Bacterially induced megastructures

That's a really beautiful post, the photographs and pictures are
fantastic as well.

"Clarifying the biochemical process through which his project could be
realized, Larsson explained in a series of emails that his "structure
is made straight from the dunescape by flushing a particular bacteria
through the loose sand... which causes a biological reaction whereby
the sand turns into sandstone; the initial reactions are finished
within 24 hours, though it would take about a week to saturate the
sand enough to make the structure habitable." The project – a kind of
bio-architectural test-landscape – would thus "go from a balloon-like
pneumatic structure filled with bacillus pasteurii, which would then
be released into the sand and allowed to solidify the same into a
permacultural architecture.""

"I researched different types of construction methods involving pile
systems and realised that injection piles could probably be used to
get the bacteria down into the sand – a procedure that would be
analogous to using an oversized 3D printer, solidifying parts of the
dune as needed. The piles would be pushed through the dune surface and
a first layer of bacteria spread out, solidifying an initial surface
within the dune. They would then be pulled up, creating almost any
conceivable (structurally sound) surface along their way, with the
loose sand acting as a jig before being excavated to create the
necessary voids. If we allow ourselves to dream, we could even
fantasise about ways in which the wind could do a lot of this work for
us: solidifying parts of the surface to force the grains of sand to
align in certain patterns, certain shapes, having the wind blow out
our voids, creating a structure that would change and change again
over the course of a decade, a century, a millenium."

"A vast 3D printer made of bacteria crawls undetectably through the
deserts of the world, printing new landscapes into existence over the
course of 10,000 years..."

What first came to mind when I saw this was ant and termite mounds.
When studying ridiculously large ant mounds, what researchers do is
pump some plaster throughout the entire structure and then let it sit.
They then excavate it and look at the overall pattern. But using
bacillus pasteurii might be more appropriate.

I can't help but think of selective laser sintering, a method of
printing 3D shapes. You have this giant bucket of "sand", you raster
scan a laser and the polymer or 'sand' polymerizes or whatever special
material you're using, and ultimately the result is the shape that you
wanted. So, what about photoactivation of a regulatory circuit of this
bacteria? Suppose you engineered a GRN in these bacteria such that the
lithification only occured once a certain gene is activated by laser
stimulation (chromophores?). Using a very specific wavelength of laser
that can get through the atmosphere, you could use a laser in orbit to
do selective laser sintering fabrication with deserts. You could
literally do rapid prototyping of deserts- it would require a
satellite in orbit, which is somewhat of a cost, although less costly
than running a giant 3D printer around on the desert forever (rather
than just positioning some mirrors up in orbit).

"Bacteria Could Steady Buildings Against Earthquakes"

http://www.spacedaily.com/reports/Bacteria_Could_Steady_Buildings_Against_Earthquakes_999.html

"""
Soil bacteria could be used to help steady buildings against
earthquakes, according to researchers at UC Davis. The microbes can
literally convert loose, sandy soil into rock. When a major earthquake
strikes, deep, sandy soils can turn to liquid, with disastrous
consequences for buildings sitting on them. Currently, civil engineers
can inject chemicals into the soil to bind loose grains together.

But these epoxy chemicals may have toxic effects on soil and water,
said Jason DeJong, an assistant professor of civil and environmental
engineering at UC Davis.

The new process, so far tested only at a laboratory scale, takes
advantage of a natural soil bacterium, Bacillus pasteurii. The microbe
causes calcite (calcium carbonate) to be deposited around sand grains,
cementing them together. By injecting bacterial cultures, additional
nutrients and oxygen, DeJong and his colleagues found that they could
turn loose, liquefiable sand into a solid cylinder.

"Starting from a sand pile, you turn it back into sandstone," DeJong
said. Similar techniques have been used on a smaller scale, for
example, to repair cracks in statues, but not to reinforce soil.

The new method has several advantages, DeJong said. There are no
toxicity problems, compared with chemical methods. The treatment could
be done after construction or on an existing building, and the
structure of the soil is not changed -- some of the void spaces
between grains are just filled in.

DeJong and his collaborators are working on scaling the method up to a
practical size, and applying for funds to test the method in the
earthquake-simulating centrifuge at UC Davis' Center for Geotechnical
Modeling. The centrifuge is part of the national Network for
Earthquake Engineering Simulation, funded by the National Science
Foundation.

A paper describing the work has been published in the Journal of
Geotechnical and Geoenvironmental Engineering. The other authors are
Michael Fritzges, a senior engineer at Langan Engineering,
Philadelphia; and Klaus Nusslein, associate professor of microbiology
at the University of Massachusetts, Amherst. The work was supported by
the National Science Foundation.
"""

Microbially Induced Cementation to Control Sand Response to Undrained Shear
http://www.bgu.ac.il/geol/classes/hazard/Front/papers/DeJong2006.pdf

And from another paper-

Applications of microorganisms to geotechnical engineering for
bioclogging and biocementation of soil in situ

"Microbial Geotechnology is a new branch of geotechnical engineering
that deals with the applications of microbiological methods to
geological materials used in engineering. The aim of these
applications is to improve the mechanical properties of soil so that
it will be more suitable for construction or environmental purposes.
Two notable applications, bioclogging and biocementation, have been
explored. Bioclogging is the production of pore-filling materials
through microbial means so that the porosity and hydraulic
conductivity of soil can be reduced. Biocementation is the generation
of particle-binding materials through microbial processes in situ so
that the shear strength of soil can be increased. The most suitable
microorganisms for soil bioclogging or biocementation are facultative
anaerobic and microaerophilic bacteria, although anaerobic fermenting
bacteria, anaerobic respiring bacteria, and obligate aerobic bacteria
may also be suitable to be used in geotechnical engineering. The
majority of the studies on Microbial Geotechnology at present are at
the laboratory stage. Due to the complexity, the applications of
Microbial Geotechnology would require an integration of microbiology,
ecology, geochemistry, and geotechnical engineering knowledge."

- Bryan
http://heybryan.org/
1 512 203 0507

Wait, why would you have to be in orbit? Find yourself a mountain, or
build a tower, and just project and draw under the horizon. This would
be using the same mechanism of xy laser scanners that draw virtual
grafitti on buildings, which I've mentioned previously here--

http://groups.google.com/group/diybio/msg/50fc34ff5d7adbc1

.. except in this case the light would be activating the regulatory
circuits in the bacteria in the pattern that you describe. You would
need a flat surface, unless you have a perfectly sloped terrain and
know some basic trig, otherwise your result will be all skewed and
weird-like. There's an interesting phenomena associated with deserts
called singing sand.

http://en.wikipedia.org/wiki/Singing_sand

"Singing sand, whistling sand or barking sand is sand that produces
sounds of either high or low frequency under pressure. The sound
emission is usually triggered by wind passing over dunes or by walking
on the sand. The sound is generated by shear stress ... the most
common frequency emitted seems to be close to 450 Hz. Singing sand
dunes, an example of the phenomenon of singing sand, produce a sound
described as roaring, booming, squeaking, or the "Song of Dunes". This
is a natural sound phenomenon of up to 105 decibels lasting as long as
several minutes that occurs in about 35 desert locations around the
world. The sound is similar to a loud, low-pitch, rumble, and it
emanates from the crescent-shaped dunes, or barchans. The sound
emission accompanies a slumping or avalanching movement of the sand,
usually triggered by wind passing over the dune or by someone walking
near the crest. Examples of singing sand dunes include California's
Kelso Dunes and Eureka Dunes, sugar sand beaches and Warren Dunes in
southwestern Michigan, Sand Mountain in Nevada, the Booming Dunes in
the Namib Desert, Africa, Porth Oer (also known as Whistling Sands)
near Aberdaron in Wales, Indiana Dunes in Indiana, Barking Sands in
Hawaii, and Singing Beach in Manchester-by-the-Sea, Massachusetts."

Here's a paper on working towards quantifying all this--

Surface elastic waves in granular media under gravity and their
relation to booming avalanches
http://www.pmmh.espci.fr/fr/morphodynamique/papers/A29_PhysRevE_75_016602.pdf

"Due to the nonlinearity of Hertzian contacts, the speed of sound c in
granular matter is expected to increase with pressure as P^(1/6). A
static layer of grains under gravity is thus stratified so that the
bulk waves are refracted toward the surface. The reflection at the
surface being total, there is a discrete number of modes (both in the
sagittal plane and transverse to it) localized close to the free
surface. The shape of these modes and the corresponding dispersion
relation are investigated in the framework of an elastic description
taking into account the main features of granular matter: Nonlinearity
between stress and strain and the existence of a yield transition. We
show in this context that the surface modes localized at the free
surface exhibit a waveguide effect related to the nonlinear Hertz
contact. Recent results about the song of dunes are reinterpreted in
light of the theoretical results. The predicted propagation speed is
compared with measurements performed in the field. Taking into account
the finite depth effects, we show that the booming instability
threshold can be explained quantitatively by a waveguide cutoff
frequency below which no sound can propagate. Therefore, we propose
another look at a recent controversy, confirming that the song of
dunes can well originate from a coupling between avalanching grains
and surface elastic waves once the specificity of surface waves (we
baptized Rayleigh-Hertz) is correctly taken into account."

Why would this be useful? Well, what comes to mind is sonic
sculptures, which are sometimes used in sonic gardens, either made out
of bamboo, steel, wood, etc.

http://www.singingbridges.net/about/ `"Singing bridges" is a sonic
sculpture, playing the cables of stay-cabled and suspension bridges as
musical instruments. To create this work I will amplify and record the
sound of bridge cables around the world. Listening in to the secret
voice of bridges as the inaudible vibrations in the cables are
translated into sound.`

http://www.marshallarts.ie/lyric.htm
http://www.math.binghamton.edu/alex/kinetic.html
and in general: http://en.wikipedia.org/wiki/Sound_sculpture

What could we make, then? Giant vocal amplifiers? Whisper to the
desert? Largest instance of RIAA copyright violations, ever
imaginable? Making wind amplification tunnels for ultrasonic and
hypersonic studies? Largest dog whistle ever? Basically this is like
patterning really really giant brass instruments. Even if you could
somehow miraculously pattern out individual instruments with
individual tones per each structure, or something, I don't know how
you would be able to play specific symphonies or musical pieces
without using something other than sound and wind to block certain
instruments for some period of time. Very large pneumatic sand
circuits? Ok, ok, maybe housing for now per the original suggestion.