Inventions and Inventors: Pairs, Years and Exam PYQs

Inventions and inventors is the most reliably scoring topic of static general knowledge. The questions are single-fact pairs, the answers never change, and the same three dozen names return paper after paper. The safest way to learn the topic is to group the pairs by field rather than to memorise a long alphabetical list, because papers set distractors from within a field: the inventor of the telephone is set against the inventor of the telegraph, not against a biologist.

Communication and computing

Charles Babbage is called the father of the computer for his difference engine and analytical engine, and Ada Lovelace, who wrote the first algorithm for that machine, is called the first programmer. Electronic mail in its modern form, with the at sign in the address, is credited to Ray Tomlinson.

Medicine and biology

• Edward Jenner developed the smallpox vaccine in 1796 and is called the father of immunology.
• Louis Pasteur gave the germ theory of disease, the process of pasteurisation and the rabies vaccine.
• Robert Koch identified the bacteria of tuberculosis and cholera.
• Joseph Lister introduced antiseptic surgery.
• Alexander Fleming discovered penicillin in 1928, the first antibiotic.
• Karl Landsteiner discovered the human blood groups.
• Banting and Best isolated insulin.
• Jonas Salk made the injectable polio vaccine and Albert Sabin the oral one.
• Watson and Crick described the double helix structure of DNA in 1953.
• Rene Laennec invented the stethoscope.

Physics, chemistry and the laboratory

Wilhelm Conrad Roentgen discovered X-rays in 1895 and received the first Nobel Prize in Physics in 1901. Henri Becquerel found radioactivity, and Marie and Pierre Curie isolated radium and polonium. Inside the atom, J. J. Thomson discovered the electron, Ernest Rutherford established the nucleus and named the proton, and James Chadwick discovered the neutron in 1932. Dmitri Mendeleev arranged the elements in the periodic table and left gaps for elements not yet found. Michael Faraday discovered electromagnetic induction and built the dynamo, the principle on which every generator still works. Evangelista Torricelli invented the barometer and Anders Celsius and Daniel Fahrenheit gave their names to the temperature scales. Among Indian scientists, C. V. Raman discovered the scattering effect that carries his name in 1928 and won the Nobel Prize in Physics in 1930, Jagadish Chandra Bose worked on radio waves and plant response, S. Chandrasekhar gave the limit on the mass of a white dwarf star, and Har Gobind Khorana shared a Nobel Prize for work on the genetic code.

Engines, flight and everyday machines

Discovery or invention

Papers often turn on the difference between the two words. A discovery finds something that already existed, such as X-rays, penicillin or the electron; an invention makes something that did not exist, such as the telephone, the dynamite stick or the transistor. Examiners exploit this by asking who discovered the electric bulb, when Thomas Alva Edison in fact invented a practical incandescent lamp in 1879 and also gave the phonograph. Three more traps are worth fixing in the memory. Marconi is credited with practical radio telegraphy, while Jagadish Chandra Bose demonstrated the transmission of radio waves earlier. The telescope was first patented by Hans Lippershey, while Galileo improved it and turned it on the sky. Vitamins are credited to several names, with Elmer McCollum for vitamins A and B, Albert Szent-Gyorgyi for vitamin C and Edward Mellanby for vitamin D, while Paul Muller is remembered instead for the insecticidal property of DDT.