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The Stanford Professor Who Resigned to Teach for Free

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Most educators dream of the opportunity to teach at an elite university, but after teaching one free online course for Stanford with 160,000 students, Sebastian Thrun realized the prestige just wasn't that important after all. Instead, he wants to teach the world for free.

That's why Thrun resigned and started up his own free, online education center called Udacity. And it's not just the students who are benefiting — the professor says he finds open education to be addictive:

"Now that I saw the true power of education, there is no turning back. It’s like a drug. I won’t be able to teach 200 students again, in a conventional classroom setting."

So far Udacity is only offering two courses: one entry-level class in building a search engine and one advanced course in programing a robotic car. But eight more are on the table for later this year.

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Switzerland Flushes $1.8 Million in Gold Down the Sewer Every Year
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Switzerland has some pretty valuable sewer systems. As Bloomberg reports, scientists have discovered around $1.8 million worth of gold in the country's wastewater, along with $1.7 million worth of silver.

Scientists at the Swiss Federal Institute of Aquatic Science and Technology examined sewage sludge and effluents, or discharged liquid waste, from 64 water treatment plants and major Swiss rivers. They did this to assess the concentrations of various trace elements, which are "increasingly widely used in the high-tech and medical sectors," the scientists explained in a press statement. "While the ultimate fate of the various elements has been little studied to date, a large proportion is known to enter wastewater."

The study, which was recently published online in the journal Environmental Science & Technology, revealed that around 94 pounds of gold makes its way through Switzerland's sewage system each year, along with 6600 pounds of silver and high concentrations of rare metals like gadolinium and niobium. For the most part, these metals don't harm the environment, researchers say.

With gold and silver quite literally flowing through their sewers, is there any way that Switzerland could turn their wastewater into wealth? Scientists are skeptical: "The recovery of metals from wastewater or sludge is scarcely worthwhile at present, either financially or in terms of the amounts which could be extracted," the release explains.

However, in the southern canton of Ticino, which is home to several gold refineries, the "concentrations of gold in sewage sludge are sufficiently high for recovery to be potentially worthwhile," they conclude.

Switzerland is famous for its chocolate, watches, and mountains, but it's also home to major gold refineries. On average, around 70 percent of the world's gold passes through Switzerland every year—and judging from the looks of it, much of it goes down the drain. As for the sewer silver, it's a byproduct of the chemical and pharmaceutical industry, which is a cornerstone of Switzerland's economy.

[h/t Bloomberg]

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14 Things You Owned in the '70s That are Worth a Fortune Now
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From old toys and housewares to books and records, these pieces of '70s memorabilia have aged (and increased in value) like fine wine.

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