Through the course of history society has been shaped by scientific discoveries that have benefitted mankind by providing a better understanding of the world and have advanced technology. One such scientist was Joseph John Thomson. Joseph John Thomson had a successful life, made important scientific discoveries, and impacted the world through his discoveries. Sir Joseph John Thomson was born on December 18, 1856 in Cheetham, a part of Manchester, England to Emma Swindells and Joseph James Thomson (Dahl, 1997). His family wanted to send him to an engineering apprenticeship working with locomotives, however there were complications with this plan so his father instead sent him to Owens college in Manchester to study engineering at fourteen years
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His major discoveries came by doing experiments with cathode ray tubes which have electrons that emitted light when negative voltage and metal plates were added, this was the discovery of the electron or corpuscle as he named it (Unknown author, 1997). A cathode tube works by creating gaseous discharge, which "occurs in a gas at low pressure when subjected to an electrical potential difference, commonly applied via electrodes at the ends of a long glass tube. The resulting glow or light emission takes various forms depending on the nature of the gas, the shape of the tube and of the electrodes” (Davis, 2007, p.294) When foil was added to the cathode ray tube he could see particles of light pass through which led him to believe cathode rays were electrons (Unknown author, 1997). With further experimenting he concluded that the mass of the particles was 3 x 10-27 g which is close to todays value of .91 x 10-27 g (Davis, 2007). This discovery of a negatively charged subatomic particle that is part of an atom led him to create the plum pudding model. Further experiments with cathode rays include: magnetic deflection, electrical deflection, and measurements of mass to charge ratio. He also discovered the first evidence of isotopes using mass spectrometry to observe different light deflections due to different
His major discoveries came by doing experiments with cathode ray tubes which have electrons that emitted light when negative voltage and metal plates were added, this was the discovery of the electron or corpuscle as he named it (Unknown author, 1997). A cathode tube works by creating gaseous discharge, which "occurs in a gas at low pressure when subjected to an electrical potential difference, commonly applied via electrodes at the ends of a long glass tube. The resulting glow or light emission takes various forms depending on the nature of the gas, the shape of the tube and of the electrodes” (Davis, 2007, p.294) When foil was added to the cathode ray tube he could see particles of light pass through which led him to believe cathode rays were electrons (Unknown author, 1997). With further experimenting he concluded that the mass of the particles was 3 x 10-27 g which is close to todays value of .91 x 10-27 g (Davis, 2007). This discovery of a negatively charged subatomic particle that is part of an atom led him to create the plum pudding model. Further experiments with cathode rays include: magnetic deflection, electrical deflection, and measurements of mass to charge ratio. He also discovered the first evidence of isotopes using mass spectrometry to observe different light deflections due to different