Making light bend backwards

Neg­a­tive re­frac­tion com­pared to nat­u­ral re­frac­tion. In nat­u­ral re­frac­tion, light go­ing from one ma­te­ri­al to an­oth­er bends in some di­rec­tion to the op­po­site side of the "nor­mal," an im­ag­i­nary line per­pen­dic­u­lar to the sur­faces. In neg­a­tive re­frac­tion, light bends back from the nor­mal.

While de­vel­op­ing new types of lens­es, re­search­ers have crafted a lay­ered ma­te­ri­al that makes light bend in a way na­ture nev­er in­tend­ed.Light nat­u­rally bends, or re­fracts, in a spe­cif­ic way when it trav­els from one ma­te­ri­al to an­oth­er. This cre­ates, for ex­am­ple, the il­lu­sion of a drink­ing straw look­ing bent when placed in wa­ter.But the new ma­te­ri­al, crafted from al­ter­nat­ing lay­ers of semi­con­duc­tors, re­fracts light back­wards—a phe­nom­e­non called neg­a­tive re­frac­tion, re­searchers say.

Neg­a­tively re­fract­ing ma­te­ri­als have been made be­fore. But this is the first that’s fully three-di­men­sion­ and made to­tally of semi­con­duc­tors, the in­vest­i­ga­tors said. Semi­con­duc­tors are sub­stances that can switch be­tween elec­tric­ally con­duct­ing and non-con­duct­ing states, which makes them key com­po­nents of elec­tron­ic de­vices.

The negative-refraction se­mi­con­duc­tor struc­ture could be use­ful in in­stru­ments such as chem­i­cal threat sen­sors, com­mu­nica­t­ions equip­ment and di­ag­nos­tics tools, the sci­en­tists said. Semi­con­duc­tors “are ex­tremely func­tion­al ma­te­ri­als. These are the things from which true ap­plica­t­ions are made,” said en­gi­neer Claire Gmachl of Prince­ton Un­ivers­ity in New Jer­sey, one of the re­search­ers.

Nat­u­ral re­frac­tion is why lens­es have to be curved, a trait that lim­its im­age res­o­lu­tion. The new ma­te­ri­al makes flat lens­es pos­si­ble, Gmachl and col­leagues said—theoretic­ally al­low­ing for the crea­t­ion of mi­cro­scopes that can fo­cus on ob­jects as small as DNA strands.A lim­ita­t­ion of the new ma­te­ri­al, though, is that it works only with in­fra­red light, a type of light with slightly low­er en­er­gy than the vis­i­ble. But the re­search­ers said they hope the tech­nol­o­gy will ex­pand to oth­er wave­lengths in the fu­ture.

The sub­stance is in a class of ma­te­ri­als called meta­ma­te­ri­als, made of tra­di­tion­al sub­stances, such as met­als or semi­con­duc­tors, ar­ranged in very small al­ter­nat­ing pat­terns that mod­i­fy their col­lec­tive prop­er­ties. This en­ables me­ta­ma­te­ri­als to ma­ni­pu­late light in ways that nor­mal ma­te­ri­als can­not. Sci­en­tists are al­so in­ves­ti­gat­ing the pos­si­bil­ity that cer­tain me­ta­ma­te­ri­als could form in­vis­i­bil­ity cloaks

At Long Last, Physicists Calculate the Proton's Mass

By Adrian Cho ScienceNOW Daily News 21 November 2008 It's one thing to know a fact, but it's another to explain it, as a curious advance in particle physics shows. Ever since the proton was discovered 89 years ago, physicists have been able to measure the mass of the particle--which, along with another called the neutron, makes up the atomic nucleus. But even with the best computers, theorists had not been able to start with a description of the proton's constituent parts and calculate its mass from scratch. Now, a team of theorists has reached that goal, marking the arrival of precision calculations of the ultracomplex "strong force" that binds nuclear matter. "It's a really big deal," says John Negele, a theorist at the Massachusetts Institute of Technology in Cambridge. "It's the first time that we've really had this kind of confidence that everything is being done right." Like a troubled teenager, the proton is a mess inside and just about impossible to figure out. In the 1970s, experimenters discovered that the proton and the neutron, known collectively as nucleons, consist of more-fundamental particles called quarks and gluons, which are the basic elements of a theory called quantum chromodynamics (QCD). In the simplest terms, a proton contains two "up" type quarks and one "down" type quark, with gluons zipping among them to bind them with the strong nuclear force. (The neutron contains two downs and an up.) In reality, a nucleon is much more complicated. Thanks to the uncertainties of quantum mechanics, myriad gluons and quark-antiquark pairs flit in and out of existence within a nucleon. All of these "virtual" particles interact in a frenzy of pushing and pulling that's nearly impossible to analyze quantitatively. "Everything interacts with everything," says Laurent Lellouch, a theorist with the French National Center for Scientific Research at the Center for Theoretical Physics in Marseille and one of 12 physicists from France, Germany, and Hungary who performed the new calculations. Ninety-five percent of the mass of a nucleon originates from these virtual particles. To simplify matters, the team took a tack pioneered in the late 1970s called lattice QCD. Within their computer programs, the researchers modeled space not as continuous but as a three-dimensional array of points. They also modeled time as passing in discrete ticks, as opposed to flowing smoothly. This turns space and time into a lattice of points. The researchers then confined the quarks to the points in the lattice and the gluons to the links between the points. The lattice sets a shortest distance and time for the interactions, greatly simplifying the problem. Still, the computation involves millions of variables and requires supercomputers. Only since about 2000 have researchers attempted to include not just all of the gluons but the fleeting quark-antiquark pairs as well. The latest work, reported today in Science, incorporates a variety of conceptual improvements to obtain estimates of the mass of the nucleon and nine other particles made of up, down, and slightly heavier "strange" quarks accurate to within a couple of percent. This isn't the first computational tour de force for particle physicists. Five years ago, others made equally precise calculations of more esoteric quantities--somewhat easier to calculate--such as those that govern the decay of a particle called a D+ meson, which contains a down antiquark and a heavy "charm" quark, notes Christine Davies, a theorist at the University of Glasgow in the U.K. Still, she says, the calculation of the well-known masses highlights the ability of lattice QCD to make accurate predictions for the strong force. "This is all good news for lattice QCD," Davies says, "because there are lots of things that we want to calculate that experimenters haven't already measured." For example, Negele says, physicists still don't know distribution of the virtual particles inside the proton or the origin of its spin. --------------------------------------------------------------------------------

Chandrayaan-1 Probe Lands On Moon

India’s first unmanned moon mission touched down on the moon on Friday, according to Indian Space Research Organization officials.

The Moon Impactor probe detached itself from the Chandrayaan-1 (moon vehicle) about 100 km from the moon's surface and crash-landed on the south pole of the moon at 10:01 a.m. EST, making India the fourth nation to have a presence on the Moon.

Miniature Indian flags painted on four sides of the MIP signaled the country's symbolic entry into moon to coincide with the birth anniversary of the country's first Prime Minister Jawaharlal Nehru, observed as Children's Day.

"It will signify the entry of India on Moon," an ISRO official said.

The MIP consists of a C-band Radar Altimeter for continuous measurement of altitude of the probe, a video imaging system for acquiring images of the surface of moon from the descending probe and a mass spectrometer for measuring the constituents of extremely thin lunar atmosphere during its 20-minute descent to the lunar surface.

During its 20-minute descent to the moon's surface, MIP took pictures and transmitted them back to the ground. The first pictures are expected to be made public on Saturday.

This Week in Physics History: Nov. 3 - 9

Nov. 7, 1492 - A meteorite crashes to Earth around noon in a wheat field near Ensisheim, Alsace. The Ensisheim Meteorite is the oldest meteorite with a known date of impact.

Nov. 8, 1854 - Johannes Rydberg, discovery of the Rydberg State of an atom, is born.

Nov. 7, 1867 - Maria Sklodowska is born, remembered to posterity as Marie Curie, pioneer in the study of radioactivity. To date, she is the only person to have earned Nobel prizes in two different fields - physics & chemistry.

Nov. 7, 1878 - Lise Meitner is born. Meitner did ground-breaking work on the discovery of nuclear fission, but was controversially not included in the 1944 Nobel award for the discovery.

Nov. 5, 1879 - Scottish physicist James Clerk Maxwell dies. Maxwell is best known for unifying electricity and magnetism through Maxwell's Laws into electromagnetic theory.

Nov. 7, 1888 - Indian physicist Sir Chandrasekhara Venkata Raman is born. Raman received the 1930 Nobel Prize in Physics for work in molecular scattering of light, specifically the discovery of the Raman effect which bears his name.

Nov. 9, 1921 - Albert Einstein is awarded the Nobel Prize in Physics, primarily for his work in explaining the photoelectric effect.

Nov. 9, 1934 - Carl Sagan, American astronomer and author, is born. Sagan became best known as a populizer of science through television specials, and both fiction and non-fiction writing. He was the author of the science fiction novel Contact, which was later made into a film starring Jodie Foster.

Nov. 6, 1944 - The Hanford Atomic Facility first produces plutonium.

Nov. 5, 1948 - American physicist William Daniel Phillips is born. Phillips won the 1997 Nobel Prize in Physics for his work in laser cooling, which uses lasers to slow the motion of gaseous molecules.

Chandrayaan-1 Camera Tested

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The Terrain Mapping camera (TMC) on board Chandrayaan-1 spacecraft was successfully operated on October 29, 2008 through a series of commands issued from the Spacecraft Control Centre of ISRO Telemetry, Tracking and Command Network (ISTRAC) at Bangalore. Analysis of the first imagery received by the Indian Deep Space Network (IDSN) at Byalalu and later processed by Indian Space Science Data Centre (ISSDC) confirms excellent performance of the camera.The first imagery (image 1) taken at 8:00 am IST from a height of 9,000 km shows the Northern coast of Australia while the other (image 2) taken at 12:30 pm from a height of 70,000 km shows Australia’s Southern Coast.

TMC is one of the eleven scientific instruments (payloads) of Chandrayaan-1. The camera can take black and white pictures of an object by recording the visible light reflected from it. The instrument has a resolution of about 5 metres.

Besides TMC, the other four Indian payloads of Chandrayaan-1 are the Hyper spectral Imager (HySI), Lunar Laser Ranging Instrument (LLRI), High Energy X-ray Spectrometer (HEX) and the Moon Impact Probe (MIP). The other six payloads of Chandrayaan-1 are from abroad.

It may be recalled that the 1380 kg Chandrayaan-1 was successfully launched into an initial elliptical orbit around the Earth by PSLV-C11 on October 22, 2008. This was followed by four orbit raising manoeuvres, which together raised Chandrayaan-1’s orbit to a much higher altitude. The spacecraft is now circling the Earth in an orbit whose apogee (farthest point to Earth) lies at 267,000 km (Two lakh sixty seven thousand km) and perigee (nearest point to Earth) at 465 km. In this orbit, Chandrayaan-1 takes about six days to go round the Earth once. The spacecraft performance is being continuously monitored and is normal.

This Week in Physics History: Oct. 27 - Nov. 2

Nov. 2, 1929 - Canadian-American physicist Richard E. Taylor is born. Taylor shared the 1990 Nobel Prize in physics for work in particle scattering that helped lead to the quark model of particle physics.

Oct. 30, 1941 - German physicist Theodor Wolfgang Hansch is born. He shared half of the 2005 Nobel Prize in Physics for his work on laser-based precision spectroscopy, which involves something called the "optical frequency comb technique."

Nov. 1, 1950 - American physicist Robert B. Laughlin is born. Laughlin's explanation of the fractional quantum Hall effect earned him the 1998 Nobel Prize in Physics.

Oct. 27, 1968 - Austrian-born physicist Lise Meitner dies. Meitner was involved in work that lead to the discovery of nuclear fission, but was not named when her collaborator Otto Hahn received the 1944 Nobel Prize in Physics.

Oct. 30, 1975 - German experimental physicist Gustav Ludwig Hertz dies. Hertz, along with James Franck, conducted the Franck-Hertz experiments regarding inelastic collisions in gases, which earned the pair the 1925 Nobel Prize in Physics. Gustav was the nephew of famed physicist Heinrich Rudolph Hertz, for whom the SI unit of frequency - the hertz - is named.

Oct. 27, 1980 - American physicist John Hasbrouck Van Vleck dies. Van Vleck received the 1977 Nobel Prize in physics for work understanding the behavior of electrons in magnetic materials.

Oct. 31, 1986 - American physicist & chemist Robert Mullikan dies. His work in molecular orbital theory earned him the 1966 Nobel Prize in Chemistry.

Oct. 27, 1992 - David Bohm, American physicist, dies at age 75. Bohm contributed to theoretical physics, introducing a controversial alternative to traditional quantum physics interpretations involving hidden variables, which has gained some measure of support in recent years, though is still considered a marginal theory. He also worked with the Manhattan Project. He left the United States in 1951, after being released from jail for refusing to answer questions to the House Un-American Activities Committee regarding previous connections with Communists.

Oct. 27, 1999 - American physicist Robert Mills dies. Mills is best known for his work Chen Ning Yang in developing the Yang-Mills field equations, crucial in quantum field theory and the principles of gauge fields.

CHANDRAYAAN-1

CHANDRAYAAN-1: India's first mission to the Moon

"THE MOON" with the history of the early solar system etched on it beckons mankind from time immemorial to admire its marvels and discover its secrets. Understanding the moon provides a pathway to unravel the early evolution of the solar system and that of the planet earth. Through the ages, the Moon, our closest celestial body has aroused curiosity in our mind much more than any other objects in the sky. This led to scientific study of the Moon, driven by human desire and quest for knowledge. This is also reflected in the ancient verse. Exploration of the moon got a boost with the advent of the space age and the decades of sixties and seventies saw a myriad of successful unmanned and manned missions to moon.Following this, a hiatus of about one and a half-decade followed. During this period we refined our knowledge about the origin and evolution of the moon and its place as a link to understand the early history of the Solar System and of the earth.

This Week in Physics History: Oct. 13 - 20

Monday October 13, 2008

Oct. 15, 1878 - The Edison Electric Light Company begins operation.

Oct. 17, 1887 - German physicist Gustav Kirchhoff dies. Kirchhoff worked extensively in the fields of electricity, spectroscopy, and thermal radiation. He coined the term black body radiation. He is probably best known for the Kirchhoff's Laws in electronics. There is also a Kirchhoff's law of thermal equilibrium, which states "At thermal equilibrium, the emissitivity of a body (or surface) equals its absorptivity."

Oct. 20, 1891 - English physicist Sir James Chadwick is born. Chadwick discovered the neutron and led the way for the discovery of nuclear fission.

Oct. 19, 1910 - American astrophysicist Subrahmanyan Chandrasekhar is born in Lahore, British India (now Pakistan). His work on stellar evolution earned him the 1983 Nobel Prize in Physics.

Oct. 14, 1914 - American chemist & physicist Raymond Davis Jr. is born. Davis received the 2002 Nobel Prize in Physics for his work in astrophysics, especially related to cosmic neutrino detection.

Oct. 17, 1933 - Fleeing Nazi Germany, Albert Einstein immigrates to the United States.

Oct. 19, 1937 - New Zealand physicist Ernest Rutherford dies. His discovery of Rutherford scattering led to the orbital theory of the atom, which helped earn him the 1908 Nobel Prize in Chemistry.

Oct. 20, 1984 - British theoretical physicist Paul Adrien Maurice Dirac dies. Dirac is one of the founders of quantum physics. He made many mathematical innovations that helped with analysis of physical systems ranging from electromagnetic phenomena to quantum physics. He earned the 1933 Nobel Prize in physics, along with Erwin Schroedinger, "for the discovery of new productive forms of atomic theory." The "Dirac equation" that he developed describes the behavior of fermions.

Oct. 13, 1987 - American physicist Walter Brattain dies. Brattain, along with Bell Labs coworkers John Bardeen and William Shockley, invented the transistor, for which the trio received the 1956 Nobel Prize in Physics.

Oct. 13, 2003 - Canadian physicist Bertram Brockhouse dies. Brockhouse received the 1994 Nobel Prize in Physics for the discovery of neutron scattering techniques to probe the structure of matter.

The Nobel Prize in Physics 2008

“Discovery of Broken Symmetries”

This year’s Nobel Prize in Physics is awarded to Yoichiro Nambu, USA and jointly to Makoto Kobayashi, Japan and Toshihide Maskawa, Japan for their “discovery of Broken Symmetries”. This year’s Nobel Laureates in Physics have presented theoretical insights that give us a deeper understanding of what happens far inside the tiniest building blocks of matter.

Yoichiro Nambu

1/2 of the prize

USA

Enrico Fermi Institute, University of Chicago Chicago, IL, USA

"for the discovery of the mechanism of spontaneous broken symmetry in subatomic physics"

Makoto Kobayashi

1/4 of the prize

Japan

High Energy Accelerator Research Organization (KEK) Tsukuba, Japan

"for the discovery of the origin of the broken symmetry which predicts the existence of at least three families of quarks in nature"

Toshihide Maskawa

1/4 of the prize

Japan

Kyoto Sangyo University; Yukawa Institute for Theoretical Physics (YITP), Kyoto University Kyoto, Japan

"for the discovery of the origin of the broken symmetry which predicts the existence of at least three families of quarks in nature"

CERN: European Organization for Nuclear Research

The Large Hadron Collider

Our understanding of the Universe is about to change... The Large Hadron Collider (LHC) is a gigantic scientific instrument near Geneva, where it spans the border between Switzerland and France about 100 m underground. It is a particle accelerator used by physicists to study the smallest known particles – the fundamental building blocks of all things. It will revolutionise our understanding, from the minuscule world deep within atoms to the vastness of the Universe. Two beams of subatomic particles called 'hadrons' – either protons or lead ions – will travel in opposite directions inside the circular accelerator, gaining energy with every lap. Physicists will use the LHC to recreate the conditions just after the Big Bang, by colliding the two beams head-on at very high energy. Teams of physicists from around the world will analyse the particles created in the collisions using special detectors in a number of experiments dedicated to the LHC. There are many theories as to what will result from these collisions, but what's for sure is that a brave new world of physics will emerge from the new accelerator, as knowledge in particle physics goes on to describe the workings of the Universe. For decades, the Standard Model of particle physics has served physicists well as a means of understanding the fundamental laws of Nature, but it does not tell the whole story. Only experimental data using the higher energies reached by the LHC can push knowledge forward, challenging those who seek confirmation of established knowledge, and those who dare to dream beyond the paradigm.

LHC Shuts Down For Two Months Due To Helium Leak

Just a week ago, the transformer failed and now a new hardware, due to its malfunction, has stopped the LHC, dead in its tracks. This time a magnet quench event has occurred due to failure of the electrical link between two of the particle accelerator's massive 30-ton superconducting magnets. The complex rectifying process will take approximately two months. The section of the tunnel will have to be warmed up, which contains the magnet. Then it will have to be cooled down to its -271°C operating temperature.

Stephen Hawking: Big Bang experiment could finally earn me a Nobel Prize

Daily Mail Reporter:09th September 2008

Experts around the world are eagerly awaiting the switch on of the world's biggest scientific experiment, and none more so than Professor Stephen Hawking. The £5billion Large Hadron Collider aims to recreate the conditions moments after the Big Bang that created the universe. It could offer Professor Hawking his best chance so far of winning a Nobel prize if it confirms his theory that black holes give off radiation. He told the BBC: 'If the LHC were to produce little black holes, I don't think there's any doubt I would get a Nobel prize, if they showed the properties I predict. 'However, I think the probability that the LHC has enough energy to create black holes, is less than 1 per cent, so I'm not holding my breath.' The British physicist put forward his idea in the 1970s but it proved controversial because many scientists believed nothing could escape the gravitational pull of a black hole. Although Hawking's theory has become accepted by the profession is remains unproven. Nobel prizes in physics are awarded only when there is experimental evidence for a new phenomenon. The Large Hadron Collider (LHC) at Cern may produce microscopic black holes that could evaporate in a flash of Hawking radiation. To do this, a massive 27km tunnel has been constructed under countryside in France and Switzerland near Geneva, which will be used to smash protons together at 99.99 per cent of the speed of light. Tomorrow morning, it will be switched on and the first attempt to send the particle beam around its entire 27km length will be made. Experts say the LHC is probably the most complex and challenging scientific endeavour since the Apollo programme put astronauts on the moon. One of the aims of the LHC is to hunt for the Higgs boson, the so-called "God particle". The Higgs is said to be the so-far undetected key to mass. If scientists can prove its existence, it could pave the way for manipulating the gravity which exists in all mass - rather like Star Trek 'tractor' beams.

Multibillion-dollar experiment to probe nature's mysteries

Deep underground on the border between France and Switzerland, the world's largest particle accelerator complex will explore the world on smaller scales than any human invention has explored before. The Large Hadron Collider will look at how the universe formed by analyzing particle collisions. Some have expressed fears that the project could lead to the Earth's demise -- something scientists say will not happen. Still, skeptics have filed suit to try to stop the project. Scientists say the collider is finally ready for an attempt to circulate a beam of protons the whole way around the 17-mile tunnel. The test, which takes place Wednesday, is a major step toward seeing if the the immense experiment will provide new information about the way the universe works. "It's really a generation that we've been looking forward to this moment, and the moments that will come after it in particular," said Bob Cousins, deputy to the scientific leader of the Compact Muon Solenoid experiment, one of six experiments inside the collider complex. "September 10 is a demarcation between finishing the construction and starting to turn it on, but the excitement will only continue to grow." The collider consists of a particle accelerator buried more than 300 feet near Geneva, Switzerland. About $10 billion have gone into the accelerator's construction, the particle detectors and the computers, said Katie Yurkewicz, spokewoman for CERN, the European Organization for Nuclear Research, which is host to the collider.

Big Bang Machine 'Absolutely Safe'

Big bang machine 'absolutely safe'

Scientists insist the most powerful particle accelerator ever built is "absolutely safe".

Concerns have been voiced over the £5 billion Large Hadron Collider (LHC) which will be switched on this Wednesday

The machine, to be based underground on the Swiss-French border, will smash protons - one of the building blocks of matter - into each other at energies up to seven times greater than any achieved before.

In the flashes from the collisions, they expect to reproduce conditions that existed during the first billionth of a second after the Big Bang at the dawn of creation.

Professor Otto Rossler, a German chemist from a group of scientists mounting a last-minute court challenge to the project, has expressed worries about the creation of black holes.

Scientists believe microscopic black holes might be generated in the machine. But according to the predictions, they will blink in and out of existence before anything scary happens.

Prof Rossler believes it is quite possible that the black holes made in the LHC will grow uncontrollably and "eat the planet from the inside".

But Particle physicist Dr James Gillies, a spokesman for the project, said: "We have received a lot of worried calls from people about it.

"There's nothing to worry about, the LHC is absolutely safe, because we have observed nature doing the same things the LHC will do. Protons regularly collide in the earth's upper atmosphere without creating black holes."

The experiments could help scientists find answers to some of the biggest questions in physics, such as why the universe looks the way it does, and how to explain mass, gravity and mysterious "dark matter".

Japanese physicists aim to unlock universe's mysteries

A worker shows the facilties of the world's largest scale synchrotron 500m in diameter which produces neutrons and neutrino and can be used for research materials and life science at the Japan Atomic Energy Agency (JAEA) Tokai Research and development center at Tokai village in Ibaraki prefecture As the world's scientists try to unzip mysteries about the universe, Japan is set to open its largest atomic science park to study the world at its smallest level