Addiction

Insider Q&A: FDA official on vaping's 'promise or peril'

There's been no honeymoon period for the Food and Drug Administration's new tobacco chief, Brian King, the public health scientist now responsible for regulating the nation's multibillion-dollar cigarette and vaping industry.

Sports medicine & Kinesiology

How to prevent injuries when playing pickleball

The game of pickleball is surging in popularity across the country. It can be played at any age and skill level. While many might assume that pickleball is a slower, lower-impact sport, experts at Mayo Clinic say it's important ...

Diseases, Conditions, Syndromes

Repeat infections with COVID-19 may become the norm

COVID-19 might be easing into a new status as a widely circulating and somewhat harsher version of the common cold, experts say—a virus that folks could contract repeatedly, even if they were recently infected.

Psychology & Psychiatry

What shaking a container can teach us about touch

We shake cereal boxes and milk cartons to figure out if there is enough for breakfast. We can easily tell if there is enough toothpaste left in the tube, or if we have enough vitamin tablets left in a bottle. For these actions, ...

Psychology & Psychiatry

A remedy against choking under pressure

The images are legendary: Tennis stars who hit the deciding match ball just outside the line, golfers who putt the ball past the cup from only inches away, and speakers who suddenly can't say a word. These individuals all ...

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Ball

A ball is a round, usually spherical but sometimes ovoid, object with various uses. It is used in ball games, where the play of the game follows the state of the ball as it is hit, kicked or thrown by players. Balls can also be used for simpler activities, such as catch, marbles and juggling. Balls made from hard-wearing materials are used in engineering applications to provide very low friction bearings, known as ball bearings. Black powder weapons use stone and metal balls as projectiles.

Although many types of balls are today made from rubber, this form was unknown outside the Americas until after the voyages of Columbus. The Spanish were the first Europeans to see bouncing rubber balls (albeit solid and not inflated) which were employed most notably in the Mesoamerican ballgame. Balls used in various sports in other parts of the world prior to Columbus were made from other materials such as animal bladders or skins, stuffed with various materials.

As balls are one of the most familiar spherical objects to humans, the word "ball" is used to refer to, or to describe, anything spherical or near-spherical.

This text uses material from Wikipedia, licensed under CC BY-SA