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Einstein, Updike and the Academy

by Paul Gilster | Mar 31, 2007 | Culture and Society | 2 Comments

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...

Freeman Dyson: Reasons for Optimism

by Paul Gilster | Mar 31, 2007 | Culture and Society | 10 Comments

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...

Double Stars May Be Aswarm with Planets

by Paul Gilster | Mar 30, 2007 | Exoplanetary Science | 15 Comments

The number of stars with possible planets keeps going up. The astronomy books I read as a kid operated under the assumption that we needed to look at Sun-like stars to find planets, and that meant single rather than double or triple systems. The tantalizingly close Alpha Centauri stars were all but ruled out because of their assumed disruptive effects on planetary orbits. No, find a nice G-class star all by itself and there you might have a solar system something like our own and, who knows, a second Earth. Today we're fitting binary stars into the planetary picture with ease. Astronomers see little reason to rule them out. Consider what David Trilling (University of Arizona) has to say about the matter in an upcoming paper: "There appears to be no bias against having planetary system formation in binary systems. There could be countless planets out there with two or more suns." Just imagine the possible sunsets. Image: Our solitary sunsets here on Earth might not be all that common...

Red Dwarf Planets: Too Dry for Life?

by Paul Gilster | Mar 29, 2007 | Exoplanetary Science | 33 Comments

Sometimes I imagine an ancient place where a dim sun hangs unmoving at zenith, and a race of philosophers and poets works out life's verities under an unchanging sky. Could a place like this, on a terrestrial world orbiting an M-class red dwarf, really exist? A new paper by Jack Lissauer (NASA Ames) casts doubt on the idea. Lissauer argues that planets inside an M dwarf's habitable zone are probably lacking in water and other volatiles, and are thus unable to produce life as we know it. The question is important because M dwarfs make up as much as 75 percent of the stars in our part of the galaxy. If we include them as candidates for life, we add a hundred billion or more potential habitats in the Milky Way alone. We've known for some time that although the proximity of such a terrestrial M dwarf planet to its star would cause it to be tidally locked -- one side in constant light, the other in darkness -- habitable regions might still occur on the dayside given a dense enough...

Odd Hexagon at Saturn’s Pole

by Paul Gilster | Mar 28, 2007 | Outer Solar System | 11 Comments

Shrouded in the night of a 15-year winter, Saturn's north pole demands specialized instruments to yield its secrets. Enter Cassini's visual and infrared mapping spectrometer, whose data on the region have disappointed no one. A six-sided honeycomb-shaped feature has emerged that was first found by the Voyager 1 and 2 spacecraft over twenty years ago. Now Cassini has, for the first time, captured the entire hexagon in a single image. What exactly is it? Think of Earth's polar regions, where winds move in a circular pattern around the pole, but ponder this difference: Saturn's vortex is a hexagon nearly 25,000 kilometers across. Four Earths would fit inside it. Click here for a QuickTime movie of the odd feature. This makes Saturn possibly the Solar System's most intriguing object when it comes to polar anomalies. The south pole sports an enormous hurricane, while the north is dominated by clouds moving along the hexagon at great rate. Indications are that the hexagon extends fully 100...

Asia Emerging II

by Paul Gilster | Mar 26, 2007 | Culture and Society | 3 Comments

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...

Asia Emerging

by Paul Gilster | Mar 26, 2007 | Culture and Society | 10 Comments

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...

OSIRIS: Asteroid Sample Return

by Paul Gilster | Mar 24, 2007 | Asteroid and Comet Deflection | 0 Comments

A little bit of asteroid 1999 RQ36 may wind up on Earth in 2017. That's assuming that NASA's OSIRIS mission launches in 2011, with the aim of investigating the properties of such Earth-crossing bodies. And while an asteroid sample may help us understand much about the early Solar System, OSIRIS offers a potentially greater benefit. It can help us sharpen our tracking skills so we can plot asteroid orbits with much greater precision. How? You'll recall that we recently discussed the the Yarkovsky Yarkovsky-O'Keefe-Radzievskii-Paddack effect. YORP is the minute push that an asteroid receives over time as it absorbs sunlight and emits heat -- let's call it the Yarkovsky Effect for short. It's a tricky thing to measure because of the uneven nature of asteroidal surfaces, and the varying wobble and rotation of each. Trying to predict an asteroid's orbit as it approaches Earth demands that we take the Yarkovsky Effect into account. And OSIRIS is tasked with measuring the effect for the...

Enceladus Geysers Mask Saturn’s Day

by Paul Gilster | Mar 23, 2007 | Outer Solar System | 3 Comments

What is it about Enceladus? I doubt anyone would have thought the tiny moon would weigh so heavily in our thinking about Saturn before Cassini, but now comes the news that Enceladus is distorting the planet's magnetic field to the point that it becomes tricky to measure the length of the Saturnian day. Count the electrically charged particles originating in the moon's geysers as the culprit -- they're actually causing Saturn's magnetic field lines to slip relative to the planet's rotation. The process seems to work like this: Gas particles are ejected from the geysers on Enceladus and become electrically charged. Captured by Saturn's magnetic field, they form a disk of plasma that wraps around the planet's equator. The rotation of the plasma disk slows down enough due to interactions with the magnetic field that the rotation period Cassini has been measuring -- based on radio emissions -- is not actually the length of Saturn's day. Instead, it's the rate of rotation of the plasma...

Asteroid Deflection: The Nuclear Option

by Paul Gilster | Mar 22, 2007 | Asteroid and Comet Deflection | 19 Comments

NASA's March report to Congress on deflecting Near-Earth Objects offers some startling assessments. Specifically, the report says this: "Nuclear standoff explosions are assessed to be 10-100 times more effective than the non-nuclear alternatives analyzed in this study. Other techniques involving the surface or subsurface use of nuclear explosives may be more efficient, but they run an increased risk of fracturing the target NEO. They also carry higher development and operations risks." Fair enough re setting off a nuke on the surface of an asteroid. But aren't we jumping the gun on other nuclear options when alternatives seem available? That's certainly the view of Rusty Schweickart, founder of the B612 Foundation, which is all about spreading the word on the threat these objects may pose to Earth. Alan Boyle discussed these matters with Schweickart in a recent post, from which this on the non-nuclear option: Schweickart argues that the so-called "nuclear standoff" option should be...

New Optics Paint Orion’s ‘Bullets’

by Paul Gilster | Mar 22, 2007 | Deep Sky Astronomy & Telescopes | 3 Comments

When you can work with a deformable mirror that compensates for atmospheric distortions, wondrous things can emerge. The Gemini Observatory (Mauna Kea, HI) used such a system coupled with a laser guide star as reference to produce an image of fast-moving 'bullets' of gas and the wakes they leave as they move through molecular hydrogen in the Orion Nebula. Some 1500 light years away from Earth, this stellar nursery has much to teach us about the birthing of stars. What we're looking at appears to be the movement of clumps of gas that have been ejected from within the nebula by some kind of violent event. They're moving outward at about 400 kilometers per second, vast gaseous agglomerations roughly ten times the size of Pluto's orbit around the Sun. At the tip of each clump you can see the blue glow of iron atoms shock-heated by friction with the surrounding cloud. The long wakes of their motion appear as orange smudges in the image below. Image: This composite image at infrared...

Institute for Advanced Concepts Scrapped

by Paul Gilster | Mar 20, 2007 | Culture and Society | 28 Comments

I've been waiting for something official re the reported closing of NASA's Institute for Advanced Concepts, but now that New Scientist is confirming the story that Keith Cowing at NASAWatch broke earlier this morning, I think it's time to comment on this grim development. NASA will save $4 million in its annual budget by closing NIAC. That means closing a program that regularly sought ideas from people outside the agency, funded them in a first round to see if they held promise, and offered more substantial second round funding to advance the best of them still further. Institute director Robert Cassanova has championed innovative ideas in propulsion, robotics, spacesuit design and more. In fact, NIAC-funded studies are so rich that browsing through this material could give science fiction authors ideas for years. I'll add that Cassanova's enthusiasm for the work was communicable. He was a great help when I was gathering NIAC material for Centauri Dreams (the book), and although he...

Quantum Weirdness and Communications

by Paul Gilster | Mar 20, 2007 | Communications and Navigation | 25 Comments

'Spooky action at a distance' is still spooky no matter how you explain it. Einstein famously used the phrase to describe quantum entanglement, where two entangled particles appear to interact instantaneously even though separated in space. Now we're talking about using the effect for communications, following the news that European scientists have proven that entanglement persists over a distance of 144 kilometers. Fortunately for would be communicators, a pair of entangled photons can be created in a process called Spontaneous Parametric Down Conversion. Once entangled, the photons stay entangled until one of them interacts with a third particle. When that happens, the other photon changes its quantum state instantaneously. The beauty of entanglement for communications is that anyone trying to listen in on a message invariably disrupts the entangled system, a result that would be easily detectable. The security potential is obvious in a world where so much banking information takes...

Another Small Step Toward Fusion?

by Paul Gilster | Mar 19, 2007 | Advanced Rocketry | 31 Comments

We're a long way from achieving practical fusion to supply our power needs, much less fusion rockets to the stars. Just how far can be gauged by a look at current research. The principle seems straightforward: Heat hot, ionized gas to the point of ignition and you can fuse hydrogen into helium. But can you contain the plasma while you're heating it? More to the point, can you get more power out of your device than you put in? Most of the effort these days is going into tokamak designs that use magnetic fields to contain the plasma. But tokamaks tap plasma currents to produce at least part of the needed field. And, says John Canik (University of Wisconsin), "The problem is you need very large plasma currents and it's not clear whether we'll be able to drive that large of a current in a reactor-sized machine, or control it. It may blow itself apart." Enter the stellarator, an alternative plasma confinement method that uses no plasma currents, but one that loses energy at a high rate...

A Practical Use for Antimatter

by Paul Gilster | Mar 17, 2007 | Antimatter | 6 Comments

If we need a huge particle accelerator to produce antimatter and use it only for exotic experiments, how are we ever going to ramp up production to the point where it becomes practical as a propulsion system? One answer may be that as we study the minute amounts of antimatter available for study today, we are learning how to use it in ways that are far more likely to catch the public eye, as in medicine. And treating cancer effectively -- ask any patient -- is anything but theoretical. At CERN (European Organization for Nuclear Research), the Antiproton Cell Experiment (ACE) has been running since 2003. It's an attempt to look at antimatter's effect on cancer cells, and its results are startling. Antiprotons, it turns out, are four times more effective than protons at destroying live cancer cells. Here's CERN's Michael Holzscheiter on the encouraging news: "To achieve the same level of damage to cells at the target area one needs four times fewer antiprotons than protons. This...

Mulling Robots and Their Names

by Paul Gilster | Mar 17, 2007 | Autonomy and Robotics | 14 Comments

Lee Gutkind takes a look at the Robotics Institute at Carnegie Mellon in Almost Human: Making Robots Think (W.W. Norton, 2007), a book entertainingly reviewed in this weekend's Los Angeles Times. Out of which this wonderful clip from reviewer M.G. Lord: I wish Gutkind had spent more time on an area that I find fascinating: the anthropomorphizing and gendering of robots, which science-fiction author Robert A. Heinlein famously explored in his novel The Moon Is a Harsh Mistress. What Heinlein created was a computer that, depending on circumstances, could switch between masculine and feminine identities. Robots are heaps of hardware, not biological entities, yet humans apparently feel more comfortable if they assign them a gender, regardless of the crudeness of the gender stereotype. The institute, for example, has robot receptionists with gendered personalities: Valerie, a "female" who complains about her dates with vacuum cleaners and cars, and Tank, a "male," who has blundered so...

Making the Case for Space

by Paul Gilster | Mar 16, 2007 | Culture and Society | 5 Comments

When you think about it, so much of science involves putting our instruments into the right place at the right time. The transit of Venus across the Sun in 1769 was an opportunity to use triangulation from opposite sides of the Earth to calculate the distance to the Sun more accurately. That effort took James Cook to Tahiti, and though the experiment failed, it remains an inspiring example of the human intellect trying to solve questions by exploration, determination and hard work. We saw yesterday that if we put instruments into much further places, we may be able to identify oceanic worlds and perhaps map their continents. Peter McCullough (Space Telescope Science Institute) wrote the most recent paper on this concept and presented it at a conference on missions that could be enabled by a return to the Moon. But the Moon itself may not be the best venue for the instruments in question, as McCullough noted in an e-mail after reading yesterday's entry: "I might comment (in...

Light Off an Alien Ocean

by Paul Gilster | Mar 15, 2007 | Exoplanetary Science | 5 Comments

If you want to put the hunt for planets around other stars in perspective, consider this. For almost all of our species' time on this planet, we have looked at the planets in our own Solar System as unresolved points of light that seemed to move upon a celestial sphere. The brief time that we have been able to see more is measured since the invention of the telescope, a tiny window compared to the millennia that went before. We are now working hard to see extrasolar planets as unresolved, moving points of light. In doing so, we're looking at ways to image these planets that would yield the greatest scientific return. Recall former NASA administrator Dan Goldin's wish to actually see the surfaces of distant exoplanets -- he talked to putting such images on the walls of our schools. One day, starshade technologies coupled with space-borne telescopes may make that possible. For now, though, there is the real potential of something closer: identifying exoplanets with oceans. The beauty...

Planets, Comets & Footballs

by Paul Gilster | Mar 14, 2007 | Outer Solar System | 13 Comments

I remember talking to the exuberant astrophysics professor Sheridan Simon about a football-shaped planet he had created one Super Bowl eve. This was at a science fiction convention and it must have been fifteen years ago. Simon frequented such venues because he had built a cottage industry around creating planets for various science fictional settings. As a lark, he had run the numbers on what would happen to the atmosphere of a world shaped like a pigskin and wound up announcing the result: "It's plaid! That's what you would see. A plaid football!" I think he was pulling my leg, and that wouldn't have been out of character either for this generous, gregarious man who died all too young. But Mike Brown's new paper in Nature brought back memories of that conversation with Sheridan Simon in spades. Brown (California Institute of Technology), who specializes in the exotica at the fringes of our Solar System, has been examining an object his team originally found. 2003 EL61 is also...

The Seas of Titan

by Paul Gilster | Mar 13, 2007 | Outer Solar System | 15 Comments

If the dark features Cassini has found near Titan's north pole really are filled with liquid, they're seas more than lakes, one of them larger than any of the Great Lakes in North America. The image below says it all, comparing the largest of these features with Lake Superior. This work is being done through radar imaging, detecting dark radar surfaces that imply smoothness. Cassini's visual and infrared mapping spectrometer is also at work as the liquid hypothesis at Titan's surface is explored. Image: This feature on Titan is at least 100,000 square kilometers (39,000 square miles), which is greater in extent than Lake Superior (82,000 square kilometers or 32,000 square miles), which is one of Earth's largest lakes. The feature covers a greater fraction of Titan than the largest terrestrial inland sea, the Black Sea. The Black Sea covers 0.085 percent of the surface of the Earth; this newly observed body on Titan covers at least 0.12 percent of the surface of Titan. Because of its...

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In Centauri Dreams, Paul Gilster looks at peer-reviewed research on deep space exploration, with an eye toward interstellar possibilities. For many years this site coordinated its efforts with the Tau Zero Foundation. It now serves as an independent forum for deep space news and ideas. In the logo above, the leftmost star is Alpha Centauri, a triple system closer than any other star, and a primary target for early interstellar probes. To its right is Beta Centauri (not a part of the Alpha Centauri system), with Beta, Gamma, Delta and Epsilon Crucis, stars in the Southern Cross, visible at the far right (image courtesy of Marco Lorenzi).

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