A balloon is an inflatable flexible bag filled with a type of gas, such as helium, hydrogen, nitrous oxide or air. Modern balloons can be made from materials such as rubber, latex, polychloroprene, or a nylon fabric, while some early balloons were sometimes made of dried animal bladders. Some balloons are purely decorative, while others are used for specific purposes such as meteorology, medical treatment, military defense, or transportation. A balloon's properties, including its low density and relatively low cost, have led to a wide range of applications.

History

In 1643 Evangelista Torricelli, an Italian physicist, showed air was something more than nothing. The Chinese, Japanese and Native American cultures led to beginning of the balloon.

The first balloon was (called the balloon of pie) invented by Brazilian-born Portuguese priest at 45 years of age, Bartolomeu de Gusmão, and the first public exhibition was to the Portuguese Court on August 8, 1709, in the hall of the Casa da Índia in Lisbon. The rubber balloon was invented by Michael Faraday in 1824; it was inflated with hydrogen and used in his experiments with that element. Rubber balloons were soon after sold for a penny a piece in parks and circuses in America. The more familiar latex balloons of today were first manufactured in London, 1847, by J.G. Ingram, but mass production did not occur until the 1930s.Fact: date=April 2007 According to the Reader's Digest, children and adults send up a billion balloons each year in celebration.

Decoration or entertainment

main: Toy balloon

Filling the balloon with air can be done with the mouth, a manual or electric inflater (such as a hand pump), or with a source of compressed gas.

When rubber balloons are filled with helium so that they float, they typically retain their buoyancy for only a day or so. The enclosed helium atoms escape through small pores in the latex which are larger than the helium atoms. Balloons filled with air usually hold their size and shape much longer.

Even a perfect rubber balloon eventually loses gas to the outside. The process by which a substance or solute migrates from a region of high concentration, through a barrier or membrane, to a region of lower concentration is called diffusion. The inside of balloons can be treated with a special gel (for instance, the polymer solution sold under the "Hi Float" brand) which coats the inside of the balloon to reduce the helium leakage, thus increasing float time to a week or longer.