Skip to main content

WHISPERING GALLERY, COMET, KIDNEY STONE AND ELLIPSE

   

     We know well about the circle, the distance between any point on the circle and the center is constant and it is called 'radius'.  Let us now consider an ellipse.  There are two centers (focus) in an ellipse.  The total distance between any point on the ellipse and two foci is constant.
     Kepler discovered that all planets revolve around the sun in the elliptical orbits.  The comets appear to us at some point of time.  They reappear after a gap of long time(for example 76 years).  People were not able to predict the motions of comets for a long time.  Then it is found that the comet travel in long elliptical path with sun at one of the foci.  Hence the long time gap for every appearance.



     There are two  famous whispering gallaries.  1. United states statuary capitol hall. 2. London's st. paul's cathedral.  They are designed in the shape of ellipse.  If a person whispers at one focus in the elliptical gallery, another person standing at the second focus can hear it loud and clear.  The two foci are seperated by hundreds of feet.  Here the sound waves starting from one focus, are reflected by the elliptically shaped walls and converge at another focus.  That is why, even a pin drop can be heard.



     Lithotripsy is the procedure of destroying kidney stone by sending high energy shock waves.  Here again, the concept used in whispering gallery is adopted.  The patients lie down in an elliptical tub.  Shockwave source is at one focus and the patient's kidney stone is at the another focus.  The stone is broken into minute pieces by the shock waves and then they pass out of the body without requiring surgery.
     Like circle, the ellipse also has its own uses and status.

Comments

Popular posts from this blog

THE EARTH, A SUPER ORGANISM

     JOIN MY COURSE: "Become a programmer in a day with python"       A man called 'love lock' (what a name) proposed a theory called Gaia theory, named after Greek Goddess.      It says, "Earth is a self-regulating organism like a human being.  The organic life in it interacts with in-organic matter and maintains atmosphere, temperature and environment".  Hence the earth is still suitable for the life to thrive.      Imagine, in a particular place, there are lot of flowers.  Some flowers are white and some are darkly coloured.  We know, white reflects light and heat while dark absorbs the same.  White flowers can thrive in hot climate.  But dark flowers requires cold climate.  The absorption and reflection balances and the environment reaches average, warm temperature at which both the flowers can co-exist.  This is the essence of "Gaia" theory.      On our earth, ...

THE PARABOLA

          A jet of water shooting from a hose pipe will follow a parabolic path.  What is the so special about parabola.    Y= x^2 Draw a graph for the above equation.  It will result in a parabola.  This parabola is also called unit parabola.  Any equation involving square will yield a parabola. Example:  Y = 2x^2 +3x+3 (also called quadratic equation)    X= 2 and -2, both  satisfies the equation 4 = X^2.  Parabolic equations always have two solutions.     Any motion taking place freely under gravity follows parabolic path. Examples:   An object dropped from a moving train,   A bomb dropped from flying plane,  A ball kicked upwards.      If a beam of light rays fall on the parabolic shaped mirror, they will be reflected and brought to focus on a point.  This fact is made use of in Dish Antenna, Telescope mirrors, etc.   ...

DISORDER IS THE "ORDER OF THE DAY"

         Imagine a balloon full of air.  The air molecules are moving randomly inside the balloon.  Let us pierce the balloon with a pin.  The air rushes out.  Why should not the air molecules stay inside the balloon safely and ignore the little hole?  That is not the way the world works.  The molecules always "want to occupy as many states as possible".  Hence the air goes out in the open to occupy more volume.   The things always goes into disorder (entropy) and the disorder increases with time.  The above statement is what we call "second law of thermodynamics".      Consider a cup of coffee on the table. Suppose the heat from entire room flows to your cup of coffee, the coffee will boil and the rest of the room will freeze.  Freezing means bringing things to order and arrangement.  It violates the second law.  Hence it will never happen.  Hence heat must flow from high ...