A jagged line etched on a fossil mussel shell may be the oldest evidence of geometric art.Photograph by Wim Lustenhouwer, VU University Amsterdam(Reuters) - It's a simple zigzag design scratched onto the surface of a freshwater mussel shell on t...
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We use the most cutting edge theories and technologies available, top astronomers, astrophysicists and astrobiologists seek answers to the mysteries of space in our universe.Since the dawn of humankind, our species has looked to the sky in wonder an...
Excerpt from cnn.comBy Thom Patterson You know those little "winglets" that point up from the tips of airliner wings? Those were developed by NASA. And, you know those little grooves in runways that channel away standing water?NASA again.America's spac...
Excerpt from AP-LOS ANGELES — The pilot of the Virgin Galactic spaceship that tore apart over the Mojave Desert didn’t know his co-pilot had prematurely unlocked its brakes, though protocol for the test flight required the co-pilot to announce the step, federal investigators said Wednesday.
Pilot Peter Siebold told the National Transportation Safety Board that he was not aware co-pilot Mike Alsbury had pulled a brake-unlocking lever before the rocket designed one day to fly tourists to the edge of space was done accelerating. Seconds later, SpaceShipTwo began to disintegrate over Southern California.
Protocol for the flight was to announce the unlocking, an agency spokesman said.
It is not clear if Siebold didn’t hear Alsbury or the co-pilot never indicated he was taking the action. The safety board plans to analyze flight audio next week, spokesman Eric Weiss said.
Virgin Galactic and said it could not comment on the investigation and referred questions to the NTSB. Siebold has not spoken publicly.
Pilots and co-pilots typically agree in advance before making important decisions, said Michael Lopez-Alegria, a former space shuttle astronaut who now consults on commercial space flight. One method is a “challenge and response” system in which one voices an intended action and the other confirms it before the action is taken.
Lopez-Alegria said he did not know whether the unlocking of SpaceShipTwo’s brakes was considered critical enough to require agreement, but “you would never take that action on your own.” He noted that in the cockpit of a commercial airliner, the pilot and co-pilot call out and confirm an action as routine as raising the wheels after takeoff.
The Oct. 31 crash about 120 miles north of downtown Los Angeles killed Alsbury, injured Siebold and cast a shadow over the immediate future of space tourism. It could take a year for the NTSB to determine the cause, though Virgin Galactic CEO George Whitesides said last week the company wants to resume test flights as early as next summer with a replacement craft.
The eventual goal is to launch spaceships carrying six passengers from a spaceport in New Mexico. For their $250,000 ticket, passengers would get a fleeting feeling of weightlessness and a spectacular view of Earth from about 62 miles up.
Pilot Siebold was hospitalized after the crash, but when he spoke to investigators Friday he had been discharged.
He told them that he was flung from the vehicle when it disintegrated. He said he unbuckled from his seat at some point during his fall that began miles above Earth, and his parachute deployed automatically.
Investigators have not revealed the exact altitude of the breakup, but previous SpaceShipTwo test flights peaked at about 10 miles, much lower than the height expected for commercial flights.
Co-pilot Alsbury could be seen on inflight video unlocking the system before the vehicle had reached Mach 1.0, Hart has said. The feathers aren’t supposed to be unlocked until the craft reaches Mach 1.4, or more than 1,000 mph. At that point, it would have reached an altitude where the thinner air would not have provided so much violent resistance.
Even after Alsbury unlocked them, the feathers were not supposed to move. For that to happen, the crew would pull a second lever. The crew didn’t take the second step, but the system engaged anyway. Two or three seconds later, the craft began to break apart.
The NTSB has said the feathers could have deployed because of aerodynamic forces on the craft. The agency said Wednesday that it is looking at those forces and reviewing safety documentation and the feather system’s design.
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Associated Press writers Brian Melley and John Antczak contributed to this report.
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bbc.com
Artist Carrie Paterson has long dreamed of beaming messages far out to the emptiness of space. Except her messages would have an extra dimension – smell.
By broadcasting formulae of aromatic chemicals, she says, aliens could reconstruct all sorts of whiffs that help to define life on Earth: animal blood and faeces, sweet floral and citrus scents or benzene to show our global dependence on the car. This way intelligent life forms on distant planets who may not see or hear as we do, says Paterson, could explore us through smell, one of the most primitive and ubiquitous senses of all.
It is nearly 40 years since the Arecibo facility sent messages out into space (Wikipedia)
Her idea is only the latest in a list of attempts to hail intelligent life outside of the Solar System. Forty years ago this month, the Arecibo radio telescope in Puerto Rico sent an iconic picture message into space – and we’ve arguably been broadcasting to aliens ever since we invented TV and radio.
However in recent years, astronomers, artists, linguists and anthropologists have been converging on the idea that creating comprehensible messages for aliens is much harder than it seems. This week, Paterson and others discussed the difficulties of talking to our cosmic neighbours at a conference called Communicating Across the Cosmos, held by Seti (Search for Extraterrestrial Intelligence). It seems our traditional ways of communicating through pictures and language may well be unintelligible – or worse, be catastrophically misconstrued. So how should we be talking to ET?
Lost in translation?
We have always wanted to send messages about humanity beyond the planet. According to Albert Harrison, a space psychologist and author of Starstruck: Cosmic Visions in Science, Religion and Folklore, the first serious designs for contacting alien life appeared two centuries ago, though they never got off the ground.
In the 1800s, mathematician Carl Gauss proposed cutting down lines of trees in a densely forested area and replanting the strips with wheat or rye, Harrison wrote in his book. “The contrasting colours would form a giant triangle and three squares known as a Pythagoras figure which could be seen from the Moon or even Mars.” Not long after, the astronomer Joseph von Littrow proposed creating huge water-filled channels topped with kerosene. “Igniting them at night showed geometric patterns such as triangles that Martians would interpret as a sign of intelligence, not nature.”
But in the 20th Century, we began to broadcast in earnest. The message sent by Arecibo hoped to make first contact on its 21,000 year journey to the edge of the Milky Way. The sketches it contained, made from just 1,679 digital bits, look cute to us today, very much of the ‘Pong’ video game generation. Just before then, Nasa’s Pioneer 10 and 11 space probes each carried a metal calling card bolted onto their frame with symbols and drawings on the plaque, showing a naked man and woman.
Yet it’s possible that these kinds of message may turn out to be incomprehensible to aliens; they might find it as cryptic as we find Stone Age etchings.
Antique tech
“Linear drawings of a male and a female homo sapiens are legible to contemporary humans,” says Marek Kultys, a London-based science communications designer. ”But the interceptors of Pioneer 10 could well assume we are made of several separate body parts (i.e. faces, hair and the man’s chest drawn as a separate closed shapes) and our body surface is home for long worm-like beings (the single lines defining knees, abdomens or collarbones.).”
Man-made tech may also be an issue. The most basic requirement for understanding Voyager’s Golden Record, launched 35 years ago and now way out beyond Pluto, is a record player. Aliens able to play it at 16 and 2/3 revolutions a minute will hear audio greetings in 55 world languages, including a message of ‘Peace and Friendship’ from former United Nations Secretary General Kurt Waldheim. But how many Earthlings today have record players, let alone extraterrestrials?
Our sights and sounds of Earth might be unintelligible to an alien audience (Nasa)
Time capsule
Inevitably such messages become outdated too, like time capsules. Consider the case of the Oglethorpe Atlanta Crypt of Civilization – a time capsule sealed on Earth in 1940, complete with a dry martini and a poster of Gone With the Wind. It was intended as a snapshot of 20th Century life for future humans, not aliens, but like an intergalactic message, may only give a limited picture to future generations. When, in 61,000 years, the Oglethorpe time capsule is opened, would Gone With The Wind have stood the test of time?
This message was taken into the stars by Pioneer - but we have no idea if aliens would be able to understand it (Nasa)
Kultys argues that all these factors should be taken into account when we calculate the likelihood of communicating with intelligent life. The astronomer Frank Drake’s famous equation allows anyone to calculate how many alien species are, based on likely values of seven different factors. At a UK Royal Society meeting in 2010 Drake estimated there are roughly 10,000 detectable civilisations in the galaxy. Yet Kultys points out that we should also factor in how many aliens are using the same channel of communications as us, are as willing to contact us as we are them, whose language we hope to learn, and who are physically similar to us.
Another barrier we might consider is the long distance nature of trans-cosmos communication. It means that many years ‒ even a thousand ‒ could pass between sending a message and receiving a reply. Paterson sees romance in that. “Our hope for communication with another intelligent civilisation has a melancholic aspect to it.
We are on an island in a vast, dark space. Imagine if communication… became like an exchange of perfumed love letters with the quiet agony of expectation... Will we meet? Will we be as the other imagined? Will the other be able to understand us?”
Ready for an answer?
Anthropologist John Traphagan of the University of Texas in Austin has been asking the same question, though his view is more cautious. "When it comes to ET, you'll get a signal of some kind; not much information and very long periods between ‘Hi, how are you?’ and whatever comes back. We may just shrug our shoulders and say 'This is boring’, and soon forget about it or, if the time lag wasn't too long, we might use the minimal information we get from our slow-speed conversation to invent what we think they're like and invent a kind concept of what they're after.”
The aliens in Independence Day (1996) did not come in peace (20th Century Fox)
Consider how easy it is to mess up human-to-human communications; I got Traphagan’s first name wrong when I e-mailed him for this article. An apology within minutes cleared up the confusion, yet if he had been an alien anthropologist on some distant planet it would have taken much longer to fix. He later confessed: "I could have thought this is a snooty English journalist and our conversation might never have happened."
Even if Earth’s interstellar messaging committees weeded out the typos, cultural gaffes are always a possibility. These can only be avoided by understanding the alien’s culture – something that’s not easy to do, especially when you’ve never met those you’re communicating with.
Rosy picture
So, what is the best way to communicate? This is still up for grabs – perhaps it’s via smell, or some other technique we haven’t discovered yet. Clearly, creating a message that is timeless, free of cultural bias and universally comprehensible would be no mean feat.
But for starters, being honest about who we are is important if we want to have an extra-terrestrial dialogue lasting centuries, says Douglas Vakoch, director of interstellar message composition at Seti. (Otherwise, intelligent civilisations who’ve decoded our radio and TV signals might smell a rat.)
The golden discs aboard the Voyager spacecraft require aliens to understand how to play a record (Nasa)
“Let's not try to hide our shortcomings,” says Vakoch. “The message we should send to another world is straightforward: We are a young civilisation, in the throes of our technological adolescence. We're facing a lot of problems here on Earth, and we're not even sure that we'll be around as a species when their reply comes in. But in spite of all of these challenges, we humans also have hope – especially hope in ourselves."
Yet ultimately what matters, says Paterson, is that they stop and consider the beings who sent them a message; the people who wanted to say: “Here are some important things. Here’s our DNA, here is some maths and universal physics. And here is our longing and desire to say “I’m like you, but I’m different.”
Excerpt from smh.com.auThe Tony Blair grin was gone but Richard Branson was unbowed by disaster when he appeared on American breakfast television on Monday morning. He vowed his program to hurl paying customers into the...
The Genographic Project traces the human journey through time and space, from our origins in the heart of Africa to the ends of the world. Cutting edge science, coupled with a cast of New Yorkers, each with their own unique genetic history.
Excerpt from
sfgate.com
MOJAVE, Calif. (AP) — Billionaire Virgin Galactic founder Richard Branson vowed Saturday to find out what caused the crash of his prototype space tourism craft that killed one of two test pilots, adding that while he remains committed to civilian space travel "we are not going to push on blindly."
In grim remarks at the Mojave Air and Space Port, where the craft known as SpaceShipTwo was under development, Branson gave no details of Friday's accident and deferred to the National Transportation Safety Board, whose team had just arrived.
"We are determined to find out what went wrong," he said, asserting that safety has always been the top priority of the program that envisions taking wealthy tourists six at a time to the edge of space for a brief experience of weightlessness and a view of Earth below.
"Yesterday, we fell short," he said. "We'll now comprehensively assess the results of the crash and are determined to learn from this and move forward."
He also criticized early speculation about crash causes. "To be honest, I find it slightly irresponsible that people who know nothing about what they're saying can be saying things before the NTSB makes their comments."
The pilot killed in the test flight was identified Saturday as Michael Tyner Alsbury, 39, of nearby Tehachapi. The surviving pilot is Peter Siebold, 43, who parachuted to safety and was hospitalized.
Both worked for Scaled Composites, the company developing the spaceship for Virgin Galactic. Scaled Composite said Alsbury was the co-pilot for the test flight. Siebold, who was piloting SpaceShipTwo, "is alert and talking with his family and doctors," the company said in a statement.
More than a dozen investigators in a range of specialties were forming teams to examine the crash site, collect data and interview witnesses, NTSB Acting Chairman Christopher A. Hart told a press conference at Mojave Air and Space Port.
"This will be the first time we have been in the lead of a space launch (accident) that involved persons onboard," said Hart, noting that the NTSB did participate in investigations of the Challenger and Columbia space shuttle disasters.
Virgin Galactic — owned by Branson's Virgin Group and Aabar Investments PJS of Abu Dhabi — plans to fly passengers to altitudes more than 62 miles above Earth. The company sells seats on each prospective journey for $250,000.
The company says that "future astronauts," as it calls customers, include Stephen Hawking, Justin Bieber, Ashton Kutcher and Russell Brand. The company reports receiving $90 million from about 700 prospective passengers.
On Saturday, Branson said none of that money has been spent and that anyone who wanted a refund could get it. However, he said, no one has asked, and instead someone signed up on the day of the accident in a show of support.
Friday's flight marked the 55th for SpaceShipTwo, which was intended to be the first of a fleet of craft. This was only the fourth flight to include a brief rocket firing. The rocket fires after the spacecraft is released from the underside of a larger carrying plane. During other flights, the craft either was not released from its mother ship or functioned as a glider after release.
The NTSB investigators were expected to head to an area about 20 miles from the Mojave airfield where debris from SpaceShipTwo fell over a wide area of uninhabited desert Friday morning. The spacecraft broke up after being released from a carrier aircraft at high altitude, according to Ken Brown, a photographer who witnessed the accident.
Friday's accident was the second this week involving private space flight. On Tuesday, an unmanned commercial supply rocket bound for the International Space Station exploded moments after liftoff in Virginia.
SpaceShipTwo is based on aerospace design maverick Burt Rutan's award-winning SpaceShipOne prototype, which became the first privately financed manned rocket to reach space in 2004. Three people died in a blast at the Mojave Air and Space Port in 2007 while testing a rocket motor for SpaceShipTwo.
Excerpt from nypost.com
As Colorado goes Election Night, so goes the nation — maybe.
The Centennial State is clearly a barometer of President Obama’s falling popularity.
The man who began his meteoric rise as the Democratic presidential nominee in Denver’s stadium in 2008 has lost much of his luster with Colorado voters and appears to be bringing down other Democrats with him.
Polls show Republican Cory Gardner ahead by seven points in his race to unseat incumbent Democratic Sen. Mark Udall, and GOP gubernatorial candidate Bob Beauprez is neck and neck with sitting Gov. John HIckenlooper.
But before Republicans pop the champagne corks, it’s worth considering the big wild card in this election.
Like the rest of Colorado’s roughly 3 million registered voters, I received my ballot in the mail about two weeks ago. This year will be the first that all Colorado voters received mail ballots, even without requesting them.
The potential for thousands more voters to cast ballots in what is usually a low-turnout midterm election could easily confound pollsters and politicos.
Conventional wisdom is that higher turnout favors Democrats — and the odds of higher turnout helping Dems in Colorado seem somewhat greater, given the demographics of the state.
Some 14 percent of eligible voters in Colorado are Hispanic. Obama improved his share of support among Colorado Hispanic voters from 61 percent in 2008 to 75 percent in 2012.
If mail ballots boost Hispanic voter participation by a few percentage points this year, it will likely redound to Democrats’ benefit. In a race as tight as the Colorado governor’s race, Hispanic voters could well determine the outcome.
But demographics don’t give the full picture. Since 2008, Democrats have benefited from a much stronger ground game that put operatives in the field to turn out their likely voters.
The effort wasn’t enough to stop populist Tea Party voters from boosting GOP fortunes in the 2010
congressional races, but Colorado was the exception. Democrat Michael Bennet won an open Senate race with just 30,000 more votes than his Republican opponent, Ken Buck.
The question in 2014 is whether mail balloting helps or erases the Democrats’ edge.
A New York Times analysis of Colorado mail ballots that had already been tallied 10 days out from the election seemed to give Republicans an advantage. Registered Republicans had mailed in ballots in higher numbers than Democrats, 42.8 percent to 32.3 percent.
But those trends may not continue. It could be that more Republicans simply cast their ballots early, which is where the Democratic ground game will come in handy.
Early voting makes it easier for “volunteers” — many of them paid political and union operatives — to go door to door to urge those who haven’t voted to do so.
Who is to stop “volunteers” from showing up with dozens of mail ballots collected from elderly voters or others who may have been pressured by union reps or family members to cast their votes?
Colorado will have regulations in place to limit the number of ballots a single individual can drop off at collection centers after 2015, but this year the possibility of ballot stuffing is real.
State election officials claim that the signature on the ballot envelope is their way to detect phony ballots. But the system hardly seems foolproof, requiring signatures to be scanned and matched against a database that may prove more cumbersome than anticipated.
Nov. 4 will be a test for Colorado — and for the nation — on this new experiment in democracy.
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| Crash site of Virgin Galactic's SpaceShipTwo |
Virgin Galactic’s SpaceShipTwo rocket plane exploded and crashed during a test flight on Friday, killing one crew member and seriously injuring another, authorities said.
The explosion came after the plane dropped away from its WhiteKnightTwo carrier airplane and fired up its hybrid rocket engine, said Stuart Witt, CEO and general manager of the Mojave Air and Space Port in California. The blast scattered debris across a two-mile swath of the desert floor north of Mojave, which is about 95 miles (150 kilometers) outside Los Angeles.
One of the two test pilots aboard the plane was killed, said Kern County Sheriff Donny Youngblood, who was among the officials dealing with the crash's aftermath.
The other parachuted to the ground and was injured. That pilot was transferred to Antelope Valley Hospital in Lancaster, California, according to Kern County Deputy Fire Chief Michael Cody.
"We hope that the survivor will be just fine," Youngblood said during a news briefing.
The pilots have not yet been identified, but both of them worked for Mojave-based Scaled Composites, according to Scaled's president, Kevin Mickey. Scaled has played a key role in developing and testing SpaceShipTwo for Virgin Galactic.
Virgin Galactic had planned to use this SpaceShipTwo to fly passengers on suborbital trips to the edge of space, beginning as early as next year. A nearly identical rocket plane is already under construction inside a Mojave hangar. More than 700 customers, including celebrities such as Ashton Kutcher and Justin Bieber, have paid as much as $250,000 to take a ride.
George T. Whitesides, Virgin Galactic's CEO, said the company would press on despite the setback.
"Space is hard, and today was a tough day," Whitesides told reporters. "We are going to be supporting the investigation as we figure out what happened today, and we're going to get through it. The future rests in many ways on hard, hard days like this. But we believe we owe it to the folks who were flying these vehicles as well as the folks who are working so hard on them to understand this and to move forward."
Witt said Mojave's close-knit aviation community was hit hard by the tragedy.
"When we have a mishap from the test community, we find that the test community is very small," he said. "We are human, and it hurts."
First powered flight in months
SpaceShipTwo's crew was testing the rocket engine in flight for the first time in more than nine months. The plane was slung beneath WhiteKnightTwo for takeoff from the Mojave Air and Space Port at about 9:20 a.m. PT (12:20 p.m. ET). When the paired planes reached a height of about 50,000 feet, about 40 minutes later, SpaceShipTwo was released for the test.
Witt said the anomaly occurred about two minutes after SpaceShipTwo dropped away and fired the rocket engine, but he didn't see any explosion. "It wasn't because something did happen. It was what I was not hearing and not seeing," Witt said.
Photographer Ken Brown, who was covering the test flight, told NBC News that he saw an explosion high in the air and later came upon SpaceShipTwo debris scattered across a small area of the desert. The WhiteKnightTwo plane and its pilots, meanwhile, landed safely.
Authorities cordoned off the crash site pending an investigation. A National Transportation Safety Board team was expected to get to the crash site Saturday morning. The Federal Aviation Administration said it was also investigating the incident.
New kind of fuel tested
During the nine months since the previous rocket-powered test in January, Virgin Galactic switched SpaceShipTwo's fuel mixture from a rubber-based compound to a plastic-based mix — in hopes that the new formulation would boost the hybrid rocket engine's performance.
Mickey said engines using the new type of fuel had been thoroughly tested on the ground. The final pre-flight qualification engine firing took place earlier this month. Friday's test marked the first time the new fuel was used in flight, but Mickey said "we expected no anomalies with the motor today."
Before Friday's flight, the most recent aerial outing was on Oct. 7, when SpaceShipTwo took an unpowered, gliding flight back to the Mojave runway.
The fatal flight was part of SpaceShipTwo's years-long test program, following up on the successful suborbital spaceflights of the smaller SpaceShipOne rocket plane in 2004. Virgin Galactic had said SpaceShipTwo's first test flight to an outer-space altitude — usually defined as 100 kilometers, or 62 miles — could have taken place before the end of the year.
The company's billionaire founder, Richard Branson, was hoping to ride on the first commercial flight next year. Over the past decade, he and his investment partners have put hundreds of millions of dollars into the Virgin Galactic venture. After Friday's crash, Branson said in a Twitter update that he was "flying to Mojave immediately to be with the team."
Jason DiVenere / Scaled CompositesNBC News' Julianne Pepitone and James Eng contributed to this report. NBCUniversal has established a multi-platform partnership with Virgin Galactic to track the development of SpaceShipTwo and televise Branson's spaceflight.
Valerie Tarico, AlterNetReligious labels help shore up identity. So what are some of the things non-believers can call themselves?Catholic, born-again, Reformed, Jew, Muslim, Shiite, Sunni, Hindu, Sikh, Buddhist…religions give people labels. The downside can be tribalism, an assumption that insiders are better than outsiders, that they merit more compassion, integrity and generosity or even that violence toward “infidels” is acceptable. But the upside is that religious o [...]
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The start of fall in the Northern Hemisphere begins Sept. 22, 2014. |
By Joe Rao, Space.com Skywatching Columnist
Sick of long, hot summer days? Well, you're in luck. Astronomically speaking, autumn is about to begin in the north.
On Monday (Sept. 22), at 10:29 p.m. EDT (0229 Sept. 23 GMT) autumn begins astronomically in the Northern Hemisphere. This also marks the start of spring in the southern half of the globe.
This date is called an equinox, from the Latin for "equal night," alluding to the fact that day and night are then of equal length worldwide. But that is not necessarily correct. [Earth's Equinoxes & Solstices Explained (Infographic)]
Not so equal
Referring to the equinox as being a time of equal day and night is a convenient oversimplification. For one thing, it treats night as simply the time the sun is beneath the horizon, and completely ignores twilight. If the sun were nothing more than a point of light in the sky, and if the Earth lacked an atmosphere, then at the time of an equinox, the sun would indeed spend one half of its path above the horizon and one half below.But in reality, atmospheric refraction raises the sun's disc by more than its own apparent diameter while it is rising or setting. Thus, when the sun looks like a reddish-orange ball just sitting on the horizon, it's really an optical illusion. It is actually completely below the horizon.
In addition to refraction hastening sunrise and delaying sunset, there is another factor that makes daylight longer than night at an equinox: Sunrise and sunset are defined as the times when the first or last speck of the sun's upper or lower limbs — not the center of the disc — are visible above the horizon.
And this is why if you check your newspaper's almanac or weather page on Monday and look up the times of local sunrise and sunset, you'll notice that the duration of daylight, or the amount of time from sunrise to sunset, still lasts a bit more than 12 hours.
In New York City, for instance, sunrise is at 6:43 a.m., and sunset comes at 6:54 p.m. So the amount of daylight is not 12 hours, but rather 12 hours and 11 minutes. Not until Sept. 26 are the days and nights truly equal. (On Sept. 26, sunrise is at 6:47 a.m., and sunset is 12 hours later).
At the North Pole, the sun currently is tracing out a 360-degree circle around the entire sky, appearing to skim just above the edge of the horizon. At the moment of this year's autumnal equinox, it should theoretically disappear completely from view, and yet its disc will still be hovering just above the horizon. Not until 52 hours and 10 minutes later will the last speck of the sun's upper limb finally drop completely out of sight.
This strong refraction effect also causes the sun's disc to appear oval when it is near the horizon. The amount of refraction increases so rapidly as the sun approaches the horizon that its lower limb is lifted more than the upper one, distorting the sun's disc noticeably.
Not as dark as it seems
Certain astronomical myths die hard. One of these is that the entire Arctic region experiences six months of daylight and six months of darkness. Often, "night" is simply defined by the moment when the sun is beneath the horizon, as if twilight didn't exist. This fallacy is repeated in innumerable geography textbooks, as well as travel articles and guides.But twilight illuminates the sky to some extent whenever the sun's upper rim is less than 18 degrees below the horizon. This marks the limit of astronomical twilight, when the sky is indeed totally dark from horizon to horizon.
There are two other types of twilight. Civil (bright) twilight exists when the sun is less than 6 degrees beneath the horizon. It is loosely defined as when most outdoor daytime activities can be continued. Some daily newspapers provide a time when you should turn on your car's headlights. That time usually corresponds to the end of civil twilight.
So, even at the North Pole, while the sun disappears from view for six months beginning Sept. 25, to state that "total darkness" immediately sets in is hardly the case. In fact, civil twilight does not end there until Oct. 8.
When the sun drops down to 12 degrees below the horizon, it marks the end of nautical twilight, when a sea horizon becomes difficult to discern. In fact, at the end of nautical twilight, most people will regard night as having begun. At the North Pole, nautical twilight does not end until Oct. 25. Finally, astronomical twilight — when the sky indeed becomes completely dark — ends Nov. 13. It then remains perpetually dark until Jan. 29, when the twilight cycles begin anew. So, at the North Pole, the duration of 24-hour darkness lasts almost 11 weeks, not six months.
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Elon Musk fears our progress in artificial intelligence is ‘seriously dangerous’
Excerpt from
sciencerecorder.com
Visionary technology figure Elon Musk has been warning the public for months about possible threats posed by artificial intelligence. But now he has a timeline.
Musk, the South African-born CEO of Tesla Motors and SpaceX, wrote that “the risk of something seriously dangerous happening is in the five year time frame. 10 years at most.”
Musk penned this comment at the bottom of an essay written by virtual pioneer Jaron Lanier called “The Myth of A.I.” The essay appeared in the publication Edge.org last week and was followed by comments from such technology notables as George Dyson, Peter Diamandis, and Kevin Kelly.
While Musk’s comment was deleted, it was picked up by sites such as Mashable and Reddit, which preserved it for a larger audience. According to these sites, Musk zeroed in on companies such as DeepMind, a British artificial intelligence company that Musk once invested in before it was purchased by Google.
“The pace of progress in artificial intelligence (I’m not referring to narrow AI) is incredibly fast,” Musk’s piece read. “Unless you have direct exposure to groups like DeepMind, you have no idea how fast-it is growing at a pace close to exponential.”
Musk mentioned that AI companies “recognize the danger” and were working to ameliorate any negative intelligences “from escaping into the Internet.”
While Musk had sent his comment privately to Edge.org by email, it was published by a site editor before it was taken down. A Musk spokesperson has said that Musk will write a longer piece outlining his thoughts on the dangers of artificial intelligence, presumably to be published on the same website.
Previously, Musk has compared AI to “summoning the demon,” nuclear war, and the “Terminator” series.