ELECTRIC CHARGE : WHY '+' ? WHY '-' ?

We all know that there are two types of electric charge. We label them as '+' and '-'. One may wonder why these charges have been labelled so? Historical evidences give no solid reason for this naming practice.

A long time ago people found that certain materials when rubbed with cloth or fur were able to pick up (attract) small objects(like a piece of paper). A piece of ebonite was said to be charged when rubbed with fur. Similarly, a glass was said to be charged when rubbed with silk. But the charge on ebonite was not similar to the charge on glass, i.e. there were two kinds of 'charge' and so for the convenience of description and identification they were labelled '-' and '+',respectively by someone or by a group of some people. '-' and '+' have no mathematical significance nor any magical reason for being labelled like that. Had they named '+' charge as '-' and '-' charge as '+', that would not have had any significant impact on the description of phenomena of electricity. Thus, electron is negatively charged because it has the same electrical properties as a piece of ebonite when rubbed with fur and proton is positively charged because of its electrical behaviour similar to the glass rubbed with silk. So let us recollect Shakespeare : What's in a name ? An electron would behave electrically similarly if it were named 'proton'!!!

DUST BOWL

American state of Oklahoma suffered severe drought situation in 1930s. there was no crop due to lack of rain and the fields had dried to the extent that the soil blew away as dust and created what was called a 'DUST BOWL' region. People had to leave that area for further survival. A similar drought situation development took place in the state of Illinois in July 1988 when the then President Ronald Reagan during his visit to the state told farmers :"This is the worst natural disaster since the Dust Bowl of 1930s."

A NASA scientist in his report to a committee of the US Congress had told that "DUST BOWL DROUGHT" was 99 per cent certain to be caused by pollution of air and that it was an early sign of a dangerous climatic change, a change which leads to a general warming of the global atmosphere. This, in turn, affects the rainfall, as well as having other side effects. He said this atmospheric pollution was the "GREENHOUSE EFFECT". Thus 'DUST BOWL' was blamed on the Greenhouse Effect.

DO YOU KNOW ?

• Gregorian calendar was introduced in 16th century. Before its introduction the new year started on March 25.
  
• The ball-point pen was invented by Lazlo Biro, a Hungarian by birth.
  
• BEZANT was the coin of Byzantine Empire. It contained 2.5 gram of gold.
  
• Evan Lendl won all Grand slams of tennis except Wimbledon.
  
• Canada has the longest coastline.
  

SOME INTERESTING FACTS

• MARCONI discovered radio waves.
• Birds can perch on the overhead power lines without receiving an electric shock because they do not touch the ground and so do not complete an electric circuit.
• Deuterium(sometimes called Heavy Hydrogen) is an isotope of hydrogen whose nucleus contains one neutron and one proton.
• The dolphin can remain under water for 20 minutes and can swim at a speed of 70 km per hour.
• A bat can listen to ultrasonic sounds.
• The potato originated in Peru.
• We produce about 200 billion red corpuscles every day.
• The dog is the oldest domesticated animal.
• HUBERT BOOTH invented the vacuum cleaner in 1902.
• The first practical type-writer was invented by Christopher Scholes and Charles Glidden in 1867. Scholes designed the QWERTY typewriter keyboard layout which is still in use.
• The highest death toll ever reported in an earthquake occurred in the eastern Mediterranean in 1201 AD, with an estimated 1100000 casualties.
  

SOME BIOLOGICAL NAMES

• Indian bee - Apis indica
  
• Cow - Bos indicus
  
• Ass - Equus assinus
  
• Kiwi - Apteryx australis
  
• Dog - Canis familiaris
  
• Goat - Capra hircus
  
• Horse - Equus caballus
  
• Cat - Felis domestica
  
• Housefly - Musca nebulo
  
• Pigeon - Columba livia
  
• House Crow - Corvus splendens
  
• Indian elephant - Elephas indicus
  
• Indian Cobra - Naja naja
  
• Rabbit - Oryctolagus cuniculus
  
• Lion - Panthera leo
  
• Tiger - Panthera tigris
  
• Indian Rhinoceros - Rhinoceros unicornis
  
• Indian frog - Rana tigrina
  
• Onion - Allium cepa
  
• Garlic - Allium sativum
  
• Tomato - Lycopersicum esculentum
  
• Banana - Musa paradisiaca
  
• Rice - Oryza sativa
  
• Green gram - Phaseolus aureus
  
• Apple - Pyrus malus
  
• Pomegranate - Pumica granatum
  
• Pea - Pisum sativum
  
• Radish - Raphanus sativus
  
• Brinjal - Solanum melongena
  
• Potato - Solanum tuberosum
  
• Sweet potato - Batatas edulis
  
• Tamarimd - Tamarindus indica
  
• Tulsi - Ocimum sanctum
  
• Grape - Vitis vitifera
  
• Maize - Zea mays
  
• Mulberry - Morus indica
  
• Betel - Piper betle
  
• Betel-nut - Areca catechu
  
• Sugarcane - Saccharum officinarum
  
• Cashew-nut - Anacardium occidentale
  
• Ground-nut - Arachis hyposea
  
• Coconut - Cocos nucifera
  
• Neem - Azadirachta indica
  
• Peepal - Ficus religiosa
  
• Cotton -Gossypium herbaceous
  
• Chilli - Capsicum frutescens
  
• Bamboo - Babusa tulda
  
• Mustard - Brassica campestris
  
• Lady's finger - Hibiscus esculentus
  
• Banyan - Ficus bengalensis
  

WONDERS OF LIVING WORLD

• Blue or Sulphur-bottom whale is the largest living animal.
  
• A sea-wasp is not a wasp but is a kind of jelly-fish.
  
• Humming birds can fly backwards.
  
• Snails, earthworms, sea cucumbers and sea hares are among the species which have both male and female sex organs in the same organism.
  
• Giraffe have the largest neck and longest tail.
  
• "Abaca"(mainly grown in Philippines) is the toughest of all natural fibers.
  
• Some fish migrate from sea to fresh water for breeding. This phenomenon is called "Anadromy".
  

NAMED UNITS OF MEASUREMENT

• Abbe : Named after Ernst Abbe(1840-1901) who had great contributions in the field of optical instruments. The unit is used to measure Linear Spatial Frequency. Its dimensins are Hz m^-1.
  
• Amagat : Named after E. H. Amagat(1841-1915) who studied gases under high pressures. Amagat volume and Amagat density are used as measures in the study of behaviour of gases under pressure. For both units UNIT PRESSURE is taken as one standard atmosphere pressure. For an ideal gas, the Amagat volume is 22.4 litres. It is the volume occupied by one gram-mole of the gas at unit pressure and 273.15 K.
  
• Ampere : Named after A. M. Ampere(1775-1836) who had major contributions in the field of electricity. It is the unit of electric current.
  
• Angstrom : Named after A. J. Angstrom(1814-1874)who had used 10^-10 m to describe wavelengths. It is a unit of length used generally at atomic levels. It is equal to 10^-10 m.
  
• Balmer : Named after J. J. Balmer(1825-1898) who was a spectroscopist. It is a unit of wave-number and represents the number of waves in one centimeter. It has the dimensions of cm^-1.
  
• Baud : Named after J. M. E. Boudot(1845-1903) who was a French telegraph engineer and had made the first teleprinter. It is a unit of telegraph signalling speed. One baud is equal to one pulse per second.
  
• Becquerel : Named after A. H. Becquerel(1852-1908),a French physicist who discovered radioactivity. It is a unit of radioactivity and 1 becquerel means one nuclear disintegration or nuclear transformation per second.
  
• Clausius : Named after R. J. L. Clausius(1822-1888). It is a unit of entropy.
  
• Coulomb : Named after C. A. Coulomb(1736-1806) who had contributed to the field of electricity as one of the pioneers. It is the unit of electric charge.
  
• Curie : Named after Pierre Curie(1859-1906) who was one of the discoverers of radium. It is a unit of radioactivity.
  
• Darcy : Named after French scientist H. Darcy(1803-1858). He investigated the flow of fluids in porous media. It is the CGS unit of permeability of porous materials.
  
• Einstein : Named after Albert Einstein(1879-1955). Einstein worked in the field of photoelectric effect and gave us the great 'Theory of relativity' for which world better remembers him. It is a unit of photoenergy.
  
• Erlang : Named after the Danish mathematician, A. K. Erlang(1879-1924). It is a telephone traffic unit used to express traffic density.
  
• Farad : Named after Michael Faraday(1791-1867). It is a unit of capacitance.
  
• Fermi : Named after E. Fermi(1901-1954) who built first atomic pile. It is a unit of distance equal to 10^-15 m.
  
• Fresnel : Named after A.J.Fresnel(1788-1827) who was an advocate of wave theory of light. It is a unit of optical frequency (1 fresnel = 10¹² Hz).