in air


A controversial theory proposing that cosmic rays are responsible for global warming is to be put to the test at CERN, the European laboratory for particle physics. Put forward two years ago by two Danish scientists, Henrik Svensmark and Eigil Friis-Christensen, the theory suggests that it is changes in the Sun's magnetic field, and not the emission of greenhouse gases, that has led to recent rises in global temperatures.
Experimentalists at CERN will use a cloud chamber to mimic the Earth's atmosphere in order to try and determine whether cloud formation is influenced by solar activity. According to the Danish theory, charged particles from the Sun deflect galactic cosmic rays (streams of high-energy particles from outer space) that would otherwise have ionized the Earth's lower atmosphere and formed clouds.

The production of a high-intensity neutrino beam at CERN requires a complex facility. A proton beam produced and accelerated by the CERN accelerators is directed onto a graphite target to give birth to other particles called pions and kaons. These particles are then fed into a system comprising two magnetic horns which focus them into a parallel beam that is directed towards Gran Sasso. Next, in a 1000 metre-long tunnel, the pions and kaons decay into muons and muon neutrinos. At the end of this decay tunnel, an 18 metre thick block of graphite and metal absorbs the protons, pions and kaons that did not decay. The muons are stopped by the rock. Impervious to all such obstacles, the muon neutrinos will leave the CERN tunnels and streak through the rock on their 732 kilometre journey to Italy.
“CERN has a tradition of neutrino physics stretching back to the early 1960s,” said Dr Aymar, “this new project builds on that tradition, and is set to open a new and exciting phase in our understanding of these elusive particles.”

According to the basic laws of physics, every wavelength of electromagnetic radiation corresponds to a specific amount of energy. The NIST/ILL team determined the value for energy in the Einstein equation, E = mc2, by carefully measuring the wavelength of gamma rays emitted by silicon and sulfur atoms.


Everyone knows that human societies organize themselves. But it is also true that nature organizes itself, and that the principles by which it does this is what modern science, and especially modern physics, is all about. The purpose of my talk today is to explain this idea.

Many physical quantities span vast ranges of magnitude. Figures 0.1 and 0.2 use images to indicate the range of lengths and times that are of importance in physics.
"String theory and other possibilities can distort the relative numbers of 'down' and 'up' neutrinos," said Jonathan Feng, associate professor in the Department of Physics and Astronomy at UC Irvine. "For example, extra dimensions may cause neutrinos to create microscopic black holes, which instantly evaporate and create spectacular showers of particles in the Earth's atmosphere and in the Antarctic ice cap. This increases the number of 'down' neutrinos detected. At the same time, the creation of black holes causes 'up' neutrinos to be caught in the Earth's crust, reducing the number of 'up' neutrinos. The relative 'up' and 'down' rates provide evidence for distortions in neutrino properties that are predicted by new theories."




We see a pulsar, then, when one of its beams of radiation crosses our line-of-sight. In this way, a pulsar is like a lighthouse. The light from a lighthouse appears to be "pulsing" because it only crosses our line-of-sight once each time it spins. Similarly, a pulsar "pulses" because we see bright flashes every time the star spins.