Reading List: Monsters
Saturday, January 30, 2016 21:49
Reading List: Countdown to a Moon Launch
Saturday, January 23, 2016 21:38
Reading List: The Hunt for Vulcan
Saturday, January 16, 2016 23:06
Reading List: Rust
Saturday, January 9, 2016 22:20
New Year's Aurora 2016-01-01
Friday, January 1, 2016 03:24
Saturday, January 30, 2016 21:49
- Regis, Ed.
New York: Basic Books, 2015.
In 1863, as the American Civil War raged, Count Ferdinand von Zeppelin,
an ambitious young cavalry officer from the German kingdom of
Württemberg arrived in America to observe the conflict and
learn its lessons for modern warfare. He arranged an audience
with President Lincoln, who authorised him to travel among
the Union armies. Zeppelin spent a month with General Joseph
Hooker's Army of the Potomac. Accustomed to German military
organisation, he was unimpressed with what he saw and left to see
the sights of the new continent. While visiting Minnesota, he
ascended in a tethered balloon and saw the landscape laid out
below him like a military topographical map. He immediately
grasped the advantage of such an eye in the sky for military
purposes. He was impressed.
Upon his return to Germany, Zeppelin pursued a military career,
distinguishing himself in the 1870 war with France, although
being considered “a hothead”. It was this
characteristic which brought his military career to an abrupt
end in 1890. Chafing under what he perceived as stifling
leadership by the Prussian officer corps, he wrote
directly to the Kaiser to complain. This was a bad career move;
the Kaiser “promoted” him into retirement. Adrift,
looking for a new career, Zeppelin seized upon controlled aerial
flight, particularly for its military applications. And he
By 1890, France was at the forefront of aviation. By 1885 the
had demonstrated aerial navigation over complex closed courses
and carried passengers. Built for the French army, it was just a
technology demonstrator, but to Zeppelin it demonstrated a capability
with such potential that Germany must not be left behind.
He threw his energy into the effort, formed a company, raised the
money, and embarked upon the construction of
Luftschiff Zeppelin 1
Count Zeppelin was not a man to make small plans. Eschewing
sub-scale demonstrators or technology-proving prototypes, he
went directly to a full scale airship intended to be militarily
useful. It was fully 128 metres long, almost two and a half
times the size of La France,
longer than a football field. Its rigid aluminium frame
contained 17 gas bags filled with hydrogen, and it was powered
by two gasoline engines. LZ 1 flew just three times. An
observer from the German War Ministry reported it to be
“suitable for neither military nor for non-military purposes.”
Zeppelin's company closed its doors and the airship was sold for
By 1905, Zeppelin was ready to try again. On its first flight, the LZ 2
lost power and control and had to make a forced landing. Tethered
to the ground at the landing site, it was caught by the wind and
destroyed. It was sold for scrap. Later the LZ 3 flew
successfully, and Zeppelin embarked upon construction of the LZ 4,
which would be larger still. While attempting a twenty-four hour
endurance flight, it suffered motor failure, landed, and while tied
down was caught by wind. Its gas bags rubbed against one another and
static electricity ignited the hydrogen, which reduced the airship
to smoking wreckage.
Many people would have given up at this point, but not the redoubtable
Count. The LZ 5, delivered to the military, was lost when carried away
by the wind after an emergency landing and dashed against a hill. LZ 6
burned in its hangar after an engine caught fire. LZ 7, the first
civilian passenger airship, crashed into a forest on its first flight
and was damaged beyond repair. LZ 8, its replacement, was destroyed
by a gust of wind while being walked out of its hangar.
With the outbreak of war in 1914, the airship went to war. Germany
operated 117 airships, using them for reconnaissance and even
bombing targets in England. Of the 117, fully 81 were destroyed,
about half due to enemy action and half by the woes which had wrecked
so many airships prior to the conflict.
Based upon this stunning record of success, after the end of the
Great War, Britain decided to embark in earnest on its own
airship program, building even larger airships than Germany.
Results were no better, culminating in the
built to provide air and cargo service on routes throughout
the Empire. On its maiden flight to India in 1930, R101 crashed and
burned in a storm while crossing France, killing 48 of the
54 on board. After the catastrophe, the R100 was retired and
sold for scrap.
This did not deter the Americans, who, in addition to their
technical prowess and “can do” spirit, had
access to helium, produced as a by-product of their
natural gas fields. Unlike hydrogen, helium is nonflammable,
so the risk of fire, which had destroyed so many airships
using hydrogen, was entirely eliminated. Helium does not
provide as much lift as hydrogen, but this can be compensated
for by increasing the size of the ship.
Helium is also around fifty times more expensive than hydrogen, which
makes managing an airship in flight more difficult. While the
commander of a hydrogen airship can freely “valve”
gas to reduce lift when required, doing this in a helium
ship is forbiddingly expensive and restricted only to the
most dire of emergencies.
The U.S. Navy believed the airship to be an ideal platform for
long-range reconnaissance, anti-submarine patrols, and other
missions where its endurance, speed, and the ability to
operate far offshore provided advantages over ships and
heavier than air craft. Between 1921 and 1935 the Navy
five rigid airships,
three built domestically and two abroad. Four of the five crashed in
storms or due to structural failure, killing dozens of crew.
This sorry chronicle leads up to a detailed recounting of
the history of the
Originally designed to use helium, it was redesigned for hydrogen
after it became clear the U.S., which had forbidden export of helium
in 1927, would not grant a waiver, especially to a Germany by
then under Nazi rule. The Hindenburg was enormous:
at 245 metres in length, it was longer than the U.S. Capitol building and
more than three times the length of a Boeing 747. It carried
between 50 and 72 passengers who were served by a crew of 40 to
61, with accommodations (apart from the spartan sleeping quarters)
comparable to first class on ocean liners. In 1936, the great ship
made 17 transatlantic crossings without incident. On its first
flight to the U.S. in 1937, it was
fire while approaching the mooring mast at Lakehurst, New Jersey.
The disaster and its aftermath are described in detail. Remarkably,
given the iconic images of the flaming airship falling to the ground
and the structure glowing from the intense heat of combustion, of
the 97 passengers and crew on board, 62 survived the disaster. (One
of the members of the ground crew also died.)
Prior to the destruction of the Hindenburg, a total
of twenty-six hydrogen filled airships had been destroyed by
fire, excluding those shot down in wartime, with a total of 250
people killed. The vast majority of all rigid airships built
ended in disaster—if not due to fire then structural failure,
weather, or pilot error. Why did people continue to pursue this
technology in the face of abundant evidence that it was fundamentally
The author argues that rigid airships are an example of a
“pathological technology”, which he characterises
Few people would argue that the pursuit of large airships for more
than three decades in the face of repeated disasters was a pathological
technology under these criteria. Even setting aside the risks from using
hydrogen as a lifting gas (which I believe the author over-emphasises:
prior to the Hindenburg accident nobody had ever been
injured on a commercial passenger flight of a hydrogen airship, and
nobody gives a second thought today about boarding an airplane with
140 tonnes of flammable jet fuel in the tanks and flying across the
Pacific with only two engines). Seemingly hazardous technologies can
be rendered safe with sufficient experience and precautions. Large lighter
than air ships were, however, inherently unsafe because they were
large and lighter than air: nothing could be done about that. They
were are the mercy of the weather, and if they were designed to be
strong enough to withstand whatever weather conditions they might
encounter, they would have been too heavy to fly. As the experience
of the U.S. Navy with helium airships demonstrated, it didn't matter
if you were immune to the risks of hydrogen; the ship would eventually
be destroyed in a storm.
The author then moves on from airships to discuss other technologies
he deems pathological, and here, in my opinion, goes off the rails.
The first of these technologies is
a U.S. program to explore the use of nuclear explosions for civil
engineering projects such as excavation, digging of canals, creating
harbours, and fracturing rock to stimulate oil and gas production.
With his characteristic snark, Regis mocks the very idea of Plowshare,
and yet examination of the history of the program belies this
ridicule. For the suggested applications, nuclear explosions were
far more economical than chemical detonations and conventional
earthmoving equipment. One principal goal of Plowshare was to
determine the efficacy of such explosions and whether they would
pose risks (for example, release of radiation) which were
unacceptable. Over 11 years 26 nuclear tests were conducted under
the program, most at the Nevada Test Site, and after a review of
the results it was concluded the radiation risk was unacceptable
and the results unpromising. Project Plowshare was shut down in 1977.
I don't see what's remotely pathological about this. You have an idea
for a new technology; you explore it in theory; conduct experiments;
then decide it's not worth pursuing. Now maybe if you're Ed Regis,
you may have been able to determine at the outset, without any of
the experimental results, that the whole thing was absurd, but a great
many people with in-depth knowledge of the issues involved preferred
to run the experiments, take the data, and decide based upon the results.
That, to me, seems the antithesis of pathological.
The next example of a pathological technology is the
Super Collider, a planned particle accelerator to be built in Texas
which would have an accelerator ring 87.1 km in circumference and
collide protons at a centre of mass energy of 40 TeV. The project was
approved and construction begun in the 1980s. In 1993, Congress voted to
cancel the project and work underway was abandoned. Here, the fit with
“pathological technology” is even worse. Sure, the project
was large, but it was mostly underground: hardly something to
“enthral” anybody except physics nerds. There were no risks
at all, apart from those in any civil engineering project of comparable
scale. The project was cancelled because it overran its budget
estimates but, even if completed, would probably have cost less than
a tenth the expenditures to date on the International Space Station, which
has produced little or nothing of scientific value. How is it
pathological when a project, undertaken for well-defined goals, is
cancelled when those funding it, seeing its schedule slip and budget
balloon beyond that projected, pull the plug on it? Isn't that how things
are supposed to work? Who were the seers who forecast all of this at the
The final example of so-called pathological technology is pure
spite. Ed Regis has a fine time ridiculing participants in the first
100 Year Starship
symposium, a gathering to explore how and why humans might be able, within
a century, to launch missions (robotic or crewed) to other star systems.
This is not a technology at all, but rather an exploration of what
future technologies might be able to do, and the limits imposed by
the known laws of physics upon potential technologies. This is
precisely the kind of “exploratory engineering” that
engaged in when he worked out the fundamentals of space flight in the
late 19th and early 20th centuries. He didn't know the details of
how it would be done, but he was able to calculate, from first
principles, the limits of what could be done, and to demonstrate that
the laws of physics and properties of materials permitted the
missions he envisioned. His work was largely ignored, which I suppose
may be better than being mocked, as here.
You want a pathological technology? How about replacing reliable base load
energy sources with inefficient sources at the whim of clouds and wind?
Banning washing machines and dishwashers that work in favour of ones
that don't? Replacing toilets with ones that take two flushes in order
to “save water”? And all of this in order to “save
the planet” from the consequences predicted by a theoretical model
which has failed to predict measured results since its inception, through
policies which impoverish developing countries and, even if you accept
the discredited models, will have negligible results on the global
climate. On this scandal of our age, the author is silent. He
- Embracing something huge, either in size or effects.
- Inducing a state bordering on enthralment among its
- …who underplay its downsides, risks, unintended consequences,
and obvious dangers.
- Having costs out of proportion to the benefits
it is alleged to provide.
Still, for all of their considerable faults and stupidities—their
huge costs, terrible risks, unintended negative consequences, and in
some cases injuries and deaths—pathological technologies possess
one crucial saving grace: they can be stopped.
Or better yet, never begun.
Except, it seems, you can only recognise them in retrospect.
Saturday, January 23, 2016 21:38
- Ward, Jonathan H.
Countdown to a Moon Launch.
Cham, Switzerland: Springer International, 2015.
In the companion volume,
Rocket Ranch (December 2015),
the author describes the
gargantuan and extraordinarily complex infrastructure which was built
at the Kennedy Space Center (KSC) in Florida to assemble, check out, and
launch the Apollo missions to the Moon and the Skylab space station.
The present book explores how that hardware was actually used,
following the “processing flow” of the
Apollo 11 launch vehicle and spacecraft from the
arrival of components at KSC to the moment of launch.
As intricate as the hardware was, it wouldn't have worked, nor would
it have been possible to launch flawless mission after flawless mission
on time had it not been for the management tools employed to
coordinate every detail of processing. Central to this
(Program Evaluation and Review Technique), a methodology
developed by the U.S. Navy in the 1950s to manage the Polaris
submarine and missile systems. PERT breaks down the progress of
a project into milestones connected by
activities into a graph of dependencies. Each activity
has an estimated time to completion. A milestone might be, say,
the installation of the guidance system into a launch vehicle.
That milestone would depend upon the assembly of the components
of the guidance system (gyroscopes, sensors, electronics, structure,
etc.), each of which would depend upon their own components.
Downstream, integrated test of the launch vehicle would depend
upon the installation of the guidance system. Many activities
proceed in parallel and only come together when a milestone
has them as its mutual dependencies. For example, the processing and
installation of rocket engines is completely independent of
work on the guidance system until they join at a milestone where
an engine steering test is performed.
As a project progresses, the time estimates for the various
activities will be confronted with reality: some will be
completed ahead of schedule while other will slip due to
unforeseen problems or over-optimistic initial forecasts.
This, in turn, ripples downstream in the dependency graph,
changing the time available for activities if the final
completion milestone is to be met. For any given graph
at a particular time, there will be a
path of activities where a schedule slip of any one
will delay the completion milestone. Each lower level milestone
in the graph has its own critical path leading to it. As
milestones are completed ahead or behind schedule, the
overall critical path will shift. Knowing the critical path
allows program managers to concentrate resources on items
along the critical path to avoid, wherever possible, overall
schedule slips (with the attendant extra costs).
Now all this sounds complicated, and in a project with the scope of
Apollo, it is almost bewildering to contemplate. The Launch Control
Center was built with four firing rooms. Three were outfitted with
all of the consoles to check out and launch a mission, but the fourth
cavernous room ended up being used to display and maintain the PERT
charts for activities in progress. Three levels of charts were
maintained. Level A was used by senior management and contained
hundreds of major milestones and activities. Each of these was
expanded out into a level B chart which, taken together, tracked
in excess of 7000 milestones. These, in turn, were broken down
into detail on level C charts, which tracked more than 40,000
activities. The level B and C charts were displayed on more than
400 square metres of wall space in the back room of firing room four.
As these detailed milestones were completed on the level C charts,
changes would propagate down that chart and those which affected
its completion upward to the level A and B charts.
Now, here's the most breathtaking thing about this: they did
it all by hand! For most of the Apollo program, computer
implementations of PERT were not available (or those that existed
could not handle this level of detail). (Today, the PERT network
for processing of an Apollo mission could be handled on a laptop
computer.) There were dozens of analysts and clerks charged with
updating the networks, with the processing flow displayed on an
enormous board with magnetic strips which could be shifted around
by people climbing up and down rolling staircases. Photographers
would take pictures of the board which were printed and distributed
to managers monitoring project status.
If PERT was essential to coordinating all of the parallel activities
in preparing a spacecraft for launch, configuration control was
critical to ensure than when the countdown reached T0, everything
would work as expected. Just as there was a network of dependencies
in the PERT chart, the individual components were tested, subassemblies
were tested, assemblies of them were tested, all leading up to
an integrated test of the assembled launcher and spacecraft. The
successful completion of a test established a tested configuration
for the item. Anything which changed that configuration in
any way, for example unplugging a cable and plugging it back in,
required re-testing to confirm that the original configuration had
been restored. (One of the pins in the connector might not have
made contact, for instance.) This was all documented by paperwork
signed off by three witnesses. The mountain of paper was
intimidating; there was even a slide rule calculator for estimating
the cost of various kinds of paperwork.
With all of this management superstructure it may seem a miracle
that anything got done at all. But, as the end of the decade
approached, the level of activity at KSC was relentless (and took
a toll upon the workforce, although many recall it as the most
intense and rewarding part of their careers). Several missions
were processed in parallel: Apollo 11 rolled out to
the launch pad while Apollo 10 was still en route
to the Moon, and Apollo 12 was being assembled and
To illustrate how all of these systems and procedures came
together, the author takes us through the processing of
Apollo 11 in detail, starting around six months
before launch when the Saturn V stages, and
command, service, and lunar modules arrived independently
from the contractors who built them or the NASA facilities
where they had been individually tested. The original
concept for KSC was that it would be an “operational
spaceport” which would assemble pre-tested components
into flight vehicles, run integrated system tests, and then
launch them in an assembly-line fashion. In reality, the
Apollo and Saturn programs never matured to this level, and
were essentially development and test projects throughout.
Components not only arrived at KSC with “some assembly
required”; they often were subject to a blizzard of
engineering change orders which required partially disassembling
equipment to make modifications, then exhaustive re-tests to
verify the previously tested configuration had been restored.
Apollo 11 encountered relatively few problems in
processing, so experiences from other missions where problems
arose are interleaved to illustrate how KSC coped with
contingencies. While Apollo 16 was on the launch
pad, a series of mistakes during the testing process damaged
a propellant tank in the command module. The only way to repair
this was to roll the entire stack back to the Vehicle Assembly
Building, remove the command and service modules, return them to
the spacecraft servicing building then de-mate them, pull the
heat shield from the command module, change out the tank,
then put everything back together, re-stack, and roll back to the
launch pad. Imagine how many forms had to be filled out. The launch
was delayed just one month.
The process of servicing the vehicle on the launch pad is described
in detail. Many of the operations, such as filling tanks with
toxic hypergolic fuel and oxidiser, which burn on contact, required
evacuating the pad of all non-essential personnel and special
precautions for those engaged in these hazardous tasks. As
launch approached, the hurdles became higher: a Launch Readiness
Review and the Countdown Demonstration Test, a full dress rehearsal
of the countdown up to the moment before engine start, including
fuelling all of the stages of the launch vehicle (and then de-fuelling
them after conclusion of the test).
There is a wealth of detail here, including many obscure items I've
never encountered before. Consider “Forward Observers”.
When the Saturn V launched, most personnel and spectators were kept
a safe distance of more than 5 km from the launch pad in case of
calamity. But three teams of two volunteers each were
stationed at sites just 2 km from the pad. They were charged with
observing the first seconds of flight and, if they saw a catastrophic
failure (engine explosion or cut-off, hard-over of an engine gimbal,
or the rocket veering into the umbilical tower), they would signal
the astronauts to fire the launch escape system and abort the
mission. If this happened, the observers would then have to dive into
crude shelters often frequented by rattlesnakes to ride out the
Did you know about the electrical glitch which almost brought the
mission to flaming catastrophe moments after launch? How lapses in
handling of equipment and paperwork almost spelled doom for the
crew of Apollo 13? The time an oxygen leak while fuelling
a Saturn V booster caused cars parked near the launch pad to
burst into flames? It's all here, and much more. This is an
essential book for those interested in the engineering details of
the Apollo project and the management miracles which made its
Saturday, January 16, 2016 23:06
- Levenson, Thomas.
The Hunt for Vulcan.
New York: Random House, 2015.
The history of science has been marked by discoveries in
which, by observing where nobody had looked before, with
new and more sensitive instruments, or at different
aspects of reality, new and often surprising phenomena
have been detected. But some of the most profound of
our discoveries about the universe we inhabit have come
from things we didn't observe, but expected to.
By the nineteenth century, one of the most solid pillars of
science was Newton's law of universal gravitation. With a
single equation a schoolchild could understand, it
explained why objects fall, why the Moon orbits the Earth and
the Earth and other planets the Sun, the tides, and the
motion of double stars. But still, one wonders: is the law
of gravitation exactly as Newton described, and does it work
everywhere? For example, Newton's gravity gets weaker as the
inverse square of the distance between two objects (for example, if
you double the distance, the gravitational force is four times
weaker [2² = 4]) but has unlimited range: every
object in the universe attracts every other object, however
weakly, regardless of distance. But might gravity not, say,
weaken faster at great distances? If this were the case,
the orbits of the outer planets would differ from the predictions
of Newton's theory. Comparing astronomical observations to
calculated positions of the planets was a way to discover
In 1781 astronomer
first planet not known since antiquity. (Uranus is dim but
visible to the unaided eye and doubtless had been seen
innumerable times, including by astronomers who included it
in star catalogues, but Herschel was the first to note its
non-stellar appearance through his telescope, originally
believing it a comet.) Herschel wasn't looking for a new
planet; he was observing stars for another project when he
happened upon Uranus. Further observations of the object
confirmed that it was moving in a slow, almost circular orbit,
around twice the distance of Saturn from the Sun.
Given knowledge of the positions, velocities, and masses of
the planets and Newton's law of gravitation, it should be possible
to predict the past and future motion of solar system bodies
for an arbitrary period of time. Working backward, comparing the
predicted influence of bodies on one another with astronomical
observations, the masses of the individual planets can be estimated
to produce a complete model of the solar system. This great work
was undertaken by
who published his
in five volumes between 1799 and 1825. As the middle of the 19th
century approached, ongoing precision observations of the planets
indicated that all was not proceeding as Laplace had foreseen.
Uranus, in particular, continued to diverge from where it was expected
to be after taking into account the gravitational influence upon
its motion by Saturn and Jupiter. Could Newton have been wrong,
and the influence of gravity different over the vast distance of
Uranus from the Sun?
In the 1840s two mathematical astronomers,
Urbain Le Verrier
in France and
John Couch Adams
in Britain, working independently, investigated the possibility that
Newton was right, but that an undiscovered body in the outer solar system
was responsible for perturbing the orbit of Uranus. After almost
unimaginably tedious calculations (done using
of logarithms and pencil and paper arithmetic), both Le Verrier and
Adams found a solution and predicted where to observe the new planet.
Adams failed to persuade astronomers to look for the new world, but Le Verrier
prevailed upon an astronomer at the Berlin Observatory to try, and
Neptune was duly
discovered within one degree (twice the apparent size of the full Moon)
of his prediction.
This was Newton triumphant. Not only was the theory vindicated, it
had been used, for the first time in history, to predict the existence
of a previously unknown planet and tell the astronomers right where to
point their telescopes to observe it. The mystery of the outer solar
system had been solved. But problems remained much closer to the Sun.
orbits the Sun every 88 days in an eccentric orbit which never exceeds
half the Earth's distance from the Sun. It is a small world, with
just 6% of the Earth's mass. As an inner planet, Mercury never appears more
than 28° from the Sun, and can best be observed in the morning or
evening sky when it is near its maximum elongation from the Sun.
(With a telescope, it is possible to observe Mercury in broad
daylight.) Flush with his success with Neptune, and rewarded with
the post of director of the Paris Observatory, in 1859 Le Verrier
turned his attention toward Mercury.
Again, through arduous calculations (by this time Le Verrier had a
building full of minions to assist him, but so grueling was the
work and so demanding a boss was Le Verrier that during his
tenure at the Observatory 17 astronomers and 46 assistants
quit) the influence of all of the known planets upon the motion
of Mercury was worked out. If Mercury orbited a spherical Sun
without other planets tugging on it, the point of its closest
approach to the Sun (perihelion) in its eccentric orbit would
remain fixed in space. But with the other planets exerting their
gravitational influence, Mercury's perihelion should advance around the
Sun at a rate of 526.7 arcseconds per century. But astronomers
who had been following the orbit of Mercury for decades measured the
actual advance of the perihelion as 565 arcseconds per century.
This left a discrepancy of 38.3 arcseconds, for which there was
no explanation. (The modern value, based upon more precise
observations over a longer period of time, for the
precession of Mercury is 43 arcseconds per century.) Although
small (recall that there are 1,296,000 arcseconds in a full circle),
this anomalous precession was much larger than the margin of error
in observations and clearly indicated something was amiss.
Could Newton be wrong?
Le Verrier thought not. Just as he had done for the anomalies of
the orbit of Uranus, Le Verrier undertook to calculate the properties
of an undiscovered object which could perturb the orbit of Mercury
and explain the perihelion advance. He found that a planet closer
to the Sun (or a belt of asteroids with equivalent mass) would do
the trick. Such an object, so close to the Sun, could easily have
escaped detection, as it could only be readily observed during a
total solar eclipse or when passing in front of the Sun's disc (a
Le Verrier alerted astronomers to watch for transits
of this intra-Mercurian planet.
On March 26, 1859,
Modeste Lescarbault, a provincial
physician in a small town and passionate amateur astronomer
turned his (solar-filtered) telescope toward the Sun. He saw
a small dark dot crossing the disc of the Sun, taking one hour
and seventeen minutes to transit, just as expected by Le
Verrier. He communicated his results to the great man, and
after a visit and detailed interrogation, the astronomer certified
the doctor's observation as genuine and computed the orbit for
the new planet. The popular press jumped upon the story. By
Vulcan was all the rage.
Other observations began to arrive, both from credible and unknown
observers. Professional astronomers mounted worldwide campaigns to
observe the Sun around the period of predicted transits of Vulcan.
All of the planned campaigns came up empty. Searches for Vulcan
became a major focus of solar eclipse expeditions. Unless the
eclipse happened to occur when Vulcan was in
with the Sun, it should be readily observable when the Sun was
obscured by the Moon. Eclipse expeditions prepared detailed star
charts for the vicinity of the Sun to exclude known stars for the
search during the fleeting moments of totality. In 1878, an
international party of eclipse chasers including Thomas Edison
descended on Rawlins, Wyoming to hunt Vulcan in an eclipse
crossing that frontier town. One group spotted Vulcan; others
didn't. Controversy and acrimony ensued.
After 1878, most professional astronomers lost interest in Vulcan.
The anomalous advance of Mercury's perihelion was mostly set
aside as “one of those things we don't understand”,
much as astronomers regard
today. In 1915, Einstein published his theory of gravitation:
general relativity. It predicted that when objects moved rapidly
or gravitational fields were strong, their motion would deviate
from the predictions of Newton's theory. Einstein recalled the
moment when he performed the calculation of the motion of Mercury
in his just-completed theory. It predicted precisely the perihelion
advance observed by the astronomers. He said that his heart shuddered
in his chest and that he was “beside himself with joy.”
Newton was wrong! For the extreme conditions of Mercury's orbit,
so close to the Sun, Einstein's theory of gravitation is required to
obtain results which agree with observation. There was no need for
planet Vulcan, and now it is mostly forgotten. But the episode is
instructive as to how confidence in long-accepted theories and wishful
thinking can lead us astray when what might be needed is an overhaul of
our most fundamental theories. A century hence, which of our beliefs
will be viewed as we regard planet Vulcan today?
Saturday, January 9, 2016 22:20
- Waldman, Jonathan.
New York: Simon & Schuster, 2015.
In May of 1980 two activists, protesting the imprisonment of a Black
Panther convicted of murder, climbed the Statue of Liberty in
New York harbour, planning to unfurl a banner high on the
statue. After spending a cold and windy night aloft, they
descended and surrendered to the New York Police Department's
Emergency Service Unit. Fearful that the climbers may have
damaged the fragile copper cladding of the monument, a
comprehensive inspection was undertaken. What was found was
The structure of the Statue of Liberty was designed by
and consists of an iron frame
weighing 135 tons, which supports the 80 ton copper skin.
As marine architects know well, a structure using two
dissimilar metals such as iron and copper runs a severe risk
of galvanic corrosion, especially in an environment such as
the sea air of a harbour. If the iron and copper were to
come into contact, a voltage would flow across the junction,
and the iron would be consumed in the process. Eiffel's
design prevented the iron and copper from touching one
another by separating them with spacers made of asbestos
impregnated with shellac.
What Eiffel didn't anticipate is that over the years
superintendents of the statue would decide to “protect”
its interior by applying various kinds of paint. By 1980 eight coats
of paint had accumulated, almost as thick as the copper skin. The
paint trapped water between the skin and the iron frame, and this set
electrolysis into action. One third of the rivets in the frame were
damaged or missing, and some of the frame's iron ribs had lost two thirds
of their material. The asbestos insulators had absorbed water and
were long gone. The statue was at risk of structural failure.
A private fund-raising campaign raised US$ 277 million to
restore the statue, which ended up replacing most of its
internal structure. On July 4th, 1986, the restored statue
was inaugurated, marking its 100th anniversary.
Earth, uniquely among known worlds, has an atmosphere with
free oxygen, produced by photosynthetic plants. While much
appreciated by creatures like ourselves which breathe
it, oxygen is a highly reactive gas and combines with
many other elements, either violently in fire, or more slowly
in reactions such as rusting metals. Further, 71% of the Earth's
surface is covered by oceans, whose salty water promotes
other forms of corrosion all too familiar to owners of boats.
This book describes humanity's “longest war”: the
battle against the corruption of our works by the inexorable
chemical process of corrosion.
Consider an everyday object much more humble than the
Statue of Liberty: the aluminium beverage can. The modern can
is one of the most highly optimised products of engineering
ever created. Around 180 billion cans are produced and consumed
every year around the world: four six packs for every living human
being. Reducing the mass of each can by just one gram will result
in an annual saving of 180,000 metric tons of aluminium worth
almost 300 million dollars at present prices, so a long list of
clever tricks has been employed to reduce the mass of cans.
But it doesn't matter how light or inexpensive the can is if
it explodes, leaks, or changes the flavour of its contents.
Coca-Cola, with a pH of 2.75 and a witches’ brew of ingredients,
under a pressure of 6 atmospheres, is as corrosive to bare
aluminium as battery acid. If the inside of the can were not
coated with a proprietary epoxy lining (whose composition
depends upon the product being canned, and is
carefully guarded by can manufacturers), the Coke would
corrode through the thin walls of the can in just three days.
The process of scoring the pop-top removes the coating around
the score, and risks corrosion and leakage if a can is stored on
its side; don't do that.
The author takes us on an eclectic tour the history of corrosion
and those who battle it, from the invention of stainless steel,
inspecting the trans-Alaska oil pipeline by sending a “pig”
(essentially a robot submarine equipped with electronic sensors)
down its entire length, and evangelists for galvanizing (zinc coating)
steel. We meet Dan Dunmire, the Pentagon's rust czar, who estimates
that corrosion costs the military on the order of US$ 20 billion
a year and describes how even the most humble of mitigation
strategies can have huge payoffs. A new kind of gasket
intended to prevent corrosion where radio antennas protrude
through the fuselage of aircraft returned 175 times its investment
in a single year. Overall return on investment in the projects
funded by his office is estimated as fifty to one. We're introduced
to the world of the corrosion engineer, a specialty which, while
not glamorous, pays well and offers superb job security, since rust
will always be with us.
Not everybody we encounter battles rust. Photographer
Csük has turned corrosion into fine art. Working at the
abandoned Bethlehem Steel Works in Pennsylvania, perhaps the rustiest
part of the rust belt, she clandestinely scrambles around the
treacherous industrial landscape in search of the beauty in
This book mixes the science of corrosion with the stories
of those who fight it, in the past and today. It is an
enlightening and entertaining look into the most mundane
of phenomena, but one which affects all the technological
works of mankind.
Friday, January 1, 2016 03:24
Click image to enlarge.
A recent solar storm produced a coronal mass ejection which is presently hitting the Earth's upper atmosphere, causing a brilliant auroral display in northern latitudes. Above is a picture I took a few minutes before midnight UTC on 2015-12-31 looking toward the north at latitude 54° North in the British Isles. You can see the southern part of the auroral oval around the geomagnetic pole. The green colour is due to atomic oxygen in the upper atmosphere excited by the energetic particles from the Sun. Toward the left you can see curtains descending from the main aurora which cut off sharply at an altitude of around 100 km where the abundance of atomic oxygen falls rapidly.
The photo above is a 30 second time exposure. The aurora, as observed with the dark-adapted unaided eye, is quite obvious in a dark sky but not as spectacular as in a long exposure photo. After your eye is dark-adapted you may be able to pick out the green colour, but you may see it only as grey.
The photo was taken with a Nikon D300
camera and Nikon 10.5 mm f/2.8 fisheye lens
with ISO sensitivity 800. Exposure was 30 seconds at f/2.8. I post-processed the image with GIMP
to stretch the contrast and remove the curvilinear distortion of the fisheye lens.
This is the first aurora I have ever seen.
Here is a mouse-over animation demonstrating how the aurora changes rapidly over time. The two images were taken about a minute apart. Move the mouse over to show the second image and away to show the first. (2016-01-01 15:14 UTC)
Mouse-over to display image one minute later.