Wednesday, August 11, 2010

Vinay Deolalikar, a mathematician who works for HP Labs, claims to have proven that P is not equal to NP. The problem is the greatest unsolved problem in theoretical computer science and is one of seven problems in which the Clay Mathematics Institute has offered million dollar prizes to the solutions.

The question of whether P equals NP essentially asks whether there exist problems which take a long time to solve but whose solutions can be checked quickly. More formally, a problem is said to be in P if there is a program for a Turing machine, an ideal theoretical computer with unbounded amounts of memory, such that running instances of the problem through the program will always answer the question in polynomial time — time always bounded by some fixed polynomial power of the length of the input. A problem is said to be in NP, if the problem can be solved in polynomial time when instead of being run on a Turing machine, it is run on a non-deterministic Turing machine, which is like a Turing machine but is able to make copies of itself to try different approaches to the problem simultaneously.

Mathematicians have long believed that P does not equal NP, and the question has many practical implications. Much of modern cryptography, such as the RSA algorithm and the Diffie-Hellman algorithm, rests on certain problems, such as factoring integers, being in NP and not in P. If it turned out that P=NP, these methods would not work but many now difficult problems would likely be easy to solve. If P does not equal NP then many natural, practical problems such as the traveling salesman problem are intrinsically difficult.

In 2000, the Clay Foundation listed the “Clay Millenium Problems,” seven mathematical problems each of which they would offer a million dollars for a correct solution. One of these problems was whether P equaled NP. Another of theseseven, the Poincaré conjecture, was solved in 2002 by Grigori Perelman who first made headlines for solving the problem and then made them again months later for refusing to take the prize money.

On August 7, mathematician Greg Baker noted on his blog that he had seen a draft of a claimed proof by Deolalikar although among experts a draft had apparently been circulating for a few days. Deolalikar’s proof works by connecting certain ideas in computer science and finite model theory to ideas in statistical mechanics. The proof works by showing that if certain problems known to be in NP were also in P then those problems would have impossible statistical properties. Computer scientists and mathematicians have expressed a variety of opinions about Deolalikar’s proof, ranging from guarded optimism to near certainty that the proof is incorrect. Scott Aaronson of the Massachusetts Institute of Technology has expressed his pessimism by stating that he will give $200,000 of his own money to Deolalikar if the proof turns out to be valid. Others have raised specific technical issues with the proof but noted that the proof attempt presented interesting new techniques that might be relevant to computer science whether or not the proof turns out to be correct. Richard Lipton, a professor of computer science at Georgia Tech, has said that “the author certainly shows awareness of the relevant obstacles and command of literature supporting his arguments.” Lipton has listed four central objections to the proof, none of which are necessarily fatal but may require more work to address. On August 11, 2010, Lipton reported that consensus of the reviewers was best summarized by mathematician Terence Tao, who expressed the view that Deolalikar’s paper probably did not give a proof that P!=NP even after major changes, unless substantial new ideas are added.

Thursday, March 9, 2006

Toronto’s public utility, Toronto Hydro Telecom, will make Canada’s largest city into a huge wireless hotspot.

“This is both an exciting and very important initiative for the city of Toronto”, said Toronto’s mayor, David Miller. “It puts us on the leading edge of the telecommunications industry nationwide and globally.”

Toronto Hydro Telecom will offer customers free access for the first six months. After that, it will begin to charge for services.

“Wi-Fi technology is the new benchmark for urban living”, stated Toronto Hydro president David Dobbin. “It’s standard equipment in many electronic devices, from laptops to portable entertainment units.”

Private telephone companies are questioning why a public utility needs to compete with the private sector.

Mike Lee of Rogers Communications Inc. questioned why the city of Toronto wanted to enter the internet access business.

“It will not be an easy business”, Lee told the National Post. “In this day and age, the focus should be on core operations more than anything. I was surprised to see they are looking to get into this business.”

Brian Sharwood, a telecom analyst in Toronto, said the municipality will likely install the wireless transmitters and receivers on its lamp posts as a way to blanket the city, a process known as “wireless mesh networking”.

Sunday, June 4, 2006

An Indonesian government volcanologist reports that Mount Merapi spewed lava and ash many times on Saturday, renewing fears of a devastating volcanic eruption.

Government geologist Subandriyo said that Merapi’s lava dome has swelled 56 feet (17 m) in the past week to a height of 330 feet (100 m), raising fears that it could collapse and release a pyroclastic flow of hot gases and rock fragments burning everything in its path. The quake is believed to contribute to the growing instability of the lava dome, scientists said.

The mountain also sent about 90 trails of molten lava down its western slope on Thursday, said geologist Tri Yani.

The announcement comes one week after a 6.3 magnitude earthquake struck the city of Yogyakarta, killing at least 6,000 people and injuring tens of thousands more. Since then, the region has experienced over one thousand aftershocks – most were weak, but some were strong enough to jolt villagers awake in the area.

Villagers in the vicinity of the mountain have started performing ancient religious rituals aimed at averting an eruption. The royally appointed guardian of the mountain, “Mbah” Maridjan, was reported to have led a silent procession of about 100 people on a march around a village near the volcano.

Saturday, June 11, 2011

A Russian programming researcher Efim Bushmanov uploaded the Skype source on Blogspot, Torrent, and Github last Tuesday. Bushmanov said that his release engineering work is “not finished,” and stated that the purpose of its release is “community involvement.”

Bushmanov said that his motivation was a story in the Wall Street Journal which described possible eavesdropping on Skype by governmental agencies. The upload to public would allow people to participate with further work on the reverse engineering which is not yet finished.

Skype responded by a promise to support security of the Skype users and to investigate and prevent the attacks this can cause: “This unauthorized use of our application for malicious activities like spamming/phishing infringes on Skype’s intellectual property. We are taking all necessary steps to prevent/defeat nefarious attempts to subvert Skype’s experience. Skype takes its users’ safety and security seriously and we work tirelessly to ensure each individual has the best possible experience.”

Some public said that Microsoft is to blame for the lack of stability of Skype since its acquisition plans were announced in the beginning of May. However, Microsoft has no operational control over Skype servers yet. The acquisition is planned to be finished by the end of 2011. Microsoft’s response included a note that despite that they have some Windows code shared with Russian government, they would fear to share Skype code, and make strong attempts to keep it unavailable to third parties.

Information Week magazine commented that the release can be legal if no part of the work involves copying the original code from Skype servers.

Paul Ducklin, head of technology for security company Sophos, noted the presence of IDA Pro (Interactive Disassembler) files in the downloads published by Bushmanov, indicating that his reverse engineering had not been conducted in a “clean room” fashion. The project included shared files which were enough for the tech company Hex-Rays to verify that the version of IDA Pro used was pirated.

Friday, December 21, 2012

Recently, Wikinews spent time with with United States Paralympic skier Jasmin Bambur who was at Copper Mountain, Colorado for the IPC Nor-Am Cup.

((Wikinews)) We’re interviewing Jasmin Bambur. He is a guy. He’s from Serbia, right?

Jasmin Bambur: Yes, ma’am, I am from Serbia but I race for US Paralympic.

((WN)) How did a Serb end up racing for the USA?

Jasmin Bambur: It’s very simple. You just get married to a fine American lady and she give you citizenship and you ski fast and you get on the team. That’s very simple.

((WN)) Why do the Australians love you so?

Jasmin Bambur: We’re a very small community, as ski racers, and we’re always great friends. So we kind of hang out together and help each other out. And then in the end, depends who wins, either hate them or love them.

((WN)) They said you’re some sort of professional racquetball player or something?

Jasmin Bambur: It’s actually team handball. It’s a sport [where] you have seven players like rugby. And yes, I played it professionally until I was 18 in Europe. And when war started in Kosovo, I moved to the United States and that’s how I end up here.

((WN)) You weren’t always a sit skier?

Jasmin Bambur: I am a sit skier now but actually the reason I am a sit skier is I had a car accident in 2000. I fell asleep driving. Driving and sleeping don’t go together. I don’t know why.

((WN)) Yeah, that’s a difficult lesson to learn. So how have you been doing at this event?

Jasmin Bambur: Skiing? I’ve been skiing for about ten years, racing about four. And so far it’s going great.

((WN)) You won a medal, at this thing, right? One of these days?

Jasmin Bambur: I won two medals in Super G, two third places, and yesterday I got second place in slalom.

((WN)) And what’s your favourite one?

Jasmin Bambur: Favourite is Super G.

((WN)) Because you go fast?

Jasmin Bambur: Yes, fast and very little turning. So that’s my pick[?].

((WN)) Thank you very, very much.

Jasmin Bambur: No problem.

Wednesday, September 8, 2010

Researchers led by a University of Pennsylvania scientist have discovered that moonlight increases the nocturnal activity of owl monkeys in South America. The researchers say this is the first long-term study showing that heat and light can affect the nocturnality of primates in the wild.

Azara’s owl monkeys were known to have regular activity patterns that included both nocturnal and diurnal (daytime) activity. These patterns changed more frequently than a few times per year along with seasonal phenomena. The study showed the monkeys’ nocturnal activity increased in warmer months and peaked on full moon nights — but decreased during full lunar eclipses on full moon nights, which occurred three times during the study.

Lead investigator and assistant professor in U.Penn.’s Department of Anthropology Eduardo Fernández-Duque explained that many animals change their activity levels with changes in environmental conditions. These changes are called “masking” in chronobiology. But the species of owl monkeys is distinguishable by its increased activity during nights with better moon light.

As Fernández-Duque explained, “The behavioral outcome for these owl monkeys is nocturnal activity maximized during relatively warm, moonlit nights. While laboratory studies have pointed to the importance of masking in determining the environmental factors that cause animals to switch from nocturnal activity patterns to diurnal ones or vice versa, our study underscores the importance of masking in determining the daily activity patterns of animals living in the wild. It also suggests that moonlight is a key adaptation for the exploitation of the nocturnal niche by primates.”

“Harsher climate, food availability and the lack of predators or daytime competition have all been proposed as factors favoring evolutionary switches in primate activity patterns,” said Fernández-Duque.

Team member Horacio de la Iglesia, of the Department of Biology at the University of Washington, pointed out that the changes of activity, though seasonal, aren’t a built-in biological clock. He was sure that they wouldn’t happen in absence of the Moon. He stated, “If there was a biological clock that they were depending on to regulate this activity, you could expect the activity to continue even in the absence of lunar light. The lunar day has not been a stable force as much as the solar day to evolutionarily select for a clock. We still have to prove it in the lab, but the evidence in this paper points to a lack of a lunar biological clock.”