Category Scientist & Invensions

Who discovered neutrons?

               An atom is made up of three types of elementary particles called electrons, protons and neutrons. The neutrons and protons constitute the nucleus of the atom while the electrons revolve around the nucleus in different orbits. Neutron is a subatomic particle that does not have any electric charge. Protons and electrons however carry equal positive and negative charges respectively but neutron has no such charge. The mass of the neutron is slightly greater than that of the proton. Do you know who discovered the neutrons?

               Neutron was discovered by a British Physicist named Sir James Chadwick. In the early 1900s, scientists were aware that an atom contained electrically charged particles called electrons and protons. Scientists believed that there must be uncharged particles also in an atom. In 1932, Chadwick showed that the radiation from the element beryllium, caused by the bombardment of alpha particles is actually a stream of electrically neutral particles. He called these particles neutrons. He also studied some other properties of these particles. Neutrons directly emitted from atomic nuclei are termed as fast neutron.

               Chadwick also explained the existence of isotopes. An isotope of an element has the same number of protons but different number of neutrons. It has, therefore, a different atomic weight. In 1935, Chadwick was awarded Nobel Prize for physics. Chadwick did pioneering work in the field of nuclear chain reactions. He played an important role in the development of the first atomic bomb during World War II.

               From the studies carried out on neutrons it has been found out that a free neutron which is outside a nucleus is unstable. On an average, a neutron decays in 12 minutes. This length of time is called half life of the neutron. Inside the nucleus, the neutrons are usually stable. When they decay inside the nucleus, that substance becomes radioactive. Beams of neutrons have high penetrating power and therefore they have high damaging effect on living tissues. Because of this, scientists working in nuclear establishments have to wear protective shields as a protection against harmful radiations.

 

G. Madhavan Nair

G. Madhavan Nair

G. Madhavan Nair (born October 31, 1943, erstwhile Travancore, presently Thiruvananthapuram, Kerala) is the former Chairman of Indian Space Research Organisation and Secretary to the Department of Space, Government of India since September 2003 and was also the Chairman, Space Commission. He was succeeded by K. Radhakrishnan. He was also the Chairman of Governing Body of the Antrix Corporation, Bangalore. Madhavan Nair was awarded the Padma Vibhushan, India’s second highest civilian honour, on January 26, 2009. He also served as the Chairman, Board of Governors, Indian Institute of Technology Patna until he stepped down voluntarily due to his alleged involvement in Antrix-Devas deal.

Known for

  • Indian Space Program

Awards

  • Padma Bhushan (1998)
  • Padma Vibhushan (2009)

Fields

  • Rocket Technology
  • Electrical and Electronics Engineering

Institutions

  • Indian Space Research Organisation
  • Bhabha Atomic Research Center

To read more about G. Madhavan Nair click G. Madhavan Nair

 

Narinder Singh Kapany

Narinder Singh Kapany

Narinder Singh Kapany (born 31 October 1926) is an Indian-born American Sikh physicist known for his work in fibre optics. He was named as one of the seven ‘Unsung Heroes’ by Fortune in their ‘Businessmen of the Century’ issue (1999-11-22).[4][5][6] He is also known as “Father of Fiber Optics”. The term fibre optics was coined by Singh Kapany in 1956. He is a former IOFS officer.

Known for

  • Pioneering work on Fiber optics

Awards

  • Pravasi Bharatiya Samman
  • The Excellence 2000 Award
  • FREng (1998)

Fields

  • Physics

Institutions

  • Agra University
  • Ordnance Factories Board
  • Imperial College of Science
  • British Royal Academy of Engineering
  • Optical Society of America
  • American Association for the Advancement of Science
  • Professor at the University of California, Berkeley (UCB)
  • University of California, Santa Cruz (UCSC)
  • Stanford University

To read more about N. S. Kapany  Click  Narinder Singh Kapany

Homi Jehangir Bhabha

Homi Jehangir Bhabha (30 October 1909 – 24 January 1966) was an Indian nuclear physicist, founding director, and professor of physics at the Tata Institute of Fundamental Research (TIFR). Colloquially known as “father of the Indian nuclear programme”, Bhabha was also the founding director of the Atomic Energy Establishment, Trombay (AEET) which is now named the Bhabha Atomic Research Centre in his honor. TIFR and AEET were the cornerstone of Indian development of nuclear weapons which Bhabha also supervised as director.

Known for

  • Indian nuclear programme
  • Cascade process of Cosmic radiations
  • point particles
  • Bhabha Scattering
  • Theoretical prediction of Muon

Awards

  • Adams Prize (1942)
  • Padma Bhushan (1954)
  • Fellow of the Royal Society

Fields

  • Nuclear Physics

Institutions

  • Atomic Energy Commission of India
  • Tata Institute of Fundamental Research
  • Cavendish Laboratory
  • Indian Institute of Science
  • Trombay Atomic Energy Establishment

To read more about Homi Jehangir Bhabha click H. J. Bhabha

What were Marconi’s contributions to science?

Guglielmo Marconi was born on 26th April, 1874 at Bologna in Italy. He studied Physics in a technical school in Leghorn, Italy and conducted his early experiments near Bologna. He was the man, who, most people say, invented Radio.

When in 1887 he came to know that Heinrich Hertz had discovered radio waves, he thought of using these waves for carrying messages. At that time messages were already being sent in Morse code using electric wires. When he was only 20, he managed to make an electric bell ring in one corner of a room with radio waves sent out from the other corner. The bell was switched on by electric pulse across about 10 metres by radio waves.

By 1895, Marconi was able to develop equipment that could transmit pulses up to a distance of about 2 km. But unfortunately the Italian Government did not take much interest in his work and he decided to try his luck in London. In 1896 he moved to London and during 1896 and 1897 gave a series of successful demonstrations of the wireless telegraphy apparatus he had developed. In May 1897, he transmitted Morse signals from Lavernock point in Wales to an island in Bristol Channel about five km. away. He subsequently started the Marconi Company in 1897.

Two years later i.e. in 1899 he transmitted a radio signal across the English Channel covering a distance of about 50 km. In 1899 he also equipped two U.S. ships to report to newspapers in New York City the progress of the yacht race for the American Cup. On December 12, 1901, the letter S was sent in Morse code across the Atlantic Ocean. The world then realized the tremendous possibilities of this new means of communication. In 1909 he received the Nobel Prize for Physics. He later worked on shortwave wireless communication, which constitutes the basis of nearly all modern long distance radio transmission. In 1930 he was chosen the President of the Royal Italian Academy.

This great physicist and inventor died on July 20, 1937.

 

 

Who was Aryabhatta?

               Aryabhatta was a great mathematician and astronomer of ancient India. The first artificial Indian satellite, ‘Aryabhatta’ launched on April 19th, 1975 was named after this famous Indian mathematician.

               Aryabhatta was born in 476 AD at Kusumapura (Pataliputra), India. He was a noted astrologer and mathematician of his times. He was the first astronomer in the world to arrive at the currently accepted theory that the earth is round and that it rotates on its own axis and travels around the sun, thus causing day and night. His works are still available. He was one of those known to have used Algebra for the first time. In 499 AD he wrote a book entitled Aryabhatiya. Written in a concise and scientific manner and in couplets it summarizes the contemporary knowledge of the science of mathematics. It was a famous book of the period and deals with astronomy and spherical trigonometry. In that book 33 rules of arithmetic, algebra and plane trigonometry were given.

                Aryabhatta gave an accurate approximation for pi (), as 3.1416 and introduced the inverse sine function into trigonometry.

               Aryabhatta made many contributions to the sciences of mathematics and astronomy. He was one of the most learned persons in King Vikramaditya’s Court. This great man died in 550 AD.