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Other discoveries and inventions: While Archimedes did not invent the lever, he wrote the earliest known rigorous explanation of the principle involved. According to Pappus of Alexandria, his work on levers caused him to remark: "Give me a place to stand on, and I will move the Earth." (Greek: δῶς μοι πᾶ στῶ καὶ τὰν γᾶν κινάσω) Plutarch describes how Archimedes designed block-and-tackle pulley systems, allowing sailors to use the principle of leverage to lift objects that would otherwise have been too heavy to move.
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Discoveries and inventions
The Golden Crown: The most widely known anecdote about Archimedes tells of how he invented a method for determining the volume of an object with an irregular shape. According to Vitruvius, a new crown in the shape of a laurel wreath had been made for King Hiero II, and Archimedes was asked to determine whether it was of solid gold, or whether silver had been added by a dishonest goldsmith. Archimedes had to solve the problem without damaging the crown, so he could not melt it down into a regularly shaped body in order to calculate its density.
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Archimedes of Syracuse(c. 287 BC – c. 212 BC) was a Greek mathematician, physicist, engineer, inventor, and astronomer. Although few details of his life are known, he is regarded as one of the leading scientists in classical antiquity. Among his advances in physics are the foundations of hydrostatics, statics and the explanation of the principle of the lever. He is credited with designing innovative machines, including siege engines and the screw pump that bears his name. Modern experiments have tested claims that Archimedes designed machines capable of lifting attacking ships out of the water and setting ships on fire using an array of mirrors.
Henri Becquerel
Antoine Henri Becquerel (15 December 1852 – 25 August 1908) was a French physicist, Nobel laureate, and one of the discoverers of radioactivity. He won the 1903 Nobel Prize in Physics for discovering radioactivity.
Early life: Becquerel was born in Paris into a family which, including him and his son Jean, produced four generations of scientists. He studied science at the École Polytechnique and engineering at the École des Ponts et Chaussées. In 1890 he married Louise Désirée Lorieux.
Career: In 1892, he became the third in his family to occupy the physics chair at the Muséum National d’Histoire Naturelle. In 1894, he became chief engineer in the Department of Bridges and Highways.
Subrahmanyan Chandrasekhar, the Physicist
Padma Vibhushan Subrahmanyan Chandrasekhar, FRS (October 19, 1910 – August 21, 1995) was an Indian born American astrophysicist. He was a Nobel laureate in physics along with William Alfred Fowler for their work in the theoretical structure and evolution of stars. He was the nephew of Indian Nobel Laureate Sir C. V. Raman.
Chandrasekhar served on the University of Chicago faculty from 1937 until his death in 1995 at the age of 84. He became a naturalized citizen of the United States in 1953.
Quantum Mechanics: A History
The history of quantum mechanics as this interlaces with history of quantum chemistry began essentially with the 1838 discovery of cathode rays by Michael Faraday, during the 1859-1860 winter statement of the black body radiation problem by Gustav Kirchhoff, the 1877 suggestion by Ludwig Boltzmann that the energy states of a physical system could be discrete, and the 1900 quantum hypothesis by Max Planck that any energy radiating atomic system can theoretically be divided into a number of discrete ‘energy elements’ ε (epsilon) such that each of these energy elements is proportional to the frequency ν with which they each individually radiate energy, as defined by the following formula: E=hn where h is a numerical value called Planck’s constant.
Picture: Niels Bohr’s 1913 quantum model of the atom, which incorporated an explanation of Johannes Rydberg’s 1888 formula, Max Planck’s 1900 quantum hypothesis, i.e. that atomic energy radiators have discrete energy values (ε = hν), J. J. Thomson’s 1904 plum pudding model, Albert Einstein’s 1905 light quanta postulate, and Ernest Rutherford’s 1907 positive atomic nucleus discovery.
What Is A Number ?
My present-day readers live in a world so dominated by numbers and number-crunching that the question might look childish or even stupid to most. But wait! Tell me what a "number" is before you decide to do something else!
The Physics of Stringed Instruments
Physics is a science that can be applied to anything. It can explain how sound is made and how it can be manipulated. This paper will explain how musical instruments, stringed instruments in particular, create the music that is part of all of our lives. There are many different types of musical instruments and many different ways to play them. They are each constructed in diverse ways to produce various sounds. Their strings are their most important part and can be created and played in different ways to create diverse sounds. Stringed instruments are very intricate and all of their many facets can be related to physics.
Using Sunlight More Efficiently
Researchers at the National Renewable Energy Laboratory (NREL) in Golden, Colo have developed a way for low-cost solar cells to more efficiently convert sunlight into electricity.The research, which increases the "lifetime" of electrons created in a solar cell so they can make more electricity, is a possible step in the direction of bringing down the relatively high cost of solar cells. Reducing cost while sustaining efficiency is the big factor in determining how soon solar power will become a major player in the energy business.
APS ENERGY EFFICIENCY STUDY
Using energy wisely will help fill your pocketbook, protect the environment, and perhaps improve national security — this according to a new report on energy efficiency issued by the American Physical Society (APS), the leading organization of physicists in the United States. The report, which looks at improving energy efficiency in the transportation sector and in buildings, makes several specific policy recommendations, such as achieving independence from fossil fuels in new buildings by 2030; reaching an average standard mileage of 35 mpg for cars and light trucks by 2020 and 50 mpg by 2030; lowering per capita energy consumption across the nation; and increasing the amount of money spent on federal energy research to match 1980 levels.