sciencecapsules

          In arctic regions, there is only ice.  How to save ourselves from freezing?      The snow is made up ice-crystals or simply ice powder.  It can be compressed into a block like brick. It has many air pockets.  Hence a block of snow is good insulator.  It will not allow heat to pass through.      A round hole is dogged in the earth.  The blocks of snow is arranged around the hole.  Then a dome like structure is constructed on the hole.  This shape gives good strength.  A small entrance is curve out at the bottom of the structure so that chill wind cannot enter.  This is Igloo, the house of Eskimos.          When the people are inside the igloo, the body heat cannot escape because of snow blocks.  Snow blocks simply traps the heat.  Then the temperature inside the igloo slowly raises, as much as above 40 degree than outside.  Suppose a oil lamp is lit inside, it will further increase the temperature.  So igloo which is made up of ice keep the people warm and safe.  --

           When you are in a room, 'the three corners running length wise, breadth wise and height wise' is our frame of reference.  We say 'middle', back, front, up and down' -all with reference to this frame.  If we travel in a train, we have moving frame of reference.      Our earth spins about itself at 1000 km per hour.  Our earth goes around the sun still more fast.  No object in the universe lies at rest.  Everything is moving.  Hence Einstein defined inertial frame of reference. Inertial frame is one which moves steadily without any acceleration.  All the laws of physics holds good in the inertial frame.      A compartment in a train which is moving at constant speed is an inertial frame.  If all the windows of the compartment is closed and if the train runs smoothly, we may feel as if we are sitting in a room built on a solid ground.  If the train stops or starts, there will be jerk (sudden acceleration) and we feel the movement of the train.  In a s

        Today, around 700 million cars speed along our roads.     A tiny amount of high energy fuel, (petrol), trapped in a small, enclosed space (engine cylinder) ignited will release an anormous amount of energy as the gas expands.  If this is done hundreds of times a minute, this energy can be harnessed to move a piston up and down.  Attaching what is known as a 'crankshaft' converts this motion to rotation.      American inventor Ford recognized that the car was so expensive because it took so long to build.  With the advent of the industrial revolution, engineers realized the potential for speeding up the manufacturing process by getting different workers each to repeat their tasks over and over again.  Ford spotted that this so called 'assembly line' could be applied to car manufacturing.  The frame work of the car moved along a line of workers, who each added a new part.  As the workers did not have to move around the factory and became expert at adding

             The Loo is a taboo subject.  But, do you know, the invention of flush toilet and mass sanitation has increased the Average person's life span by 20 years.      Why open defecating is strongly discouraged?  It is because faeces are hot beds of disease.  Just 1 gm of faeces can contain 10 million viruses, 1 million bacteria and 100 worm eggs.  It mainly causes cholera and diarrhea.  Even today, four out of two people only have  access to toilets of any kind.     There are many kinds of toilets. FLUSH TOILET      It is common and popular one in India.  The 'night soil' is flushed out by stream of water.   Below the seat of the toiler, water carrying tube is shaped like U.  Hence, some water always stands in it.  It act like water seal and stop the return of human waste and odor. VACUUM TOILET      In train and airplane this toilet is used.  It is difficult to use fluid water in fast moving train or flying plane.  The waste is sucked up by the vacuum

         We planned to fly from Bangalore to Dubai.  In the early hours, after long travel from the city, we reached Bangalore airport. In front of the airport, an army man was standing ready with a rifle, behind sand bags.  A notice read, "No questions.  Keep your distance".   First, we went to our airline desk, got boarding pass, also got our suitcases booked.  The suit-cases were carried away by the conveyor belt.  Using escalators, we went further.      After taking some refreshments, we went further.  Then security-check time:  We have to remove wallet, belt, phones, bags and other electronic devices from our body and place them on a tray.  They travel by belt, scanned, watched keenly by security persons.  Then we have to remove our shoes and glasses,empty pockets.  We were scanned by metal detector.  We have to lift up the arms and stand like a bird.  Then we were let in.  Now we could put our accessories back on our person.  Now we are free bird with in the airp