Merging galaxies could explain large elliptical galaxies

Posted on by
Reply

Ars Technica: The largest galaxies in the universe are elliptical, rather than spiral like the Milky Way. Although theory and observation can account for the formation of small elliptical galaxies, how the extremely large ones formed is uncertain. A new set of observations may help to resolve the question. The Herschel Multi-tiered Extragalactic Survey detected a very bright object at a distance of 10 billion light years. Further observations revealed that the object consists of a merging pair of so-called submillimeter bright galaxies (SBGs) and that the exceptional brightness is due to intense star formation, on the order of 1600 to 2400 solar masses worth of stars each year. Researchers estimated that the result of the collision would be a giant elliptical galaxy with a star mass equivalent to 400 billion Suns. Given that giant elliptical galaxies in the nearby universe no longer host much star formation, the collision of a pair of SBGs is consistent with the idea of the giant galaxies forming through mergers that trigger a temporary burst of star formation.

Navy research submersible finishes $41 million retrofit

Posted on by
Reply

Nature: In 1964 the US Navy commissioned the DSV Alvin, a small, manned research submarine. Since its launch, Alvin has been responsible for several major discoveries such as ecosystems powered by hydrothermal vents instead of sunlight. In 2011, after making observations of the Deepwater Horizon oil spill, the vessel began a $41 million retrofit that has just been completed. On 25 May, Alvin will leave Woods Hole Oceanographic Institution in Massachusetts for a series of certification cruises off the coast of Oregon. Its upgrades include a larger sphere with extra windows and cameras for human occupants, longer manipulator arms, and a larger sample collection container. The new titanium sphere is capable of reaching depths of 6500 m, but the craft will still be limited to its previous maximum depth of 4500 m because its lead-acid batteries are not suitable for the lower mark. Susan Humphries, who was in charge of the retrofit, hopes that lithium-ion batteries will soon be safe enough to be added during regular maintenance in the next 5 years.

Scientists identify molecule that triggers itching in mice

Posted on by
Reply

Science News: An itch is believed to be recognized by neurons that have fibers extending into the skin. The neurons then trigger the release of neurotransmitter molecules that pass the signal to neurons in the spinal cord and then into the brain. Mark Hoon and Santosh Mishra of the National Institute of Dental and Craniofacial Research in Bethesda, Maryland, determined which molecules were produced by the original neurons and identified one, natriuretic polypeptide b (Nppb), as the most abundant. They then removed the gene in mice that produces Nppb and tested the mice’s reaction to the injection of itch-inducing substances. The Nppb-lacking mice did not respond to the injections. The researchers also tried blocking the reception of Nppb by neurons in the spinal cords of normal mice and found another significant reduction in scratching in response to itching. The research revealed that only a fraction of the neurons with fibers in the skin produced Nppb. The other neurons could be responsible for producing the chemicals that transmit pain or temperature.

New filter material sorts molecules by shape

Posted on by
Reply

MIT Technology Review: Oil refining entails sorting hydrocarbon molecules by size and shape. At a typical refinery, an energy-intensive distilling process separates the crude oil into fractions of various molecular sizes. Further processing or the use of additives is required to create fuels of specific octane levels. A new metal-organic material developed by Jeffrey Long of the University of California, Berkeley, and his colleagues eliminates the need for distillation or additives by sorting molecule size and shape in one step. By varying the metals and organic molecules in the material, researchers can change the size and shape of the pores in it and the way the pores interact with specific molecules. The material that Long and his colleagues made is a lattice of microscopic triangular tunnels designed to sort five different types of six-carbon atom hydrocarbon molecules that determine octane ratings. When the six atoms form a linear structure, a low octane fuel, they move slowly through the material. Larger, branching hydrocarbon arrangements move more quickly through the tunnels. The hydrocarbons pass through the material in regular intervals, making separation easy. The material is still experimental and would have to be produced at larger scales and incorporated into current refineries before it could be effectively commercialized.

Entanglement shown between photons that never coexist

Posted on by
Reply

Science: The entanglement of two particles (or photons) is a quantum mechanical effect in which measuring one of the particles instantaneously determines the state of the other, regardless of the distance between them. And entanglement can be swapped between pairs of entangled particles by creating two sets of particles and then performing a “projective measurement” of one particle of each pair. The measurement simultaneously entangles and destroys the measured particles, and it entangles the two other particles even if they had previously been measured. Now, Eli Megidish and Hagai Eisenberg of the Hebrew University of Jerusalem and their colleagues have used this swapping technique to entangle two photons that never coexisted. The time-separated effect was predicted by the original quantum theory, but this recent work is the first demonstration of it. The technique could be useful in the development of quantum communications systems.

Oklahoma tornado surprisingly quick forming and long lasting

Posted on by
Reply

Los Angeles Times: The Oklahoma City suburb of Moore has been hit by major tornadoes in 1999, 2003, and now 2013. Weather experts believe that the tornado strikes are just a case of statistical bad luck and that the town’s specific location does not make it especially prone to storm formation. However, the middle part of the US is called Tornado Alley because it is the meeting area of warm, humid air from the Gulf of Mexico to the south and cool, dry air from the Rocky Mountains to the west. The two masses of air create swirling winds that spawn massive supercell thunderstorms. On the day of the most recent tornado, a lot of warm, moist air lay near the ground, with a quick drop in temperature as altitude increased. And a nearby dissipating storm may have caused a surge of low-level air that fed the circulation driving the storm. The resulting storm developed incredibly quickly, with the supercell forming in 10 to 15 minutes. The tornado itself lasted for 50 minutes and traveled for 20 miles, whereas most tornadoes last less than 10 minutes. Weather scientists hope to use extensive radar measurements and other observational data to try to determine why the tornado formed so quickly.

Periodic table gets updates for some atomic weights

Posted on by
Reply

New Scientist: The order of the elements listed in the periodic table is dependent on the number of protons in the nucleus. However, each element has a variety of isotopes with varying numbers of neutrons in the nucleus, so each isotope has a slightly different mass. What’s more, the relative concentrations of each isotope can vary in different locations and environments. The International Union of Pure and Applied Chemistry (IUPAC) defines the standard atomic weight of the elements as listed on the periodic table based on the weighted mean of the stable isotopes of each element. Two years ago the IUPAC began listing a range of weights instead of a single value for elements that have varying concentrations depending on location and environment. And with the new change it is now listing both bromine and magnesium with ranges. Updates were also made to the weights of germanium, indium, and mercury.

South African R&D spending drops but effects are uncertain

Posted on by
Reply

Nature: South Africa spent just under 21 billion rand ($2.2 billion) on research and development in the 2009–10 budget year, according to a recently released survey. That amount was down 86 million rand from the previous year, the first drop in spending in more than a decade. And for the third straight year, spending was down as a percentage of GDP. Perhaps even more significantly, private investment in R&D in the same period dropped 9.7% from the previous year. Science minister Derek Hanekom attributes the federal funding decrease to the global financial crisis and a failed 2006 tax rebate. He also points to the shelving of an experimental nuclear reactor project that did not receive necessary private funding. But he thinks that since 2010, the country has turned the corner. Despite the reduction in spending, the number of papers published by South African researchers has increased as has the number of citations received. Critics in South African industry, however, worry that the loss of funding will have a longer lasting impact than the short term numbers indicate.

Report shows progress on Iran’s nuclear program

Posted on by
Reply

New York Times: The International Atomic Energy Agency issued a report showing that Iran has made progress across the board in its nuclear production program. Over three months, the country’s low-enriched uranium stockpile grew 8% to 10 tons. The focus is the enrichment of uranium-235, a reactor fuel that can be further enriched for use in weapons. And Iran is slowly raising the level of enrichment to 20% purity and converting the uranium to metal oxide form, which will purportedly be used as reactor fuel. The number of centrifuges used for enrichment grew by 1395 since February, for a total of 14 244. Only 689 of those centrifuges are of a new advanced form, and none appear to be in use yet. However, the country is also making progress on a heavy-water reactor at its Arak facility; the reactor can be used for producing plutonium that would also be useful in weapons. The report comes a month before Iran’s presidential election and during a hiatus in diplomacy after previous multiparty talks fell apart. US and Israeli officials say they would still have several months in which to respond if Iran began directly working on constructing a weapon. Talks are expected to begin again after the election, and levels of fuel are still below Israel’s declared limit for military action.

Iceland expands volcano monitoring capabilities

Posted on by
Reply

BBC: The Icelandic Meteorological Office (IMO) is beginning the installation of an expanded network of monitors and sensors as part of the FutureVolc project. Funded in part by the European Union, the project is a response to the 2010 eruptions of Eyjafjallajökull, which shut down air traffic across Europe. The IMO is adding a range of monitors that will be looking for small movements or tremors in the ground or the curving of Earth’s surface that could indicate a magma buildup. Other sensors will detect changes in gas emissions. All of the installations will provide real-time data to the IMO’s offices in Reykjavik. The IMO hopes to increase its ability to detect imminent eruptions several hours to days early. At many sites, residents are currently lucky to have 1 to 2 hours’ warning. The scientists will also be studying ash types and dispersal patterns to better plan for future air traffic disruptions. An Airbus report says the 2010 eruptions resulted in $5 billion in lost business revenue worldwide.