From the molecular nanomachines within a tiny cell to the large-scale structure of the universe, design is everywhere to be found. Sometimes the best defense of intelligent design is just to ponder the details. Here are some new illustrations:
Fastest Creature Is a Cell
If you were asked what the fastest creature on earth is, would you guess a cheetah or a peregrine falcon? There’s an even faster critter you would probably never guess. It’s called Spirostomum ambiguum, and it’s just 4mm in size. This protozoan, Live Science says, can shorten its body by 60 percent in just milliseconds. How does it do it? Scientists “have no idea how the single-celled organism can move this fast without the muscle cells of larger creatures,” the article says. “And scientists have no clue how, regardless of how the contraction works, the little critter moves like this without wrecking all of its internal structures.” Saad Bhamla, a researcher at Georgia Tech, wants to find out. And in the process, he will gain design information that can be applied in human engineering:
“As engineers, we like to look at how nature has handled important challenges,” Bhamla said in the release. “We are always thinking about how to make these tiny things that we see zipping around in nature. If we can understand how they work, maybe the information can cross over to fill the gap for small robots that can move fast with little energy use.” [Emphasis added.]
Cells Do “The Wave”
Speaking of speed, most cells have another faster-than-physics trick. When a cell needs to commit hari-kari, it performs an act something like “The Wave” in a baseball stadium. Researchers from Stanford Medicine, investigating programmed cell death or apoptosis, noticed wave-fronts of specialized destroying enzymes, called caspases, spreading throughout the cell faster than diffusion could explain.
Publishing in Science, they hypothesized that “trigger waves” accelerate the process of apoptosis, similar to how a “wave” of moving arms can travel rapidly around a stadium even though each person’s arms are not moving that fast. Another example is how one domino falling can trigger whole chains of dominoes across a gym floor. The mechanism presupposes that the elements, like the dominoes, are already set up in a finely-tuned way to respond appropriately. This may not be the only example of a new design principle. It may explain how the immune system can respond quickly.
“We have all this information on proteins and genes in all sorts of organisms, and we’re trying to understand what the recurring themes are,” Ferrell said. “We show that long-range communication can be accomplished by trigger waves, which depend on things like positive feedback loops, thresholds and spatial coupling mechanisms. These ingredients are present all over the place in biological regulation. Now we want to know where else trigger waves are found.”
The Complicated Ballet
Just organizing a chromosome is a mind-boggling wonder. But what do enzymes do when they need to find a spot on DNA that is constantly in motion? It’s enough to make your head spin. Scientists at the University of Texas at Austin describe it in familiar terms:
Thirumalai suggests thinking of DNA like a book with a recipe for a human, where the piece of information you need is on page 264. Reading the code is easy. But we now understand that the book is moving through time and space. That can make it harder to find page 264.
Yes, and the reader might be at a distant part of the nucleus, too. The challenge is not just academic. Things can go terribly wrong if the reader and book don’t meet up properly. They call it a “complicated ballet” going on.
“Rather than the structure, we chose to look at the dynamics to figure out not only how this huge amount of genetic information is packaged, but also how the various loci move,” said Dave Thirumalai, chair of UT Austin’s chemistry department. “We learned it is not just the genetic code you have to worry about. If the timing of the movement is off, you could end up with functional aberrations.”
Strong Succulent Seeds
The seed coats of some plants, like succulents and grasses, have an odd architecture at the microscopic level. Researchers at the University of New Hampshire, “inspired by elements found in nature,” noticed the wavy-like zigzags in the seed coats and dreamed of applications that need lightweight materials that are strong but not brittle.
The results, published in the journal Advanced Materials, show that the waviness of the mosaic-like tiled structures of the seed coat, called sutural tessellations, plays a key role in determining the mechanical response. Generally, the wavier it is, the more an applied loads [sic] can effectively transit from the soft wavy interface to the hard phase, and therefore both overall strength and toughness can simultaneously be increased.
Researchers say that the design principles described show a promising approach for increasing the mechanical performance of tiled composites of man-made materials. Since the overall mechanical properties of the prototypes could be tuned over a very large range by simply varying the waviness of the mosaic-like structures, they believe it can provide a roadmap for the development of new functionally graded composites that could be used in protection, as well as energy absorption and dissipation.
Small High Flyers
You may remember the episode in Flight about Arctic terns, whose epic flights were tracked by loggers. Another study at Lund University found that even smaller birds fly up to 4,000 meters (over 13,000 feet) high on their migrations to Africa. Only two individuals from two species were tracked, but the researchers believe some of the birds fly even higher on the return flight to Sweden. It’s a mystery how they can adjust their metabolism to such extreme altitude, thin air, low pressure, and low temperature conditions.
Don’t Look for Habitable Planets Here
The centers of galaxies, we learned from The Privileged Planet, are not good places to look for life. Cross off another type of location now: the centers of globular clusters. An astronomer at the University of California, Riverside, studied the large Omega Centauri cluster hopefully, but concluded that “Close encounters between stars in the Milky Way’s largest globular cluster leave little room for habitable planetary systems.” The core of the cluster has mostly red dwarfs, which have their own habitability issues to begin with. Then, Stephen Cane calculated that interactions between the closely-associated stars in the cluster would occur too frequently for comfort. His colleague Sarah Deveny says, “The rate at which stars gravitationally interact with each other would be too high to harbor stable habitable planets.”
Solar Probe Launches
The only habitable planet we know about so far is the earth. Surprisingly, there is still a lot about our own star, the sun, that astronomers do not understand. A new mission is going to fly to the sun to solve some of its mysteries, Space.com reports, but like the old joke says, don’t worry: it’s going at night. Named the Parker Solar Probe after 91-year-old Eugene Parker, who discovered the solar wind in 1958, the spacecraft carries a specially designed heat shield to protect its instruments. The probe will taste some of the material in the solar corona to try to figure out why the corona is much hotter than the surface, the photosphere. See Phys.org to read about some of the mission’s goals.
Speaking of the solar wind, charged particles from the sun would fry any life on the earth were it not for our magnetic field that captures the charged particles and funnels them toward the poles. Word has it that Illustra Media is working on a beautiful new short film about this, explaining how the charged particles collide with the upper atmosphere, producing the beautiful northern and southern lights — giving us an aesthetic natural wonder as well as planetary protection.
Photo: Large Omega Centauri cluster, by NASA, ESA, and Hubble SM4 ERO, via U.C. Riverside.