For computer scientists, ants are most familiar from ant colony optimization. These algorithms rely on simulating how ants lay, follow, and modify pheromone trails to find efficient paths from their hives to food sources. Hence, it might come as a surprise that this is not a universal feature of ants. The cataglyphis niger desert ant […]... Read more »
Feinerman, O., & Korman, A. (2012) Memory Lower Bounds for Randomized Collaborative Search and Implications to Biology. 26th International Symposium on Distributed Computing (DISC). DOI: 10.1007/978-3-642-33651-5_5
With the development of statistical mechanics, physicists became the first agent-based modellers. Since the scientists of the 19th century didn’t have super-computers, they couldn’t succumb to the curse of computing and had to come up with analytic treatments of their “agent-based models”. These analytic treatments were often not rigorous, and only a heuristic correspondence was […]... Read more »
It's hard to keep your footing in a steep tunnel made of loose dirt while others are scrambling around and over your body. Harder still in pitch blackness. That's why fire ants build tunnels that will catch them when they fall—a strategy human engineers might want to steal.
"Slips and missteps are likely a constant, recurring feature of life underground," says Nick Gravish, a graduate student in Daniel Goldman's rheology and biomechanics lab at Georgia Tech. Yet ants have to traverse their tunnels quickly, especially when there's a colony emergency like a flood or destruction by a gardener's spade.
To study how ants engineer their tunnels, Gravish brought the fire ant Solenopsis invicta into the lab. Invasive to countries around the world and packing a nasty sting, these South American ants deal out plenty of hardship. But Gravish was interested in how they handle adversity themselves.
First, the ants were put into "laboratory soil" (actually tiny glass balls) to dig. Researchers took x-ray CT scans of the resulting tunnels and found that no matter the moisture of the "soil" or the size of the glass beads, ants dug circular tunnels of approximately the same diameter. That diameter was just a little bit more than the length of their bodies, not counting legs or antennae.
This suggested that the diameter of the tunnel was crucial to the fire ants. To see how well the ants moved within these tunnels, the researchers recorded video of them climbing as fast as they could. ("We startled them into climbing at high speed by exhaling gently into the nest," Gravish says.) They saw that ants were able to navigate their tunnels quickly, reaching speeds of more than 9 body lengths per second. They also saw that sometimes the ants slipped and had to recover their footing.
In addition to their tunnels, the researchers recorded ants climbing in vertical glass tubes. To get a better idea of how ants corrected their falls, the scientists jolted the tubes to knock the ants off the walls while they were climbing. (If you enjoy videos in the falling-bugs genre, this study generated several new additions. Here's one video of several ants falling and stopping themselves.)
Now the reason ants build tunnels so close in diameter to their own body length became clear. Ants responded to a fall by spreading all their appendages wide and waiting until they jammed to a stop. "One of the coolest things we found was that fire ants used their antennae to brace themselves," Gravish says. While falling, the ants turned these delicate sensors into extra load-bearing limbs.
When the glass tube width increased to 1.3 times the ants' body length, the strategy began to fail. The tunnels ants built themselves had an average diameter of just 1.06 times their body length, the authors report in PNAS. It seems fire ants put most of the responsibility for stopping falls on the tunnels themselves. After that, all a plummeting insect has to do is stretch out its limbs.
Gravish likens this strategy to the way humans build stairs. Steps are engineered to fit our bodies. If they're too tall or short, we struggle to use them (or maybe just fall down them). But with the right design, our environment works with us to get us where we're going.
This strategy could inspire how we design robots for confined spaces such as search-and-rescue zones, Gravish says. For instance, "falling is usually considered a failure mode for a robot." But fire ants seem to use little falls to descend more quickly through their tunnels. If engineers knew the size of the cracks and crevices in a disaster area, they might be able to send in many inexpensive robots designed to tumble through those spaces—rather than one very expensive robot built to keep its footing.
What about humans ourselves: would we benefit from building tunnels that were only as wide as our head-plus-torso length, like the ants? Gravish points out that fire ants often fall many body lengths before catching themselves, making this not such a great strategy for people. "Ants have a robust exoskeleton," he says. "We humans are quite soft in comparison."
Images: ant in tunnel by Laura Danielle Wagner; ants falling by Gravish et al.
Gravish, N., Monaenkova, D., Goodisman, M., & Goldman, D. (2013). Climbing, falling, and jamming during ant locomotion in confined environments Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.1302428110
... Read more »
Gravish, N., Monaenkova, D., Goodisman, M., & Goldman, D. (2013) Climbing, falling, and jamming during ant locomotion in confined environments. Proceedings of the National Academy of Sciences. DOI: 10.1073/pnas.1302428110
University of Illinois at Urbana-Champaign researchers have developed a cradle and app for the iPhone that uses the phone’s built-in camera and processing power as a biosensor to detect toxins, proteins, bacteria, viruses and other molecules. Having such sensitive biosensing capabilities in the field could enable on-the-spot tracking of groundwater contamination, combine the phone’s GPS … Read More →... Read more »
Duke University engineers have developed a new safer method for catalytic hydrogen production. According to the authors of the study, it does not require high temperatures and produces smaller amounts of toxic chemicals than other industrial hydrogen production technologies.... Read more »
Shodiya, T., Schmidt, O., Peng, W., & Hotz, N. (2013) Novel nano-scale Au/α-Fe2O3 catalyst for the preferential oxidation of CO in biofuel reformate gas. Journal of Catalysis, 63-69. DOI: 10.1016/j.jcat.2012.12.027
A Science publications is one of the best ways to launch your career, especially if it is based on your undergraduate work, part of which you carried out with makeshift equipment in your dorm! That is the story of Thomas M.S. Chang, who in 1956 started experiments (partially carried out in his residence room in […]... Read more »
Pais, D., & Leonard, N. (2013) Adaptive network dynamics and evolution of leadership in collective migration. Physica D: Nonlinear Phenomena. DOI: 10.1016/j.physd.2013.04.014
Today, I am passing through New York City on my way to Princeton’s Center for Computational Intractability for a workshop on Natural Algorithms and the Sciences (NA&S). The two day meeting will cover everything from molecular algorithms for learning and experiments on artificial cells to bounded rationality in decision-making and the effects of network topology […]... Read more »
Randy Olson reviews a research paper that shows us how bigger groups can make more accurate decisions.... Read more »
Wolf, M., Kurvers, R., Ward, A., Krause, S., & Krause, J. (2013) Accurate decisions in an uncertain world: collective cognition increases true positives while decreasing false positives. Proceedings of the Royal Society B: Biological Sciences, 280(1756), 20122777-20122777. DOI: 10.1098/rspb.2012.2777
The breakthrough technique that allowed scientists to obtain one-of-a-kind, colorful images of the myriad connections in the brain and nervous system is about to get a significant upgrade.... Read more »
Peter Reuell. (2013) ‘Brainbow,’ version 2.0. Harvard Gazette. info:/
For over twenty-three hundred years, at least since the publication of Euclid’s Elements, the conjecture and proof of new theorems has been the sine qua non of mathematics. The method of proof is at “the heart of mathematics, the royal road to creating analytical tools and catalyzing growth” (Rav, 1999; pg 6). Proofs are not […]... Read more »
Speculative fiction is the home of countless machines that fly in space, yet resemble humanoid lifeforms. Scientists are now working on the next generation of robots that will blaze a trail in space by going where humans simply can’t maneuver on their own. Like so many things in the field of space exploration, the descendents … Read More →... Read more »
Toralf Boge, & Ou Ma. (2011) Using Advanced Industrial Robotics for Spacecraft Rendezvous and Docking simulation. Robotics and Automation (ICRA), 1-4. DOI: 10.1109/ICRA.2011.5980583
A team of computer scientists in Spain applied a quantum PageRank algorithm to a network with 7 webpages. They found that the quantum PageRank sometimes ordered the webpages differently in terms of importance, but averaging the quantum PageRank score over time recovered the classical ordering.... Read more »
I spent last week at Web Science 2013 in Paris. And what a well spent time that was. Web Science was for sure the most diverse conference I have ever attended. One of the reasons for this diversity is that Webscience was collocated with CHI (Human-Computer-Interaction) and Hypertext. But most importantly, the community of Webscience …Read More... Read more »
Peter Kraker, Kris Jack, Christian Schlögl, Christoph Trattner, & Stefanie Lindstaedt. (2013) Head Start: Improving Academic Literature Search with Overview Visualizations based on Readership Statistics. Web Science 2013. info:/
A robot can struggle to discover objects in its surroundings when it relies on computer vision alone. But by taking advantage of all of the information available to it – an object’s location, size, shape and even whether it can be lifted – a robot can continually discover and refine its understanding of objects, say researchers at Carnegie Mellon University’s Robotics Institute.... Read more »
Byron Spice. (2013) More Than a Good Eye: Carnegie Mellon Robot Uses Arms, Location and More To Discover Objects. Carnegie Mellon University News. info:/
‘Superlattice’ structure could give a huge boost to oxygen reaction in fuel cells, increasing their power potential.
New research at MIT could dramatically improve the efficiency of fuel cells, which are considered a promising alternative to batteries for powering everything from electronic devices to cars and homes.... Read more »
David L. Chandler. (2013) Unleashing oxygen. MIT News. info:/
University of Utah metallurgists created a “recipe” to produce solar cell material in a microwave oven. Using this kitchen appliance, a nanocrystal semiconductor suitable for photovoltaic applications can be manufactured rapidly from cheap abundant and less toxic metals than other semiconductors.... Read more »
Sarswat, P., & Free, M. (2013) An investigation of rapidly synthesized Cu2ZnSnS4 nanocrystals. Journal of Crystal Growth, 87-94. DOI: 10.1016/j.jcrysgro.2013.03.022
A little over a year ago, a research team started to develop a vital part of a Finnish invention – an electric solar wind sail for interplanetary journeys. Now, a prototype has been successfully manufactured and tested.... Read more »
Anneli Waara. (2013) One step closer to solar wind-powered spacecraft. Uppsala University. info:/
A combination of graphene with other similar 2D crystals will allow to significantly increase the efficiency of solar cells and create the next generation of optoelectronic devices, scientists have revealed.... Read more »
Britnell, L., Ribeiro, R., Eckmann, A., Jalil, R., Belle, B., Mishchenko, A., Kim, Y., Gorbachev, R., Georgiou, T., Morozov, S.... (2013) Strong Light-Matter Interactions in Heterostructures of Atomically Thin Films. Science. DOI: 10.1126/science.1235547
Last week, my father sent me a link to the 100 top-ranked specialties in the sciences and social sciences. The Web of Knowledge report considered 10 broad areas of natural and social science, and for each one listed 10 research fronts that they consider as the key fields to watch in 2013 and are “hot [...]... Read more »
Rendell L, Boyd R, Cownden D, Enquist M, Eriksson K, Feldman MW, Fogarty L, Ghirlanda S, Lillicrap T, & Laland KN. (2010) Why copy others? Insights from the social learning strategies tournament. Science, 328(5975), 208-213. PMID: 20378813
Scientists from the SLAC National Accelerator Laboratory and Stanford University have developed a relatively cheap, long-life “flow” battery that can be used to mitigate power fluctuations from solar and wind energy plants, therefore enabling them to become major suppliers to the electrical grid.... Read more »
Yang, Y., Zheng, G., & Cui, Y. (2013) A membrane-free lithium/polysulfide semi-liquid battery for large-scale energy storage. Energy , 6(5), 1552. DOI: 10.1039/C3EE00072A
Do you write about peer-reviewed research in your blog? Use ResearchBlogging.org to make it easy for your readers — and others from around the world — to find your serious posts about academic research.
If you don't have a blog, you can still use our site to learn about fascinating developments in cutting-edge research from around the world.
Research Blogging is powered by SMG Technology.
To learn more, visit seedmediagroup.com.