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Continue reading ‘Links for the week of February 26th, 2010′
Tag Archive for 'research'
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Continue reading ‘Links for the week of December 24th, 2009′
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Continue reading ‘Links for the week of November 15th, 2009′
It seems a bit of Vaudeville is still lingering around the Academe…
THE GRADUATE SCHOOL
of
THE UNIVERSITY OF COLORADO AT BOULDER
DISSERTATION DEFENSE
of
Zane A. Selvans
FOR THE DEGREE
DOCTOR OF PHILOSOPHY
Date/Time: 2:30pm, Friday, 20th November, 2009
Bldg./Rm: Benson Earth Sciences (BESC) 380
Examining Committee Members:
- Karl Mueller
- John Wahr
- Robert Pappalardo
- Bruce Jakosky
- John Spencer
OUTLINE OF STUDIES
Major Field: Geological Sciences
BIOGRAPHICAL NOTES
A descendant of Dust Bowl migrants, Zane grew up near Fresno in California’s San Joaquin Valley. He left as soon as humanly possible, and got his BS in Computer Science at the Caltech in Pasadena. After a brief stint working in Silicon Valley (which unfortunately did not result in any kind of dot-com stock option fortune), he returned to Caltech via sea kayak to work with Mars Global Surveyor data, mapping Mars’ south polar layered deposits. While he has been a student at CU Boulder since the fall of 2002 you may not have seen much of him lately, because in early 2006 his wife and advisor both moved to Caltech/JPL, and like a long period comet, he slid back down into that place’s deep potential well to be with them. Next year, Zane intends to spend a lot of time on his bicycle.
THESIS
Time, Tides and Tectonics on Icy Satellites
Faculty Advisor: Karl Mueller
ABSTRACT
In the outer solar system, we cannot directly use the radiometric dating techniques widely applied in terrestrial geology. We also lack the detailed understanding of the correspondence between crater size-frequency distributions and absolute ages that the radiometric dating of lunar samples has given us in the inner solar system. Additionally, many geologically interesting surfaces on the icy satellites are insufficiently cratered to allow us to infer precise relative ages. Thus it is desirable to find other ways to construct geological chronologies that function well in the outer solar system. In this work I develop two techniques.
The first compares the linear tectonic features covering Jupiter’s moon Europa to modeled tensile fractures resulting from tidal stresses due to the non-synchronous rotation (NSR) of the satellite’s decoupled, icy, lithospheric shell. The amount of shell rotation required to align a feature with the stress field resulting from NSR is used as a proxy for time. This translation is potentially convolved with a phase lag between the tidal potential and the stresses it induces, resulting from the shell’s partially viscous response to the NSR forcing. The geography of individual lineaments is found to be no more consistent with NSR stresses than chance would predict, however, the ensemble of global lineaments displays a non-uniform apparent rate of lineament formation throughout the time period recorded by the surface. This non-uniformity may be explained either by steady state fracture formation, activity, quiescence and erasure, or by a transient episode of tectonics.
The second technique encodes the myriad superposition relationships evident between Europa’s tectonic features as a directed graph enabling algorithmic analysis. The observed superposition relationships are generally insufficient to construct complete stratigraphic stacks, but we can calculate the degree to which they corroborate or contradict another hypothesized order of formation. We find that they tend to corroborate the hypothesis that the lineaments are tensile fractures due to NSR stresses.
Together these results offer cautious support for the idea that Europa’s shell rotates independently of its silicate interior, and demonstrate techniques useful in comparing tectonic features on other icy satellites to hypothesized mechanisms of formation.
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Continue reading ‘Links for the week of August 20th, 2009′
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- Wal-Mart To Become Green Umpire – Wal-Mart arguably has more control over and insight into its supply chain than any other company on earth. The information they need in order to be able to force their suppliers to produce the goods as cheaply as humanly possible overlaps substantially with the information required to provide transparent information about the environmental impacts of those same products. Wal-Mart says they want to use this power for good… for telling, in condensed form, the sustainability back-story for their products. But will they tell the truth? Will it be transparent? Will it be verifiable? And even if it is… will their customers care? Might it change their customer base?
- Howtoons – A series of comics which both tell stories, and inspire kids to build their own toys and tools. Wonderful hacker propaganda.
- Where's the Real Bottleneck in Scientific Computing? – A story about a computer scientist talking to physicists who have hundreds of thousands of lines of code, and don't know what version control or unit testing is. Hmm. I guess I don't really know what unit testing is either.
- Software Carpentry – A Python based tutorial for scientists and engineers who need to learn how to (actually) program. How could it have taken this long to appear?
Aaron suggested that my paper would would be much better if it read more like one of my blog posts, and less like a litany of torture lab notebook. So here it is in parts, written as if I intended for you, dear reader, to read it. (But don’t worry Bob, I’m actually working on the real paper). It’ll probably be cathartic, as one of the things I hate about writing papers is the formalistic language. It makes the content less readable, less enjoyable, less human. I just don’t see the point. If the content is up here, then anyone who feels the same way can get an idea of what’s going on without wading through all the passive voice crap. It’ll also help me enjoy writing it, and let me feel like I got it out of my system. Plus, on the internet, color figures are free (not $350 for the first page, $175 for each additional page… I mean jeez, that’s like a year’s worth of hosting fees just for one paper), you can insert links, and nobody has to pay $3975 per year for a subscription. Oh, and sweet, I also get to retain the copyright. Honestly, paper journals are so sad. Of course there’s that pesky peer review, but you’ll find a comment form at the bottom of the page, and if you actually make it that far, by all means let me know what you think. In a production environment, the publication would be hosted on a neutral third party site, precluding me from editing or deleting comments, verifying everybody’s identities, and ensuring that the content was archived effectively. Alas, we’re not there yet. Maybe this will seem ridiculous at this point in the grad school experience, but I actually maybe for the first time understand why someone would want to give a talk. I have results, they’re interesting (if you’re into this kind of thing), but I don’t really know what they mean.
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- Christian high school discussion of climate change – Kurt Klein's AP Environmental Science class is reading Richard B. Alley's Two Mile Time Machine, about paleoclimate, ice cores, and abrupt climate change events. (tagged: climate ice science greenland education religion )
- Prefabricated Passive Houses in the USA – Bau Technologies is attempting to bring pre-fabricated (or rather off-site constructed) passive houses to the US. Looks awesome. (tagged: architecture sustainability energy efficiency passivhaus design )
- Yogurt making tips – Detailed instructions on how to make yogurt, and also a source for equipment and cultures. (tagged: food yogurt homemade cooking recipe )
- Climate Wars – A Canadian radio show exploring some of the climate change scenarios which have been studied by the US Dept. of Defense in a personal, "War of the Worlds" kind of way. Be forewarned, this is apocalypse porn, and probably not productive unless you need to get yourself riled up. (tagged: politics climate sustainability future war )
- Our Passive House — the first passive house in Utah. – A Utah couple chronicles the design and construction of their passive house, with blog posts and photos. Great to see these things going up on this side of the Atlantic finally! (tagged: passivhaus sustainability design architecture buildings )
- Will Allen: Street Farmer – A long profile of Will Allen and his intensive urban farming project in Milwaukee: "Growing Power". Aquaponics and vermicomposting of donated food wastes. This is realistic urban farming at a moderate scale. (tagged: sustainability urban food agriculture compost )
- Gini coefficient | Wikipedia – A wonderfully simple and general mathematical measure of the non-uniformity of a distribution, mostly used in economics, but applicable elsewhere just as well. (tagged: economics math wikipedia research science finance )
- Here comes the data: OECD Factbook eXplorer – There are terabytes of interesting data out there that nobody can actually understand, because we don't have good interfaces for playing with it, and poking around. This is the OECD's attempt to offer a window into its own demographic treasure trove. Obviously inspired by the gapminder, from Google and Hans Rosling. (tagged: data maps statistics visualization demographics oecd economics )
- The Choice of Cities – I'm not convinced we really know why the humans are coming to the cities. Whether it's a pull, or a push. How the migrants feel about their lot. Is it, globally, the same as the push we had in this country a hundred years ago? Or was it a pull? What happened when the frontier closed, when all the land was spoken for, and the factories and mines and mills were opened for business.
And what will cities look like once everyone has arrived? If we actually reach that day, when the countryside is emptied, and the flow staunched, then how will cities develop going forward? What will their margins look like? Will the slums filled with newcomers vanish? What will they be replaced with? (tagged: technologie urban design economics history technology poverty )
- Bike Among the Ruins – Detroit is half abandoned. The houses are almost free. The streets are empty and the people are poor. It's also flat. Could a cyclone of bicycles wipe clean the slate, even within the sight of our beloved, bankrupted, and now employee owned husk of an industrial titan… GM? (tagged: bicycle transportation urban design economy )
- Behind the Veil by Eve Arnold – A series of photographs of women, from Afghanistan and the middle east from 1969. Very different from our "Summer of Love"… (tagged: photos islam afghanistan women )
- The Revolution Will Not Be Digitized – Iran is one of the first places we get to see old school blood in the streets mixed with the new age of instantaneous, ubiquitous communication. We've tended to focus on the positive aspects, while briefly forgetting the potential powers of an electronic police state, which is to some degree what Iran has built. No massive army of eavesdroppers and informants is needed in such a regime. A few deep packet inspection boxes from Siemens sitting on the fiber backbone, and a few on the microwave towers from Nokia. Technology is largely neutral. (tagged: technology politics internet privacy government twitter web2.0 iran )
- 55 km to Amsterdam – A day of inter-city transportation by bicycle in the Netherlands. Can it really be that idyllic? (tagged: bicycle transportation netherlands infrastructure )
- 1993 Y Hike Pictures – Wow, pictures of myself from 1993 on the Y Hike. I still remember just about everyone in that group. I look so… young! (tagged: caltech yhike backpacking wilderness sierras )
- Traitor Joe's | Greenpeace – Trader Joe's doesn't make any effort to source sustainably caught fish. Unfortunately, with 70-80% of global commercial fisheries in collapse, it's virtually impossible to sell (or buy) most tasty fish species ethically. (tagged: sustainability fish traderjoes ocean food )
- Organic Farms as Subdivision Amenities – Housing developments that incorporate small organic farms, CSAs even, instead of the usual golf-course crap. How would one adapt this for denser living I wonder? (tagged: design agriculture urban csa food architecture )
- Enphase Energy System Monitoring – Another real-time and historical solar power monitoring system. This one is installed on the roof of one of the Boulder Housing Coalition Co-ops in Boulder. Pretty awesome! Smart grid indeed. (tagged: solar energy technology transparency electricity )
- Caltech Building Dashboard – A near real time view of the power being generated by Caltech's 200 kW PV installation on the Holliston parking structure. Also shows historical data and weather information. Pretty cool. Would be great to just have the raw datastream available via an API too… and be able to see all the Caltech's per-building consumption too. (tagged: energy solar caltech pasadena technology transparency data internet )
- How To Destroy Half the Planet for the Low, Low Price of 5% of Global GDP – Never mind the possibility of unforseen climatic consequences. Even if the pessimistic IPCC scenarios are right, and even if they "only" reduce global GDP by 5% over the next 100 years, that purely economic metric is not sufficient, because it turns out you can wipe 2.5 billion people and their nations off the face of the Earth, mainly in the tropics, and only reduce global GDP by 5%. Cold comfort, that. (tagged: climate economics gdp )
- Walter Mebane's statistical analysis of Iran's election results – Walter Mebane at UW Madison has done several statistical analyses of the Iranian election results, and finds significant irregularities in the Ahmedinejad results. (tagged: election iran statistics democracy fraud system:filetype:pdf system:media:document )
- Carbon Cap and Trade Debate – Ralph Cavanagh (legislative council for NRDC) and Jim Lazar, an economist, debate the merits of Cap and Trade, for an hour and a half. Looks interesting, but don't have time to watch it at the moment (tagged: video towatch climate policy economics )
- Property Assessed Clean Energy Bonds – PACE bonds are a way of overcoming the capital intensivity of many energy efficiency retrofits which make sense in the mid to long-term, but not on the typical short term investors time horizon. They also allow homeowners who may move before their investment in efficiency has paid for itself to pass on the obligation to future owners, instead of losing the investment. They also shift the costs of doing energy efficiency from capital expenses to debt servicing, which is advantageous in many jurisdictions for tax purposes. Berkeley, CA and Boulder, CO pioneered them for municipalities, but they can also work in a commercial context. (tagged: energy efficiency sustainability finance green debt investing bonds )
- It’s Now Legal to Catch a Raindrop in Colorado – Colorado has taken its first tentative steps down the road to legalizing… rainwater harvesting. I hope they go all the way. I'd hate to have to end up breaking yet another immoral law. (tagged: environment colorado water law sustainability rain green architecture design )
- Welcome to Tällberg – A "conference" analogous to the WEF in Davos, but held in Sweden, in the woods, and with sustainability as the given goal, instead of economic growth. Would be an interesting stop on the Green Cities Bike Tour. (tagged: green economics technology politics policy design conference )
- Power Struggle – A commentary on Steven Chu's position that we need major basic scientific and technological breakthroughs to successfully tackle our energy problems in the context of global warming. The hope is that in the short term, the vast array of incremental changes we have available is enough to get us started, and that by mid-century, the major breakthroughs will have been forthcoming. Ah, non-linear dynamics. (tagged: technology science energy climate non-linear sustainability policy )
- The Great American Bubble Machine – An article from Rolling Stone, by Matt Taibbi, on the endless bubble building shenanigans that Goldman Sachs has engaged in over the years, and their supposed current machinations to engineer a bubble in the as-of-yet uncreated market for greenhouse gas emissions. Markets, I like. Markets run by some Great American Gangster Kingpin, not so much. Especially not this particular market. Remember: Nature doesn't do bailouts. (tagged: economics finance goldmansachs capitalism climate bailout )
- The Economics of Ideas – An article about Paul Romer by Kevin Kelly, musing on the problems and benefits of having an economy which is primarily driven by informational goods. (tagged: economics technology non-linear )
- Paul Romer: A Theory of History, with an Application – Paul Romer talks about two different kinds of informational goods: "technology" and "rules". The former being knowledge about how to re-arrange the material world to increase its value to humans, and the latter being constraints on the ways we interact with each other. His "new/endogenous growth" theory suggests that overwhelmingly, wealth creation throughout history has been due to these two kinds of goods, and that they are virtually infinite resources. What he does not explicitly admit in the talk though, is that much of our increased apparent wealth has come at the cost of virtual liquidation of material resources. Truly sustainable growth absolutely must close the materials loop somehow. Better sooner than later. The rest of his idea is wonderful: we need a system which enables rule set entrepreneurs, or we aren't going to get sufficient innovation in the field. He suggests myriad autonomous city states, and I agree emphatically. (tagged: economics urban society non-linear politics longnow )
- The Swimming Cities of Serenissima – Improvised and chaotic houseboats built from found bits, floating down the Mississippi (2006-2007), or the Hudson (2008), or sailing the Adriatic from Slovenia to Venice (2009). Like a tiny maritime Burning Man. Only a couple of boats today… What if it were an armada? (tagged: art boat performance sailing )
- Transparency means nothing without justice – Government transparency is necessary, but not sufficient. If police violence is recorded and publicized, and nobody cares, it doesn't matter. This is in come sense emblematic of the coup in western propaganda. You don't need to control the media as the Soviets did or the Chinese do, if your population is comfortable enough not to care what's happening out there to someone else, and if their voting patterns are firmly tied to other issues (especially social issues like abortion), the idea of a democratic revolt becomes fairly abstract. I think this where a lot of the government's fear of economic recessions comes from. When people are out of work, or even hungry, suddenly they become a lot more excitable. (tagged: transparency law police politics technology internet )
- Condensing steam without water – Concentrating solar thermal power stations are ultimately designed to run a steam turbine, just like a gas-fired power plant. That means they need water (to turn into steam). Problematically, most such plants use water as a condensing coolant (70% of Caltech's water usage is as coolant for our 14MW worth of gas-fired power)… which is going to be hard to come by in the desert, where CSP will be built. Thankfully, there's a way to recondense steam without using a water coolant – but it does require a huge cooling tower. Not so great in Pasadena, but probably fine in the Mojave, next to acres and acres of mirrors. (tagged: solar energy technology sustainability green electricity water )
- Rousing a Latent Defense Mechanism to Fight HIV – It turns out there is a gene in humans that produces a protein which inhibits infection by HIV, but it has a mutation – a premature stop codon – which prevents it from being effectively synthesized. This mutation doesn't exist in most Old World monkeys (and that's apparently why they can't get HIV). Undoing the mutation allows the protein to be synthesized, and grants HIV immunity to human cells. I imagine that undoing bad mutations like this, and our inability to synthesize vitamin C, might be the first place we see human germ-line engineering outside of disease avoidance (preventing e.g. cystic fibrosis). Really, these mutations are hard to distinguish from genetic diseases – they're just diseases that we, as a species, have learned to live with. (tagged: genetic engineering hiv aids biology science research plos medicine )
- Anna in the Middle East – Anna Baltzer is a Jewish American who got a Fulbright fellowship to live in the West Bank in 2005, and document the experiences of Palestinians. She's been giving presentations about it ever since. Some parts of her presentation are available via YouTube too. From the 15 minutes I watched she seemed like a level headed critic. She's speaking in Boulder and Denver in May. (tagged: israel palestine politics fulbright peace war )
- Twitter + Stimulus = Humans are Gullible – A wonderful demonstration of the power of the confirmatory bias. Twitter is the perfect platform for the injection of random falsehoods. Too short for citations. Instantaneous distribution. Make sure your followers are predisposed to agree with what you say, and you can get them to believe just about anything – within that constraint. Too bad the author seems to think this only applies to conservatives. (tagged: politics twitter statistics propaganda )
I went to this year’s second Everhart Lecture yesterday by Josh Spurgeon, who is working with Harry Atwater and Nate Lewis, trying to develop cheap, scalable solar cells. As with most of the Everhart Lectures, it was a very well presented talk. Unlike many of them, it was directly relevant to a real-world problem: how can humanity continue to utilize on the order of 10TW of power, without changing the composition of the atmosphere (see Nate Lewis’ excellent presentation for more information). The ultimate solution to that problem will almost certainly involve directly capturing incident solar energy, because the potential resource available is both vast and relatively concentrated, when compared to other sources of renewable energy. But solar has two very serious problems today: it is expensive (both in absolute terms on a per watt installed basis, and in an up-front capital expenditure sense), and it is not available when the sun isn’t shining. Whatever the solution looks like, in order to scale up to 10TW, it needs to use only earth-abundant, non-toxic materials. In semiconductor photovoltaics then, silicon probably has an unassailable lead. It’s the second most abundant element in the Earth’s crust, and it’s about as toxic as sand (though silicon semiconductor fabrication has serious toxicity associated with it and certainly needs to be made closed-loop). Exotic materials like cadmium-telluride, and copper-indium-gallium-selenide (CIGS) are unlikely to scale to tens of terawatts, simply because of the limited availability of elements like indium and tellurium. Additionally, owing to the vast silicon microprocessor industry, we are much better at micro and nano-scale manipulation of silicon than any other material on Earth (ignoring for the moment biological systems).
