Jagadish Chandra Bose in the context of Crystal detector


Jagadish Chandra Bose in the context of Crystal detector

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⭐ Core Definition: Jagadish Chandra Bose

Sir Jagadish Chandra Bose (/bs/; IPA: [d͡ʒɔɡod̪iʃ t͡ʃɔn̪d̪ro boʃu]; 30 November 1858 – 23 November 1937) was a Bengali polymath in British India with interests in biology, physics and writing science fiction. He was a pioneer in the investigation of radio microwave optics, made significant contributions to botany, and was a major force behind the expansion of experimental science on the Indian subcontinent. Bose is considered the father of Bengali science fiction. A crater on the Moon was named in his honour. He founded the Bose Institute, a premier research institute in India and also one of its oldest. Established in 1917, the institute was the first interdisciplinary research centre in Asia. He served as the Director of Bose Institute from its inception until his death.

Born in Mymensingh, Bengal Presidency (present-day Bangladesh), during British governance of India, Bose graduated from St. Xavier's College, Calcutta (now Kolkata, West Bengal, India). Prior to his enrollment at St. Xavier's College, Calcutta, Bose attended Pabna Zilla School and Dhaka Collegiate School, where he began his educational journey. He attended the University of London to study medicine, but had to give it up due to health problems. Instead, he conducted research with Nobel Laureate, Lord Rayleigh at the University of Cambridge. Bose returned to India to join the Presidency College of the University of Calcutta as a professor of physics. There, despite racial discrimination and a lack of funding and equipment, Bose carried on his scientific research. He made progress in his research into radio waves in the microwave spectrum and was the first to use semiconductor junctions to detect radio waves.

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👉 Jagadish Chandra Bose in the context of Crystal detector

A crystal detector is an obsolete electronic component used in some early 20th century radio receivers. It consists of a piece of crystalline mineral that rectifies an alternating current radio signal. It was employed as a detector (demodulator) to extract the audio modulation signal from the modulated carrier, to produce the sound in the earphones. It was the first type of semiconductor diode, and one of the first semiconductor electronic devices. The most common type was the so-called cat's whisker detector, which consisted of a piece of crystalline mineral, usually galena (lead sulfide), with a fine wire touching its surface.

The "asymmetric conduction" of electric current across electrical contacts between a crystal and a metal was discovered in 1874 by Karl Ferdinand Braun. Crystals were first used as radio wave detectors in 1894 by Jagadish Chandra Bose in his microwave experiments. Bose first patented a crystal detector in 1901. The crystal detector was developed into a practical radio component mainly by G. W. Pickard, who discovered crystal rectification in 1902 and found hundreds of crystalline substances that could be used in forming rectifying junctions. The physical principles by which they worked were not understood at the time they were used, but subsequent research into these primitive point contact semiconductor junctions in the 1930s and 1940s led to the development of modern semiconductor electronics.

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Jagadish Chandra Bose in the context of International Committee on Intellectual Cooperation

The International Committee on Intellectual Cooperation, sometimes League of Nations Committee on Intellectual Cooperation, was an advisory organisation for the League of Nations which promoted international exchange between scientists, researchers, teachers, artists and intellectuals. Established in 1922, it counted such figures as Henri Bergson, Albert Einstein, Sarvepalli Radhakrishnan, Jagadish Chandra Bose, Nitobe Inazo, Marie Curie, Gonzague de Reynold, Leonardo Torres Quevedo, and Robert A. Millikan among its members.

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Jagadish Chandra Bose in the context of Horn antenna

A horn antenna or microwave horn is an antenna that consists of a flaring metal waveguide shaped like a horn to direct radio waves in a beam. Horns are widely used as antennas at UHF and microwave frequencies, above 300 MHz. They are used as feed antennas (called feed horns) for larger antenna structures such as parabolic antennas, as standard calibration antennas to measure the gain of other antennas, and as directive antennas for such devices as radar guns, automatic door openers, and microwave radiometers. Their advantages are moderate directivity, broad bandwidth, low losses, and simple construction and adjustment.

One of the first horn antennas was constructed in 1897 by Bengali-Indian radio researcher Jagadish Chandra Bose in his pioneering experiments with microwaves. The modern horn antenna was invented independently in 1938 by Wilmer Barrow and G. C. Southworth The development of radar in World War II stimulated horn research to design feed horns for radar antennas. The corrugated horn invented by Kay in 1962 has become widely used as a feed horn for microwave antennas such as satellite dishes and radio telescopes.

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Jagadish Chandra Bose in the context of Plant cognition

Plant intelligence is a field of plant biology which aims to understand how plants process the information they obtain from their environment. Plant intelligence has been defined as "any type of intentional and flexible behavior that is beneficial and enables the organism to achieve its goal".

Plant neurobiology is a subfield of plant intelligence research that claims plants possess abilities associated with cognition including anticipation, decision making, learning and memory. Terminology used in plant neurobiology is rejected by the majority of plant scientists as misleading, as plants do not possess consciousness or neurons, thus the term plant gnosophysiology is infrequently used. Most plant scientists tend to avoid using the term "intelligence" to refer to plants in their published research, despite the rise of the term in popular science writing.

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