HEALTH AND WELLNESS

                                          Cuttlefish can change their color and camouflage themselves, becoming almost invisible to the human eye. According to one report, cuttlefish “are known to have a diverse range of body patterns and they can switch between them almost instantaneously.” How do cuttlefish do it?            The cuttlefish changes color by using the CHROMATOPHORE , a special kind of cell found under its skin. Chromatophores contain sacs that are full of colored pigment and that are surrounded by tiny muscles. When the cuttlefish needs to camouflage itself, its brain sends a signal to contract the muscles around the sacs. Then the sacs and the pigment within them expand, and the cuttlefish quickly changes its color and pattern. The cuttlefish may use this skill not only for camouflage but also to impress potential mates and perhaps communicate.           Engineers at the University of Bristol, England, built an artificial cuttlefish skin . They sandwiched

         Astronomers have discovered that they do not know what makes up over 90 percent of the universe. What is more, the discoveries that led to question their understanding of the fundamentals of physics itself. Of course, such questions are nothing new.           Toward the end of the 19 th century, physicists observed something odd about the speed of light. They found that relative to an observer, light always traveled at the same speed no matter how fast the observer was moving. But that seemed to defy natural law! The problem was addressed in 1905 in Albert Einstein’s special theory of relativity, which showed that distance [length], time, and mass are not absolutes. Then, after a flash of intuition that he termed “the happiest thought of my life,” Einstein began to develop his general theory of relativity, which he published in 1916. In this revolutionary work, Einstein wove gravity , space, and time together and refined the physics of Isaac Newton.           

                                    In the hands of a trained craftsman, a lump of soft clay can be formed into practical any shape. Embryonic stem cells are the living equivalent of that piece of moist clay; they have the prospective to give rise to virtually all of the over 200 cell types making up the human body. How do they do this? Consider what happens to a newly fertilized egg cell.           Soon after fertilization an egg cell begins to divide. In humans about five days of cell division results in a minute ball of cells called a BLASTOCYST . It is essentially a hollow sphere that is composed of a shell-like outer cell layer and a small cluster of about 30 cells called the inner cell mass, which is attached to the inside wall of the sphere. The outer cell layer becomes the PLACENTA ; the inner cell mass, the human embryo.          At the blastocyst stage, though, the cells of the inner cell mass have not yet begun to specialize into specific cell types, such as nerve

            Scientists have long known that the eyes of mammals contain neurons that respond to light and set the body’s internal, or circadian, clock. It was long assumed that this light-sensing function was performed by known visual cells called rods and cones. But in 1999, report the journal Science, researchers found that “mutant mice lacking all rods and cones [who are thus functionally blind] still have light-responsive clocks.” This led researchers to the conclusion that “some other cells in the eye had to be sensing light”            Now these elusive light sensors have been found. Although intermingled with the image-forming rods and cones, the sensors form “a separate visual circuit, running in parallel with this image-forming visual system,” explains Science. The newly discovered circuit’s functions include governing pupil size and melatonin release, synchronizing the body’s internal clock with the cycle of light and dark and other tasks. It may even play a role in

                                                             Few fish grab our attention the way the clown fish does. Perhaps it wins our hearts with its fancy coloring, which may remind us of a circus clown. Or maybe we are struck by its surprising choice of home –among the stinging tentacles of a sea anemone. Not surprisingly, another name for the clown fish is anemonefish .              Like many Hollywood actors, clown fish are not averse to photographs. Divers and snorkelers can usually expect clown fish to pose for pictures, since they rarely stray far from home and are not particularly shy.            But what makes clown fish amazing is their seemingly risky lifestyle. Living among poisonous tentacles would seem to be comparable to setting up home in a nest of serpents. Still, clown fish and their anemone of choice are inseparable. What makes this strange partnership possible and successful?           Like most good partnerships, clown fish and anemones give and ta

                                                               Have you ever looked at the night sky through a telescope? Many who have can tell you that they still remember the first time they found themselves looking at the planet Saturn. It is almost a startling sight. Against a backdrop of endless black dusted with countless glittering stars, there hangs a luminous orb wreathed with flat, elegant rings!            What are these rings? Back in 1610, when the astronomer Galileo first looked at Saturn through his handmade telescope, the view was so fuzzy that Saturn looked like a planet with ears –a central orb flanked by two smaller ones. As telescopes improved over the years, astronomers saw the rings more clearly, but they still argued over the composition of the rings. Many asserted that the rings were rigid, solid disks. Not until 1895 did astronomers have convincing proof that the rings were composed of many particles of rock and ice.          The book The Far Plane