What are the odds for survival of a technological society? We don't know yet, having but one example to work with, but it's interesting to speculate, as Ray Villard does in a recent online post, about the kinds of intelligence that may evolve in the universe. All too often we equate technology with intelligence, which may skew our view of projects like SETI. Energized by the American Association for the Advancement of Science meeting in San Diego last week, Villard is thinking that intelligent life may have appeared on our planet not once but twice, and one of those life-forms is never going to be found by listening to radio wavelengths. The case for cetaceans seems strong. Here's Villard on the matter: Physiologically, dolphins have a brain architecture and brain mass-to-body mass ratio that is closer to that of humans than for any other species on Earth. Many years of experiments on captive dolphins show that they are self-aware, have a sense of self-identity, do detailed problem...
Gravitational Lensing Measures the Universe
Data from the Keck telescope (Mauna Kea), the Hubble Space Telescope and the Very Large Array have been used in conjunction with the findings of the Wilkinson Microwave Anisotropy Probe to offer up a new way to measure the size of the universe, as well as how rapidly it is expanding and how old it is now. By determining a value for the Hubble constant, the work confirms the age of the universe within a span of 170 million years as 13.75 billion years old. I'm always fascinated with work involving gravitational lensing -- just yesterday we looked at using the Sun's lensing effects for potential SETI investigations -- and here we have a classic case of measuring how light traveled from a bright, active galaxy along different paths to reach the Earth. A strong gravitational lens like the one used in this study, called B1608+656, creates multiple images of the same galaxy lying behind the lensing object. Studying the time the light took along each path, it was possible to gather...
SETI: The Solar Sail Perspective
I love what Dan Wertheimer, a Berkeley astronomer and one of the powers behind the SETI@Home distributed computing project, told a session at the recent AAAS meeting in San Diego. Wertheimer was talking about the possibility of using the Sun's gravitational lens for SETI purposes, and as quoted by Alan Boyle, said that such an observatory could "read the license plates on an extrasolar planet." That reminded me of Claudio Maccone's whimsical but mind-boggling remark at the interstellar conference in Aosta last July, which went in much the same direction. What could lensing do? "We could see the roads of their cities. We could see the cars they are driving." Drake has made the case for using the Sun's gravitational lens for SETI purposes for a long time now, and he repeated it at the TED 2010 conference in Long Beach. As to Maccone, he has long championed the FOCAL mission to the gravitational lens that would exploit the fantastic magnifications available at 550 AU and beyond. But it...