# Unique properties of water **URL:** \ **Category:** Factual Questions\ **Created:** [December 9, 2018, 3:57pm UTC](https://boards.straightdope.com/t/unique-properties-of-water/825851 "2018-12-09T15:57:52Z")\ **Posts on this page:** 6\ **Page:** 3
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [December 12, 2018, 8:55pm UTC](https://boards.straightdope.com/t/unique-properties-of-water/825851/41 "2018-12-12T20:55:13Z")
> [@md2000](#): > > IIRC it is around 0F /-17C that ice stops expanding as it gets colder and starts contracting. See the chart in this [link](https://physics.stackexchange.com/questions/342707/coefficient-of-linear-expansion-of-ice) that I gave earlier. There’s no such “hump” in that range. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [December 12, 2018, 10:39pm UTC](https://boards.straightdope.com/t/unique-properties-of-water/825851/42 "2018-12-12T22:39:47Z")
But ice isn’t slippery at very cold temperatures. ---
**Author:** ![EastUmpqua](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eastumpqua/32/6025_2.png) [@EastUmpqua](https://boards.straightdope.com/u/EastUmpqua)\ **Post date:** [December 13, 2018, 2:52am UTC](https://boards.straightdope.com/t/unique-properties-of-water/825851/43 "2018-12-13T02:52:31Z")
Another cool thing about water is how much energy it can transfer to the Earth’s atmosphere when warm, moist air gets trapped below cold, dry air (e.g. leeward of the Rockies in N. America). This instability can result in a very rapid phase change from gas to liquid and release a ton of energy. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [December 13, 2018, 12:34pm UTC](https://boards.straightdope.com/t/unique-properties-of-water/825851/44 "2018-12-13T12:34:43Z")
> [@Chronos](#): > > But ice isn’t slippery at very cold temperatures. Indeed, if the explanation at Wikipedia is correct, then ice should be pretty damn grippy as we get toward -250F. In reality, the temperature at which good grip can be achieved (even with ordinary shoes, as opposed to skates) is much higher. It’s been years since I experienced outdoor temperatures much below 0F, but ISTR ice on the sidewalk being not terribly hazardous at those temps. The thing is that ice is slippery at temperatures below what is predicted by the pressure-melting/friction-heating theories. ---
**Author:** ![Enola\_Straight](https://avatars.discourse-cdn.com/v4/letter/e/dec6dc/32.png) [@Enola\_Straight](https://boards.straightdope.com/u/Enola_Straight)\ **Post date:** [December 13, 2018, 2:54pm UTC](https://boards.straightdope.com/t/unique-properties-of-water/825851/45 "2018-12-13T14:54:48Z")
The angle of the molecule itself…104.4775 deg…just happens to be the optimum angle to tessellate 4-space. Water could be used to construct a four dimensional hyper-object. Like a time crystal? > **[Time crystal](https://en.wikipedia.org/wiki/Time_crystal)** > > In condensed matter physics, a time crystal is a quantum system of particles whose lowest-energy state is one in which the particles are in repetitive motion. The system cannot lose energy to the environment and come to rest because it is already in its quantum ground state. Because of this, the motion of the particles does not really represent kinetic energy like other motion; it has "motion without energy". Time crystals were first proposed theoretically by Frank Wilczek in 2012 as a time-based... ---
**Author:** ![EastUmpqua](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eastumpqua/32/6025_2.png) [@EastUmpqua](https://boards.straightdope.com/u/EastUmpqua)\ **Post date:** [December 13, 2018, 10:21pm UTC](https://boards.straightdope.com/t/unique-properties-of-water/825851/46 "2018-12-13T22:21:47Z")
Wikipedia: A tessellation of a flat surface is the tiling of a plane using one or more geometric shapes, called tiles, with no overlaps and no gaps. In mathematics, tessellations can be generalized to higher dimensions and a variety of geometries. And… A normal tiling is a tessellation for which every tile is topologically equivalent to a disk, the intersection of any two tiles is a single connected set or the empty set, and all tiles are uniformly bounded. This means that a single circumscribing radius and a single inscribing radius can be used for all the tiles in the whole tiling; the condition disallows tiles that are pathologically long or thin.[23] Is water a normal tiling? [Previous page](https://boards.straightdope.com/t/unique-properties-of-water/825851.md?page=2)