SETI public: Fw: Love Code: A twist of light only mantis shrimp can see

From: Ronald C. Blue (ron_at_u2ai.us)
Date: Sat Mar 22 2008 - 08:03:54 PDT

  • Next message: Alex Michael Bonnici: "SETI public: TheStar.com: Scientists envision aliens who are strangely familiar"

    > http://www.sciencenews.org/articles/20080322/fob2.asp
    >
    > Love Code: A twist of light only mantis shrimp can see
    >
    > Davide Castelvecchi
    >
    > For love, some would twist the laws of physics. Short of doing that,
    > mantis
    > shrimp communicate with the other sex by spinning light waves, biologists
    > find. The feat seems to be unique to this animal.
    >
    > Light is made of electromagnetic waves. These are electric and magnetic
    > fields that wiggle perpendicular to each other and to a light ray's
    > direction. Many invertebrates have sophisticated eyes that can detect
    > wavelengths of light invisible to humans. Some, including bees, can also
    > distinguish linearly polarized light. That's when a light ray's electric
    > field wiggles not in varying directions, but rather in one precise
    > direction that forms a right angle to the ray.
    >
    > Researchers now show that mantis shrimp­which actually look more like
    > small
    > lobsters­can tell when light is circularly, rather than linearly,
    > polarized. That means that the electric field twists like a corkscrew as
    > the light ray moves. The corkscrew can twist right or left­or, in
    > biological terms, be right- or left-handed.
    >
    > Roy Caldwell of the University of California, Berkeley, suspected that one
    > species of mantis shrimp, Odontodactylus cultrifer, might be able to
    > distinguish circular polarizations. Animals in this species, especially
    > adult males, are rare. But 2 years ago, thanks to a tip from a crustacean
    > enthusiast, Caldwell obtained a 4 inch-long adult male originally from
    > Indonesia.
    >
    > ©2008 Society for Science & the Public.
    >


  • Next message: Alex Michael Bonnici: "SETI public: TheStar.com: Scientists envision aliens who are strangely familiar"

    This archive was generated by hypermail 2.1.6 : Sat Mar 22 2008 - 08:08:06 PDT