April 12 is a memorable date, the anniversary of Yuri Gagarin's 108-minute orbital flight in 1961. It's also the date, some twenty years later, when NASA launched Columbia, the first Space Shuttle (and boy do I remember the trepidation of watching that one go up). Celebrating these milestones is Yuri's Night, marked by 119 parties scheduled in 32 countries on six continents. Check the celebration site for parties near you. And for stay-at-homes, be aware that Second Life is hosting one of the venues online. Thanks to Frank Taylor for the tip on this. And note (via Larry Klaes) David S. F. Portree's fine tribute to Gagarin's accomplishment. Nice cover of an early 1930's Science Wonder Stories on the same page. Somewhere Hugo Gernsback is smiling...

Could a cloud of two-foot wide sunshades 60,000 miles long save the Earth from a global warming emergency? Roger Angel (Steward Observatory, University of Arizona) has been studying the idea of making the spacecraft out of micron-thick glass weighing one gram per sunshade. That's the weight of a butterfly for each unit, but we're talking about trillions of them out at the L1 Lagrangian point, an almost fixed zone in relation to Earth whose mild orbital instability can be overcome by onboard intelligence. Total sunshade mass: 20 million tons. This article in the Arizona Daily Wildcat has more on the improbable concept and what Angel is doing today: One of the big problems for the project is getting the total mass of all the sunshades into space...so Angel came up with using electromagnetic force to propel the spacecraft up a two-kilometer launch tube. The launch tube would have a series of electrical coils that propel the rocket until it accelerates to escape velocity, about 25,000...

Back in the 1980's, I was active as a shortwave listener. I was, in radio jargon, an SWL and not a ham, meaning I only listened and didn't transmit. It was great fun to tune in distant stations, and the more challenging the better, which is why the Falkland Islands were always high on the list (I never received their station), and Tristan da Cunha was the ultimate catch (all but impossible here on the US east coast). It wasn't long before I drifted into utility DXing, listening for non-broadcast stations in remote places, everything from low-frequency aviation beacons to ship-to-shore communications, and I got a kick out of monitoring radiotelephone traffic from places like Little America (Antarctica) back to the States. Finally my interests converged and I started thinking about the ultimate DX -- receiving a signal from the stars. SETI efforts were in their early days then, but I began to wonder whether an amateur receiving rig could hope to snag some kind of extraterrestrial...

John Updike reviews Walter Isaacson's new biography of Einstein in The New Yorker, from which this excerpt on why a job in the Swiss patent office was actually a good thing for the young genius: "Had he been consigned instead to the job of an assistant to a professor," Isaacson points out, "he might have felt compelled to churn out safe publications and be overly cautious in challenging accepted notions." Special relativity has a flavor of the patent office; one of the theory's charms for the fascinated public was the practical apparatus of its exposition, involving down-to-earth images like passing trains equipped with reflecting mirrors on their ceilings, and measuring rods that magically shrink with speed from the standpoint of a stationary observer, and clocks that slow as they accelerate — counterintuitive effects graspable with little more math than plane geometry. Einstein would later say, upon taking his first professorship (at Zurich), that in doing so he had become...

Centauri Dreams believes profoundly in what I might call 'realistic optimism.' While an aggressive belief in the human future can be overstated, it's important to remember that intellectual fashions come and go, leaving many a futurist trying to explain another failed prediction. The view here is that the vast problems that face our species are solvable through common sense and technology, and that somehow we will engage our tools to get us off-planet before we annihilate ourselves. Playing into this notion is the work of David Haussler, cited recently by Freeman Dyson as one reason for his own deeply optimistic view of the future. Studying the human genome, Haussler and team at UC Santa Cruz discovered a section of DNA called Human Accelerated Region 1. HAR1 evidently shows up in the genomes of a wide range of species, from mouse to chicken to chimpanzee. It was apparently unchanged for about three hundred million years, as Dyson told Benny Peiser in a recent interview (see this New...

by Gregory & Elisabeth Benford We left February 17, 2007 on a considerable, month-long trip, starting with Hong Kong, where we caught the Lunar New Year Celebration (Chinese New Year). Then on to Colombo, Sri Lanka, to visit Arthur Clarke. Arthur has post polio syndrome and thus very little memory or energy. He turns 90 this December and wants to keep in touch with the outer world, mostly through the Internet. He has few friends left in Colombo. Arthur took us to the Swimming Club for lunch, a sunny ocean club left over from the British days (commonly called the Raj). Members swam in the pool and enjoyed buffet lunch. It felt somehow right to watch the Indian Ocean curl in, breaking on the rocks, and speak of space: the last, greatest ocean. Image: Elisabeth, Arthur C. Clarke, and Greg in ACC's home study in Colombo. Our hotel with a similar ocean view, the Galle Face, is the oldest grand Raj hotel east of the Suez Canal, dating from before the Civil War, and reeks of atmosphere. On...

by Gregory Benford Centauri Dreams is pleased to present the travels of Gregory Benford, just returned from a multi-week journey that took him to Sri Lanka to see Arthur C. Clarke, around the southern Indian coast all the way to Bombay, thence to Jaipur, Delhi and finally on to Singapore. The well-known physicist and science fiction author portrays lands awash in history but laden with potential for a possible future off-planet. Will a China/India space race revitalize manned spacecraft technologies? Enjoy the journey and be sure to check the Benford & Rose site for the author's recent essays and commentaries. We left February 17, 2007 on a considerable, month-long trip, starting with Hong Kong. We caught the Lunar Celebration at Chinese New Year—huge crowds, spectacular fireworks. Then on to Colombo, Sri Lanka, to visit Arthur C. Clarke. Arthur has post polio syndrome and thus very little memory or energy. He turns 90 this December and wants to keep in touch with the outer...