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Math

Researcher Modifies Sieve of Eratosthenes To Work With Less Physical Memory Space (scientificamerican.com) 44

grcumb writes: Peruvian mathematician Harald Helfgott made his mark on the history of mathematics by solving Goldbach's weak conjecture, which states that every odd number greater than 7 can be expressed as the sum of three prime numbers. Now, according to Scientific American, he's found a better solution to the sieve of Eratosthenes: "In order to determine with this sieve all primes between 1 and 100, for example, one has to write down the list of numbers in numerical order and start crossing them out in a certain order: first, the multiples of 2 (except the 2); then, the multiples of 3, except the 3; and so on, starting by the next number that had not been crossed out. The numbers that survive this procedure will be the primes. The method can be formulated as an algorithm." But now, Helfgott has found a method to drastically reduce the amount of RAM required to run the algorithm: "Now, inspired by combined approaches to the analytical 100-year-old technique called the circle method, Helfgott was able to modify the sieve of Eratosthenes to work with less physical memory space. In mathematical terms: instead of needing a space N, now it is enough to have the cube root of N." So what will be the impact of this? Will we see cheaper, lower-power encryption devices? Or maybe quicker cracking times in brute force attacks? Mathematician Jean Carlos Cortissoz Iriarte of Cornell University and Los Andes University offers an analogy: "Let's pretend that you are a computer and that to store data in your memory you use sheets of paper. If to calculate the primes between 1 and 1,000,000, you need 200 reams of paper (10,000 sheets), and with the algorithm proposed by Helfgott you will only need one fifth of a ream (about 100 sheets)," he says.
Space

China's Giant Radio Telescope Begins Searching For Signals From Space (ctvnews.ca) 41

Years of work and millions of dollars later, China finished its alien-hunting telescope in May this year. Now the country says its telescope has begun its operation. The company flipped the switch over the weekend, hoping to find signals from stars and galaxies -- and more importantly from extraterrestrial life. The telescope also illustrates China's growing ambition to stay among the frontrunners in space efforts. AP reports: Beijing has poured billions into such ambitious scientific projects as well as its military-backed space program, which saw the launch of China's second space station earlier this month. Measuring 500 metres in diameter, the radio telescope is nestled in a natural basin within a stunning landscape of lush green karst formations in southern Guizhou province. It took five years and $180 million to complete and surpasses that of the 300-meter Arecibo Observatory in Puerto Rico, a dish used in research on stars that led to a Nobel Prize. The official Xinhua News Agency said hundreds of astronomers and enthusiasts watched the launch of the Five-hundred-meter Aperture Spherical Telescope, or FAST, in the county of Pingtang. Researchers quoted by state media said FAST would search for gravitational waves, detect radio emissions from stars and galaxies and listen for signs of intelligent extraterrestrial life. "The ultimate goal of FAST is to discover the laws of the development of the universe," Qian Lei, an associate researcher with the National Astronomical Observatories of the Chinese Academy of Sciences, told state broadcaster CCTV. "In theory, if there is civilization in outer space, the radio signal it sends will be similar to the signal we can receive when a pulsar (spinning neutron star) is approaching us," Qian said.
The Internet

What Vint Cerf Would Do Differently (computerworld.com) 116

An anonymous Slashdot reader quotes ComputerWorld: Vint Cerf is considered a father of the internet, but that doesn't mean there aren't things he would do differently if given a fresh chance to create it all over again. "If I could have justified it, putting in a 128-bit address space would have been nice so we wouldn't have to go through this painful, 20-year process of going from IPv4 to IPv6," Cerf told an audience of journalists Thursday... For security, public key cryptography is another thing Cerf would like to have added, had it been feasible.

Trouble is, neither idea is likely to have made it into the final result at the time. "I doubt I could have gotten away with either one," said Cerf, who won a Turing Award in 2004 and is now vice president and chief internet evangelist at Google. "So today we have to retrofit... If I could go back and put in public key crypto, I probably would try."

Vint Cerf answered questions from Slashdot users back in 2011.
Space

Cisco Blamed A Router Bug On 'Cosmic Radiation' (networkworld.com) 141

Network World's news editor contacted Slashdot with this report: A Cisco bug report addressing "partial data traffic loss" on the company's ASR 9000 Series routers contended that a "possible trigger is cosmic radiation causing SEU [single-event upset] soft errors." Not everyone is buying: "It IS possible for bits to be flipped in memory by stray background radiation. However it's mostly impossible to detect the reason as to WHERE or WHEN this happens," writes a Redditor identifying himself as a former [technical assistance center] engineer...
"While we can't speak to this particular case," Cisco wrote in a follow-up, "Cisco has conducted extensive research, dating back to 2001, on the effects cosmic radiation can have on our service provider networking hardware, system architectures and software designs. Despite being rare, as electronics operate at faster speeds and the density of silicon chips increases, it becomes more likely that a stray bit of energy could cause problems that affect the performance of a router or switch."

Friday a commenter claiming to be Xander Thuijs, Cisco's principal engineer on the ASR 9000 router, posted below the article, "apologies for the detail provided and the 'concept' of cosmic radiation. This is not the type of explanation I would like to see presented to the respected users of our products. We have made some updates to the DDTS [defect-tracking report] in question with a more substantial data and explanation. The issue is something that we can likely address with an FPD update on the 2x100 or 1x100G Typhoon-based linecard."
Space

SpaceX Blast Investigation Suggests Breach in Oxygen Tank's Helium System (reuters.com) 78

Weeks after a SpaceX rocket exploded inexplicably, engineers at Elon Musk's company have traced the flaw to its source. Space today released the initial results of its investigation, in which it says that a breach in helium system in the Falcon 9's liquid oxygen system caused the sudden flare up. From a Reuters report: SpaceX, owned and operated by technology entrepreneur Elon Musk, was fueling a Falcon 9 rocket on the launch pad in Florida on Sept. 1 in preparation for a routine test-firing when a bright fireball suddenly emerged around the rocket's upper stage. "At this stage of the investigation, preliminary review of the data and debris suggests that a large breach in the cryogenic helium system of the second stage liquid oxygen tank took place," SpaceX said in a statement posted on its website. No one was hurt in the explosion, which could be heard 30 miles (48 km) away from SpaceX's launch pad 40 at Cape Canaveral Air Force Station. The cause of the accident is under investigation.
Data Storage

Amazon Is Killing Off Its $12/Year Plan For Unlimited Photo Storage (petapixel.com) 49

To many's surprise, Amazon introduced a consumer-focused storage option -- unlimited photo backup for only $12 per year. This was Amazon's attempt to lure customers away from Google, Dropbox, and iCloud. But it seems, even for Amazon, $12 per year for so much storage space is not feasible. The company has reportedly started to inform the customers that the plan is being discontinued. PetaPixel reports: Subscribers of the plan, which was launched in March 2015, are taking to the web to report receiving an email from Amazon informing them of the change. Amazon is offering customers free months of the Unlimited Storage plan, which costs $60 per year. It seems that some people are being offered a standard 3-month free trial of the service, while others are being offered a 12-month free period.
Government

Senate Panel Authorizes Money For Mission To Mars (usatoday.com) 134

An anonymous reader quotes a report from USA Today: With a new president on the horizon, a key Senate committee moved Wednesday to protect long-standing priorities of the nation's space program from the potential upheaval of an incoming administration. Members of the Commerce, Science and Transportation Committee passed a bipartisan bill authorizing $19.5 billion to continue work on a Mars mission and efforts to send astronauts on private rockets to the International Space Station from U.S. soil -- regardless of shifting political winds. Under the Senate bill, NASA would have an official goal of sending a crewed mission to Mars within the next 25 years, the first time a trip to the Red Planet would be mandated by law. The legislation would authorize money for different NASA components, including $4.5 billion for exploration, nearly $5 billion for space operations and $5.4 billion for science. Beyond money, the measure would: Direct NASA to continue working on the Space Launch System and Orion multi-purpose vehicle that are the linchpins of a planned mission to send astronauts to Mars by the 2030s. The bill includes specific milestones for an unmanned exploration mission by 2018 and a crewed exploration mission by 2021. Require development of an advanced space suit to protect astronauts on a Mars mission. Continue development of the Commercial Crew Program designed to send astronauts to the space station -- no later than 2018 -- on private rockets launched from U.S. soil. Expand the full use and life of the space station through 2024 while laying the foundation for use through 2028. Allow greater opportunities for aerospace companies to conduct business in Low Earth Orbit. Improve monitoring, diagnosis and treatment of the medical effects astronauts experience from spending time in deep space.
Earth

Stephen Hawking Wants To Find Aliens Before They Find Us (cnet.com) 280

Stephen Hawking is again reminding people that perhaps shouting about our existence to aliens is not the right way to go about it, especially if those aliens are more technologically advanced. In his new half-hour program dubbed, Stephen Hawking's Favorite Places, the theoretical physicist and cosmologist said (via CNET):"If intelligent life has evolved (on Gliese 832c), we should be able to hear it," he says while hovering over the exoplanet in the animated "U.S.S. Hawking." "One day we might receive a signal from a planet like this, but we should be wary of answering back. Meeting an advanced civilization could be like Native Americans encountering Columbus. That didn't turn out so well." Hawking manages to be both worried about exposing our civilization to aliens and excited about finding them. He supports not only Breakthrough: Listen, but also Breakthrough: Starshot, another initiative that aims to send tiny nanocraft to our closest neighboring star system, which was recently found to have an Earth-like planet.
Space

Wildfire at Vandenberg Air Force Base Threatens ULA, SpaceX Launches (latimes.com) 55

Longtime Slashdot reader Bruce Perens writes: A fire at Vandenberg Air Force Base on the California coast -- currently over 10,000 acres in size -- has approached the pads used by SpaceX and United Launch Alliance. No structures have been damaged, but power lines have been destroyed. There is about 1000 feet of firebreak around each pad, but the presence of smoke and the absence of electrical power is potentially a problem for rockets, payloads, and ground-support equipment. The WorldView 4 satellite, a Delta 4 rocket, and a SpaceX Falcon 9 rocket with at least 7 (potentially 11) Iridium satellites are known to be on site. Ground support equipment at the base constitutes the United States' only access to polar orbit for large rockets without overflying populated areas. Liquid oxygen stored on the site may already have been released as a precaution or boiled off, and there are large supplies of rocket fuel, but these have so far not been a hazard. The Soberanes fire near Big Sur, located 180 miles farther South on the California coast, has gone on for two months, burning 185 square miles and costing over $200 million dollars to fight with no end in sight. Obviously, it's dry out there. The fire forced officials to cancel the Atlas V rocket launch on Sunday, and the next attempt won't occur for a week.
China

China Confirms Its Space Station Is Falling Back to Earth (popularmechanics.com) 272

The Tiangong-1, China's prototype space station which was launched in September 2011, is no longer under the control of China. PopularMechanics reports: China's Tiangong-1 space station has been orbiting the planet for about 5 years now, but recently it was decommissioned and the Chinese astronauts returned to the surface. In a press conference, China announced that the space station would be falling back to earth at some point in late 2017. Normally, a decommissioned satellite or space station would be retired by forcing it to burn up in the atmosphere. This type of burn is controlled, and most satellite re-entries are scheduled to burn up over the ocean to avoid endangering people. However, it seems that China's space agency is not sure exactly when Tiangong-1 will re-enter the atmosphere, which implies that the station has been damaged somehow and China is no longer able to control it. This is important because it means Tiangong-1 won't be able to burn up in a controlled manner. All we know is it will burn up at some point in late 2017, but it is impossible to predict exactly when or where. This means that there is a chance debris from the falling spacecraft could strike a populated area.
Mars

Elon Musk Scales Up His Ambitions, Considering Going 'Well Beyond' Mars (arstechnica.com) 289

An anonymous reader writes: For most of its 14-year existence, SpaceX has focused on designing and developing the hardware that will lead to its ultimate goal: colonizing Mars. These plans have remained largely secret from the general public, as company founder Elon Musk has dropped only the barest of hints. But that is expected to change on Sept. 27, during a session at the International Astronautical Congress, when Musk details some of these plans for the first time in a public forum. However, on the eve of the meeting, Musk dropped a surprise on Twitter. The workhorse spacecraft that will carry approximately 100 tons of cargo or 100 people to the surface of Mars, which until now has been popularly known as the Mars Colonial Transporter, can't be called that, Musk said. "Turns out MCT can go well beyond Mars, so will need a new name..." he tweeted on Friday evening. By Saturday evening he had a new name dubbing the spacecraft the "Interplanetary Transport System," or ITS. Mars, it turns out, isn't the solar system's only marginally habitable world for would-be new world colonists. The Moon, Venus, the asteroid Ceres, and outer Solar System moons Titan and Callisto all have some advantages that could allow for colonies to subsist. However, Mars has generally been the preferred destination -- due to its relative proximity to Earth, a thin atmosphere, and sources of water ice. Musk now seems to be suggesting that some of these more distant destinations, especially moons around Jupiter and Saturn, might be reachable with the Interplanetary Transport System.
Sci-Fi

SciFi TV Series 'Space Patrol Orion' Celebrates Its 50th Anniversary (wikipedia.org) 73

In Germany the phrase "Fallback to Earth!" is about as cult as "Engage warp drive," reports Long-time Slashdot reader Qbertino: One of the oldest science fiction TV serials, the famous German "Raumpatrouille Orion" (Space Patrol Orion) turned 50 today. Heise.de has a scoop on the anniversary in German [or roughly translated into English by Google]. The production of Space Patrol Orion predates Star Trek by roughly a year and was a huge hit in Germany, gaining the status of a "street sweeper" (Strabenfeger), referring to the effect it's airing had on public life.
The special effects are pretty good for 1966 -- you can watch episode one on YouTube. (And feel free to share other related videos in the comments.) "In the series, nations no longer exist and Earth is united," according to Wikipedia, which reports that Commander Cliff McLane and his loyal crew fight an alien race called the Frogs, and "He is notoriously defiant towards his superiors."
China

China's Atomic Clock in Space Will Stay Accurate For a Billion Years (rt.com) 111

The space laboratory that China launched earlier this week has an atomic clock in it which is more accurate than the best timepiece operated by America's National Institute of Standards and Technology, according to Chinese engineers. The atomic called, dubbed CACS or Cold Atomic Clock in Space, will slow down by only one second in a billion years. In comparison, the NIST's F2 atomic clock, which serves as the United States' primary time and frequency standard, loses a second every 300 million years. From an RT report:"It is the world's first cold atomic clock to operate in space... it will have military and civilian applications," said Professor Xu Zhen from the Shanghai Institute of Optics and Fine Mechanics, who was involved in the CACS project. An atomic clock uses vibrations of atoms to measure time, which are very consistent as long as the atoms are held at constant temperature. In fact, since 1967 the definition of second has been "9,192,631,770 vibrations of a cesium-133 atom." In a cold atomic clock, the atoms are cooled down with a laser to decrease the effect of atom movement on the measurements. CACS goes even further and eliminates the pull of Earth's gravity by being based in orbit.
Space

Pluto Is Emitting X-Rays (digitaltrends.com) 106

An anonymous reader quotes a report from Digital Trends: Scientists have noticed the tiny trans-Neptunium object emitting X-rays, which, if it is confirmed, is both a baffling and exciting discovery. Carey Lisse and Ralph McNutt from Johns Hopkins University Applied Physics Laboratory and a team of colleagues detected the X-rays by pointing the Chandra X-Ray Obervatory telescope in Pluto's direction four different times between February 2014 and August 2015. Seven photons of X-ray light were detected during these observations, confirming the team's hypothesis that the dwarf planet is detectable on the X-ray spectrum, potentially due to the presence of an atmosphere. Their findings have been published in the scientific journal Icarus. Why is this such a big deal? First of all, it would challenge what scientists have previously believed to be true of Pluto's nature. Until now, the popular description of the dwarf planet is as a tiny ball of frozen rock slowly meandering around the sun some 3.6-billion miles away. One of the possible explanations for why Pluto is emanating X-rays would be that the high energy particles emitted by the sun are stripping away and reacting with Pluto's atmosphere, producing the X-rays that are visible to Chandra. There are other potential explanations, such as haze particles in Pluto's atmosphere scattering the sun's X-rays are possible, though unlikely given the temperature of the X-rays observed. It is also possible that these X-rays are actually bright auroras produced by the atmosphere, but that would require Pluto to have a magnetic field -- something that would have been detected during New Horizon's flyby, yet no evidence of one was found.
Iphone

Apple Replaced the Headphone Jack On the iPhone 7 With a Fake Speaker Grill (businessinsider.com) 248

Not long ago, Apple CEO Tim Cook explained why the company felt a need to remove the headphone jack from the new iPhones -- the iPhone 7 and iPhone 7 Plus. He said, "that jack takes up a lot of space in the phone, a lot of space. And there's a lot of more important things we can provide for the consumer than that jack." His colleague Phil Schiller cited "courage" for the same. As people learn to live in a world where they have to use a dongle to use their existing pair of headphones, gadget repair community iFixit found today that Apple isn't really using that "extra space" it got after getting rid of the headphone jack. BusinessInsider reports: "In place of the headphone jack, we find a component that seems to channel sound from outside the phone into the microphone... or from the Taptic Engine out," they write. Yep -- in the place where the headphone jack used to be there's a piece of molded plastic. "No fancy electronics here, just some well-designed acoustics and molded plastic," iFixit writes.iFixit adds, "Closer inspection shows a new, second lower speaker grille that leads ... nowhere? Interesting." Update: 09/16 21:21 GMT by M : Apple says it's a "barometric vent." The Verge reports: Apparently adding all the waterproofing to the iPhone 7 and 7 Plus meant that it was more of a sealed box, and so to be able to have an accurate and working barometer, Apple used that space. The barometer is the thing that allows a phone to measure altitude, and Apple points out that on the iPhone 7 it can measure even minor changes like climbing a flight of stairs.
Businesses

Logitech Buys Saitek (betanews.com) 69

PC accessories maker Logitech announced that it is acquiring Saiket brand and its line of flight sim controller assets from MadCatz for $13 million in cash. From a report on BetaNews: Today, the company announces a surprising acquisition. Logitech has officially bought Saitek -- maker of simulation controllers. While the move was unexpected, it actually makes a lot of sense. Logitech gains entry into a niche gaming segment that depends heavily on high-priced controllers. "First, these products are just great. We know a thing or two at Logitech about what makes a gaming product stand out and these products deliver exceptional experiences. Don't take our word for it -- we've seen the Saitek fans on the forums. Second, simulation games are cool and getting cooler. Whether you're into driving, flying or exploring space, there are fresh new titles available and more to come. Some of these titles are even VR enabled and we believe that dedicated controllers will stimulate and enhance the total VR experience," says Logitech.
Sci-Fi

28 Years A Smeghead: Red Dwarf Is Coming Back (theguardian.com) 153

BarbaraHudson writes: Unless you're a smeghead, you'll be excited to know that (after 28 years after the smash cult sitcom began) Red Dwarf seasons 11 and 12 are now in production. The Guardian reports: "'I've known these guys longer than I've known my wife,' says Charles (Lister). 'That was what it came down to -- a choice between staying in Coronation Street or doing this.' Last year, after 10 years on the cobbliest of soaps, Charles left. He missed comedy, and the opportunity to strap on the famous dreads came up. 'I was like 'I've got to do it.' It's a career-defining role.' As it was with Llewellyn's (Kryton) re-application of the rubber head: 'The only reason I do it now -- and I don't do any other acting, it drives me mad -- is because it's being with your mates for a few weeks.' 'There's nothing similar about us,' says John-Jules (Kat). 'Except we all have Red Dwarf.'"
China

China Launches Second Space Lab (space.com) 88

Reader hackingbear writes: China's next space laboratory, Tiangong-2 launched from the country's Jiuquan Satellite Launch Center today at 10:04 a.m. EDT (1404 GMT) on a Long March 2F carrier rocket. Like its predecessor Tiangong-1, Tiangong-2 is an orbiting space lab -- but this latest model has made several improvements in the series. Among the advances: astronauts can remain on the station up to 30 days; New systems allow in orbit refueling of propellant; and 14 new experiments in a wide range of sciences including composite material fabrication, advanced-plant cultivation, gamma ray burst polarization, fluid physics, space-to-earth quantum communications. The space lab is also equipped with a cold atom space clock, that has an estimated precision of 10 to the power of minus 16 seconds, or a one-second error every 30 million years, enhancing accuracy of time-keeping in space by one to two orders of magnitudes. This exactitude will help measure previously undetectable fluctuations for experiments conducted in zero-gravity.The Tiangong 2, while is an experimental space station, is still operational. The astronauts that would come on board next month are to spend a full month up there -- a longer period of time than possible on Tiangong 1.
Advertising

Samsung Stops Airing Galaxy Note 7 Commercials, Preps Early Launch of Galaxy S8 (sammobile.com) 86

An anonymous reader writes: Given the bad press surrounding Samsung in regard to the faulty Galaxy Note 7 batteries, the company appears to have stopped airing Galaxy Note 7 commercials on TV. You know it's bad when they have reportedly stopped airing commercials in their home country, South Korea. One of the reasons behind the move is because sales of the Galaxy Note 7 have been suspended for over a week now, and will not be resuming until there is enough inventory to replace all Galaxy Note 7 units that have already been shipped. Some analysts believe sales might not be resumed until next month. Samsung will be using the ad space to market their other products like TVs and refrigerators. In addition, the company may be looking to launch the successor to the Galaxy S7 ahead of schedule. Kim Sang-pyo, an analyst for KB Investment and Securities said in a report: "If Samsung's flagship smartphone launch is delayed to the end of the first quarter of next year, the profitability of the mobile business division could be worsened next year," states the analyst. SamMobile also recently revealed the new model numbers for the Galaxy S8: the SM-G950 and the SM-G955. One model will feature a smaller screen, the other larger -- similar to the Galaxy S7 and S7 edge, though both phones might have a curved display this time around.
United States

Bank of America Analysts Say There's A 50% Chance We Live In The Matrix (independent.co.uk) 284

Bank of America analysts have suggested that there is a 20 to 50 percent chance that the world around us is a "Matrix-style virtual reality." The report stated, "It is conceivable that with advancements in artificial intelligence, virtual reality, and computing power, members of future civilizations could have decided to run a simulation of their ancestors." The idea is certainly nothing new, as many influential visionaries have come to similar theories. What some may find most unusual about the report is who issued it. According to Business Insider, Merrill Lynch, Bank of America's wealth management company, sent out a briefing to investors outlining their Matrix theory. In response, Slashdot reader marmot7 writes: Personally, I'd like to see all that brain power go toward a better and more stable banking system, not toward the promoting the nihilistic and self-indulgent idea that this might be the Matrix. Don't worry that banks behave in ways that create instability, it's not real. Just relax and enjoy the ones and zeroes. I have no doubt there are good, well meaning people there. I just don't really need my bank weighing in on the mystery of reality any more than I need them to come up with a unified theory of physics at long last. Well, unless it's in their spare time then by all means.

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