Solar power: Scientists have been mucking about with it since the ’40s (at least), but photovoltaic energy still falls into the realm of novelty. So why hasn’t solar made it out of the dark ages already? The simple answer is: money and land. Sure, sunlight itself is free — but building a solar array costs $10,000 and requires 300 square feet just to get 1 kilowatt per hour (a kilowatt-hour averages 8.6 cents in the US).

Prototypes from the SunHopes project skirt the land issue by getting vertical — with energy-capturing balloons! Taking home the “Forward Thinking” award from the Re:Vision sustainable design competition, SunHopes’ 10-foot-wide balloons produce 1 kilowatt per hour while gracefully floating up out of everyone’s way. Better still, the project aims to minimize cost, with each balloon netting a target cost of $4,000 — a considerable bargain compared to the $10,000 it currently takes to build a solar field that produces the same amount of energy.

The price tag (not to mention the visibility) is probably too high for SunHopes to start littering suburbia with towering silver saucers just yet, but a wide array of niche applications — off-the-grid living, emergencies, naval operations — make this an interesting opportunity for solar power to gain a new foothold in the sky. [via Inhabitat]

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[I]f the greenhouse reduction achieved in the Sydney CBD during Earth Hour was sustained for a year, it would be equivalent to taking 48,616 cars off the road for a year.

This year, 370 cities worldwide took the pledge; and now Earth Hour 2008 has come and gone. Was it a success? While results seemed a little mixed, one thing is for sure: Sydney and Manila both earned gold stars. Just take a look at Boston.com’s photo gallery:

^{[photo courtesy the Associated Press]}

Inspiring, no? And the Earth Hour Flickr pool is filling up with some equally dramatic photos. (Way to go, Seattle!)

Even Google got in on the act.

^{[photo courtesy pirate johnny]}

OK, I worry that this post might be coming off as a bit breathless … but after seeing environmentalist Bill McKibben speak at D2E Boston, it’s hard not to be all fired up about climate change. Yesterday, McKibben dropped this sobering statistic: NASA researchers recently concluded that the maximum safe atmospheric concentration of carbon dioxide is roughly 350 parts per million. And we shot past that benchmark 20 years ago — we’re at 385 ppm right now.

McKibben offers this analogy: Let’s say your doctor tells you that your cholesterol is dangerously high. Sure, you may not be doubled over with a heart attack right this second, but unless you’re looking to become a young, well-marbled corpse, McKibben says, “you have to stop eating cheese.” Consider Earth Hour a slice of cheese not eaten.

McKibben’s latest effort is 350.org, a global-warming activist movement still in its infancy. Check it out!

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^{[image courtesy Joshua Klein]}

The secret’s out: Crows are terrifyingly smart. What kind of intelligence are we talking about here? Well, for starters, the corvid family has demonstrated theory of mind (potentially) and tool use — cognitive powers once thought to belong solely to primates. Even more remarkably, scientists have observed that crows are not only capable of mastering complex behaviors (such as, say, dropping nuts into crosswalks and waiting for the red light to go retrieve their conveniently cracked snacks), but they also can teach other crows. Noting this ability to transmit newly acquired skills, some experts are claiming that crows are not just clever — they have a culture. And now, researcher Joshua Klein is giving them an economy. Well, sort of.

Crows might be bright, but unfortunately, they’re also really good at annoying humans. Instead of viewing them as pests to be eradicated, Klein proposes that we should be giving them something useful to do, thus promoting a mutually beneficial relationship between man and bird.

Initially, he wanted to teach crows how to pick up garbage, but imparting the distinction between, say, a piece of junk wood and a shingle attached to a roof seemed overly complicated. (”Crows are very good at disassembling things,” Klein adds.) So he devised a study in which crows learn how to use a vending machine — tasty peanuts in exchange for shiny coins. “Ostensibly, if we could teach one crow to use the vending machine, we could teach them all,” Klein claims. Sounds like just a stupid pet trick? Klein counters: “There is $216 million in lost coins every year.”

To hear more from the man himself, check out a video of his thesis presentation here; for the ADD set, here’s the 1-minute version.

[Thanks to BoingBoing, for pointing out his TED 2008 talk last month.]

A sobering thought: With these already-brainy birds just getting smarter and smarter, looks like they should be kicking humans off the World Supreme Intellect pedestal in no time.

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