Is Wireless Power Closer Than We Think?

A few years back, Marin Soljačić was driven from bed by the insistent beeping of his mobile phone. But it wasn’t beeping for him to answer it, it was beeping for him to plug it in. Since that night, the assistant professor of physics at MIT, has been thinking about ways to start his phone charging as soon as he enters his home - without the need for plugs or wires.

Jennifer Chu at Technology Review writes that Soljačić considered using radio waves, but found that most of their energy would be lost in transmission. Targeted methods like lasers require a clear line-of-sight and could be dangerous for anything in their way. According to Chu, he eventually settled on a phenomenon called magnetic resonance coupling, in which two objects tuned to the same frequency exchange energy strongly but interact only weakly with other objects.

“A classic example is a set of wine glasses, each filled to a different level so that it vibrates at a different sound frequency. If a singer hits a pitch that matches the frequency of one glass, the glass might absorb so much acoustic energy that it will shatter; the other glasses remain unaffected.”

Now, Soljačić and his team have successfully demonstrated the use of magnetic resonance coupling to power a 60 watt light bulb from a distance of roughly two meters - and through a thin wall.

The most effective setup, thus far, transfers power over a distance of two meters with about 50 percent efficiency. The team is looking at other materials to decrease coil size and boost efficiency. “While ideally it would be nice to have efficiencies at 100 percent,” says Soljačić. “So realistically, 70 to 80 percent could be possible for a typical application.”

While some wireless power technologies have emerged in the marketplace, Soljačić’s technique differs in that it might one day enable devices to recharge automatically, whenever they come within range of a wireless transmitter.

[via cleantechnica]

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The Amazing Story behind the 256 Year-Old Man

Li Ching-Yun. Image from The People’s Republic of China

According to the 1933 obituaries in both Time Magazine and the New York Times, Li Ching-Yun was reported to have buried 23 wives and fostered 180 descendants by the time he died at the age of 256.

Was he really that old? Could he have forgotten his own birthday or exaggerated his claim? Environmental Graffiti investigates.

The Secrets to an Interminable Life

“Keep a quiet heart, sit like a tortoise, walk sprightly like a pigeon and sleep like a dog.” These were the words of advice Li gave to Wu Pei-fu, the warlord, who took Li into his house to learn the secret of extremely long life.

Li maintained that inward calm and peace of mind were the secrets to incredible longevity. His diet after all, was mainly based on rice and wine.

From 0 to 256

Unsurprisingly, not much is known about Li Ching-Yun’s early life. We know he was born in the province of Szechwan in China, where he also died. We also know that by his tenth birthday, Ching-Yun was literate and had travelled to Kansu, Shansi, Tibet, Annam, Siam and Manchuria gathering herbs. After that, it gets a bit fuzzy…

Apparently, for over one hundred years, Li continued selling his own herbs and then subsequently sold herbs collected by others. He also (according to Time) had six-inch long fingernails on his right hand.

You might be thinking that he looked decrepit, shrivelled, leather-like and creepy, however sources at the time were astonished at his youthfulness. Was this suspect? Was Li Ching-Yun as old as he claimed he was, or was his birthday a clerical error or exaggeration?

Let’s take a brief look at both sides…

The Nine Lives of Li Ching-Yun

By his own admission he was born in 1736 and had lived 197 years. However, in 1930 a professor and dean at Minkuo University by the name of Wu Chung-chien, found records “proving” that Li was born in 1677. Records allegedly showed that the Imperial Chinese Government congratulated him on his 150th and 200th Birthdays.

So the question is, had he forgotten his own birthday? Was this even the same Li Ching-Yun?

Looking at all of this from a medical and documented perspective: Jeanne Louise Calment, a French woman who died in 1997 so far holds the title for the person who has roamed the earth the longest: 122 years, which is a phenomenal length of time.

That means, that if the records discovered by Wu Chung-chien were accurate, Li Ching-Yun’s age would surpass the official record by more than 130 years. Is this even medically possible?

The detail, which seems to prove both arguments and debunk them at the same time, is Li’s youthful appearance, noted in a 1928 article from the New York Times. Visually and physically, he appeared to look like a typical 60 year-old. Does this therefore signify a superhuman body capable of lasting one quarter of a millennium, or is the story of Li Ching-Yun based on a series of half-truths, lies or exaggerations?

Unfortunately, we may never know. You may draw your own logical conclusions.

[via environmentalgraffiti]

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Your computer keyboard is 5 TIMES dirtier than a toilet seat

How your computer keyboard is FIVE TIMES dirtier than your toilet seat - and could even give you 'qwerty tummy'


Computer keyboards can harbour more harmful bacteria than a lavatory seat, it has been claimed.

Many users are at risk of becoming ill with stomach bugs, according to the consumer group Which?

It warned that 'qwerty tummy', named after the first six letters on a keyboard, could sweep through workplaces after tests on equipment in its own London offices showed alarming results.

One keyboard was so dirty that a microbiologist ordered it to be removed, quarantined and cleaned.

It had 150 times the acceptable limit for bacteria and was five times as filthy as a typical lavatory seat.

Anyone who eats a sandwich or piece of fruit having been tapping on such a keyboard can pick up bacteria that could lead to a stomach upset.

The scientist swabbed 33 keyboards for food poisoning bugs e.coli, coliforms, staphylococcus aureus and enterobacteria and compared the results to those found on a lavatory seat and lavatory door handle.

Four of the keyboards were considered a potential health hazard and one was "condemned".

Two had "warning levels" of staphylococcus aureus and two others had "worryingly elevated" levels of coliforms and enterobacteria, "putting users at high risk of becoming ill from contact".

The expert said the findings were typical of offices all over Britain.

Which? computing editor Sarah Kidner said: "The shocking results revealed that some of these keyboards were harbouring harmful bacteria that could potentially give their users a stomach upset.

"The germs found could cause food poisoning symptoms such as diarrhoea.

"The main cause of a bug-infested keyboard is eating lunch at desks, as the food deposits encourage the growth of millions of bacteria.

"Poor personal hygiene, such as dodging hand washing after going to the lavatory, may also be to blame.

"Most people don't give much thought to the grime that builds up on their PC, but if you don't clean your computer, you might as well eat your lunch off a lavatory seat."

Which? found that one in ten people never clean their keyboard, while 20 per cent never clean their mouse.

Around half cleaned their keyboard less than one a month.

The modern practice of "hotdesking", in which staff sit at different desks every week, means that workers do not know who has been using their keyboard before them.

Miss Kidner said workers and home PC users should give their keyboards a regular clean, adding: "It's quite simple to do and could prevent your computer becoming a health hazard."

Which? says users should unplug computers before wiping surfaces with a damp, soft, lint-free cloth.

Keyboards should be unplugged, turned upside down and shaken.

[via dailymail.co.uk]

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Man Wants to Turn Big Truck Traffic into Electricity

While the Japanese are trying to produce electricity from train station gates (!?), entrepreneur Terry Kenney is going after a bigger target: Trucks.

It took him eight years to get a working prototype, but now there's one working at the Port of Oakland which Kenney calls the "Dragon Power Station". Special plates are set on the road, and as big trucks drive over them (about 2,500 of them per day at the port), they compress a tank of hydraulic fluid under the road, which in turn creates a series of pumping actions that turns a generator to produce electricity.

By June, the Dragon should generate about 5,000 to 7,000 kilowatt-hours of electricity each day, or enough to power up to 1,750 homes. Not bad for a prototype.

Of course there's no such thing as a free lunch. That energy actually comes from the fossil fuels burned by the trucks. The benefits of that system is that they are harnessing energy that would otherwise be lost, and doing so in a way that isn't noticeable in practice to the thousands of trucks.

[via treehugger]

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Earth is losing dirt at an alarming rate

Nutrient-rich topsoil is being eroded much faster than it can be replenished, experts say.

While many worry about the potential consequences of atmospheric warming, a few experts are trying to call attention to another global crisis quietly taking place under our feet.

Call it the thin brown line. Dirt. On average, the planet is covered with little more than three feet of topsoil -- the shallow skin of nutrient-rich matter that sustains most of our food and also appears to play a critical role in supporting life on Earth.

"We're losing more and more of it every day," said David Montgomery, a geologist at the University of Washington. "The estimate is that we are now losing about 1 percent of our topsoil every year to erosion, most of this caused by agriculture."

"It's just crazy," fumed John Aeschliman, a fifth-generation farmer who grows wheat and other grains on the Palouse near the tiny town of Almota, just west of Pullman.

"We're tearing up the soil and watching tons of it wash away every year," Aeschliman said. He's one of a growing number of farmers trying to convince others to adopt "no-till" methods, which involve no tilling of the land between plantings, leaving crop stubble to reduce erosion and planting new seeds between the stubble rows. Montgomery has written a popular book, "Dirt," to call public attention to what he believes is a neglected environmental catastrophe. A geomorphologist who studies how landscapes form, Montgomery describes modern agricultural practices as "soil mining" to emphasize that we are rapidly outstripping the Earth's natural rate of restoring topsoil. "Globally, it's clear we are eroding soils at a rate much faster than they can form," said John Reganold, a soils scientist at Washington State University. "It's hard to get people to pay much attention to this because, frankly, most of us take soil for granted."

The National Academy of Sciences has determined that cropland in the U.S. is being eroded at least 10 times faster than the time it takes for lost soil to be replaced.

The United Nations has warned of worldwide soil degradation -- especially in sub-Saharan Africa, where soil loss has contributed to the rapidly increasing number of malnourished people. Healthy topsoil is a biological matrix, a housing complex for an incredibly diverse community of organisms -- billions of beneficial microbes per handful, nitrogen-fixing fungi, nutrients and earthworms whose digestive tracts transform the fine grains of sterile rock and plant detritus into the fertile excrement that gave rise to the word itself ("drit," in Old Norse).

As such, true living topsoil cannot be made overnight, Montgomery emphasized. Topsoil grows back at a rate of an inch or two over hundreds of years.

"Globally, it's pretty clear we're running out of dirt," Montgomery said. Ron Myhrum, state soil scientist with the U.S. Department of Agriculture's office in Spokane, Wash., agreed that global soil loss is a huge problem. But Myhrum said erosion rates in the Northwest region have improved recently because of better conservation farming practices.

"We don't have the kind of dust storms here we used to have," Myhrum said. "What's more alarming to me than erosion is conversion of farmland to urban use."

[via detnews]

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