Wednesday, March 18, 2020

Henri Becquerel and the Discovery of Radioactivity

Henri Becquerel and the Discovery of Radioactivity Antoine Henri Becquerel (born December 15, 1852 in Paris, France), known as Henri Becquerel, was a French physicist who discovered radioactivity, a process in which an atomic nucleus emits particles because it is unstable. He won the 1903 Nobel Prize in Physics with Pierre and Marie Curie, the latter of whom was Becquerel’s graduate student. The SI unit for radioactivity called the becquerel (or Bq), which measures the amount of ionizing radiation that is released when an atom experiences radioactive decay, is also named after Becquerel. Early Life and Career Becquerel was born December 15, 1852, in Paris, France, to Alexandre-Edmond Becquerel and Aurelie Quenard. At an early age, Becquerel attended the preparatory school Lycà ©e Louis-le-Grand, located in Paris. In 1872, Becquerel began attending the École Polytechnique and in 1874 the École des Ponts et Chaussà ©es (Bridges and Highways School), where he studied civil engineering. In 1877, Becquerel became an engineer for the government in the Department of Bridges and Highways, where he was promoted to engineer-in-chief in 1894.  At the same time, Becquerel continued his education and held a number of academic positions. In 1876, he became an assistant teacher at the École Polytechnique, later becoming the school’s chair of physics in 1895. In 1878, Becquerel became an assistant naturalist at the Musà ©um d’Histoire Naturelle, and later became the professor of applied physics at the Musà ©um in 1892, after his father’s death. Becquerel was the third in his family to succeed this position. Becquerel received his doctorate from the Facultà © des Sciences de Paris with a thesis on plane-polarized light- the effect utilized in Polaroid sunglasses, in which light of only one direction is made to pass through a material- and the absorption of light by crystals. Discovering Radiation Becquerel was interested in phosphorescence; the effect utilized in glow-in-the-dark stars, in which light is emitted from a material when exposed to electromagnetic radiation, which persists as a glow even after the radiation is removed. Following Wilhelm Rà ¶ntgen’s discovery of X-rays in 1895, Becquerel wanted to see whether there was a connection between this invisible radiation and phosphorescence. Becquerel’s father had also been a physicist and from his work, Becquerel knew that uranium generates phosphorescence. On February 24, 1896, Becquerel presented work at a conference showing that a uranium-based crystal could emit radiation after being exposed to sunlight. He had placed the crystals on a photographic plate that had been wrapped in thick black paper so that only radiation that could penetrate through the paper would be visible on the plate. After developing the plate, Becquerel saw a shadow of the crystal, indicating that he had generated radiation like X-rays, which could penetrate through the human body. This experiment formed the basis of Henri Becquerel’s discovery of spontaneous radiation, which occurred by accident. Becquerel had planned to confirm his previous results with similar experiments exposing his samples to sunlight. However, that week in February, the sky above Paris was cloudy, and Becquerel stopped his experiment early, leaving his samples in a drawer as he waited for a sunny day. Becquerel did not have time before his next conference on March 2 and decided to develop the photographic plates anyway, even though his samples had received little sunlight. To his surprise, he found that he still saw the image of the uranium-based crystal on the plate. He presented these results on March 2 and continued to present results on his findings. He tested other fluorescent materials, but they did not produce similar results, indicating that this radiation was particular to uranium. He assumed that this radiation was different from X-rays and termed it â€Å"Becquerel radiation.† Becquerel’s findings would lead to Marie and Pierre Curie’s discovery of other substances like polonium and radium, which emitted similar radiation, albeit even more strongly than uranium. The couple coined the term â€Å"radioactivity† to describe the phenomenon. Becquerel won half of the 1903 Nobel Prize in Physics for his discovery of spontaneous radioactivity, sharing the prize with the Curies. Family and Personal Life In 1877, Becquerel married Lucie Zoà © Marie Jamin, the daughter of another French physicist. However, she died the following year while giving birth to the couple’s son, Jean Becquerel. In 1890, he married Louise Dà ©sirà ©e Lorieux. Becquerel came from a lineage of distinguished scientists, and his family contributed greatly to the French scientific community over four generations. His father is credited with discovering the photovoltaic effect- a phenomenon, important for the operation of solar cells, wherein a material produces electrical current and voltage when exposed to light. His grandfather Antoine Cà ©sar Becquerel was a well-regarded scientist in the area of electrochemistry, a field important for developing batteries that studies the relationships between electricity and chemical reactions. Becquerel’s son, Jean Becquerel, also made strides in studying crystals, particularly their magnetic and optical properties. Honors and Awards For his scientific work, Becquerel earned several awards throughout his lifetime, including the Rumford Medal in 1900 and the Nobel Prize in Physics in 1903, which he shared with Marie and Pierre Curie. Several discoveries have also been named after Becquerel, including a crater called â€Å"Becquerel† both on the moon and Mars and a mineral called â€Å"Becquerelite† which contains a high percentage of uranium by weight. The SI unit for radioactivity, which measures the amount of ionizing radiation that is released when an atom experiences radioactive decay, is also named after Becquerel: its called the becquerel (or Bq). Death and Legacy Becquerel died from a heart attack on August 25, 1908, in Le Croisic, France. He was 55 years old. Today, Becquerel is remembered for discovering radioactivity, a process by which an unstable nucleus emits particles. Although radioactivity can be harmful to humans, it has many applications around the world, including the sterilization of food and medical instruments and the generation of electricity. Sources Allisy, A. â€Å"Henri Becquerel: The Discovery of Radioactivity.† Radiation Protection Dosimetry, vol. 68, no. 1/2, 1 Nov. 1996, pp. 3–10.Badash, Lawrence. â€Å"Henri Becquerel.† Encyclopà ¦dia Britannica, Encyclopà ¦dia Britannica, Inc., 21 Aug. 2018, www.britannica.com/biography/Henri-Becquerel.â€Å"Becquerel (Bq).† United States Nuclear Regulatory Commission - Protecting People and the Environment, www.nrc.gov/reading-rm/basic-ref/glossary/becquerel-bq.html.â€Å"Henri Becquerel – Biographical.† The Nobel Prize, www.nobelprize.org/prizes/physics/1903/becquerel/biographical/.Sekiya, Masaru, and Michio Yamasaki. â€Å"Antoine Henri Becquerel (1852–1908): A Scientist Who Endeavored to Discover Natural Radioactivity.† Radiological Physics and Technology, vol. 8, no. 1, 16 Oct. 2014, pp. 1–3., doi:10.1007/s12194-014-0292-z.â€Å"Uses of Radioactivity/Radiation.† NDT Resource Center; www.nde-ed.org/EducationResou rces/HighSchool/Radiography/usesradioactivity.htm

Monday, March 2, 2020

Homoioteleuton - Definition and Examples in English

Homoioteleuton s in English Homoioteleuton is the use of similar sound endings to words, phrases, or sentences.   In rhetoric, homoioteleuton is regarded as a figure of sound. Brian Vickers equates this figure with assonance or prose rhyme (In Defence of Rhetoric, 1988).  In The Arte of English Poesy (1589), George Puttenham  compared the Greek figure of homoioteleuton to our vulgar rhyme, offering this example: Weeping, creeping, beseeching I wan / The love at length of Lady Lucian. Etymology:  From the Greek, like ending Pronunciation:  ho-moi-o-te-LOO-ton Also Known  As:  near  rhyme, prose rhyme Alternate Spellings:  homeoteleuton,  homoeoteleuton Examples My mother weeping, my father wailing, my sister crying, our maid howling, our cat wringing her hands. (Launce in Act II, scene three of The Two Gentlemen of Verona by William Shakespeare)The quicker picker upper. (Advertising slogan for Bounty paper towels)That’s why, darling, it’s incredibleThat someone so unforgettableThinks I’m unforgettable too. (Unforgettable, sung by Nat King Cole)Loose lips sink ships. (Public service ad during World War II)Crispety, crunchety, peanut-buttery Butterfinger. (Advertising slogan for Butterfinger candy bar)I must aim at lucidity, simplicity and euphony. (William Somerset Maugham, The Summing Up, 1938)But, in a larger sense, we cannot dedicate, we cannot consecrate, we cannot hallow, this ground. (President Abraham Lincoln, The Gettysburg Address, 1863)He would clap his hands, lick his lips, narrow his eyes into a squinty gaze and extemporize, patronize, chastise, sermonize and crack wise all at the same time. (Linton Weeks, de scribing U.S. Secretary of Defense Donald Rumsfeld in Rumsfeld, A Newsmaker Whos Certainly Hard to Follow. The Washington Post, November 9, 2006) Chieftain Iffucan of Azcan in caftanOf tan with henna hackles, halt! (Wallace Stevens, Bantams in Pine-Woods)A very delectable, highly respectable,Threepenny-bus young man! (W.S. Gilbert, Patience, 1881)Reinhart and Rogoff admitted their errors but claimed, incorrectly, that it remains true that high public debt levels are correlated with slower growth. In fact, as sensible economists observed when their study first came out, correlation is not causation. (The Nation, May 13, 2013) Homoioteleuton as a Pattern of Repetition Homoioteleuton is a series of words with similar endings such as those with the Latinate suffixes -ion (e.g., presentation, action, elaboration, interpretation), -ence (e.g., emergence), and -ance (e.g., resemblance, performance). These suffixes work to nominalize verbs (transform verbs into nouns) and tend to appear most regularly in what Williams (1990) referred to as the various -eses (idioms such as legalese and bureaucratese. Like other patterns of repetition, homoioteleuton helps to build or reinforce connections, as in this example from the English politician Lord Rosebery in an 1899 speech: Imperialism, sane imperialism . . . is nothing but this - a larger patriotism. (James Jasinski, Sourcebook on Rhetoric. Sage, 2001)