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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Immediately after Fincke's medical event, NASA officials said they wouldn't name the affected astronaut, citing medical privacy concerns. During a news briefing the next day, NASA's chief health and medical officer J.D. Polk said the incident wasn't an injury in the course of work, though he stopped short of saying whether it was some other kind of injury.
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