by Paul Gilster | Jan 29, 2010 | Culture and Society |
The New Horizons probe to Pluto/Charon is approaching Uranus’ orbit, prompting the team’s Twitter poster to remember Challenger’s final crew in a tweet late yesterday. Challenger was lost on January 28, 1986, just as Voyager 2 reached Uranus, and thus we had the joy of a new planetary encounter mingling with grief for a fallen crew. I remember that day as vividly as anyone, I suppose. I was doing an intensive flight instruction seminar in Maryland, a weekend push that had me flying all day with students trying to improve their instrument landing skills. We were just headed out for another session when the news came, and a number of the pilots went to the closest TV to see for themselves.
We looked and shook our heads in disbelief. Then we got back into our respective cockpits and took off again, trying to keep those images out of our minds to focus on things like holding patterns and ADF approaches. Grim memories because of their context. This morning also seems grim because of the recent death, evidently a suicide, of Andrew Lange, an astrophysicist at Caltech whose young career (he died at 52) was devoted to the microwave background that tells us so much about the early universe.
The investigation of the cosmos has always struck me as joyous and it’s troubling to examine it in the context of sudden death. But Lange’s contribution was immense. His Boomerang experiment, discussed in this New York Times feature, flew in 1998 over Antarctica. Boomerang stood for Balloon Observations of Millimetric Extragalactic Radiation and Geophysics. The balloon made a ten-day flight at 120,000 feet, detecting and mapping the microwave glow of the universe as it was when only 400,000 years old. The results suggested a flat universe, one that would keep expanding.
The finding was consistent with the theory of inflation, an incredible expansion of the universe in its earliest moments. The Times story quotes Marc Kamionkowski (Caltech) as saying, “Boomerang was just crystal clear; it was the shot heard around the world.” The findings were backed by the Maxima experiment, which Lange had a hand in, and the Cosmic Anisotropy Telescope. They were later confirmed by the Wilkinson Microwave Anisotropy Probe (WMAP). The 1998 finding of the universe’s accelerating expansion fits the Boomerang results nicely — if there was not enough matter in the universe to make it flat, we now learned there was certainly enough energy.
It could be said, then (and Michael Turner at the University of Chicago makes this case) that Lange’s Boomerang team were the first to demonstrate that the geometry of the universe is flat. He went on to work on detectors for continuing the study of the cosmic microwave background. What forces drove his own life to its early end we can only leave to conjecture, but it’s one of life’s redemptive elements, as Challenger reminded us, as Columbia reminded us, that while death can turn exhilaration into stunned silence, it cannot still the resurgence of spirit that hands over the work to new volunteers who will bring new missions home. Requiescat in pace.
by Paul Gilster | Jan 28, 2010 | Exotic Physics |
It was in 1900 that mathematician David Hilbert created a list of the most significant unsolved problems for mathematics at a conference in Paris. The list would eventually be fleshed out to reach a total of 23 problems. Hilbert’s Paris talk, “The Problem of Mathematics,” began this way:
Who among us would not be happy to lift the veil behind which is hidden the future; to gaze at the coming developments of our science and at the secrets of its development in the centuries to come? What will be the ends toward which the spirit of future generations of mathematicians will tend? What methods, what new facts will the new century reveal in the vast and rich field of mathematical thought?
The Wikipedia entry on Hilbert notes that the 23 problems, fewer than half of which were presented at the meeting, have gone on to be discussed throughout the following century, with some remaining unresolved to this day. I look at Hilbert’s introduction and think about how apropos the idea of gazing at ‘coming developments of our science’ is to what we do here. Maria Spiropulu, a senior scientist at CERN near Geneva, used Hilbert when talking to the New York Times‘ Dennis Overbye about a weekend conference that recently concluded in Los Angeles. The Physics of the Universe Summit had a grand title, and Spiropulu hoped to use it to “…set out the questions for the next nine decades.”
Now, of course, we have the Large Hadron Collider, which offers the chance to create conditions similar to those existing in the earliest moments of the universe. The trick is in making sense out of what it may show us. Lisa Randall (Harvard) pointed to Galileo’s maxim that physics progresses more when working on small problems than talking about large ones, which could be taken as a way of saying that no matter how elegant a theory may be, it often runs into problems when we get into the details. Supersymmetry, for example, could explain things like dark matter, but Randall points out that no supersymmetric effects have turned up yet as deviations in the Standard Model of physics. Randall believes they should have.
Overbye’s article on the Summit lays out its interesting methodology:
Organized into “duels” of world views, round tables and “diatribes and polemics,” the conference was billed as a place where the physicists could let down their hair about what might come, avoid “groupthink” and “be daring (even at the expense of being wrong),” according to Dr. Spiropulu’s e-mailed instructions. “Tell us what is bugging you and what is inspiring you,” she added.
Adding to the air of looseness, the participants were housed in a Hollywood hotel known long ago as the ‘Riot Hyatt,’ for the antics of rock stars who stayed there.
The eclectic cast included Larry Page, a co-founder of Google, who was handing out new Google phones to his friends; Elon Musk, the PayPal electric-car entrepreneur, who hosted the first day of the meeting at his SpaceX factory, where he is building rockets to ferry supplies and, perhaps, astronauts to the space station; and the filmmaker Jesse Dylan, who showed a new film about the collider. One afternoon, the magician David Blaine was sitting around the SpaceX cafeteria doing card tricks for the physicists.
Wish I were a friend of Page’s — I could use a Nexus One! This is a lively bunch and ideas must have been flying. Gordon Kane (University of Michigan) opined that the Large Hadron Collider would indeed discover supersymmetry but offered no explanations that would point to a theory of dark energy. One big question at a time. Overbye quotes Lawrence Krauss (Arizona State) on the matter of theories and their application, and this, too, is entertaining:
“We get the notions they are right because we keep talking about them,” he said. Not only are most theories wrong, he said, but most data are also wrong — at first — subject to glaring uncertainties. The recent history of physics, he said, is full of promising discoveries that disappeared because they could not be repeated.
Physics can take us from optimism to pessimism in a heartbeat. Are we on the verge of discovering a true ‘theory of everything?’ Or are we likely to be more confounded with each new assault on the secrets of the universe? We haven’t a clue how to explain dark energy, and dark matter remains undetected. For that matter, as Overbye notes, we’ve assumed that dark matter is a kind of particle. What if, instead, it is an ‘entire spectrum of dark behaviors’? Are there forces as well as particles on what these physicists are calling the ‘dark side’?
No answers here, but plenty of questions, in keeping with Dr. Spiropulu’s wish to emulate Hilbert. As a series of investigative doors wide open to the 21st Century, the topics discussed here lead to both exhilaration and confusion. We’ve seen much the same thing occurring in the exoplanet hunt, where we hardly thought we’d find anything as outrageous as planets orbiting a pulsar, or ‘hot Jupiters’ existing breathtakingly close to their stars. The trick seems to be to build the tools that let us push farther and deeper into nature, without prejudging what we will find. ‘Prepare to be surprised’ is as good a motto for today as any.
by Paul Gilster | Jan 27, 2010 | Astrobiology and SETI |
As I’m just finishing up Richard Holmes’ The Age of Wonder (Pantheon, 2009), the Royal Society had been on my mind even before the two-day conference on SETI that concluded yesterday made the news. If you haven’t read the Holmes book, by all means do so. It’s a fascinating study of the development of science and the imagination in the late 18th Century and into the Romantic era, with cameos by the likes of Shelley and Keats and in-depth discussions of everyone from Pacific voyager Joseph Banks to the chemist Humphry Davy. It’s a cliché to say I couldn’t put the book down, but this one fully deserves the compliment.
With the Royal Society now in its 350th year, a conference steeped in SETI and questions of astrobiology seems made to order as we track the data from our far-flung space observatories. I wanted to mention that Paul Davies’ public lecture at the conference, called “The Eerie Silence: Are We Alone in the Universe,” will be made available at the Royal Society video archive within a week or so. Davies (Arizona State), a physicist and popular science writer, argued at the conference that we should look here on Earth to see whether life has appeared on our planet more than once. A ‘shadow biosphere,’ one representing forms of life entirely different from our own, might be present in isolated ecological niches.
Addendum: The Davies talk is now available here.
Davies is thinking of places like the dry valleys of Antarctica, or lakes saturated with salt, or volcanic vents. It’s an idea we’ve examined here before, and one you can follow up on in Davies’ article “Are Aliens Among Us?”, which ran in late 2007 in Scientific American Vol. 297, No. 6, pp. 36-43 and is available online. Davies’ book The Eerie Silence: Renewing Our Search for Alien Intelligence, is to be published by Houghton Mifflin Harcourt in April.
Pondering Davies’ ideas, London’s Times Online notes that a US Geological Survey team led by Felisa Wolfe-Simon is investigating places like Mono Lake in California, where arsenic contamination might support life-forms that use arsenic the same way other life-forms use phosphorus. Not everyone agrees, of course, and the article quotes Colin Pilinger, leader of the Beagle 2 Mars landing attempt, as saying that looking for arsenic-based life is ‘wildly science fiction,’ and ‘you’d be off your trolley’ to look for it.
I wish I could have been at this conference to have heard Pilinger’s own talk, not to mention Alfred Harrison’s. The latter, from the University of California at Davis, took on the huge question of how humans would react to the reception of a signal confirming the existence of extraterrestrial intelligence. Here’s his response to the Times:
“It is easy to imagine scenarios resulting in widespread psychological disintegration and social chaos. But historical prototypes, reactions to false alarms and survey results suggest that the predominant response to the discovery of a microwave transmission from light years away is likely to be equanimity, perhaps even delight.”
And the Guardian‘s coverage of the conference looks at the parallel some people make with the famous 1938 ‘War of the Worlds’ broadcast of Orson Welles, which caused some in the radio audience to panic at the thought of an invasion from Mars. Harrison dismisses the idea:
“The public reaction was overstated. Most people who thought the broadcast was real took sensible actions to protect themselves,” Harrison said. “Surveys suggest most people think they will be fine, but they worry about others freaking out.”
I’m not sure which surveys Harrison is referring to, but one that supports him was presented as far back as 1996 at the OSETI II conference in San Jose (CA), where Miguel Sabadell and Fernando Salamero (University of Zaragoza, Spain) demonstrated that there was widespread public interest in extraterrestrial contact. Asked whether contact with ETI would be good for mankind, an overwhelming 79 percent answered Yes, and 77 percent agreed that if we receive a SETI signal, we should answer.
Also supporting Harrison were the results of a 2002 Roper poll that concluded:
“Most Americans appear comfortable with and even excited about the thought of the discovery of extraterrestrial life. Three-quarters of the public claim they are at least somewhat psychologically prepared for the discovery of extraterrestrial life, and nearly half are very prepared.”
This story in Nature News looks at Simon Conway Morris’ contribution to the conference. Morris, a paleontologist at Cambridge, points to examples of convergent evolution in Earth’s biological history to make the case for there being a limited number of ways to organize a sensorium or a society. The lives of intelligent aliens could, in other words, be every bit as violent as the lives of beings on Earth. Whatever the case, Martin Dominik (University of St. Andrews, UK) notes that no government has plans for what to do if intelligent life is confirmed elsewhere in the universe. One hope for the conference is that it will persuade policy makers to take the matter into consideration as the numerous imponderables of such contact are examined.
by Paul Gilster | Jan 26, 2010 | Outer Solar System |
Adding punch to the National Research Council’s recent report on detecting near-Earth objects is the first asteroid detection by WISE, the Wide-Field Infrared Survey Explorer. We’ve focused in these pages primarily on WISE’s ability to spot nearby brown dwarfs, but the mission is going to map the entire sky in infrared light and its discoveries should range from the inner system to distant galaxies. As an asteroid hunter, WISE is demonstrating it will be second to none, quickly spotting the object now designated 2010 AB78, a finding soon confirmed at visible light wavelengths at the University of Hawaii’s 2.2-meter instrument at Mauna Kea.
At 158 million kilometers from Earth, the asteroid, some 1 kilometer in diameter, poses no impact threat for the foreseeable future, but all asteroid and comet detections from WISE move nonetheless to the Minor Planet Center in Cambridge (MA) and follow-up observations then establish firm orbital data for newly discovered objects. The thinking is that WISE will find some 100,000 previously undetected asteroids in the main belt, in addition to hundreds of near-Earth objects.
“We are thrilled to have found our first new near-Earth object,” said Amy Mainzer (JPL), the principal investigator of NEOWISE, a program to mine the collected WISE data for new solar system objects. “Many programs are searching for near-Earth objects using visible light, but some asteroids are dark, like pavement, and don’t reflect a lot of sunlight. But like a parking lot, the dark objects heat up and emit infrared light that WISE can see.”
WISE gives us abundant new data, but it’s worth remembering that we’re still mining what Galileo and the two Voyager probes sent us from the outer Solar System. Data retrieval and management is going to be a huge issue as information continues to accumulate from our current missions. Scientists at the Southwest Research Institute (SwRI) are using both Galileo and Voyager data in their comparative study of the Galilean moons Ganymede and Callisto, two objects roughly similar in size and composition but strikingly different in physical appearance.
The model suggested by the SwRI researchers is that 3.8 billion years ago, in the era known as the Late Heavy Bombardment, the two moons diverged sharply in development. SwRI’s Amy Barr explains:
“Impacts during this period melted Ganymede so thoroughly and deeply that the heat could not be quickly removed. All of Ganymede’s rock sank to its center the same way that all the chocolate chips sink to the bottom of a melted carton of ice cream. Callisto received fewer impacts at lower velocities and avoided complete melting.”
Image: Interior density structures created by an outer solar system late heavy bombardment onto Ganymede (top row) and Callisto (bottom row). The left column shows the density at the surface as a function of latitude and longitude, and the right column shows a slice through the center of the globe. Colors show the density, with black representing pure rock, blue representing mixed ice and rock, and white showing pure ice. Credit: SwRI.
Working with colleague Robin Canup, Barr sees Ganymede and Callisto as twins that, like the Earth and Venus, took sharply different directions. Because it was closer to Jupiter, Ganymede received twice as many cometary hits as Callisto, and was struck at higher average velocity. This allowed a self-sustaining core to form during the Late Heavy Bombardment on Ganymede but not Callisto. Here again we see the huge effect of impactors on planetary development, effects highlighted by the surface of our own Moon. Comparative planetology teases all this out of old data even as the flood of new information from WISE, Kepler, CoRoT and others continues to build.
by Paul Gilster | Jan 25, 2010 | Culture and Society |
Keeping up with Tibor Pacher isn’t easy. My opponent on a bet about the future of interstellar flight (see the Long Bets site for details), Tibor has many irons in the fire, including what appears to be a labor of love called MiniSpaceWorld (MSW). The exhibit, now in its planning stages, will showcase the state of the art in rocketry and the directions our technology is taking us, all through miniatures and modeling. Tibor patterned the idea after the well-known Miniatur Wunderland in Hamburg, which taps the energy of model railroaders to create a rail-themed model universe. Extending the idea into the realm of astronautics is an attempt to educate and inspire a broad audience about space topics.
MSW’s layout is ambitious, ranging as far back in time as the earliest experiments in rocketry and moving out to the outer planets and beyond, all packed into roughly 3500 square meters in two levels. In December, the results of the first MSW design contest were presented at an award ceremony in Budapest. The leader of the prize jury was Austrian scientist and science fiction writer Herbert Franke, who spoke about science fiction’s ability to inspire and motivate young people to study science.
But I also want to mention MSW judge Patrick Gyger, who is director of the remarkable Maison d’Ailleurs, a museum of science fiction in Yverdon-les-Bains, Switzerland. The ‘house of elsewhere’ is Europe’s largest research and documentation center for research into science fiction, with a library of 50,000 books in forty languages dating back to the 16th Century. Science fiction was the theme of the evening at the award venue, the Congress Hall of the Hungarian Academy of Science in the castle district of Budapest. Hungarian actor Oszkár Gáti read Ray Bradbury’s short story ‘The Rocket’ (about creating great things out of small beginnings) and German musician Barbara Buchholz performed theremin music. Among the guests were Imre Ikvai-Szabó, Deputy Major of Budapest, and leaders of the Hungarian Astronautical Society.
You can have a look at the winning entries of the 2009 design contest (two of the teams shared first prize) here. Ahead in 2010 is a photo exhibition in Budapest featuring the contest, the design and construction of an ‘MSW on Tour’ mobile showcase featuring the Moon and the Google Lunar X Prize, planning for the 2010 design contest, and the design of a 60-80 square meter exhibit on astronomical themes for Hungary’s Futura Science Center, which is expected to open in the spring of 2012. As I said, keeping up with Tibor is never easy, and he’s also working, through his peregrinus interstellar effort, on a project called Faces from Earth to compile messages that would fly on future deep space missions. More about Faces from Earth, and its Mosaic Earth offshoot, in coming weeks from Tibor himself.
Images: Tibor Pacher (above), MSW audience (below). Credit: Zoltán Trupka.
