Skip to main content

WHAT IS A PROOF?

      We have over 300 different proofs for the Pythagoras theorem. Is proving easy? Can you prove anything?

    Let us take one example. Consider the following map.



    How many colors, (minimum) you need to color this map. No adjacent state should have the same color. You can say with confidence "At least 4 different colors are required". Are 4 colors enough to color any map? 

    Is there any map where five colors will be needed. Nobody had the answer until 1976. But four crayons seemed to be sufficient for any map. Nobody felt the need for the fifth color. At the same time, no one was able to prove that only 4 colors are a minimum requirement with certainty.

    It is thrown as a challenge to the math community. They were forced to answer the question "what is a proof?

    After the computers came into being, In 1976 with the aid of hundreds of computer processing time, the mathematician Appel and Haken firmly turned the four-color conjuncture into a four-color theorem. And map makers who had known it for years said, "told you so".

    Back to "what is proof". Mathematical proof is 100 percent, concrete certainty. And the proof lies at the very heart of mathematics."

    There are several methods to find the proof. Let us learn one way here.

    A man has ten blue socks in his drawer. He wants to take out one correct pair of socks(same color). How many socks he has to take out (randomly) to get the correct pair?

    Suppose he takes out two socks.  It may be black, blue or blue, black or black and black or blue and blue. We cannot be certain. Suppose, he pulls 4 socks from the drawer, it may be blue, black, blue and black, and so on and on. He has to try all the 200000 different combinations before arriving at an answer. But, it will take a long time.

    But we can prove that "only 3 socks are needed to get a correct pair' using logic.

    First, he has to take out 2 socks. If they have the same color, he will be having the correct pair in his hands. If they have different colors, he has to take out one more sock. The third sock is going to be one of these two colors, the three socks must certainly contain a pair. Hence three socks is the maximum needed.

   Hene proving is not that easy. But once proved, it is certain forever.

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 oxygen constitute 20% of the atmosphere.  The oxygen level is always mai

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.      Inverted parabola shape is used in the construction of buildings and bridges.  Because the shape is able to bear more weight.      A plane

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 temperature to low temperature and not the other way.        The air molecules in y