Freezing Water in Unbreakable Containers Some listeners may recall a science class
in which an excitable teacher walked to the front of the class to show off a small, cracked
steel container, seemingly damaged by an incredibly powerful, but tiny force; only for said teacher
to reveal that the damage had been done by nothing more than water. However, what would happen if you put the
water in a container it couldn’t break out of and then froze it? The short answer is that the water still turns
into ice; however, if it genuinely cannot break the bonds of the container it is trapped
inside, it turns into a very different kind of ice than we’re used to seeing. We currently know of 15 different “solid
phases” of water, aka ice, with each type being distinct due to differing density and
internal structure. The form you’re likely most familiar with
is Hexagonal Ice which is what happens when water freezes normally under regular conditions. If you keep lowering the temperature of Hexagonal
ice, it eventually becomes Cubic Ice; tweak the temperature and pressure further and you
can create Ice II, Ice III all the way up to Ice XV. Due to the inherent difficulty of producing
such high/low pressures and temperatures, it has taken science up until as recently
as 2009 to fully document every known form of ice. The majority of ice’s final forms were discovered
in part by a group of researchers in the Chemistry department of Oxford University who were able
to create Ice XII, XIV and XV for the first time. In the case of Ice XV, creating it involved
taking Ice VI and slamming the temperature down to -143 degrees Celsius before exposing
it to pressure 10,000 times greater than the Earth’s own atmosphere. This final form of ice, and by extension form
of water, still managed to surprise even the minds at Oxford when against all of their
expectations, it proved to be totally antiferroelectric, being unable to hold a charge at all. But in the simplest sense, the different forms
of ice are created through a varying combination of both pressure and temperature, the exact
combinations of which can be found out by taking a quick look at the phase diagram of
water linked to in the show notes. However, scientists can artificially tip the
scales in their favour through various means. For example, when creating Ice XIII and XIV,
Dr Christoph Salzmann and his team at Oxford used careful measures of hydrochloric acid
to alter the temperature needed to create the ice. If the above seems rather simple in the scheme
of things, that’s because it was and other scientists, such as Professor John Finney
(who was part of the team that discovered and created Ice XII in 1996) noted as much
when questioned about it, commenting that Salzmann’s team had done in a few years
what other researchers couldn’t do in 40. Back to the question at hand, regular ice,
or at least the version you were familiar with before we told you about the other 14
kinds, is capable of applying massive amounts of force when it freezes and expands. This is due to a very unique trait of water,
mainly that it is less dense as a solid than as a liquid. This density disparity is due to how the molecules
of water react upon freezing; water molecules join together in a rigid hexagonal structure
which leaves a small, but nonetheless significant gap between the atoms that wasn’t there
when the water was liquid. For the curious, water reaches its densest
point at 4 degrees Celsius; any cooler or hotter and it begins to expand. So exactly how much force is the ice capable
of exerting? Well, people have been trying to work this
out for a long time. In 1784 and 1785, one Major Edward Williams
took advantage of the weather in Quebec and repeatedly tried and failed to find a method
of containing ice. Williams at first tried to seal water inside
of artillery shells, the cast iron plugs of which were launched 475 feet at an astonishing
20 feet per second when the pressure become too great. Unperturbed, Williams then took to anchoring
the plugs in place using hooks, only for the shells to split in two. In another experiment, an attempt was made
to fill cannons made of one inch thick cast iron with water only for them too to split
when it was frozen. Academics in Florence later tried to fill
a ball made of one inch thick brass with water only for that too to crack when it was frozen. They later worked out that the force required
to do so clocked in at around 27,720 pounds. For a more exact answer, you need to once
again go back to the water phase diagram linked in the show notes, which shows that ice will
turn into Ice II when the pressure reaches 300 Mega Pascals, which is exactly, 43,511.31
pounds of force per square inch. In other words, that’s the amount of pressure
a container would need to be able to survive to stop water turning into regular ice, instead
causing it to turn into Ice II. So, to answer the initial question, if you
froze water inside a container so strong it couldn’t turn into ice, it would still turn
into ice, just a slightly different type of ice in terms of scientific classification
and its internal structure.
