| Tree Electricity Runs Nano-Gadget [ The following is an exact transcript of this podcast. ]If scientists have their way, we may someday be tapping maples--not for pancake fixin’s, but for power. Because researchers from the University of Washington in Seattle have found there’s enough electricity flowing in trees to run an electronic circuit. [More] rss.sciam.com |
Getting Those Varmints to Vamoose without Lethal Measures Dear EarthTalk: What would you recommend as a non-toxic/non-lethal way to keep squirrels, gophers and groundhogs away? --Faye Gillette, Coarsegold, CA [More] rss.sciam.com |
Romanticism undone: Invasive species, global warming taking toll on plants at Thoreau's Walden Pond Henry David Thoreau famously catalogued the plants around Walden Pond more than 150 years ago, and the information he gathered then is helping to illustrate the effects of invasive species and global warming on the area today. [More] rss.sciam.com |
Doing Science in the Past History is not often thought of as a science, but it can be if it uses the “comparative method.” Jared Diamond, professor of geography at the University of California, Los Angeles, and James A. Robinson, professor of government at Harvard University, employ the method effectively in the new book they have co-edited, Natural Experiments of History (Harvard University Press, 2010). In a timely study comparing Haiti with the Dominican Republic, for example, Diamond demonstrates that although both countries inhabit the same island, Hispaniola, because of geopolitical differences one ended up dirt poor while the other flourished.Christopher Columbus’s brother Bartolomeo colonized Hispaniola in 1496 for Spain, establishing the capital at Santo Domingo on the eastern side of the island. Two centuries later, during tensions between France and Spain, the Treaty of Ryswick in 1697 granted France dominion over the western half of the island. Because France was richer than Spain at this time and slavery was an integral part of its economy, it turned western Hispaniola into a center of slave trade with staggering differences in population: about 500,000 slaves in the western side of the island as compared with only 15,000 to 30,000 slaves in the eastern side. [More] Hispaniola - Dominican Republic - Haiti - Jared Diamond - France rss.sciam.com |
Origami Observatory: Behind the Scene with the Webb Space Telescope (preview) The mirror, a perfect hexagon of gunmetal gray, stands vertically on a low platform. It is about two inches thick and more than four feet wide, a precisely carved slab of beryllium that gleams in the low light of this optics laboratory near San Francisco Bay. My guide, chief engineer Jay Daniel, watches my footing as I step gingerly in front of the mirror to see my reflection. “It’s like your bathroom mirror,” Daniel says, chuckling.The other side of this looking glass, though, is nothing like a household vanity. The slab of metal is mostly hollow, drilled out by machinists to leave an intricate triangular scaffold of narrow ribs. It is beautiful in its geometric precision, and I resist the urge to touch one of the knifelike edges. The polished front layer that remains, Daniel says, is a mere 2.5 millimeters thick. From its starting weight of 250 kilograms, the entire mirror now weighs just 21 kilos. That is light enough for a rocket to hoist 18 of them deep into space, where the curved mirrors will join as one to form the heart of the most audacious space observatory ever launched. [More] Mirror - Space observatory - Origami - Paper - Crafts rss.sciam.com |