Zoetrope

A zoetrope is one of several pre-film animation devices that produce the illusion of motion by displaying a sequence of drawings or photographs showing progressive phases of that motion. The name Zoetrope was composed from the Greek root words ζωή zoe, "life" and τρόπος tropos, "turning".

The zoetrope consists of a cylinder with slits cut vertically in the sides. On the inner surface of the cylinder is a band with images from a set of sequenced pictures. As the cylinder spins, the user looks through the slits at the pictures across. The scanning of the slits keeps the pictures from simply blurring together, and the user sees a rapid succession of images, producing the illusion of motion. From the late 19th century, devices working on similar principles have been developed, named analogously as linear zoetropes and 3D zoetropes, with traditional zoetropes referred to as "cylindrical zoetropes" if distinction is needed.

Invention

An earthenware bowl from Iran, over 5000 years old, could be considered a predecessor of the zoetrope. This bowl is decorated in a series of images portraying a goat jumping toward a tree and eating its leaves. Another device which one historian of Chinese technology called "a variety of zoetrope" was created around 100 BC by the inventor Ding Huan (丁緩), but the exact nature of that device, which is commonly misreported in derivative sources, and the historian's definition of "a variety of zoetrope" are both very unclear.

3D printing

3D printing, also known as additive manufacturing (AM), refers to various processes used to synthesize a three-dimensional object. In 3D printing, successive layers of material are formed under computer control to create an object. These objects can be of almost any shape or geometry and are produced from a 3D model or other electronic data source. A 3D printer is a type of industrial robot.

Futurologists such as Jeremy Rifkin believe that 3D printing signals the beginning of a third industrial revolution, succeeding the production line assembly that dominated manufacturing starting in the late 19th century. Using the power of the Internet, it may eventually be possible to send a blueprint of any product to any place in the world to be replicated by a 3D printer with "elemental inks" capable of being combined into any material substance of any desired form.

3D printing in the term's original sense refers to processes that sequentially deposit material onto a powder bed with inkjet printer heads. More recently, the meaning of the term has expanded to encompass a wider variety of techniques such as extrusion and sintering-based processes. Technical standards generally use the term additive manufacturing for this broader sense.

State Fair

A state fair is a competitive and recreational gathering in the United States. It may also refer to:

California State Fair

The California State Fair is the annual state fair for the state of California. The fair is held at Cal Expo in Sacramento, California.

History

California

California (ⁱ/ˌkælᵻˈfɔːrnjə/ KAL-ə-FORN-yə, /ˌkælᵻˈfɔːrniə/ KAL-ə-FAWR-nee-ə) is a state located on the West Coast of the United States. It is the most populous U.S. state, with 39 million people, and the third largest state by area (after Alaska and Texas). California is bordered by Oregon to the north, Nevada to the east, Arizona to the southeast, and the Mexican state of Baja California to the south. It contains the nation's second most populous census statistical area (Greater Los Angeles Area) and the fifth most populous (San Francisco Bay Area), and eight of the nation's 50 most populated cities (Los Angeles, San Diego, San Jose, San Francisco, Fresno, Sacramento, Long Beach, and Oakland). Sacramento has been the state capital since 1854.

What is now California was first settled by various Native American tribes before being explored by a number of European expeditions during the 16th and 17th centuries. It was then claimed by the Spanish Empire as part of Alta California in the larger territory of New Spain. Alta California became a part of Mexico in 1821 following its successful war for independence, but was ceded to the United States in 1848 after the Mexican–American War. The western portion of Alta California was organized as the State of California, which was admitted as the 31st state on September 9, 1850. The California Gold Rush starting in 1848 led to dramatic social and demographic change, with large-scale immigration from the east and abroad with an accompanying economic boom.