Friday, March 24, 2006

Doctor Who Science: Icecanoes

At one point I was going to write a 'science' in Doctor who book except no publisher seemed interested (or solvent) at one and the same time, until alas, someone else did. But here's a bit I prepared earlier anyway...

The aim was to have at least one entry for each of the TV stories, cross-indexed by topic and story, thus:

Index entries for text below.

Planet of The Daleks – ICECANOES
Planet of The Daleks – INVISIBILITY example of
Planet of The Daleks – CRYOGENIC SUSPENSION example of
Allotropes, see ICECANOES
ICECANOES

Specimen Text.

ICECANOES

Definition

Not a form of Kayek used to negotiate a frozen lake: but a natural planetological feature, found on the world Spirodon (Planet of the Daleks). An icecano is to a volcano what ice is to lava.

Use/importance in story.

Seizing on the natural underground refrigeration implicit in a planet with ice instead of lava running through it the Daleks have invaded Spirodon to store a massive army for their future conquest of the galaxy and to study the natives’ INVISIBILITY. The Cybermen adopted a similar policy towards the erstwhile iceworld Telos see CRYOGENIC SUSPENSION.

Scientific Plausibility.

How is this possible? Well for a start we’re told the ice is an allotropic form with different properties. “Allotropy” refers to variations in the chemical bond structure between atoms of the same kind, the most obvious example being Carbon: with its carbon, diamond, and buckminsterfullerene forms.

Interestingly the Nestene in an Alan Moore comic strip in DWM, Business As Usual purchase their way into the plastics industry, by offering “an entirely new way of bonding carbon atoms”, at the time the strip was written, Buckminsterfullerenes were not widely known. Another triumph of prediction for Alan Moore and Doctor Who, or the insideous influence of the Nestene Consciousness? Only you can decide.

Ice, normal ice, is not an allotrope but a phase state of water. The implication here is that the allotropic form has a much higher melting point and can form a sort of freezing high pressure slush, that is spewed out of the interior of Spirodon.

There are two problems with this.

1) It’s unclear exactly how the water got into the interior of the planet in the first place without blowing a massive steam bubble as it hit molten rock, but we could assume that a) the planet lacks an iron core, and hence has no magnetic field – a feature the Dalek’s may also appreciate, and that b) during the accretion/planet building phase of the Spirodon solar system a giant ice asteroid acted as a “seed” for the planet’s coallescence. Plausibility of a planet having a core of ice: low, but not impossible.

2) Even if a planet did have an Ice core, it wouldn’t act like that. It is true that there are allotropic forms of the normal hexagonal “snowflake” crystal form of water ice, either found on Earth, or predicted as theoretical structures in high pressure environments. These are named Ice I (and onwards in Roman numerals), and there are a number of subforms. Ice with a “c” prefix for instance “Ice cI” has a cubic rather than an hexagonal structure, and water under great pressure (2.3 Gpa(2)) can form Ice VII(3), at temperatures of over 100 degrees C.

GigaPascals. The SI unit of pressure is the pascal, symbol Pa, the special name given to a pressure of one newton per square metre (N/m2). A GigaPascal is 1,0E+9, or 1 billion (1,000,000,000) newtons per square metre. The pressure of the Earth’s atmosphere at sea-level (one standard atmosphere) is roughly 100,000 Pa, so Ice VII forms spontaneously from water at about 23,000 atmospheres of pressure.

Other uses of allotropic or “odd” ice in fiction.

Terry Pratchett has a planet made entirely of water with Ice VII at the core in The Dark Side Of The Sun].

Kurt V makes use of Ice-7 to destroys the world by making the oceans freeze at room temperature.

Plausibility of allotropic ice acting like it does in Planet of The Daleks: very low, because even if allotropic Ice can exist at higher temperatures, you can’t actually use it to freeze things unless it is at lower temperatures. If Ice VII was being shot out of an Icecano, it wouldn’t freeze a Spirodonian but burn him. “He burned to death in a block of ice, officer”.

Thematic plausibility

And yet, it’s appropriate that the Daleks and invisibility are bound up together with a planet of Ice. Appropriate for the Daleks because thematically they carry the Nazi ideology reworked as science fiction, and it was the Nazis, who, among their other scientific and moral errors, subscribed to the so called “Glacial Cosmogony” or the Universal Ice Doctrine (Welteislehre) of Hans Horbinger according to which the moon was covered in ice, and the stars were ice crystals. Nazi analogues then, would not be surprised to find worlds of Ice. Ice is appropriate for invisibility because Ice has a nearly perfect refractive index, 1.31 to that of glass (1.5), water (1.33), and air (1.0003), and because in H. G. Well’s The Invisible Man, it is the snow that is his undoing.

Sources for bibliography at end:
N. H. Fletcher. The Chemical Physics of Ice. Cambridge University Press. Cambridge, 1970.

2 comments:

Stuart Douglas said...

That sounds considerably more interesting than 'Tea Spoon and an Open Mind' that I flicked through in the bookshop the other day.

Really, Simon - you need to get this kind of thing (and the typo definitions collection) published.

Not that you don't already know that...

Tardieu said...

I always loved Asimov's chatty, way of presenting science. Usually starting with a story then shooting off on various tangents as the mood took him. The breadth of reference both factual and fictional makes a terrific read.