Physics Today Daily Edition

Subscribe to Physics Today Daily Edition feed
Please follow the links to view the content.
Updated: 2 days 21 hours ago

Attention grows for the Anthropocene, “an argument wrapped in a word”

24 March 2015
Should scientists proclaim a human geological epoch, creating a “weapon” for both sides in the “battle over the fate of the planet”?

Sound lab used to simulate and promote Heathrow expansion

24 March 2015
Guardian: The prospect of a third runway at the UK’s busy Heathrow Airport has many local residents upset because of the potential for even more noise. To help mitigate people’s fears, Arup SoundLab in central London has simulated what the proposed expanded airport would sound like. In the lab, technicians can re-create different scenarios that include various combinations of aircraft, times of day, and distances from the airport. Because older, noisier planes are being phased out and newer, quieter planes are being introduced, the lab is also set up to compare current and future sound scenarios. Heathrow officials suggest that the new runway, which will require steeper landing approaches and keep planes flying higher for longer, may even provide some respite from the noise.

Nonstick coating means nothing left in the bottle

24 March 2015

New York Times: Getting the last of anything out of a bottle usually involves scraping the inside. Depending on the viscosity of the substance, up to a quarter of the contents of a bottle may end up being thrown out. Now, Kripa K. Varanasi of MIT and graduate student J. David Smith have created a startup, called LiquiGlide, to market a coating they developed that allows a bottle's contents to easily slide out, regardless of the viscosity. Thanks to its porous surface, their material traps a lubricant that can be customized to best match the properties of the intended contents of the bottle. The lubricant makes the inner surface of the container superhydrophobic, which prevents the contents from binding to the container's interior.

Europe's power grid survives solar eclipse

24 March 2015

New Scientist: Last week's solar eclipse was visible across much of Europe. That meant that the solar generating capacity of many countries was reduced briefly and other energy sources needed to be deployed. Since 2006, the European Union has spent €3 billion ($3.28 billion) on developing smart-grid technologies to help balance the distribution of energy in response to fluctuations in demand or production. In Germany, for instance, which gets 26% of its power from solar and wind, last week's eclipse provided an important test of the grid's ability to handle sudden changes. To be on the safe side, the country doubled its network staff for the day and also turned off four aluminum plants that draw a lot of power. During the eclipse, Germany's solar energy production dropped from 38.2 GW to 23.2 GW. No problems were reported, however, in either Germany or any of the countries that contribute the other 51 GW of solar power in the EU.

Jupiter may have determined number of planets in solar system

24 March 2015
Los Angeles Times: Our inner solar system is unusual in that it has far fewer planets than most other planetary systems discovered so far. Why it is not crowded with so-called super-Earths, planets with masses exceeding those of Earth, may be due to Jupiter, whose early orbit of 3–10 astronomical units from the Sun varied wildly before settling in to its current one of 5–5.5 AU. A group of researchers has proposed that in the early solar system, a young Jupiter may have migrated toward the Sun, sweeping along many of the other, smaller objects around it. In the process, those objects may then have collided with each other, broken up into dust, and drifted along into the Sun. As Jupiter reversed course and settled in to its current orbit, the remaining debris formed into the solar system’s terrestrial planets. The discovery of more exoplanetary systems should help determine whether that scenario is likely.

Diamond steps up for thin films

23 March 2015
MIT Technology Review: Diamond possesses remarkable physical properties—it is strong, transparent, and thermally conductive. Hence, thin films made from diamond could be extremely useful in various electronic and mechanical micro- and nanodevices. However, growing diamond thin films requires stringent conditions, including high temperatures and an atmosphere of pure hydrogen. Now a group of researchers has shown how diamond nanosheets can be grown on a substrate of quartz and then transferred elsewhere as needed. At a thickness of about 180 nm, the diamond separates naturally from the quartz and can be moved and attached to another surface, such as an electronic circuit, through the use of a sticky film. Because it is so labor-intensive, the current technique is not yet viable for mass production of diamond-based devices.

Ukraine to join Horizon 2020 program

23 March 2015
Nature: Ukraine is set to become an associate member of the European Horizon 2020 program, once the country’s parliament votes to approve the agreement. Horizon 2020 is the world’s largest multinational funding program dedicated to research and innovation. Over the period 2014 to 2020, it will make available some €80 billion in science funding. It is the first European Union (EU) program in which Ukraine has chosen to participate since the signing of the Ukraine–European Union Association Agreement in 2014. Membership will allow Ukrainian scientists, research institutions, and enterprises to compete with EU member states for funding. In addition, Ukraine will be able to host European Research Council (ERC) grant recipients and participate in the program’s governance.

Large Hadron Collider's second run to start this week

23 March 2015
BBC: The Large Hadron Collider (LHC), at CERN in Switzerland, is about to begin phase two of its operations. Phase one began in 2008, when the LHC fired its first protons, and lasted until early 2013. Since then, the world’s largest and most powerful particle collider has been undergoing a period of maintenance and upgrades. Each of its 10 000 superconducting electromagnets has been inspected and reinforced to withstand the extreme conditions meant to simulate those that occurred shortly after the Big Bang. At the same time, most of the LHC's seven detectors have also been undergoing service and upgrading. They've been prepared for the return of the proton beams, which will have nearly twice the collision energy of those during the first run. The restart will be a gradual process, with the proton beams reaching full circle no earlier than Wednesday.

Earth’s tectonic plate motion is jittery

23 March 2015
Science: Earth’s continents are continually shifting, and the pace of their movement is irregular, sometimes rapid and sometimes slow. Researchers at the EarthByte program at the University of Sydney in Australia have been studying the complex interplay between deep-Earth and surface processes and have developed a computer model that breaks down tectonic plate movements into 1-million-year intervals. They have found that although the plates tend to shift about 4 cm per year, they can move as fast as 20 cm per year over geologically brief time periods of 10 million years or so. And oceanic plates appear to move faster than continental plates. What causes the plates to speed up and slow down is still not entirely understood. The researchers say that rising plumes of molten rock in Earth’s mantle could provide lubrication between it and the continents, and rocky protrusions on the underside of the massive continents may create drag to slow them down. The group plans to look next at ancient plate movement before the breakup of Pangea into multiple continents.

Chromosomes’ smallest structure revealed

23 March 2015
It’s long been thought that at size scales of tens of nanometers, our genetic material is packaged in a neat, orderly way. New observations show that that’s not the case.

Moon's ice indicates past polar shift

20 March 2015

Science: At the Lunar and Planetary Science Conference this week, an unexpected finding about the location of the Moon's ice was announced. Unlike the ice found on most planetary bodies in the solar system, the Moon's ice does not cover its north and south poles, but rather is located several degrees away from its poles. Matthew Siegler of the Planetary Science Institute in Dallas, Texas, and his colleagues reexamined data collected by the Lunar Prospector mission, which orbited the Moon 16 years ago. They realized that the two patches of lunar ice were directly opposite each other. The most likely explanation for this arrangement is that the ice was originally deposited at the lunar poles, and at some point, the Moon's axis must have shifted by more than 5°. None of the known asteroid impacts are large enough or in the right location to have been the cause. Siegler's team believes the outpouring of lava that created the Oceanus Procellarum some 3.5 billion years ago could have unbalanced the axis.

EU and China to choose first joint space project

20 March 2015

Nature: On 16 March, the European Space Agency (ESA) and the Chinese Academy of Sciences closed a call for proposals for a joint space mission. The ESA has contributed instruments to a Chinese satellite before, but this will be the first mission to be a collaboration from the start. The two agencies are each contributing the equivalent of just over $53 million to the project, a funding amount that limits its size. Another limitation is that the mission should focus on something other than Mars or the Moon, which are already being studied through other projects. The agencies received 16 proposals, which included studying radio signals, x-ray imaging of Earth's magnetosphere, and looking at "hot objects" with an extreme-UV telescope. The proposals will be examined based on technological feasibility and scientific merit. By the end of the year, the best will be selected to undergo further review, with a final decision to be made in 2017.

Green-glowing fungi attract more bugs

20 March 2015
Los Angeles Times: Although bioluminescence has been observed in fungi, it is relatively rare. Among the some 100 000 known fungal species, just 71 have the ability to glow like fireflies. Rather than constantly emitting green light, however, at least one species—Neonothopanus gardneri—appears to be regulated by the circadian clock, according to a recent study published in Current Biology. N. gardneri glows brilliantly at night and shuts off during the day. The reason may have to do with the attraction of insects, which could help spread the fungi’s spores in the dense Brazilian coconut forests where they grow. The researchers tested their theory through the use of prosthetic, acrylic-resin, mushroom-shaped objects artificially illuminated with green LEDs. The fake mushrooms attracted many more beetles, ants, and other insects than did the dark control traps.

Record low reported for Arctic sea ice

20 March 2015
BBC: This year the maximum level of sea ice in the Arctic Ocean, as measured on 25 February, was found to be 130 000 km2 below the previous record low, which was set in 2011. Since satellite records began in the late 1970s, the annual mean Arctic sea-ice thickness has decreased by 65%, according to a recent study. Although the Arctic Ocean will continue to freeze each winter and thaw each summer, regardless of climate change, scientists are observing a fairly clear pattern of substantial sea-ice loss over time. The consequences could prove profound for people, animals, and plants not only in polar regions but also around the world, said Bob Ward of the Grantham Research Institute on Climate Change and the Environment at the London School of Economics.

Physics in West Germany

20 March 2015
In 1966 Physics Today published an overview of physics in the increasingly prosperous country.

Weather radar polarimetry

20 March 2015
Dual-polarization radar promises to improve the modeling of convective storms.

Minibeams may minimize damage in cancer treatment

19 March 2015
Splitting a radiotherapy proton beam into submillimeter pieces can spare normal tissue along the way.

Hybrid drone developed for package deliveries

19 March 2015
MIT Technology Review: A new hybrid gas–electric drone can fly longer and carry heavier payloads than current models. Developed by Top Flight Technologies, the six-rotor unmanned aerial vehicle (UAV) uses batteries to supplement a gasoline-powered engine. The UAV can fly for more than two hours over distances up to 160 km and can carry a payload weighing as much as 9 kg. That is much longer and farther, and with a much heavier payload, than has been achieved by any battery-operated drone on the market. Such a craft is being sought by such internet-based retail and delivery companies as Google, Amazon, and DHL as an efficient and inexpensive way to deliver packages. Top Flight’s hybrid drones may be available for purchase by the end of the year.

Dwarf galaxy gamma-ray signal could come from dark-matter collisions

19 March 2015

Ars Technica: Last week, it was announced that several new dwarf galaxies surrounding the Milky Way had been found. Now, a team led by Alex Geringer-Sameth of Carnegie Mellon University has found that the closest of those galaxies, Reticulum 2, emits gamma rays. The finding is notable because dwarf galaxies generally lack the usual objects, such as black holes and pulsars, that produce gamma rays. And no previous dwarf galaxy has ever been found emitting gamma rays. The signal from Reticulum 2 could be detectable simply because it is the closest dwarf galaxy yet found. Because dwarf galaxies have a high concentration of dark matter, they are believed to be good candidates for study to try to find out what kind of particles dark matter is made of. Geringer-Sameth's team believes that the gamma-ray signal could be evidence of self-interacting dark-matter particles, such as WIMPs, colliding with each other. However, there are still too many characteristics of Reticulum 2 that need to be clarified before that theory can be confirmed.

Royal Society chooses structural biologist Nobel laureate as new president

19 March 2015
Nature: Venkatraman Ramakrishnan has been selected to become the UK Royal Society's new president later this year. He will replace Paul Nurse, a geneticist who has served as president since December 2010. Ramakrishnan is currently the deputy director of the Medical Research Council Laboratory of Molecular Biology. After earning a PhD in physics, he moved into biology and shared the 2009 Nobel Prize in Chemistry for his work on ribosomes, the molecules that construct proteins from DNA. As president of the Royal Society, Ramakrishnan will be serving as the public head of an organization that promotes scientific investment and directly funds research across all fields of study in the UK.

Pages