Category Great Scientist

Henri Becquerel was a French physicist who discovered radioactivity through his investigations of uranium and other substances.

       Becquerel had become a highly respected physicist by 1896. After the discovery of the x-ray in 1895, Becquerel began to investigate whether there was a fundamental connection between this form of invisible radiation and visible light.

      His expertise with phosphorescent materials, his familiarity with uranium compounds, and his general skill in laboratory techniques, including photography, all played a key role in his discovery of radioactivity. Becquerel experimented by placing phosphorescent crystals on a sealed photographic plate that had been wrapped in opaque paper, and never exposed to direct light.

    After the plate was developed, images were visible on it. He passed the results on to Madame Curie, who named this phenomenon radioactivity. In 11903, Becquerel shared the Nobel Prize for physics with the chemists Pierre and Marie Curie.

Ivan Pavlov, a Russian physiologist, is an iconic figure who was the first to offer a scientific approach to psychology.

     Pavlov studied medicine under a famed physiologist of the time, S.P. Botkin, who taught him a great deal about the nervous system. Pavlov is known primarily for his work in conditioned response.

     He conducted a legendary experiment in which he trained hungry dogs to drool at the sound of a bell, or buzzer. Moments before feeding, a bell was rung to measure the dogs’ saliva production when they heard the bell.

     Pavlov found out that once the dogs had been trained to associate the sound of the bell with food, they would produce saliva, whether or not food followed. Pavlov became fully convinced that human behavior could be understood and explained best in physiological terms, rather than in mentalist terms. He won the 1904 Nobel Prize for physiology or medicine.

Thomas Edison’s story is truly an inspiring one. He struggled at school, but loved reading and conducting experiments.

      This American inventor began sending and receiving messages via Morse code an electronically conveyed alphabet using different clicks for each letter at the age of 15. Later, he invented a version of the telegraph that could send four messages at once. In 1877, Edison invented the phonograph. The phonograph was a machine that recorded and played back sounds. He perfected the phonograph by recording ‘Mary had a little Lamb’ on a piece of tin foil!

     In 1878, Edison invented the light bulb, as well as the power grid system, which could generate electricity, and deliver it to homes through a network of wires.

    Edison registered 1,093 patents in the US, as he continued to invent products. He made significant contributions to storage batteries and motion pictures. His inventions changed the world forever, and Edison remains a colossus in the field of science to this day.

Wilhelm Rontgen, a German scientist, was the recipient of the first Nobel Prize in physics. Rontgen carried out research in several fields, but his main claim to fame is the discovery of X-rays.

        In 1895, Rontgen was conducting an experiment by passing an electric current through a gas at extremely low pressure. He noticed that even though the room was dark, and the tube was covered with black carbon, a screen covered with fluorescent material was being lit up.

      By placing a photographic plate at the other end, Rontgen was able to capture the image that was being lit up by these unknown rays. Since he did not know the nature of these rays, he called them X-rays. The first X-ray ever taken was an image of Rontgen’s wife’s hand. His discovery of X-rays ushered in a great revolution in the fields of physics and medicine.

Robert Koch was a famous German physician who gained renown as one of the founders of bacteriology and microbiology. Koch was very much interested in how the disease known as anthrax spread from cattle to humans.

           He laid down four criteria in 1890 for establishing the cause of an infectious disease. These rules are known as ‘Koch’s postulates’. Many of the basic principle and techniques of modern bacteriology were adapted, or devised by Robert Koch, who therefore is often regarded as the chief founder of that science.

        Robert Koch’s brilliant contributions were acknowledged in 1905, and he won the Nobel Prize for medicine for his groundbreaking work on tuberculosis. Directly or indirectly, Koch has influenced authorities in many countries to introduce public health legislation based on knowledge of the origin of various infections.

     He is also responsible for a more enlightened attitude towards the measure for controlling such disease, and the hygiene that must be observed for preventing, as well as treating them.