Monday, December 13, 2004

Apple #9: Balloons


I gave a balloon to a kid today. The balloon was yellow, and the kid liked it.

The first known balloons were made out of animal parts such as bladders or intestines:
  • Jesters and troubadours sometimes inflated the entrails of recently slaughtered animals and "entertained" with them. They even manipulated the inflated animal parts into various shapes.
  • The Aztecs made animal shapes out of the bowels of cats. The bowels were cleaned, turned inside out, twisted, and sewn together at each inflated twist with vegetable thread. When allowed to dry, this thread created a nearly airtight seal. The shaped entrails were then burned in sacrifice with great ceremony. After a highly contagious disease killed most of the cats, the Aztecs took to using the innards of humans, sacrificed apparently for the sole purpose of producing the shaped bowels.

In the 1800's, balloons made of rubber appeared:

  • The first rubber balloon was made by noted physicist Michael Faraday, in 1824, for use in his experiments with hydrogen. He cut two sheets of rubber, laid them together and pressed the edges, which made the sticky rubber adhere. The inside of the balloon was then dusted with flour to prevent the rest of the rubber from sticking to itself.
  • In 1847, J.G. Ingram in London made the first vulcanized rubber balloons, which can be regarded as the forerunner of today's toy balloons.

In the late 1900's, manufacturers began using other materials to make balloons

  • Mylar balloons, which are metallized nylon, were first developed for the New York City Ballet in the 1970's
  • Most toy balloons are now made of latex, which is biodegradable. Exposure to sunlight and microorganisms attack the latex and degrade it. Evidence of this degradation can be seen in the oxidation or "frosting" of the balloons.
  • Latex is harvested from a particular type of rubber tree, in much the same way that sap is gathered from maple trees for syrup.

What happens when a balloon is let go:

  • When a typical helium balloon is released, it rises at a rate of about 2 meters per second. As it rises, it encounters increasingly cooler temperatures and the air pressure drops, which makes the balloon continue to expand. After about 90 minutes, it reaches 28,000 feet (about 5 1/2 miles). At this height, the air temperature has dropped to -40 degrees C and the balloon has expanded to about 700% of its original, uninflated size. This is when the balloon bursts.
  • The bang when a balloon bursts is the sound of the stretched edges of the torn latex snapping back to their pre-inflated size, which happens faster than the speed of sound, thus creating a small sonic boom.

Some literature in which balloons have been mentioned:

  • "Papa," said Jack, "can't you make me a balloon with this piece of whale entrail?" (Swiss Family Robinson)
  • "Gasses are generated in him [the sperm whale]; he swells to a prodigious magnitude; becomes a sort of animal balloon." (Moby Dick)


No comments:

Post a Comment

If you're a spammer, there's no point posting a comment. It will automatically get filtered out or deleted. Comments from real people, however, are always very welcome!