Science of the week

In no particular order, here is a list (with brief summaries) of science related articles I enjoyed the past week. Some of these could be older, doesn’t matter though.

  1. A lifespan is a billion heartbeats. Remarkably, there exist simple scaling laws relating animal metabolism to body mass. Larger animals live longer; but they also metabolize slower, as manifested in slower heart rates. These effects cancel out, so that animals from shrews to blue whales have lifespans with just about equal number of heartbeats — about one and a half billion, if you simply must be precise. In that very real sense, all animal species experience “the same amount of time.” – Ten Things Everyone Must Know About Time
  2. Damascus steel rules. Nanotechnology in ancient craft. In 2006, however, researchers at the Institut fur Strukturphysik at the Technische Universität Dresden…obtained a small sample of a Damascus sabre from the Berne Historical Museum in Switzerland, and inspected it using high-resolution transmission electron microscopy.  Anelectron microscope, which uses electrons rather than light particles (photons), can resolve images of objects that are smaller than a nanometer (a billionth of a meter). Remarkably, they found the presence of so-called carbon nanotubes, a material that is on the cutting edge of nanotechnology! Carbon nanotubes possess unusual electrical properties, similar to graphene, and have many potential applications in electronics.  It is their mechanical properties that really stand out, however — multi-walled carbon nanotubes (tubes within tubes) can have a tensile strength roughly fifty times greater than steel, at a much lower density and with significant flexibility. – Ancient swords, modern nanotechnology
  3. Why Michael Douglas went on a killing spree. In 1998, a physicist named Boris Kerner with the Daimler Benz Research Institute in Stuttgart, Germany…classified traffic into three basic categories: freely flowing, jammed (solid state), and a bizarre intermediate state called synchronized flow, in which densely packed “car molecules” move in unison, like members of a marching band. When this happens — when all the cars are traveling at close to the same average speed because of the vehicle density on the roadway — they become highly dependent on one another. Highly correlated traffic means that a tiny perturbation — a butterfly flapping its wings, or a single driver braking unexpectedly  — will send little ripples of corresponding slowdowns through the entire chain of cars behind him/her. That’s one reason why slowdowns and traffic jams occur most commonly at merge points, especially exit and entrance ramps, or when lanes are closed due to road construction. A state of steady synchronized flow, punctuated by these tiny ripple effects (“narrow jams”) can persist indefinitely, but the balance is delicate and highly unstable. If the volume of cars continues to increase, the density continues to increase, and eventually you get a “pinch effect” — that frustrating “stop and go” phenomenon, in which you escape one narrow jam only to encounter another a little further down toe road, until they all converge into a single wide jam. Traffic comes to a standstill. Collective road rage may ensue, and the next thing you know, Michael Douglas is on a shotgun-toting rampage. – Crosstown Traffic

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