In this third and final part of the series we briefly recap the specs of the elevated canal project that got
me to thinking about the uses of such elevated canals
The Magdeburg Canal Bridge in Germany might technically be called a navigable aquaduct but it differs
in both feel and practicality from earlier efforts. Compare the smaller ones shown on this web page
Sodium has a weight of 23, oxygen 16 so thats 46+16
or 62 divided by 46 or about 74% sodium.
So, .6 percent sodium oxide x .74 percent sodium
means lunar crust material is about
0.444 percent sodium. or 1 part in 225.
For every gigaton of lunar crust we can produce
4.44 megatons of sodium metal
which is liquid between the temperatues of 98 and 882 °C
and and has a density of .927
when liquid so it
would float on water if you could avoid the
exploding on contact thing.
That one inconvenient fact
probably has cut short a number of Earthly sodium based
naval careers short right there.
As it happens a waterfall of sodium hitting actual water
would look something
like the Fire Falls on Krypton. Hit splatter ***BLADOOM ***
AND EACH PIECE of debris REPEATS the cycle
UNTIL IT IS ALL DONE.
This is just a few tons of sodium. Don’t try it with a million tons. Word.
Understandably, Lunar colonization advocates have thought of the more
glamorous lunar substances like titanium or aluminum or iron. Lunar sodium
neglected because on Earth it is hideously dangerous
to handle in any kind of environment
where it can contact water: Which is to say even in deserts.
When we colonize the Moon we need to not let
Even wise habits born on Earth constrain our thinking.
Notice the wise safety precautions show in these videos.
Presents a phase of pioneer agricultural economy in the early nineteenth century. Portrays Ohio Valley farmers as they fell trees, prepare the lumber, and build a flatboat to carry their produce down the river to market.
This movie is part of the collection: Prelinger Archives
OK I’ll settle for Lunar sprocket locomotives pulling barges along the endless silvery sodium canal lines or maybe solar powered paddlewheel tugs.
I don’t want to hear the phrase “Lunar Riverboat Gambler.”
Are we clear on that part? Good.
This is a map of the lunar surface–
note the 13 km spread between highest and lowest.
That is the equivalent of an Earth gravity elevation of around 2.1 km well within the strength
of limits material limits of iron so elevated iron canals holding liquid sodium will
work if solar heated when needed (or heated by stored solar heat)
and shaded when cooling is required, leveled and filled with Sodium.
The vision is of
a pair of 50 meter wide elevated canals in a 30000 km network
making it easy to sail (OK motor)
from pole to equator ignoring terrain roughness.
(if 10 meters deep 1000 cubic meters of sodium per linear meter of canal, 1 million tons or so
a kilometer, if 30000 km of canals 30 billion tons of sodium requiring mining of about
7 trillion tons of Moon rock– something more than the mass of Phobos–)
The cool part about this is that even in vacuum there is a certain amount
of natural evaporation of even very high vaporizing materials just by the nature
of vapor pressure in vacuum. (Other than near absolute zero)
This is why the 1940s thought that some asteroids were contraterrene matter
(anti-matter) like in the classic works SEETEE SHIP https://en.wikipedia.org/wiki/Seetee_Ship
and SEETEE SHOCK (by Jack Williamson) would
actually have been quite conspicuous.
The (then unknown) solar wind would encounter the vapor pressure
if not the actual surface
and there would be gamma rays.
The upshot of this is that the Lunar canals will start to look like Martian like canals
not in color but in the fact that their linear point to point nature
will have not merely say a pair of 50 meter wide elevated canals
but the sodium metal evaporate from vapor pressure will SHINE
along the canal path at full Moon night on Earth,
coating the regolith for at least kilometers either side over much time.
Sodium vapor pressure
at T (K)
Note that of course typical temperatures in a shaded lunar canal way will be lower,
nonetheless over time–
As the sodium vapor escapes it will condense outside the canal and
basically coat the lunar surface for kilometers on either side.
Over many lunations, definite lines will emerge connecting canal nodes–
thus making our moon resemble–
the pre-1965 picture of Mars as sketched by Percival Lowell!
The final canal network is of course fun to imagine but in the beginning where would you put the first 3000 km of canals?
I would link the poles, the highest point on the equator (farside) for a key launching place,
(a surface skimming orbit will not impact anywhere else) the hi-Titanium mare on Nearside
and high Aluminum terrain in the highlands, as well as the richest Thorium and Potassium
deposits on nearside. Basically for any mineral to link at least the richest sites
so you can mine with the minumum efforts
High volatile sites would of course be a key target such to supply gasses and compounds. .
Sulfur is also available in some minerals. I would link the sub Earth point for a comm antenna,
the anti-Earth point for a radio telescope– you can see the attraction of the idea.
Readers are welcome to list places on the Lunar surface you think should be linked with lunar riverboats.
When will the next great era of canal building begin?