Month: April 2017

The Sequoyah Nuclear Plant. (credit: Nuclear Regulatory Commission)

After the Three Mile Island nuclear reactor meltdown in Pennsylvania in 1979, regulators moved to overhaul safety requirements for nuclear power plants. This led to the temporary closure of some older nuclear power plants governed by the Tennessee Valley Authority (TVA) when they couldn’t meet the Nuclear Regulatory Commission’s (NRC) newly tightened standards.

Now, Carnegie Mellon assistant professor of economics and public policy Edson Severnini says those closures may have caused reduced birth weight in children in the area at the time, due to pollution exposure from the increased reliance on coal-burning power plants. The sudden removal of nuclear power, which doesn’t emit any greenhouse gases, led to a ramp-up in the amount of power being provided by nearby coal plants, Severnini wrote. That led to increases in particle pollution in areas adjacent to coal power plants, measured by the Environmental Protection Agency (EPA) in total suspended particulates (TSP).

At the same time, average birth weight for infants declined 134 grams.

NASA

The Alpha Magnetic Spectrometer has served during the last six years as a silent witness to the formation of the universe, quietly collecting about 100 billion cosmic rays, particles, and nuclei with energies up to 1 trillion electron volts. "The results show unexpected phenomena—they are not predicted by current cosmic ray models—and this is changing our understanding of the cosmos," principal investigator Sam Ting told Ars.

But as this publication recently reported, there is a problem with the AMS particle detector's cooling system, and NASA is planning an extensive set of repairs. This will likely include a series of "Hubble-esque" spacewalks in 2018 to install a new cooling system for the $2 billion instrument. After the initial story, Ting provided Ars with more information about the scope and timing of the repairs.

(credit: Imagination Technologies)

A year on from Apple being locked in potential buyout talks with Imagination Technologies, the iPhone maker is set to abandon the British chip design company.

Shares in Imagination were in free-fall on Monday morning, after it confirmed it would lose its biggest customer by 2019. "Apple is of a view that it will no longer use the group’s intellectual property in its new products in 15 months to two years time, and as such will not be eligible for royalty payments under the current license and royalty agreement," it said.

Last year, the struggling UK-based semiconductor supplier axed 350 jobs and said it needed to slash millions of pounds in operating costs, after it warned that a slump in iPhone sales has hurt the business. Roughly half of its revenues derives from a licensing deal with Apple.

(credit: Roland)

Ikutaro Kakehashi, the founder of pioneering electronic instrument company Roland, has died aged 87.

Kakehashi's influence on both the development of electronic music and the pop charts is enduring. Following the founding of Roland in the 1970s, Kakehashi—an accomplished engineer—set his sights on developing a sophisticated electronic drum machine, which culminated with the release of iconic Roland TR-808 in 1980.

Unlike its contemporaries, which used recorded audio samples to help create drum sounds, the TR-808 was an entirely analogue instrument that used transistors to generate its sounds. While a commercial and critical flop on release, the TR-808 gained a cult following, quickly becoming the go-to drum machine for the nascent electronic dance and hip-hop scenes of the '80s.

Enlarge / Unfortunately, determing quantum computing speed is not as easy as deciding on the track like ol' Robert Kerr did for Canada at the 1908 British Amateur Athletic Association (AAA) Championships. (credit: Topical Press Agency/Getty Images)

When it comes to quantum computing, mostly I get excited about experimental results rather than ideas for new hardware. New devices—or new ways to implement old devices—may end up being useful, but we won't know for sure when the results are in. If we are to grade existing ideas by their usefulness, then adiabatic quantum computing has to be right up there, since you can use it to perform some computations now. And at this point, adiabatic quantum computing has the best chance of getting the number of qubits up.

But qubits aren't everything—you also need speed. So how, exactly, do you compare speeds between quantum computers? If you begin looking into this issue, you'll quickly learn it's far more complicated than anyone really wanted it to be. Even when you can compare speeds today, you also want to be able to estimate how much better you could do with an improved version of the same hardware. This, it seems, often proves even more difficult.

It's fast, honest

Unlike classical computing, speed itself is not so easy to define for a quantum computer. If we just take something like D-Wave's quantum annealer as an example, it has no system clock, and it doesn't use gates that perform specific operations. Instead, the whole computer goes through a continuous evolution from the state in which it was initialized to the state that, hopefully, contains the solution. The time that takes is called the annealing time.