balloon

balloon

[buh-loon]
balloon, lighter-than-air craft without a propulsion system, lifted by inflation of one or more containers with a gas lighter than air or with heated air. During flight, altitude may be gained by discarding ballast (e.g., bags of sand) and may be lost by releasing some of the lifting gas from its container.

Although interest in such a craft dates from the 13th cent., the balloon was not actually invented until the late 18th cent., when two French brothers, Joseph and Jacques Étienne Montgolfier, experimented with inverted paper and cloth bags filled with heated air and, in 1783, caused a linen bag about 100 ft (30 m) in diameter to rise in the air. In the same year the Frenchmen Pilâtre de Rozier and the marquis d'Arlandes made one of the first balloon ascents by human beings, rising in a hot-air-filled captive balloon (i.e., one made fast by a mooring cable to prevent free flight) to a height of 84 ft (26 m). In 1766 the English scientist Henry Cavendish had shown that hydrogen was seven times lighter than air, and the usefulness of this gas in balloon ascension was demonstrated in Dec., 1783, by J. A. C. Charles of France, who with his associates successfully ascended in a hydrogen-filled balloon and traveled 27 mi (43 km) from the starting point.

The first ascent in England was made by James Tytler, a Scottish writer, in 1784, and in 1793 the French balloonist J. P. Blanchard made an ascent at Philadelphia. Blanchard, with Dr. John Jeffries, an American physician, also made the first sea voyage by balloon, crossing the English Channel in 1784. Among the noted balloon voyages of the 19th cent. was that made by the Swedish engineer S. A. Andrée, who, in 1897, attempted unsuccessfully to reach the North Pole by balloon. In the American Civil War and World War I, captive balloons were used to observe troop movements and to direct gunfire. Captive balloons, called barrage balloons, were used as obstacles against low-flying aircraft in World War II.

The helplessness of the free balloon in controlling direction led to the development of the dirigible balloon (see airship). In 1932 the Swiss physicist Auguste Piccard, one of the major figures in 20th-century ballooning, ascended in a balloon with a sealed spherical gondola to a height of 55,500 ft (17,000 m); since then manned balloons have reached heights of 100,000 ft (30,500 m) and unmanned balloons have exceeded 140,000 ft (42,500 m). The Americans Ben Abruzzo, Maxie Anderson, and Larry Newman made the first transatlantic crossing in 1978, and in 1981 Abruzzo, Newman, Rocky Aoki, and Ron Clark crossed the Pacific. In Mar., 1999, Jacques Piccard, Auguste's grandson, and Briton Brian Jones made the first nonstop balloon flight around the world; the American Steve Fossett completed the first nonstop solo circumnavigation in July, 2002. Today high-altitude hydrogen balloons carry aloft radios and other instruments, used to transmit meteorological readings or to take photographs free from atmospheric distortion.

In contemporary sporting balloons, which use air heated by a small gas-fired burner, altitude is controlled by varying the temperature of the heated air. Hot-air balloons represent the fastest-growing segment of ballooning. Gas bags made with space-age materials are more durable and weigh far less than the traditional silk; heaters have similarly become more efficient. While ballooning remains dangerous, the hot-air balloon's slow response time offers a unique sensation of effortless motion through the atmosphere.

See A. Hildebrandt, Balloons and Airships (1976); J. P. Jackson and R. J. Dichtl, The Science and Art of Hot Air Ballooning (1977); B. Piccard and B. Jones, Around the World in 20 Days (1999).

Large airtight bag filled with hot air or a lighter-than-air gas such as helium or hydrogen that can rise and float in the atmosphere. Experimental attempts may have begun by 1709, but not until 1783 did J.-M. and J.-É. Montgolfier develop a fabric-bag balloon that would rise when filled with hot air. Balloons provided military aerial observation sites in the 19th century and were used in the 20th century by scientists such as Auguste Piccard to gather high-altitude data. The first round-the-world balloon flight was achieved in 1999 by Bertrand Piccard and Brian Jones. Seealso airship.

Learn more about balloon with a free trial on Britannica.com.

A balloon is a flexible bag filled with a type of gas, such as helium, hydrogen, nitrous oxide or air. Early balloons were made of dried animal bladders. Modern balloons can be made from materials such as rubber, latex, polychloroprene or a nylon fabric. 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

It is believed the fiftheenth century African Americans made balloons out of paper. Japanese made origami air-filled objects; but they did not float. "Indians of Central and South America made balls balls of rubber much as we make ballons today" (Reader's Digest). In 1643 Evangelista Toricelli, an Italian physicist, showed air was some more than nothing. The Chinese,Japanese and Native American cultures led to beginning of the balloon . The first balloon was invented by Brazilian-born Portuguese priest, Bartolomeu de Gusmão, and the first public exhibition was to the Portuguese Court on August 8, 1709, in the hall of the Casa da India 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.According to the Reader's Digest, children and adults send up a billion ballons each year.

Applications

Decoration or entertainment

Party balloons are mostly made of natural latex tapped from rubber trees, and can be filled with air, helium, water, or any other suitable liquid or gas. The rubber's elasticity makes the volume adjustable.

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 the 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.

Beginning in the late 1970s, some more expensive (and longer-lasting) foil balloons have been made of thin, unstretchable, less permeable metalized plastic films. These balloons have attractive shiny reflective surfaces and are often printed with color pictures and patterns for gifts and parties. The most important attribute of metalized nylon for balloons is its light weight, increasing buoyancy and its ability to keep the helium gas from escaping for several weeks.

Professional balloon party decorators use electronic equipment to enable the exact amount of helium to fill the balloon. For non-floating balloons air inflators are used. Professional quality balloons are used, which differ from most retail packet balloons by being larger in size and made from 100% biodegradable latex.

Balloon modeling and balloons in art

Balloon artists are entertainers who twist and tie inflated tubular balloons into sculptures (see balloon animal). The balloons used for balloon sculpture are made of extra-stretchy rubber so that they can be twisted and tied without bursting. Since the pressure required to inflate a balloon is inversely proportional to the diameter of the balloon, these tiny tubular balloons are extremely hard to inflate initially. A pump is usually used to inflate these balloons.

Decorators may use hundreds of helium balloons to create balloon sculptures. Usually the round shape of the balloon restricts these to simple arches or walls, but on occasion more ambitious "sculptures" have been attempted. It is also common to use balloons as tables decorations for celebratory events. Table decorations normally appear with 3 or 5 balloons on each bouquet. Ribbon is curled and added with a weight to keep the balloons from floating away.

Water balloons

Water balloons are thin, small rubber balloons intended to be easily broken. They are usually used by children, who throw them at each other, trying to get each other wet, as a game or practical joke. They can be used in competitions or games. They are often smaller than regular balloons.

Balloon rockets

Balloons are often deliberately released, creating so called balloon rocket or rocket balloon. Rocket balloons work because the elastic balloons contract on the air within them, and so when the mouth of the balloon is left open, the gas within the balloon shoots out, and, due to _law_of_reciprocal_actions, the balloon is propelled forward. This is fundamentally the same way that a rocket works.

Flying machines

Large balloons filled with hot air or buoyant gas have been used as flying machines since the 18th century. The earliest flights were made with hot air balloons using air heated with a flame, or hydrogen; later, helium was used.

Medicine

Angioplasty is a surgical procedure in which very small balloons are inserted into blocked or partially blocked blood vessels near the heart. Once in place, the balloon is inflated to clear or compress arterial plaque, and to stretch the walls of the vessel, thus preventing myocardial infarction. A small stent can be inserted at the angioplasty site to keep the vessel open after the balloon's removal.

Balloon catheters are catheters that have balloons at their tip to keep them from slipping out. For example, the balloon of a Foley catheter is inflated when the catheter is inserted into the urinary bladder and secures its position.

Safety and environmental concerns

There has been some environmental concern over metalized nylon ballons, as they don't biodegrade or shred as rubber balloons do, and a helium balloon released into the atmosphere can travel a long way before finally bursting or deflating. Release of these types of balloons into the atmosphere is considered harmful to the environment. This type of balloon can also conduct electricity on its surface and released foil balloons can become entangled in power lines and cause power outages.

Released balloons can land almost anywhere, including on nature preserves or other areas where they pose a serious hazard to animals through ingestion or entanglement. Latex balloons are especially dangerous to marine life because latex retains its elasticity for 12 months or more when exposed to sea water rather than air. Because of the harm to wildlife and the effect of litter on the environment, some jurisdictions even legislate to control mass balloon releases. Legislation proposed in Maryland, USA was named after Inky, a pygmy sperm whale who needed 6 operations after swallowing debris, the largest piece of which was a mylar balloon.

See also

Notes

"Reader's Digest: Stories Behind Everyday Things"New York:Reader's Digest,1980.

External links

Search another word or see balloonon Dictionary | Thesaurus |Spanish
Copyright © 2014 Dictionary.com, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature