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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The California Fast Food Workers Union, an affiliate of the Service Employees International Union, drafted a Constitutional Pledge to California Workers’ Rights for workplaces to sign that affirms a commitment to protecting workers and “keep ICE from going where they are not allowed”.