Hanging out with rock scientists
Later today I fly to Houston [1] to participate in the Geological Society of America (GSA)'s 2008 annual meeting [2]. The conference itself is huge, with attendance easily in the thousands. Over the past few weeks, it's amused me to no end all the advertisements for the latest spectrographic rock analyzer that I've gotten in the mail. It's almost like being a real scientist, or something.
Anyway, I'm going to present my work on models of species body size evolution at the "Paleontology I - Macroevolution, Diversity, and Biogeography" session. I guess rocks and fossils are close enough that it fits. The talk will be short, but I'm going to try to cover not just my work that appeared in Science with Doug Erwin, but also my more recent work on birds and the diversification of mammals 70 million years ago.
I'm very much looking forward to the conference: it'll be an opportunity to interact with scientists who are very focused on understanding the incredibly complex history of life on this planet, and to learn about new and interesting mysteries (to me, at least). With any luck, I'll come back with new colleagues I can talk to about things like the origin of diversity, the importance of extinction events to fundamental innovation (a topic that relates to technological innovations, too), etc. With any luck, I'll also come back with some new ideas to work on.
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[1] The conference center is in downtown Houston, which is where a lot of damage from Hurricane Ike happened, so it'll also be interesting to see how well Houston has recovered. Earlier this summer, I spent a week in New Orleans, and it was eye opening to see both how much and how little recovery has been done there, even two years after Hurricane Katrina.
[2] To get a discount on the conference fees, I signed up to be an official member of the GSA. Thankfully, there was not pre-requisite that I own a rock hammer, or have a rock collection at home! At various points now, I've been a member of professional organizations in physics, computer science, biology, political science, and geology... yow.
Posted on October 04, 2008 in Self Referential | permalink | Comments (0)
Workshop: Analyzing Graphs, Theory and Applications
The only time I've ever been to NIPS [1] was to present the results of my first research project in grad school [2]. It was a fun trip, especially because the NIPS workshops are held at the Whistler ski resort [3]. The NIPS conference is now home to a lot of machine learning research, and this year I'm helping out with a workshop on the methodological side of network analysis. Although I won't be able to actually attend the workshop, I have high hopes for it [4], as methodological questions are pretty fundamental to our ability to say both interesting and useful things about networks, and their relevance to the many branches of science that now use them. So, get those TeX compilers humming!
NIPS 2008 Workshop on Analyzing Graphs: Theory and Applications
December 12, 2008 at NIPS at Whistler Canada
Organizers: Edo Airoldi (Princeton), David Blei (Princeton), Jake Hofman (Yahoo! Research), Tony Jebara (Columbia U.), and Eric Xing (CMU).
Submission Deadline: Friday, October 31, 2008
Description: Recent research in machine learning and statistics has seen the proliferation of computational methods for analyzing graphs and networks. These methods support progress in many application areas, including the social sciences, biology, medicine, neuroscience, physics, finance, and economics.
This workshop will address statistical, methodological and computational issues that arise when modeling and analyzing graphs. The workshop aims to bring together researchers from applied disciplines such as sociology, economics, medicine and biology with researchers from mathematics, physics, statistics and computer science. Different communities use diverse ideas and mathematical tools; our goal is to foster cross-disciplinary collaborations and intellectual exchange.
We welcome the following types of papers:
- Research papers that introduce new models or apply established models to novel domains,
- Research papers that explore theoretical and computational issues, or
- Position papers that discuss shortcomings and desiderata of current approaches, or propose new directions for future research.
All submissions will be peer-reviewed; exceptional work will be considered for oral presentation. We encourage authors to emphasize the role of learning and its relevance to the application domains at hand. In addition, we hope to identify current successes in the area, and will therefore consider papers that apply previously proposed models to novel domains and data sets.
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[1] NIPS stands for Neural Information Processing Systems, but has become one of the main machine learning conferences.
[2] Which is still unpublished, not because it's wrong or bad, but because I'm lazy. I like to think that I'm saving it for a "rainy day", but who am I really kidding?
[3] Of course, on that trip, like a fool, I didn't ski at all. Just presented my results, tromped around in the snow, ate some good food, and did almost all the work for a new paper on the bus and plane back to New Mexico.
[4] This is partly because I'm friends with many of the organizers, who care about many of the same things I do in terms of methodological accuracy.
Posted on September 25, 2008 in Conferences and Workshops | permalink | Comments (0)
We're still here
Despite some mildly ridiculous fears that science (in the form of the Large Hadron Collider at [1] CERN in Gevena Switzerland) would cause the world would end yesterday we're still here. Whew. It must have been God's Will. To celebrate, here's a mildly ridiculous rap song about the LHC experiment (which, quite pleasantly, gets the physics right).
(Tip to Tanya for the video.)
Update 12 September 2008: The New York Times has run a well written piece by Brian Greene on the LHC and it's significance.
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[1] For more information about what CERN is, check out this 3 minute video on YouTube about it.
Posted on September 11, 2008 in Humor | permalink | Comments (1)
Workshop: Flows and Networks in Complex Media
For folks interested in flows of stuff on networks (e.g., traffic flows like cars or internet packets), this sounds like a great workshop. I don't recognize many names on the list, but the two I do (Dirk Helbing and Sid Redner) are excellent.
Institute for Pure & Applied Math (IPAM) Workshop on Flows and Networks in Complex Media (ADN)
April 27 - May 1, 2009 at IPAM on UCLA's campus (Los Angeles, USA)
Organizers: M. C. Carvalho (GA Tech), Karl Kempf (Intel), Stephan Mischler (U, Paris IX), Benedetto Piccoli (Consiglio Nazionale delle Ricerche) and Christian Ringhofer (AZ State).
Description: This workshop will be directed towards particle flows in complex topologies, either given in the form of networks and graphs, or in the form of random or quasi - periodic media. The aim of the workshop will be to bring together an interdisciplinary group of researchers in different areas such as traffic flow simulation, supply chain management and physical flows in random media. These areas share a number of common challenges and require therefore the usage of similar mathematical toolboxes. These challenges include the incorporation of the stochasticity of the flow and the topology into averaged macroscopic models via appropriate homogenization methods, the existence of intermediate regimes, consisting only of a limited number of cars, clients or particles, and the resulting need to develop hybrid modeling tools linking particle and discrete event simulation models to macroscopic fluid equations.
Posted on September 09, 2008 in Conferences and Workshops | permalink | Comments (2)
The Internet is dead. Long live the Internet.
Having come of age during the rise of the Internet, it's hard to imagine what it was like to do science back in the communication dark ages without tools like email, electronic journals, Wikipedia, etc. Most of my research has some component that requires quickly communicating with people over vast distances [1]. This ease of interaction is all based on a few critical components of the Internet. First, the Internet is fast, in the sense that the Internet's routers and transmission lines allow information to get from A to B extremely quickly. Second, the Internet is navigable, meaning that A knows how to get to B using one of those quick routes. If either of these things failed, the Internet would quickly fall apart and people would go back to phoning and faxing each other [2]. Yuck.
What's not widely known is that there's a real danger that the second of these two won't hold in the future. If so, trying to quickly reach Google, your humble blogger or anyone else may become as difficult as trying to drive from New York to Santa Fe without the help of a map or road signs. The problem is that the system that makes the Internet navigable is fundamentally flawed, and it's not clear how to fix it now that everyone depends so heavily on there being a working Internet. That is, we can't just turn the whole Internet off while we move everyone over to the new improved system.
One flaw is that the system wasn't designed to have the whole, or even a large fraction of the, world online. It was always thought that we would roll out a new series of tubes [3] down the road, but then something happened: the Internet became wildly popular, and that idea was ruined. A second flaw is that the system assumes everyone is always honest. The Internet's navigability comes from, basically, a massive but highly accurate game of telephone. In the children's version of this game, errors are introduced accidentally, and everyone laughs at the end about how strange the messages become. In the Internet version, a malicious person can introduce an error strategically, allowing them to eavesdrop on other messages (a la the NSA) or hijack messages before they reach their destination. It was recently demonstrated that these kinds of attacks are, in fact, relatively easy to do. We've been lucky so far that these kinds of attacks haven't been more widely used.
These and other issues make it very clear that the future of the Internet (and my scientific productivity!) depends on designing a more robust system, to which we can smoothly transition while still using the current broken version. But how exactly would a better system work? Earlier this summer, I coörganized a mini-workshop at SFI with some folks from CAIDA (Cooperative Association for Internet Data Analysis) based at UC San Diego about exactly this question. The attendees were primarily folks from the Internet-branch of the network science community, and the talks were focused heavily on alternative ways to make the Internet navigable. The result of the meeting was not a solution to the problem, but rather a set of questions that we think probably need to be answered before a real solution can be made.
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[1] Usually, this is because my collaborators are remote; one of them I wrote two papers with before meeting him in person for the first time earlier this year.
[2] Increasingly phone calls depend on the same technology (packet switching) that runs the Internet, but originally, phone calls depended on a different kind of system (circuit switching), which guaranteed the delivery of information (i.e., no garbled conversations because of network congestion) but was significantly less flexible.
[3] This was a naive view, of course, but it's hard to make accurate predictions, especially about the future. The future was supposed to be based on something called IPv6, but if everyone used IPv6 today, it would break the Internet even faster. Fortunately, or unfortunately, almost no one uses IPv6 and it seems that no one is really planning to, either.
Posted on August 30, 2008 in Networks | permalink | Comments (0)
Cows are magnets.
Hot off the press at the Proceedings of the National Academy of Science is an article about magnetoreception in cows and deer [1]. Begall and colleagues, perhaps having spent far too much time playing with Google Earth, noticed that grazing cows and deer [2] seem to slightly prefer aligning themselves N-S, like magnets in the Earth's magnetic field. From the abstract
To test the hypothesis that cattle orient their body axes along the field lines of the Earth's magnetic field, we analyzed the body orientation of cattle from localities with high magnetic declination. Here, magnetic north was a better predictor than geographic north. [3]
Time to rewrite the physics textbooks, I guess: Cows are spheres, yes, but magnetic spheres!
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[1] S. Begall, J. Cerveny, J. Neef, O. Vojtech and H. Burda, "Magnetic alignment in grazing and resting cattle and deer." PNAS 105, 13451-13455 (2008).
[2] I was very disappointed, when I read through the article itself, to find no satellite pictures of cows aligned N-S. Indeed, there was not a single picture of a cow (or deer)!
[3] This is a good control to test the possibility that the E-W orientation of the sun drove the animals to prefer N-S in order to maximize the absorbed solar radiation. So, it seems that there really is some kind of weak magnetoreception going on. Now it's a matter of figuring out what biological compounds convey this magnetic sensitivity, and how its response to the Earth's field percolates up to behavioral tendencies.
Posted on August 26, 2008 in Things that go squish | permalink | Comments (3)
Welcome to the club, Magpie (Pica pica)
The past 20 years have already been a humbling experience for people sympathetic to the idea that humans are unique among animals. For many years, it was thought that tool use was an exclusive trait of humans, but then the evidence rolled in that other primates routinely use tools. The real shocker, of course, is that some birds also use tools [1]. And so it also went for cultural knowledge , long-term planning behavior, creativity, and dreaming. All of these behaviors are seen not just in other mammals, but in some species of birds. All this evidence makes it increasingly difficult to argue that there is much fundamentally special about Homo sapiens, except perhaps the coincidence of all of these behaviors in a single species.
To this list of human-like behaviors that birds exhibit, it seems we can now add self-recognition, at least for the European Magpie (Pica pica) [2]. This idea is usually illustrated by the so-called mirror test [3]: some kind of mark is placed on an animal in a spot they cannot normally see (on their chin, forehead, etc.), and a mirror is then placed so that they can see the mark on themselves. The usual interpretation of the resulting behavior is that if the animal recognizes themselves in the mirror, they will scratch directly at the foreign mark that they cannot normally see [4]. This kind of mirror use is seen in all the great apes (humans older than 18 months, bonobos, chimpanzees, organutans and gorillas), dolphins, killer whales and elephants.
Of course, we still have no explanation of what allows such mirror-recognition to happen. Is it the size of the brain alone? (Probably not, but size is likely important in some ways.) Is there some special structure in the brain that mediates it? (Maybe. It would be interesting to stick some of these animals into a CT scanner while they're doing this test to see if there are homologous regions of the brain that light up.) Etc. One thing that's interesting about this new discovery of self-recognition in Magpies is that these birds are in the corvid family, which includes other clever birds like crows. This group of birds are fairly large, and thus have relatively large brains, so it may be that whatever neurological structures facilitate self-recognition, they require relatively large masses of neurons. From a more general perspective though, it's exciting that all of these "complex" behaviors appear in birds. Because their brains are structured quite differently from mammal brains, it suggests that there's not one single way to create "intelligent" brains. If it turns out that there are many many ways to create complex behavior, then perhaps one day we'll figure out what the essential structures and dynamics are, and be able to build one from scratch.
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[1] This is pretty clearly a case of convergent evolution, since surely not all of the interceding species between birds and mammals were also tool users.
[2] H. Prior, A. Schwarz and O. Güntürkün, "Mirror-Induced Behavior in the Magpie (Pica pica): Evidence of Self Recognition." PLoS Biology 6, e202 (2008).
[3] The mirror test has, in fact, been heavily criticized for its indirectness and its bias toward human-style self-recognition. Of course, as anyone who's encountered the mind-numbing stupidity of corporate customer service, it can be extremely difficult to judge from behavior alone whether an animal is actually a thinking being. Examples abound of humans fooling ourselves and each other on this issue. If you ever want to experience this difficulty first-hand, try discussing with someone else whether your subjective experience of the world is similar or different from theirs.
[4] The control for this kind of experiment is to use two different color marks, one that is flesh- (or feather-)colored and one that is not.
Posted on August 20, 2008 in Obsession with birds | permalink | Comments (0)
