Skip to main content

WORLD OF CURVES VS FLAT WORLD

     


     A convex surface (facing us) has positive curvature and a concave surface has a negative curvature.  A flat surface has zero curvature.  For example, a banana peel has positive curvature outside and negative curvature inside.


     Take a paper and roll it as cylinder.  Length wise, you can draw a straight line.  Hence, lengthwise its curvature is zero.  But, across you can only draw circle or curve.  In this direction it has positive curvature.  If you multiply '+' and '0', you get 0.  Hence the curvature of cylinder at any point is 'zero'.  This is called "Gaussian curvature" of cylinder. Because of 'zero' curvature, you can roll a flat paper into cylinder and back.

     Next take a sphere, all sides, it is curved convexly.  Hence at any point, it has positive  Gaussian curvature.  Hence spherical surface cannot be converted into flat one.  Take an orange.  Peel its skin.  Put on the floor.  stomp on it.  It will not be made into smooth circle.  It will only tear and break.

     Similarly, our globe surface cannot made into smooth flat map.  It will be somewhat distorted.  The areas of countries cannot be brought into uniform scale easily.
     You cannot wrap a foot ball in a gift paper smoothly.  The wrinkles will always be there.
     When flat clothes are made into dress.  It has to cover curved body gracefully.  That is the challenge of fashion designer.

     The geometry, we studied is only applicable to flat surface and called Euclidean geometry.  Convex and concave surfaces have different geometries.  For example, a triangle on a sphere has a total of more than 180 degrees.

     How to measure the curvature?  Take the curve to be measured.  Draw a closely touching and smoothly fitting circle to it.  Measure its radius.  The reciprocal of radius gives the curvature. For a straight line, the radius is infinity and the curvature is zero.  In physics, the amount of electric charges present on a metal surface is proportional to the curvature.

     We live in a spherical world.  But we can easily understand the flat world only.    
                                 ------------------------------------ 

Comments

Post a Comment

Popular posts from this blog

Your heart -you do not know

  Size and Location: The human heart is roughly the size of a clenched fist and is located slightly to the left of the center of the chest. Despite its relatively small size, the heart plays a crucial role in pumping blood throughout the entire body. Heartbeat Variability: The heart does not beat at a constant rate. The interval between heartbeats can vary, and this variability is considered a sign of a healthy heart. Factors such as breathing, emotions, and physical activity influence the heartbeat. Electrical Conduction: The heart's contractions are controlled by electrical impulses. The sinoatrial (SA) node, often called the "natural pacemaker," generates electrical signals that regulate the heartbeat and coordinate the pumping of blood. Blood Pumping Capacity: On average, the human heart pumps about 2,000 gallons (or 7,570 liters) of blood each day. Over a lifetime, this amounts to pumping enough blood to fill several Olympic-sized swimming pools. Heart Chambers and V...

THE WORK HORSE "="

    One cannot think of  a mathematical step without 'is equal to ' .  It balances right hand side and left hand side.  It aids simplification and manipulation of a mathematical expression. example: 2(A+B)  = C 2A+2B  = C         2A = C-2B           A = C-2B/ 2   In an electronic calculator,  the pressing of ' = " sign executes an asthmatic expression  or simply calculates.       In computer languages, it plays very important role.                                                                 A = B   When a computer looks at this expression, the value stored in the location named B is just transferred to the storage named A .  After execution both A and B will have the same value an...

How does your smart phone detect motion, steps, rotation, and location?

 How it works-1  An accelerometer in a smartphone is a microelectromechanical system (MEMS) device that measures acceleration and tilt. It works by detecting changes in motion by measuring the vibration or acceleration of the device. The accelerometer consists of a small mass suspended on a spring inside a sealed chamber. When the device is subjected to acceleration, the mass moves relative to the device, causing a change in capacitance that can be measured and processed by the smartphone's hardware. The accelerometer measures acceleration in three dimensions (x, y, and z) and provides data that the smartphone's software can use to determine the device's orientation, detect motion, and track changes in velocity and acceleration. The accelerometer is used for a variety of purposes in a smartphone, including screen rotation, motion tracking for games and fitness apps, and detecting the position of the device for navigation and location services. Additionally, it can be used t...