1561: Water Phase Diagram

2015-08-07T15:21:30Z

Metaspy: /* Explanation */ VI in Roman numerals is six, not four

{{comic
| number = 1561
| date = August 7, 2015
| title = Water Phase Diagram
| image = water_phase_diagram.png
| titletext = Vanilla Ice was produced in small quantities for years, but it wasn't until the 90s that experimenters collaborated to produce a sample that could survive at room temperature for several months.
}}

==Explanation==
{{incomplete| Ethion of scientific detail required.}}

This is a modified version of the {{w|phase diagram}} for water. A "phase diagram" is a chart that shows the states, or "phases", that a substance will be in under various temperatures and pressures. Water's phases are particularly well-studied; on a [http://ergodic.ugr.es/termo/lecciones/water1.html real phase diagram for water], there are a great many phases listed.

Most people are familiar with three phases of water—solid, liquid, and gas—and with the fact that an increase in temperature will cause water to change from one state to another. The gas and liquid phases ("water vapor" and "liquid water") are quite straightforward; however, there is in fact not one single solid phase of water ("ice"), but a variety of numbered phases ("ice I" through "ice XV" are currently recognized), several of which are divided into sub-categories. Ordinary, everyday ice is known as "{{w|Ice Ih|ice I<sub>h</sub>}}" ("ice one-h"). Most of the more unusual forms of ice only form under very high pressures.

Randall's phase diagram starts out realistically, though slightly simplified in several ways. For one, it simply uses the name "ice" for the usual form(s). It is focused in on a narrower area than the more complete diagram linked earlier; on that version, the "ice V" region is quite small, and "ice III" is barely visible, whereas both are quite plain to see on Randall's diagram. Lastly, Randall has the pressure scale increase downwards (which facilitates the David Bowie/Queen entry being "under" pressure), where most phase diagrams have pressure increase upwards.

As the diagram continues downwards and the pressure increases, the jokes begin. Beyond the moderately high-pressure forms of ice (ice II, III and V), a real phase diagram has ice VI; Randall has "{{w|Vanilla Ice}}" (the name of a white rap/hip-hop artist from the 1990s). Vanilla Ice's biggest hit, "{{w|Ice Ice Baby}}", used samples from the earlier song "{{w|Under Pressure}}", by {{w|David Bowie}} and {{w|Queen (band)|Queen}}; accordingly, on Randall's diagram, the "Vanilla Ice" region transitions to "David Bowie & Queen" when it is under (even higher) pressure.

Further references to "Ice Ice Baby" are found in the title text. Near the beginning of the song, Vanilla Ice raps the line, "All right stop, collaborate and listen". The unusual choice of "collaborate" in this line has made it memorable, and the word is used in the title text (in a more typical context). The phrase "survive at room temperature for several months" is likely a reference to "Ice Ice Baby" being Vanilla Ice's only major hit, humorously suggesting he faded out of the public view after a few months of fame. Finally, even the word "sample" may be deliberately chosen as a reference to the sampling of "Under Pressure".

Roman number six (VI) can be interpreted as acronym for Vanilla Ice.

Lastly, another image is faintly visible just below and to the right of the "Water Vapor" label. It appears to be a copy of an actual phase diagram for water [https://commons.wikimedia.org/wiki/File:Phase_diagram_of_water.svg from Wikipedia]. It is unclear why this image is present in the picture; it may be some sort of hidden message, or perhaps an error.

===Related comics===
Randall has referenced "Ice Ice Baby" and "Under Pressure", separately and together, on many previous occasions, notably in [[159: Boombox]].

The [[what if?]] that was current at the time of this comic's publication was [http://what-if.xkcd.com/138/ 138: Jupiter Submarine], which began with an even more fanciful phase diagram: that of a submarine.
It also contains a reference to the songs "Under Pressure" and "Ice Ice Baby" in one figure.

The title text of [[1434: Where Do Birds Go]] whimsically suggests another possible phase of water/ice.

==Transcript==
:[A phase diagram is shown with eight labeled regions]

:[The horizontal axis, increasing in value to the the right is labeled:]
:Temperature

:[The vertical axis, increasing in value downwards is labeled:]
:Pressure

:[Region alongside the "Pressure" axis covering about half of its length is labeled:]
:Ice

:[Region spanning top-right corner of graph, i.e. higher temperatures and lower pressures. Below and to the right of the label there seems to be an insert of a small picture of the real phase diagram. The region is labeled:]
:Water vapor

:[Region below "Water vapor" and to the right of "Ice" is labeled:]
:Liquid water

:[Three small regions below "Ice" are going from left to right on the same pressure region, the last ending just under "Liquid water". They are each labeled:]
:Ice II
:Ice III
:Ice V

:[Region below "Ice II", "Ice III", "Ice V" and "Liquid water" is labeled:]
:Vanilla Ice
:(Ice VI)

:[Below "Vanilla Ice" there is a dashed line with two arrows pointing downwards. The region below the dashed line is labeled:]
:David Bowie & Queen

{{comic discussion}}

[[Category: Charts]]

explain xkcd - User contributions [en]

1561: Water Phase Diagram