North Korea in space
On Dec. 12, North Korea finally managed to launch a satellite into orbit after 14 years and four failed attempts. The rocket used was the three-stage Unha-3, the same type that exploded after 90 seconds in the disastrous April 2012 launch. The satellite itself is about the size of a washing machine and, according to the North Korean government, is designed to monitor forests, watch for natural disasters, help with agriculture, and forecast the weather.
But the satellite does not appear to be functioning. The rocket successfully delivered it to the right location, but its orbit is unstable. It was supposed to transmit the “Song of General Kim Jong-il” to commemorate the one-year anniversary of the North Korean leader’s death, but no transmissions have been detected.
“The preponderance of the evidence suggests that the satellite failed either during the ascent or shortly afterwards,” said Harvard astronomer Jonathan McDowell to the New York Times.
The United States is concerned that North Korea’s space program is an excuse to test rockets for military purposes. Four U.S. warships were put in place to shoot down the rocket if it veered off course and threatened either Japan or the Philippines. The launch was most likely in violation of two UN Security Council resolutions forbidding North Korea to carry out any launch using ballistic missile technology.
Yangtze porpoise on decline
A six-week survey by the Institute of Hydrobiology at the Chinese Academy of Sciences and the World Wildlife Fund concluded that the finless porpoises of the Yangtze River are being driven to extinction. A previous survey carried out in 2006 spotted 1,225 of the porpoises living in the river. Less than half that number were seen this time.
The finless porpoises are one of the few remaining freshwater cetaceans (an order that also includes dolphins and whales) and are only found in the Yangtze and two nearby lakes. Another cetacean, the baiji (Yangtze River dolphin), famously chronicled by Douglas Adams in his book Last Chance to See…, was declared extinct after the 2006 survey. Both the river dolphins and finless porpoises navigate through the water using sonar. The high levels of noise caused by the river’s heavy shipping traffic disrupt this process, interfere with the porpoises’ feeding, and cause many to die by running into ships.
The porpoises are also vulnerable to overfishing and pollution. The Yangtze is heavily polluted – about 20 billion tonnes of waste are dumped every year, according to David Dudgeon, a University of Hong Kong ecologist. Overfishing has caused a decline in the porpoises’ food sources, and some fishing methods can harm the porpoises by accident.
Scientists are calling for the porpoises to be upgraded from class II to class I endangered status and for the creation of more porpoise reserves.
“If the situation does not improve significantly,” says Wang Ding, the chief scientist of the 2012 survey, “they may follow the fate of baiji in 15 years.”
One small step for quantum computing
A new experiment published in Science could be a step forward for quantum computing. Quantum computers are capable of performing calculations that would take an impractically long time to carry out on ordinary (classical) computers. There has been substantial progress on the theory of quantum computation, but an actual quantum computer is impossible to build with current technology. Recently there has been a lot of research into quantum-enhanced computing, which demonstrates principles of quantum computing with experiments that can be run with current technology.
Researchers at the University of Oxford built a simple boson-sampling computer, a device that was first proposed in a 2010 paper by Scott Aaronson and Alex Arkhipov of MIT. This computer was able to solve a sampling problem for four photons that would take a long time to solve classically. The experiment could easily be scaled up for more photons, but for a classical computer each additional particle doubles the time it takes to perform the calculation. According to Aaronson, the most powerful supercomputer on Earth could not solve the problem with 100 photons.
Another group based in Australia carried out its own boson-sampling experiment at the same time, and teams in Italy and Austria have posted preprint papers of similar experiments. So far, these computers have no practical use, says Aaronson, but they are laying the foundations for the development of quantum computers.