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

         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) and ignited will release an enormous 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 'crank shaft' converts this motion to rotation.      American inventor ford recognised that the car was so expensive because it took so long to build.  With the advent of the industrial revolution, engineers realised 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 framework 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 become expert at a

         Dubai has trade and tourism based economy.  They go for world's top and best.  Hence there is no wonder in their attempt to build world's tallest building. FACTS AND FIGURES      It has 163 floors.  The total height is 829.8 m, nearly one kilometer .  It took 6 years for construction.  Each floor was completed in just three days time.  It can shelter 35000 people.  At any moment there are 10000 people in it.  It is the tallest free standing structure in the world.  It is constructed mainly using vertical concrete pumping.  1000 pieces of art will  adorn the interiors.  The exterior temperature at the top of the building is said to be 6 degree c cooler than its base.  A 304 - room Armani hotel occupies 15 lower floors.  It has 900 private residential apartments which according to the developer sold out within eight hours of being on the market.  The building has 57 elevators and 8 escalators.  The speed of the elevator is 10 m/s.  The building also has 2909 stai

         We know the conservation of energy, mass, and momentum are cornerstones of science.  We have studied the 'Law of conservation of angular momentum' in school physics.  It also holds some surprising facts.  We will see them now.      Momentum is the product of mass and velocity.  Angular momentum is the product of the 'moment of inertia' and angular velocity.  The moment of inertia plays the role of mass in a circular motion.  It is roughly the product of rotating mass and its distance from the axis of rotation. Hence Angular momentum = Moment of inertia* angular velocity = constant or Mass * distance from axis*angular velocity = constant   In the above formula, if one quantity increases, another quantity must decrease to keep the product constant.     A dancer on an ordinary floor or ice floor sometimes spins herself.  If she out-stretches her arms, she will spin slowly.  If she brings her arms close to her chest, she will spin rapidly. Here mome

         How they measure chance? what are the basic operations in probability? Let us find out.       In tossing of a coin, there are two events-- head and tail.  The chance one event occurring = one/total number of events.  That is 1/2.  You have 50% chance of getting head or tail for each toss.  If you toss a coin, one time you should get head and next time you should get tail, so the formula says.  But both the times, you may get head or tail.  If you toss the coin 100 times, roughly 50 times you will get head and tail.  On the long run, the formula proves correct.     On throwing dice, there are six events (1,2,3,4,5,6).  Hence chance of getting an 'event' for a throw is 1/6.  There are three important logical operations in probability.  Let us go for it.   OR operation:     What is the chance or probability getting 1 or 6 in a roll.  Here, either 1 or 6 will do for us.      Probability  of getting 1 is 1/6      probability of getting 6 is 1/6 Now add both  1

1. Add two numbers        2+2 = 4 2. Add the number repeatedly      4+4 +4 = 12   3*4 = 12 That is multiplication 3. Now multiply repeatedly       12*12*12 = 1728  12ˆ3 = 1728     That is taking power     Let us go backwards. 1. Take cube root of 1728, we get 12                      (dividing repeatedly) 2. Divide 12 by 3, we get 4                         (subtracting repeatedly) 3. Subtract 2 from 4, we get 2  Addition is the basic operation, in moving forward.  But subtraction is the basic operation when moving backward.      Using addition and subtraction, we can move to and fro in mathematical process and get the desired answers. Calculus designed in similar fashion.     As an example consider a freely falling body.  We know the acceleration is 9.8 m /sˆ2 1. Acceleration= g = 9.8 m/sˆ2     if we integrate acceleration with respect to time,  2. we get  gt   Velocity of freely falling body.   If we further integrate velocity with respect to time.  3. we

         Whenever we wait for the city buses, they do not turn up for a long time or they come in groups of 3 or 4.  Why this happens?   Say, buses in a particular route are scheduled to arrive at a 'stop' for every 12 minutes.  That is, 5 buses are expected in a bus-stop in an hour.  But they are bunched up or scattered away due to heavy traffic or other odd reasons.  But there is a statistical formula (exponential distribution) using which, we can calculate our 'chance' of getting  a bus in an interval of time.       P = 1-eˆ(-rk) P- probability or chance of occurrence of event in the interval of time 0 sec to k second.     e- 2.71 ... Euler's constant.     r - rate of occurrence of events  In our case;  k = 5 minutes  r = 1/12:   one bus arrives for every 12 minutes. or 1/12 of a bus arrives at every minute. Now p = 1- 2.71 ˆ[-5(1/12)]             = 1-2.71 ˆ[-5/12]             = 1- 1/ 2.71 ˆ5/12             = 1-0.66  or 34 / 100 = 34% Hence o

          If you toss a coin 5 times, 4 times you may get head and one time you may get tail.  Toss it 10 times, it may be head 7 times or 3 times tail.  Toss it 100 times. Roughly 50 times you will get head or tail.  If you do 10000 times, Most likely 5000 times we get head or tail.  A computer can easily simulate this process.  As the 'number' increases, we reach the fifty percent probability. 7/10 is not 50%  But 5007/10000 is.      Let us roll the dice three times, it may be 2,4,6.  The average is 2+4+6/3 =4.  But, if we roll the dice many, many times and find the average, it will settle down exactly at 3.5.   1,1,2,3,5,8,13....144,233....      The above is the Fibonacci series, Adding the previous two numbers, you get the next number.  Now take successive numbers one by one and find their ratio.     2/1 = 2     3/2 = 1.5     5/3 = 1.666     8/5=1.6   13/8 = 1.625  21/13 = 1.615...  233/144 = 1.6180  377/233 = 1.6180...   On the long run, the ratio settles

       In a land line, voice is converted into electrical signals by a microphone and sent through wire.  The sound is reproduced by the speaker at the other end.  Now we have modern technology called fiber optics.  Here voice or digital data is first converted into electrical signals and then into light signals(laser or infra red) using electronic element.  It is then sent through glass fibers (strands).      We know, electric current flows through metal wire because electrons are pulled by voltage difference.  But how the light will travel through glass fibers without oozing out?  Imagine long narrow hall way.  Its walls fitted with mirrors.  Hallway goes zig-zag.  If you send a torch light beam to a mirrored wall, it will reflect and re-reflect on the walls again and again and travel trough the hallway.  Similarly, laser beam travels through glass strands using 'total internal reflections'.       Total internal reflection :  If a ray of light goes from glass to ai

CLASS V Student A :  What is the boiling point of water? Teacher:      100 degree c is said to be the boiling point of water. Student A:   Why 100 degree c ? Teacher:  At 100 degree c , water bubbles up and evaporates. Student A:  O.K. CLASS X Student B:  What is really happening at the boiling point? Teacher:  Liquid water changes into gaseous state.  At the boiling point, the water molecules gains enough energy to flight the air molecules and escapes into the atmosphere.  Hence at 100 degree c, the water vapour pressure and the atmospheric pressure equals. CLASS XII  Student C:  What you mean by 'liquid changes into gas'? Teacher:  The water molecules has positive end and the negative end.  The positive side of one molecule attracts negative side of another molecule.  Hence the water molecules cling together as a drop, as a liquid.  As the temperature increases, the molecules gains energy and break free from the electrostatic bonds.  The free molecules bubble

                A man should earn because everything has a price even drinking water.  A man starts earning after education.  His income will not be proportional to his work.  The earnings will be less than the quantum of his work  initially.  Because he is learning the trick and tools of the trade.  During the middle age of a man (Man includes woman), his income will match his work output.  When he further moves  into the old age, his income will increase but work and duty may decline.  Because, he mostly will do supervisory and management roles.      Incomes are two kinds.  One is active and the other is passive.  You earn active income by physically doing work, that is by doing day-job.  Passive income comes from rent, interest etc .  As you age, active income should decrease and passive income should rise. HOW TO RAISE THE PASSIVE INCOME?  1. By renting your property like house, shop, car etc.  Buying a new property and renting is not advisable or profitable.  Your inherit

1. Why the circular waves in the pond goes on expanding? 2. When you happened to be in a room, why all the outside noise appears to came from the door step? 3. Why tsunami affects only some parts of the land? 4. When any wave pass through a gap, it spread out in semi-circular fashion, why?      All these questions are answered by "Huygen's principle".  What is that?      Say, you drop a stone in a placid sheet of water.  Circular waves are created and starts expanding.  Huygen's principle says, "every point in a circular wave acts as a secondary source of waves.  And new wavelet starts from these points and move forward (as if a stone is dropped at every point of the circle).  The new wave front is the envelop (collection) of these wavelets".    This principle is a good tool (not a law) to predict the path and the progress of waves.  Now we can answer the above questions.: 1. Since every point on a wavefront act as source; the  new wavelets alwa

     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

             In normal dictionary, the words are arranged according to alphabetical order.  But we can arrange the words according the frequency of occurrence.  That is, most used words will appear first, less used words follows.  Then each word will have a rank and frequency.  If we multiply rank and frequency, we get a number.  That number will be the same (more or less) for all the words and it is a constant.  That is zipf's law. [ In the above paragraph, five  'the' are present out of 70 words. hence frequency percentage is 5*100/70=7.1% ]      Frequency percentage * rank = constant.      The most used words in English is 'The'.  It occurs 7 times in 100 words.  Or the percentage of frequency is 7 % .  A list is given below. Rank R     word       frequency            constant                              percentage F           F * R = C    1.            the                6.8%            1 * 6.8 =6.8 %    2.             of                3.1

          6.25 , here 6 is the first digit.      72.5, 7 is the first digit      12.65  1 is the first digit.      We think, all the digits (1 to 9) have equal probabilities to appear as first digit.  That is, they has to appear 1 out of 9 times - 11% probability.      But a man, named Benford researched heavily and gave a law.  "The 'one' appears as a first digit 30% of the time".  The small numbers 1,2,3 appears more as first digit than large numbers like 7,8,9.     Benford law holds good in baseball statistics, area of rivers, population sizes, street address, city populations, super market prices etc.     Let us consider door numbers in a street which has 30 houses. 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19.20,21,22,23,24,25,26,27,28,29, 30. 1 appears 11 times as first digit out of 30.  So around 30% times.     Let us say, a price starts at 1 dollar and goes up 10% every time. 1.00.1.10, 1.21,1.33,1.46,1.61,1.77,1.95,2.14,2.36,2.59..... S

         There is a popular book by name 'who moved my cheese'.  It is just little booklet.  The central point in the book is: 'The block of cheese will be moved now and then, the cat should be always ready to go that extra mile'.  Meaning: the world will change continuously, the people must adopt and update themselves continuously.     Let us take the example of music industry.  Long, long ago, music means live concert only.  Then it was recorded and played on a disc using vibrating needle.  Next music was recorded on a plastic tape using magnetism.  It was compact than a disc.  Earphones came.  It helped us to listen music without disturbing others.  Next music was recorded on a CD using pits and pumps which were etched by laser.  Pits and bumps represents zeros and ones using which music is coded.  Now,music is digitized.      Next silicon chips (electronic memory) stored music.  Now, 'apps' streams desired music to your smart phone.  The 'app'

             We know, vibrations produce sound.  When a bell is stroked; it vibrates; creates air pressure waves; reaches our ear; vibrates air drum; and we perceive the sound.  Every object vibrates with its own frequency (no. of vibrations per second).  Our ear is designed to hear the frequency range 20-20000 cycles per second.  If the sound frequency is above 20000 cycles, it is called ultrasound.  Some animal can hear ultrasound but we can not.  People have found many uses for the ultrasound.  First, how to produce such a high frequency sound.      Here the quartz crystal comes to our help.  It is 'silicon oxide'.  Positive and negative charges are evenly distributed in it.  So it is electrically neutral.  But if we press that crystal, the charges are displaced; positive charges move to one side; negative charges move to another side; electrical field is created; a voltage develops.  If we connect the two sides of quartz externally, current (electrons) will flow.  Hen

              Today, everybody can afford a fountain pen.  but long back, only the rich can buy a fountain pen.  Then, people used what is called a 'dip pen' or a quill.  A bird's feather was taken.  It was sharpened at one end.  People dipped it in a ink  bottle and wrote with it.  You know, frequent dipping was required.      Fountain pen was invented.  It has a surprising science behind it.  First, it has so many parts.  reservoir, nib, feed or collector, cap, clip, barrel miniature piston mechanism or ink cartridge and even a breathing hole.      Take an ink bottle.  Open its wide mouth.  Try to write with it.  We know, the ink will uncontrollably flow out.  We will only create a nasty mess and will not write a word.      We are aiming for the controlled leak in the pen.  Hence the design of the pen is very important.      Now cover the ink  bottle with its cap and make a thin hole with a pin.  Turn the bottle upside down.  Ink will not fall through the hole be

        You can, if you own a new Tesla car.  Bond lifts up the car side ways even up to 90 degrees and drives it on just tow wheels.  He again brings the car back to normal position without toppling.  It may be a screen gimmick.  But today, It can be real.      First, we should understand stability.  Consider 'Thanjavur doll'.  It is heavy and hemispherical at the bottom.  If you push the doll to one side, it will not fall down but will return and oscillate back into its original position.  Why?      Center of gravity (CG) of a body is a point in the body at which all the weight of the body acts.  Or, at CG, one can balance the body with a tip.      Draw a vertical line from the CG. If the line falls with in the base of the body, it will have good stability.  That is, when a body is pushed to one side and the line from CG falls with in its base, the body will return to its original position.  If the vertical line crosses the base, the body will topple.      To ac

           On earth, we pour the coffee in a cup and drink it without any effort.  "Drinking coffee' works smoothly because of earth's gravity, but in space, in the absence of gravity, the liquid misbehave or stay put.      Say, a astronaut wants to drink coffee. Let us also assume that there is some coffee in a cup. (even pouring liquid in a cup is impossible in zero gravity).  The man takes the cup and brings it close to the mouth.  Suppose he gives some shakes to the cup, a little coffee may go into his mouth.  The remaining coffee may go all over his face and the body.      In zero gravity, every thing stays still or moves in  random directions.  If forces are given on them, the things behave unpredictably.  Hence, even 'sipping a coffee' is a task in the space station.  It is solved by designing a coffee cup based on the principle of 'capillary action'.      What is capillary action?  Take a glass tube of narrow width, say 0.5 mm and put in

           On land we measure distance in kilometers and miles.  For a ship sailing in ocean for months and for a jet plane flying from one continent to another, these measurements will not be suitable because earth is spherical and curved.  That is where the 'nautical mile' comes in.  Let us understand the concept.      The earth roughly takes 365 days to go round the sun once.  Hence mathematicians divided a circle into 360 equal parts and defined the total angle of circle as 360 degrees.      To improve accuracy,  one degree is sub-divided into 60 minutes and a minute is further segmented into 60 seconds.  The same technique is followed in the clocks since the clock handles move in circles.      We have drawn imaginary vertical and horizontal lines on the earth called latitude and longitude.  They are based on angle measured in degrees.  They are used by GPS to pinpoint a location on the surface of the earth.      Nautical mile is the distance suspended by one mi

         Men communicated through sign language long back.  It is still used by physically challenged people.  Men invented language.  It paved way for the oral and written communication.      When distance increases, how to communicate?  Written message on palm leaf, cloth,paper  were sent on horses, trains and ships.  Today, we call it snail mail.  But it is still vogue.      Telephone , telex, telegram were invented.  Messages were sent through wires with electricity. Voice was converted into electrical signal and sent through telephone cables.  In telegram, two sounds represented each alphabet in English.  The letters are converted into sounds and sounds into electrical pulses.  Then the pulses travel from one post office to another.  The postmaster had to undergo special course to decipher the message in those days.      Radio was born.  That is, Radio waves receiver set.  Speech and songs were converted into electricity than into Radio waves(electromagnetic waves) and tra