Arrived yesterday afternoon at the Orlando Hilton for the 100 Year Starship Symposium. I'll try to get updates out on my Twitter feed @centauri_dreams when possible. The WiFi here has been mostly good but it did go down this morning for a time, so bear with me.
by Dave Moore Dave Moore, a frequent Centauri Dreams contributor, tells me he was born and raised in New Zealand, spent time in Australia, and now makes his home in California. "As a child I was fascinated by the exploration of space and science fiction. Arthur C. Clarke, who embodied both, was one of my childhood heroes. But growing up in New Zealand in the 60s, anything to do with such things was strictly a dream. The only thing it did lead to was to getting a degree in Biology and Chemistry." But deep space was still on Dave's mind and continues to be, as the article below, drawing on his recent paper in the Journal of the British Interplanetary Society, attests. "While I had aspirations at one stage of being a science fiction writer," Dave adds, "I never expected that I would emulate the other side of Arthur C. Clarke and get something published in JBIS." But he did, and now explains the thinking behind the paper. The words from "Science Fiction/Double Feature" in the Rocky...
Einstein's Special Theory of Relativity remains much in the news after a weekend of speculation about the curious neutrino results at CERN. Exactly what is going on with the CERN measurements remains to be seen, but the buzz in the press has been intense as the specifics of the experiment are dissected. It will be a while before we have follow-up experiments that could conceivably replicate these results, but it's interesting to see that another aspect of Einstein's work, the General Theory of Relativity, has received a new kind of confirmation, this time on a cosmological scale. Here we're talking not about the speed of light but the way light is affected by gravitational fields. The work is out of the Niels Bohr Institute at the University of Copenhagen, where researchers say they have tested the General Theory at a scale 1022 times larger than any laboratory experiment. Radek Wojtak, an astrophysicist at the Institute, has worked with a team of colleagues to analyze measurements...
Are humans ever likely to go to the stars? The answer may well be yes, but probably not if we're referring to flesh-and-blood humans aboard a starship. That's the intriguing conclusion of Keith Wiley (University of Washington), who brings his background in very large computing clusters and massively parallel image data processing to bear on the fundamental question of how technologies evolve. Wiley thinks artificial intelligence (he calls it 'artificial general intelligence,' or AGI) and mind-uploading (MU) will emerge before other interstellar technologies, thus disrupting the entire notion of sending humans and leading us to send machine surrogates instead. It's a notion we've kicked around in these pages before, but Wiley's take on it in Implications of Computerized Intelligence on Interstellar Travel is fascinating because of the way he looks at the historical development of various technologies. To do this, he has to assume there is a correct 'order of arrival' for technologies,...
If neutrinos really do travel at a velocity slightly higher than the speed of light, we have a measurement that challenges Einstein, a fact that explains the intense interest in explaining the results at CERN that we discussed on Friday. I think CERN is taking exactly the right approach in dealing with the matter with caution, as in this statement from a Saturday news release: ...many searches have been made for deviations from Einstein's theory of relativity, so far not finding any such evidence. The strong constraints arising from these observations make an interpretation of the OPERA measurement in terms of modification of Einstein's theory unlikely, and give further strong reason to seek new independent measurements. And this is followed up by a statement from CERN research director Sergio Bertolucci: "When an experiment finds an apparently unbelievable result and can find no artifact of the measurement to account for it, it's normal procedure to invite broader scrutiny, and this...
If you're tracking the interesting news from CERN on neutrinos moving slightly faster than the speed of light, be advised that there is an upcoming CERN webcast on the matter at 1400 UTC later today (the 23rd). Meanwhile, evidence that the story is making waves is not hard to find. I woke up to find that my local newspaper had a headline -- "Scientists Find Signs of Particles Faster than Light" -- on the front page. This was Dennis Overbye's story, which originally ran in the New York Times, but everyone from the BBC to Science Now is hot on the trail of this one. The basics are these: A team of European physicists has measured neutrinos moving between the particle accelerator at CERN to the facility beneath the Gran Sasso in Italy -- about 725 kilometers -- at a speed about 60 nanoseconds faster that it would have taken light to make the journey. The measurement is about 0.0025 percent (2.5 parts in a hundred thousand) greater than the speed of light, a tiny deviation, but one of...
Because the financing for missions like Kepler is supported by tax dollars, it's gratifying to see the public getting actively involved in working with actual data from the Kepler team. That's what has been going on with the Planet Hunters site, where 40,000 users from a wide variety of countries and backgrounds have been analyzing what Kepler has found. Planet hunter Debra Fischer (Yale University), a key player in the launch of Planet Hunters, has this to say: "It's only right that this data has been pushed back into the public domain, not just as scientifically digested results but in a form where the public can actively participate in the hunt. The space program is a national treasure -- a monument to America's curiosity about the Universe. It is such an exciting time to be alive and to see these incredible discoveries being made." So far, so good on the citizen science front. Using publicly available Kepler data, Planet Hunters has found two new planets, both of them discarded...
With a fierce interest in nearby brown dwarfs, I often neglect the significant part of the WISE mission devoted to asteroids. WISE (Wide-Field Infrared Explorer) has catalogued more than 157,000 asteroids in the main belt and discovered 33,000 new objects as part of its NEOWISE activities. Here the benefits of infrared wavelengths become apparent, for we know little about the reflectivity of a given asteroid and thus have trouble figuring out how large it is. Using infrared, WISE can relate light in these frequency ranges to the size and temperature of the object. Having established size, mission scientists can re-calculate the asteroid's reflectivity. NEOWISE is actually an enhancement to the WISE data processing system that makes for better detection of moving objects in the WISE data. In addition to the asteroids mentioned above, NEOWISE has also detected more than 500 Near-Earth Objects (NEOs) and roughly 120 comets. We've had plentiful studies at visible wavelengths from groups...
The confirmation of a planet circling two stars, recounted in these pages yesterday, is actually the result of a long process. Jean Schneider (CNRS/LUTH - Paris Observatory) noted in a follow-up comment to the Kepler-16b story that investigation of such systems dates back to 1990 (see citation below), while Alex Tolley has pointed out that the great space artist Chesley Bonestell was painting imaginary planets orbiting binary stars fully sixty years ago. So the idea isn't new, but the confirmation was obviously useful, and in more ways than we might have expected. For one thing emerging from the Kepler-16b paper is that the smaller of the two stars in this binary system, an M-dwarf, is now the smallest low-mass star to have both its mass and radius measured at such precision. The question of stellar mass and M-dwarfs is significant because a new paper by Philip Muirhead (Cornell University) and colleagues goes to work on the parameters of low-temperature Kepler planetary host stars...
I'm just back from a long trip and am only now catching up on some of the news stories from late last week. Among these I should mention the discovery of the world with the double sunset, identified through Kepler data and reminiscent of the famous scene from Star Wars, where Luke Skywalker stands on the soil of Tatooine and looks out at twin suns setting. I remember carping about the scene when it first came out because it implied a planet that orbited two stars at once. Now we have confirmation that such a configuration is stable and that planets can exist there. Kepler-16 isn't a habitable world by our standard definition, but much more like Saturn, cold and gaseous. One of the stars it circles is a K dwarf of about 69 percent the mass of our Sun, while the other is a red dwarf of about 20 percent solar mass. Some 220 light years away in the direction of the constellation Cygnus, the system is fortuitously edge-on as seen from Earth, allowing Kepler scientists to identify the...
The largest variations in brightness ever seen on a cool brown dwarf have turned up on the brown dwarf 2MASS 2139 (known as 2MASS J21392676+0220226 to its friends). The findings, reported at the Extreme Solar Systems II conference in Jackson Hole, Wyoming, show a remarkable 30 percent change in brightness in a period of just under eight hours. The assumption is that brighter and darker patches of atmosphere are periodically moving into view as the brown dwarf rotates. In fact, Ray Jayawardhana (University of Toronto), co-author of the paper on this work, thinks one possibility is something similar to what we see in our own Solar System. “We might be looking at a gigantic storm raging on this brown dwarf, perhaps a grander version of the Great Red Spot on Jupiter in our own solar system,” says Jayawardhana, “or we may be seeing the hotter, deeper layers of its atmosphere through big holes in the cloud deck.” Image: Astronomers have observed extreme brightness changes on a nearby brown...
This is a big week for exoplanet news with the continuing presentations at the Extreme Solar Systems II conference in Wyoming. But I'm going to have to be sporadic with posts this week because of ongoing commitments. The papers for the upcoming 100 Year Starship Symposium are due within days, which is a major driver, but I've also got even more important matters unrelated to my interstellar work to attend to. I'll probably be able to get another post off this week, and then we can catch up a bit next week. For now, here's a story I want to get in that involves things we can't see. Remember 'Invisible Invaders'? This 1959 drive-in classic involved aliens you can't see in spaceships that are likewise transparent, arriving on Earth to take over the bodies of the recently deceased. John Agar and Robert Hutton spent a lot of this movie chasing a comely physicist (Jean Byron) when they weren't working out a way to foil the aliens' plans to take over our planet in three days. Knowing my...
With the online press conference re new results from the HARPS spectrograph (High Accuracy Radial Velocity Planet Searcher) now being discussed, I want to pause for a moment before getting into them to mention the ongoing Extreme Solar Systems II conference, which runs until the 17th at quite a venue, Jackson Lake Lodge in Wyoming. The tentative program is available online, with the welcome news of new HARPS and Kepler results and any number of intriguing talks on everything from debris disk imaging around nearby stars to core accretion models. We’ll doubtless be talking about some of these findings in coming weeks. But for now, on to the HARPS discussion at the Wyoming conference. The take-away quote from today’s news was this, from Michel Mayor (University of Geneva): “The harvest of discoveries from HARPS has exceeded all expectations and includes an exceptionally rich population of super-Earths and Neptune-type planets hosted by stars very similar to our Sun. And even better —...
We've been assuming all along that it would take the Kepler mission three years-plus to detect true Earth analogues, meaning planets orbiting Sun-like stars at about the Earth's orbital distance. Now it turns out that figure may have to be extended, as this article in Nature makes clear. Author Ron Cowen points out that a close analysis of approximately 2,500 of the tens of thousands of stars in the Kepler field are flickering more than expected, and that spells trouble. Image: Kepler's field of view superimposed on the night sky. Credit: Carter Roberts. The reason: The dip in starlight signalling the presence of a planet can be masked by the unexpected noise in the Kepler data. As described by Kepler scientist Ron Gilliland (Space Telescope Science Institute), the signal of an Earth analogue -- assuming a star much like the Sun -- should be a drop of about 85 parts per million when the planet passes in front of its star, lasting a statistical average of 10 hours, and occurring once...
Quite a few people involved with Tau Zero and many of the Project Icarus team are planning to be in Orlando at the end of the month for the 100 Year Starship Symposium. I know about most of these, but if you haven't already told me that you are planning to attend, please leave me a note in the comments to this post. I'm looking forward to meeting many Centauri Dreams readers there.
Are dozens of Type Ia supernovae waiting to happen within a few thousand light years of the Earth? New research from the Harvard-Smithsonian Center for Astrophysics suggests the answer is yes. Type Ia events are thought to occur when a white dwarf accretes material from a companion star. The idea is that the white dwarf -- a stellar remnant that is no longer capable of fusion -- eventually exceeds the so-called Chandrasekhar mass, roughly 1.4 times the mass of the Sun. When a star pushes past the limit, gravity compacts the dwarf to the point of runaway nuclear fusion, and a spectacular stellar event appears in the heavens. Type Ia supernovae are a well studied phenomenon, but a continuing problem with these events is that the scenario doesn't quite explain everything we see, or don't see. Most Type Ia supernovae show none of the hydrogen and helium near the explosion that we would expect. As this news release from the CfA notes, the gas should be there, in the form of remnant...
We've talked often in these pages about Near Earth Objects (NEOs) and the potential danger posed not just by them but by objects from much further out in the Solar System if they were to take an Earth-crossing trajectory. But it's also true that NEOs have a certain allure even if they are potentially dangerous. They're close enough to consider a manned mission, and even a small 2-kilometer sized metallic NEO could contain rich metals and minerals worth trillions of dollars. Of course, what metals markets would do if we suddenly had access to such an object is another matter. And mining an NEO, not a new concept, is still on the impractical side. But Hexi Baoyin (Tsinghua University, Beijing) and colleagues are proposing a possible solution. The temporary capture into Earth orbit of an NEO by creating a small velocity change could allow a relatively low-cost trajectory to the object that would provide mining opportunities. And indeed, various asteroid deflection schemes from solar...
It makes perfect sense to me that we usually think of extraterrestrial intelligence in terms of technology. After all, when we listen to the stars for the whisper of a distant signal, we're saying that SETI is all about finding something that was produced with tools, like a beacon. Or if we extend the thought to science fiction, we might dream of studying alien civilizations through their ruins on long-dead worlds, learning about them by studying what they once built. After all, this is how we do archaeology, digging up spear-points or the bricks of ziggurats, the things that a culture leaves behind that it built with its tools. But will we always confine the idea of intelligence to the presence of an artifact? Science writer and Astronomy Now editor Keith Cooper examines the question in Dolphins, Aliens, and the Search for Intelligent Life, an incisive new essay for Astrobiology Today, one that offers us a new technology that may prove that intelligence doesn't necessarily need...
Most people think that SETI is worth doing, whether or not they actually believe there are other technological civilizations in the galaxy. Ben Zuckerman, a professor of astronomy at UCLA, is certainly in the skeptics' camp, thinking there are no technological ETs in the Milky Way, but he's quoted in this story from QUEST (KQED San Francisco) as calling for more SETI. "Given that the costs are not very high," says Zuckerman, "why not continue the search?" Zuckerman, who once worked with Carl Sagan in graduate school, no longer thinks we live in a crowded galaxy, but a potential discovery of this magnitude justifies the relatively modest expenditure. It's not surprising to find Jill Tarter echoing Zuckerman. The recent funding problems of the Allen Telescope Array have not daunted the woman who more than anyone else has come to represent the search for other intelligent life. And although she believes we may one day come to the 'extraordinary conclusion' that we really are alone, the...
The key to a sane life is perspective. Or at least that's how I feel when I see an image like the famous Apollo 8 shot of a gorgeous blue Earth rising over the barren, cratered Moon. Great images of the kind the space program deals up can change how we see everything -- the Apollo 8 image is widely thought to have energized environmental and ecological thinking in its day. We also have a few striking images showing both the Earth and the Moon together. The one I always fall back on is the one below, a barren Moon with a living Earth swimming in black space. It was a departing gift from the Galileo spacecraft as it left on its long journey to Jupiter in 1989. Image: On its way to Jupiter, the Galileo spacecraft looked back and captured this remarkable view of Earth and the moon. The image was taken from a distance of about 3.9 million miles. The brightly colored Earth contrasts strongly with the moon, which reflects only about a third as much sunlight as Earth. Contrast and color have...
