Crowlspace

Back in 1940 a pulp magazine publisher was looking around for some inspiration to create an SF offering for the hungry hordes of teenagers (boys usually) chasing something to read. Thus was born “Captain Future”, in a series of short-novel length adventures, mostly by long-time SF stalwart Edmond Hamilton (not always under his own name.)

I first encountered Curt Newton, the Captain’s ‘secret identity’, in Dave Kyle’s classic “A Pictorial History of Science Fiction” (and it’s companion volume) from the 1970s, which covered an immense range of SF up to that point in time – perhaps explaining my love for pre-1950s SF. Recently I’ve discovered that many of the novels are now online…

Captain Future (in French)

…the novels online, as PDFs, are available in English and French, a discovery I only made in the last few days. Of course there was the Japanese anime version from the 1970s as well, but I never watched it as a kid and it lacks that kitsch charm of the original 1940s/50s early artwork. However it is really popular in Germany, so who am I to complain.

After reading its associated material – a description of the planets called “Worlds of Tomorrow” – I realised it seemed very familiar. Just about every planet and moon had breathable atmospheres in Edmond Hamilton’s Solar System, even the big planets, and everyone was inhabited by some race of humans adapted a bit to local conditions. Unlike many (dreadful) SF writers before him, Hamilton usually tried to give these aspects plausible (for 1940s ignorance of physics) explanations:

(1) The big planets are warmed to habitability by radioactivity.
(2) A gravity-equaliser worn by everyone made visits to Jupiter feasible for non-natives.
(3) All the varieties of human derive from interstellar colonists, the Denebians, thus explaining their kinship.

…and so on. He even has the occasional correct hit – for example the fictional Pluto has three moons, Charon, Cerebrus and Styx. The real Pluto, of course, has three known moons and the largest is Charon. Hamilton was just following the mythological naming convention associating Pluto with underworld figures, but the fact he imagined moons when none were known (Charon was discovered in 1978) is a plus IMO.

Of course Hamilton needed to propel Captain Future’s ship, “Comet”, around at high-speed and thus he used that favourite of old SF, atomic power, but deriving from copper, and liberated by bombarding the copper with particles from cyclotrons. Oh well, all adventure SF has its share of technobabble…

Update on my UFO… I saw it again, but this time it was a bit more clearly a plane in the sunlight. No wonder so many dodgey videos of UFOs get taken – a featureless point of light in the daylight sky just doesn’t fit in the everyday person’s mental categories. You have to really, really watch the regular traffic of the sky to get to know the real anomalies.

“New Scientist” article on the evolution of whales and why they didn’t learn to breathe water…

Why Whales Don’t Have Gills

…basically it’s too much hard work for not enough oxygen. Whales, as mammals, need a good oxygen supply and there just isn’t enough in sea water to get at without the whale getting exhausted. Moving all that water in and out of one’s lungs/gills is very hard work – a mammal would need to breathe kilograms of sea water at a time rather than the mere grams of air it does breathe.

Often people wonder: why don’t we colonize the sea instead of space since it is so much closer?

But how close is it really? Beyond a few metres the pressure rises to levels that challenge our freedom to move – you can’t ascend too rapidly without risking the “bends”. Plus there’s very little oxygen, little light and very little else. In space pressure is never a problem and light is everywhere. In the sea any kind of heat processing suffers from the heat-sapping presence of water, but in space one can vapourise metals and silicates via concentrated sunlight.

So I have a few reservations about the whole “colonise the sea instead of space” idea. As NASA has long realised the two require similar and yet dissimilar technologies – it uses underwater laboratories as training environments for its astronauts, but isn’t planning on colonising the great oceanic deserts anytime soon.

Addendum:
Kurt9’s comment makes another good point…

The ocean is a remarkably hostile environment from a structural engineering standpoint. Seawater is corrosive and you have 50 meter rogue waves to deal with. You also have to deal with typhoons if you are not within 5 degrees latitude of the equator. Space is actually a more benign environment for structures, but is very expensive to access as of yet.

The popular Space Press has heard about VASIMR and its amazing potential for interplanetary travel for over a decade. What’s neglected in most presentations is the hefty power requirement of high-performance VASIMR systems. No current power source is up to the task of propelling vehicles to Mars in 39 days or so.

A paper that the amazing “39 days” time-frame might be quoted from is this one…

Andrew Petro’s Presentation from 2002 at NASA

…but it’s a pretty hefty vehicle needed to achieve that performance, some 600 tons of which 476 tons is propellant and 22 tons of payload. Powering a 200 MW VASIMR is no small exercise either requiring considerable advancement in nuclear power in-space. Franklin Chang-Diaz, chief scientist working on VASIMR, discussed the kind of power-source needed in this paper…

Fast, Power-Rich Space
Transportation, Key to
Human Space Exploration
and Survival

…which describes a vapour or plasma core nuclear reactor with an MHD power-extractor/converter which gets a specific power of about 2 kWe/kg of power system. It’d mass about 100 tons to give a 200 MWe supply. Thus the 39 day VASIMR mass-breakdown is…

476 tons propellant
100 tons power-supply
24 tons payload/structure

…quite a hefty machine, but that’s the price of top performance.

High-power is no small task to supply for a reasonable power-supply mass in-space. A terrestrial power-reactor can’t just be deployed in space as many of its systems are designed requiring both gravity and open-cycle sources of water and air available as heat-sinks. Thermal power conversion of heat to electricity is inherently inefficient in space because the only way to dump waste heat – other than as a hot gas jet – is via radiators, and to be light-weight radiators operate best at about 75% the temperature of the heat-source. Thus the efficiency is usually less than 25%. Thermoelectric conversion might one day improve this figure out of sight, but currently 20-30% is the best performance squeezed out of Stirling cycles and similar thermal power conversion systems.

But what of non-thermal power conversion? Magneto-HydroDynamic (MHD) power converters have been researched for decades, but on Earth these have issues with sufficient ionizing of the working fluid stream. In space, using highly-ionizing systems like vapour, gas or plasma core reactors and MHD comes into its own, allowing very high conversion efficiencies for low system masses.

A popularized discussion from the University of Florida… NEP with Vapor Core Reactor & MHD

Some additional papers…
Vapor-Gas Core Nuclear Power Systems
with Superconducting Magnets
Development of Liquid-Vapor Core Reactors with MHD
Generator for Space Power and Propulsion Applications

Fire and Ice, Venus and Mars, are just beyond the limits of the Habitable Zone in our solar system. How might worlds turn out differently? Consider the science-fictional creations of Tenebra (Hal Clement) and Arrakis (Frank Herbert) – both orbit relatively close to their stars, Altair and Canopus, yet are strikingly different. Tenebra has retained its water, but as a super-critical atmosphere/ocean with an infernally hot surface temperature varying between 380-370^oC. The pressure and gravity are crushing, but also the ground is unstable due to the highly reactive atmosphere – super-critical water – dissolving and recrystalising the rocks continually. Arrakis is hot, but not inhumanly so everywhere, and it is utterly dry, with only tiny ice-caps. Every scrap of water is conserved and, unless needed, stored up.

Surprisingly Arrakis/Dune isn’t absurd. A world with more land than sea – a world of, at most, disconnected lakes – is more stable against the higher levels of insolation that threaten to propel it into a super-torrid Greenhouse state like Tenebra, or Venus. Recent findings from Earth’s “Evil Twin” indicate distinct types of rock masses rather than uniform lava-plains – in otherwords, continental land-masses. Thus Venus may once have been more like Earth, with Earth-like geological processes making Earth-like land. Then it “died” in a planetary autoclave as its oceans evaporated in what’s called a “runaway greenhouse” effect – a rise in water vapour causes more heat retention, producing even more water vapour and even more heat… until it’s all steam and the planet cooks. This runaway is thought to occur when the heat from the Sun is 30-40% higher than what Earth currently receives, though that’s complicated somewhat by more reflective cloud masses forming.

But what happens when there’s not enough water to runaway? Hot, but reflective desert plains, can bounce a fair bit of heat away, and the lack of water means things never runaway like on Venus or Tenebra. According to work by Yutaka Abe and colleagues such a “Land-Planet” can remain hospitable, in part, at up to 70% more heat input from the Sun.

At the other end of the heat-scale does water or desert make a difference? see Part II