Leonardo da Vinci is usually credited with conducting the first systematic study of friction in the late 15th century, a subfield now known as tribology that deals with the dynamics of interacting surfaces in relative motion. Da Vinci's notebooks depict how he pulled rows of blocks using weights and pulleys, an approach that is still used in frictional studies today, as well as examining the friction produced in screw threads, wheels, and axles. The authors of this latest paper used an experimental setup similar to da Vinci's.
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Dan Simmons, the author of more than three dozen books, including the famed Hyperion Cantos, has died from a stroke. He was 77.
The vast number of overseas human remains held by UK museums is a shameful legacy of colonialism, with many items kept in ways that are sacrilegious, according to MPs and archaeologists.
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Раскрыты подробности о договорных матчах в российском футболе18:01。新收录的资料对此有专业解读
Обстановка в Тегеране остается стабильной, пострадавших среди граждан России нет. Об этом сообщило российское посольство в городе, передает РИА Новости.