Balloons

Balloons are flexible enclosures that float in air when filled with a gas lighter than air or when the air inside is heated. They range from small party balloons to large research and weather balloons, and they can be made of latex or foil.

Most disposable party balloons are made of latex, a natural rubber, or foil-coated plastic known as Mylar. Party balloons are typically filled with helium or air; hot air balloons used for recreation rely on a burner to heat the air inside a large fabric envelope.

Balloons have a long history. Hot air balloons were demonstrated by the Montgolfier brothers in 1783. In the same year, hydrogen balloons flown by Jacques Charles and the Robert brothers established gas balloons as an ascent method, complementing the earlier hot air designs.

Today balloons serve many purposes. They are used for decorations, celebrations, and advertising. In scientific and meteorological work, weather balloons carry instruments to measure temperature, pressure, humidity, and wind as they ascend, providing data about the upper atmosphere. Balloons are also employed in environmental monitoring, sonar, and aerial surveys.

Safety and environmental concerns accompany balloon use. Balloons can pose choking hazards, and deflated or discarded balloons contribute litter and may harm wildlife. Hydrogen balloons carry flammability risks, while helium—though non-flammable—has faced supply constraints. Releasing balloons into the environment is discouraged or prohibited in many areas due to fire risks and harm to wildlife and power infrastructure. After use, balloons should be deflated and disposed of properly.