Category Archives: General
By James Dacey
Astronomers believe they may finally be able to explain the origin of the “cold spot”, a glaringly large cool region in the cosmic microwave background (CMB). Maps of the CMB, such as that created by the Wilkinson Microwave Anisotropy Probe (WMAP) and more recently by the Planck mission, reveal the distribution of radiation left over after the Big Bang. When in 2004 researchers noticed this cold spot on the map, they soon realized it was either a sign of exotic physics linked to the Big Bang itself or it was caused by some sort of structure in the foreground between the CMB and the Earth.
By Anna Demming
This year marks 20 years since Stephen Chou, Peter Krauss and Preston Renstrom first published their work showcasing a versatile approach for mass production of identical nanostructures for the electronics industry. This technique is called nanoimprint lithography and it involves pressing a nano-patterned structure into a hot molten polymer. As the polymer cools, the pattern stamped into it sets so that it can be used as a mould to make several identical replicas of the original structure.
Just as the printing press brought literature to the masses, it is easy to imagine how this nanofabrication technique could have a significant impact on the production of integrated circuits. To commemorate the development, Nanotechnology has published a perspective article on the technique, and I had a chance to talk to the author Qiangfei Xia of the University of Massachusetts at Amherst about the technique’s advantages, challenges and outlook for the future.
By Michael Banks
Scientists at the European Space Agency (ESA) are hoping that the Philae lander, which successfully landed on a comet last year, will re-establish contact soon as it travels closer to the Sun. Philae was part of ESA’s Rosetta mission that was launched in 2004 but when Philae separated from Rosetta in November, it landed on the comet in an awkward position. This meant that the craft’s solar panels did not receive enough sunlight to recharge its battery, but the lander’s 10 instruments were able to carry out measurements before it went into hibernation mode about 50 hours after landing.
By Tamela Maciel at the APS April Meeting in Baltimore, Maryland
A group of undergraduate students at Drexel University in Philadelphia is ready to click “confirm” on an Amazon order that will include a weather balloon, a memory storage device, a GPS, a Geiger counter and a BeagleBoard computer (described to me as a “beefier version of Raspberry Pi”). For less than $2000, this team of physics, engineering and computer-science students plans to launch a weather-balloon experiment that will measure the effects of cosmic rays on DRAM memory devices at high altitudes.
The team is part of the Drexel University Society of Physics Students and the members presented their experiment design at the April Meeting of the American Physical Society in Baltimore, Maryland, last weekend.
DRAM is a very quick and simple type of electronic memory – each bit takes the form of a capacitor that either has charge or doesn’t, according to whether it’s storing a zero or one. Unfortunately, this simple design can make the bits very sensitive to radioactivity or cosmic rays, which can cause bits to flip values and introduce “soft errors” into the data.
By Margaret Harris
It’s the issue no-one is talking about in the run-up to the UK’s general election on 7 May, but I’m convinced that a brand-new party is set to make significant inroads on the British political scene, increasing both its overall share of the vote and its number of parliamentary seats.
“What is this bold new force?” I hear you ask. “Is it the Green Party? The Scottish or Welsh nationalists? The UK Independence Party (UKIP)?” My friends, it is none of these. Nor is it the Conservatives, Labour or the Liberal Democrats (the three parties that traditionally grab the lion’s share of seats at Westminster), or any of the parties representing Northern Ireland. It is something far more novel. More interesting. And above all, more able to solve the Schrödinger equation.
I’m talking about the Physics Party.
By Matin Durrani
Here at Physics World, we’ve had a regular programme of videos since 2009, when I led the way into a brave new multimedia world by interviewing the director-general of CERN Rolf-Dieter Heuer. What Heuer had to say was pretty interesting and the question-and-answer format is a common genre among online videos, but I have to admit that a film of two guys talking to each other while sitting on chairs in an office isn’t the most riveting thing you could ever watch. Even if the chairs were at CERN and one was occupied by the boss of one of the world’s top physics labs.
Since those early days, Physics World has developed and diversified its multimedia efforts, thanks in part to the ideas and inspiration of my colleague James Dacey, who has the rather grand job title of multimedia projects editor. Our content now includes a rolling programme of video documentaries, our 100-second-science strand and even an animation.
By Hamish Johnston
Cosmic rays, dark matter and other astrophysical mysteries are being debated with much vigour at a three-day conference that began this morning at CERN in Geneva. Called “AMS Days at CERN”, the meeting will include presentations of the latest results from the Alpha Magnetic Spectrometer (AMS).
Located on the International Space Station, the AMS measures the energy of high-energy charged particles from the cosmos – otherwise known as cosmic rays. These particles are of great interest because they offer us a window into some of the most violent processes in the universe. Some cosmic rays have probably been accelerated during supernova explosions while others could be produced as matter is sucked into the supermassive black holes that lie at the centres of many galaxies.
By Hamish Johnston
California might be suffering a punishing drought, but a tiny corner of the Golden State is now the coldest place on Earth. This tiny super-cold patch was created at Stanford University by Mark Kasevich and colleagues, who have used “matter-wave lensing” to cool a cloud of about 100,000 rubidium atoms to less than 50 pK. That is just 50 × 10–12 degrees kelvin above absolute zero.
The temperature of a cloud of atoms is defined by the average velocity of the atoms as they drift about. Kasevich’s team used a series of lenses to reduce this average motion to less than 70 µm/s, which corresponds to 50 pK. This shatters the previous record of 1 nK for matter-wave lensing and represents “record-low kinetic temperatures” according to Physical Review Letters, where the research is described.
By Hamish Johnston
The first proton beams of the second run of the Large Hadron Collider (LHC) were circulated earlier today. Travelling in opposite directions around the collider at CERN in Geneva, each beam was injected at 450 GeV. If all goes well over the next few days, the energy of each beam will be increased to the operating energy of 6.5 TeV.
By Michael Banks
Cat litter and radioactive waste – not a combination you would normally expect to come across (although some cat owners may disagree).
But a report by the US Department of Energy has squarely blamed kitty litter for the explosion of a single drum of nuclear waste – dubbed “68660” – that burst open at the Waste Isolation Pilot Plant (WIPP) in New Mexico in February 2014.
A year-long investigation by a nine-member panel – led by David Wilson of the Savannah River National Laboratory – has concluded that the incident was caused by the use of the wrong brand of feline litter.
As cat litter is highly absorbent, for years it has been used to help keep nuclear waste contained. Indeed, each barrel of waste at the WIPP is filled with about 26 kg of the stuff.