3153: Hot Water Balloon

2025-10-14T14:13:23Z

2607:FB90:352F:816D:AD2:E251:5009:4CCE: Mentions the 2025 international balloon fiesta, which was taking place during the time of posting.

{{comic
| number = 3153
| date = October 10, 2025
| title = Hot Water Balloon
| image = hot_water_balloon_2x.png
| imagesize = 484x232px
| noexpand = true
| titletext = Despite a reputation for safety, the temperatures and surprisingly high pressures make them even more dangerous than the air kind, but the NTSB refuses to investigate accidents because they insist there is no 'transportation' involved.
}}

==Explanation==
{{incomplete|This page was created during a romantic water balloon ride. Don't remove this notice too soon.}}

{{w|Hot air balloon}}s are an [[2940|inconvenient and dangerous]] form of transport in which riders float into the sky in a basket suspended from a large balloon filled with hot air. Considering that the majority of passenger-carrying balloons use hot air, the specificity of the term “air balloon” could be taken to imply that there is another variant that uses something hot other than air. ("Hot air" should rather be considered as a compound term, in contrast to, for example, hydrogen or helium-filled balloons.) {{w|Water balloons}} are typically relatively small, sealed (unlike hot air balloons, which are open at the base), full of cold water, and intended to be thrown in a water balloon fight, a common way to have fun{{cn}} and cool down during hot weather. This comic combines the hot air balloon and the water balloon to create a “vehicle” consisting of a basket attached to a large balloon of heated water.

Such a balloon would float in cooler water, but not in air, unless its contents were heated so strongly that the balloon was filled with steam (i.e. water in gaseous form). A steam-filled balloon would produce more lift than an air-filled balloon of the same size and temperature, since the molecular weight of water is less than the average molecular weight of air, but would have new problems. Its high temperature would be dangerous to work with, and it would be necessary to construct the balloon of materials that would tolerate long-term immersion in steam. If any of the steam cooled below the boiling point of water, it would immediately condense, collapsing that part of the balloon; the buoyancy of the steam would be lost as the same weight of liquid water displaced less of the air outside the envelope. The nearly-boiling water would be an additional hazard to nearby people. To reduce the constant loss of heat from the balloon, with resulting condensation, it would be necessary to insulate the balloon, which would increase its weight, and therefore reduce its carrying capacity.

The title text clarifies that the hot water balloon is not just useless, but actually dangerous, as it has a large container full of hot, pressurized water, naturally leading to accidents. However, the {{w|National Transportation Safety Board}} (NTSB) doesn’t consider the stationary hot water balloon to be a form of {{w|transportation}}, since it doesn't move, and thus they claim any hot water balloon accidents should not fall under their purview. Considering that it is probably a business, hot water accidents would be usually reported to {{w|Occupational Safety and Health Administration}} (OSHA) instead, under criteria for [https://www.cdc.gov/niosh/docs/2016-106/pdfs/2016-106.pdf Occupational Exposure to Heat and Hot Environments]. This title text is similar to that of [[3131|3131: Cesium]] which also expressed a goal of causing an agency to investigate outside their usual purview.
This comic was likely inspired by the International Balloon Fiesta, which was being held in New Mexico during the time of posting.

==Transcript==
{{incomplete transcript|Don't remove this notice too soon.}}
:[A large water balloon is sitting on the ground, with cords connected to a basket nearby with Cueball and Megan inside. The water balloon's color patterns are like a hot air balloon's. Ponytail pokes the balloon with a :finger, and a squirrel is on the ground looking at the basket.]
:[There are squiggly heat lines ({{w|The_Lexicon_of_Comicana#Examples|indotherms}}) emanating from the balloon, as well as movement lines ({{w|The_Lexicon_of_Comicana#Examples|agitrons}}) above the balloon. Above them it says:]
:bloop bloop

:[Text below panel:]
:Hot water balloon rides turn out to be significantly less romantic than the air kind.
{{comic discussion}}<noinclude>
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Ponytail]]

explain xkcd - User contributions [en]

3153: Hot Water Balloon