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Voyager 1 Has Left the Solar System!

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Today, it was announced that Voyager 1 has left the solar system for interstellar space.

It’s not the first time the announcement has been made.

In October 2012, it was thought the intrepid probe, first launched in September 1977, had blasted out of the heliosheath and left the solar system—until a couple of months later, when particles weren’t quite acting as scientists thought they should in a region that came to be called the “magnetic highway”—the outer boundary of the heliosphere, where the sun’s magnetic particles and those from interstellar space mingle, not unlike a two-lane highway.

Scientists had thought two things would happen when Voyager officially left the solar system: That the solar winds would fade to nothing (which happened), and that the magnetic fields of the region would change direction marking the end of the sun’s influence. That one didn’t happen.

In recent months some scientists have been reassessing the data and saying “Yes, it might have left the solar system after all.” Now, NASA has confirmed that.

The whole debate was enough of a headache to get a nice ribbing from former JPL employee turned XKCD cartoonist Randall Munroe.

The Future of Interstellar Space Travel

Voyager 1 is now the first craft to officially leave the solar system, pacing along at 38,610 miles per hour. Others are set to follow.

Voyager 1's sister craft, Voyager 2, is not yet beyond the solar system, but is just a few years behind, traveling at a more sluggish crawl of around 35,000 MPH.

Two other probes, Pioneer 10 and 11, will also leave the solar system someday. Pioneer 10 was reported to have left by the New York Times in 1983except it was just past the orbit of Neptune at the time. Pioneer 11 accomplished this feat in 1990. But as the Voyagers have revealed, that is far, far shy of the end of the solar system.

Currently, Voyager 1 is more than 125 times the distance (called an AU, or astronomical unit) from the Earth to the Sun. Pioneer 10 is far behind that, projected at 109 AU in 2012. Communication was lost in 2003. Voyager 2 is still active, and is approximately 103 AU out. Pioneer 11, which NASA lost contact with in 1995, is estimated to be at 86 AU as of 2012.

We’d of course be remiss not to mention New Horizons, the craft currently on a trajectory for Pluto, which it will swoop by in 2015 before continuing on to the outer solar system. Thus far, it’s only about 27 AU out from the sun. It is expected to leave the solar system in 2029. A booster rocket of the craft is also on a path set to exit the solar system.

Little Green Men

With some push from Carl Sagan, both Voyager probes were given a “Golden Record,” a phonograph of words and images meant to tell aliens of existence here on earth, should the probes be found. Classical music melds with sounds of nature and a series of hellos in various languages on the disc.

Included in the music selections? “Johnny B. Goode” by Chuck Berry.

The Pioneers contain simple plaques, showing two naked humans, the position of the solar system in relation to a group of stars, and the location of the Earth within the solar system. (Prior to Pluto’s demotion, of course.)

Speaking of Pluto, New Horizons doesn’t have an equivalent to either on board. There are a few objects on board, though, which might pique the interest of the discoverers, even if they’ll have no way to tell what they are. Included is a CD with the names of 400,000 persons, as well as the ashes of Clyde Tombaugh, the astronomer who first discovered Pluto in 1930. A Florida state quarter and a scrap of SpaceShipOne are among the few other personal effects on the craft.

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London's Sewer-Blocking 'Fatbergs' Are Going to Be Turned Into Biodiesel
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UK officials can't exactly transform the Whitechapel fatberg—a 143-ton trash mass lurking in London's sewer system—into treasure, but they can turn it into fuel. As The Guardian reports, Scottish biodiesel producer Argent Energy plans to convert parts of the noxious blockage into an environmentally friendly energy source.

For the uninitiated, fatbergs (which get their names from a portmanteau of "fat" and "icebergs") are giant, solid blobs of congealed fat, oil, grease, wet wipes, and sanitary products. They form in sewers when people dump cooking byproducts down drains, or in oceans when ships release waste products like palm oil. These sticky substances combine with floating litter to form what could be described as garbage heaps on steroids.

Fatbergs wash up on beaches, muck up city infrastructures, and are sometimes even removed with cranes from sewer pipes as a last resort. Few—if any—fatbergs, however, appear to be as potentially lethal as the one workers recently discovered under London's Whitechapel neighborhood. In a news release, private utility company Thames Water described the toxic mass as "one of the largest ever found, with the extreme rock-solid mass of wet wipes, nappies, fat and oil weighing the same as 11 double-decker buses."

Ick factor aside, the Whitechapel fatberg currently blocks a stretch of Victorian sewer more than twice the length of two fields from London's Wembley Stadium. Engineers with jet hoses are working seven days a week to break up the fatberg before sucking it out with tankers. But even with high-pressure streams, the job is still akin to "trying to break up concrete," says Matt Rimmer, Thames Water's head of waste networks.

The project is slated to end in October. But instead of simply disposing of the Whitechapel fatberg, officials want to make use of it. Argent Energy—which has in the past relied on sources like rancid mayonnaise and old soup stock—plans to process fatberg sludge into more than 2600 gallons of biodiesel, creating "enough environmentally friendly energy to power 350 double-decker Routemaster buses for a day," according to Thames Water.

"Even though they are our worst enemy, and we want them dead completely, bringing fatbergs back to life when we do find them in the form of biodiesel is a far better solution for everyone," said company official Alex Saunders.

In addition to powering buses, the Whitechapel fatberg may also become an unlikely cultural touchstone: The Museum of London is working with Thames Water to acquire a chunk of the fatberg, according to BBC News. The waste exhibit will represent just one of the many challenges facing cities, and remind visitors that they are ultimately responsible for the fatberg phenomenon.

"When it comes to preventing fatbergs, everyone has a role to play," Rimmer says. "Yes, a lot of the fat comes from food outlets, but the wipes and sanitary items are far more likely to be from domestic properties. The sewers are not an abyss for household rubbish."

[h/t The Guardian]

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Does Self-Control Deplete Over the Course of the Day? Maybe Not, Says New Study
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For months now, I’ve been trying to cut out sugar from my diet. I’ve read about all the ways my sweet tooth will be the death of me, and I’ve resolved to give it up. And yet, even as I write this, my long-term goal to eat healthy is losing out to my eternal desire to eat M&Ms at my desk. Is it because it’s the end of the day, and I’ve been trying to make choices for eight hours already? Or is it something else?

A new study in PLOS One pushes back on the popular theory known as "ego depletion," which hypothesizes that self-control is a finite resource that depletes throughout the day, much like energy levels. Instead, researchers from the University of Toronto and the learning technology company Cerego found that people's self-control depletes when it comes to doing one task for a long period of time, but that self-control fatigue isn't a factor when you're switching tasks. In other words, it's hard to say no to the box of cookies all day long, but saying no to the box of cookies won't impede other acts of self-control, like your ability to focus on your homework instead of turning on the TV.

The study used data from Cerego, which publishes online study materials, examining the study behaviors of two groups of college students using the Cerego system as part of semester-long psychology courses. The researchers looked at data from two groups of users, one group of 8700 students and one of almost 8800, focusing on how long they worked during each session and how well they performed at the memory tests within the curriculum.

If self-control really is a finite resource, it should be depleted by the end of the day, after people presumably have spent many hours resisting their first impulses in one way or another. But the researchers found that this wasn't true. Overall, students didn't do any better if they used the program earlier in the morning. Instead, performances peaked around 2 p.m., and people logged in to use the software more and more as the day went on, suggesting that the motivation to learn doesn't fall off at night (though that may also be because that's when college students do their homework in general).

However, mental resources did seem to be drained by doing the same task for a long period of time. The researchers found that after a certain point, students' performance dropped off, peaking at about 28 minutes of work. They made about 5 percent more mistakes 50 minutes into the session compared to that peak.

When it comes to the idea that we exhaust our store of self-control, the authors write, "the notion that this fatigue is completely fluid, and that it emerges after minutes of self-control, is under considerable doubt."

The notion of ego depletion comes from a 1998 study in which researchers asked participants to hang out in a room full of fresh-baked cookies, telling them to eat only from a bowl of radishes, leaving the cookies untouched. Then, those volunteers worked on an impossible puzzle. Volunteers who had spent time avoiding the delicious pull of cookies gave up on the mind-boggling task an average of 11 minutes earlier than a group of volunteers who were brought into the same room and allowed to eat as many cookies as they wanted. (Lucky them.)

Since then, the idea has taken off, leading to hundreds of subsequent studies and even influencing the habits of people like Barack Obama, who told Vanity Fair in 2011 that he only wore blue or gray suits in order to cut down on the non-vital decisions he had to make throughout the day.

This current study isn't the first to challenge the theory’s veracity, though. In 2016, a 2000-person replication study by some of the same authors (with scientists in 23 different labs) pushed back on the theory of ego depletion, finding that short spurts of self-control didn't have any effect on subsequent tasks. This study just adds to the evidence against the well-established idea.

So it's looking more and more like ego depletion isn't a good excuse for my afternoon vending-machine habit. Perhaps the true secret to excellent self-control is this: Just be a raven.


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