Reading List: What If?
Sunday, November 15, 2015 21:50
Reading List: Farside
Monday, November 2, 2015 22:24
Reading List: Concrete Planet
Sunday, October 25, 2015 23:30
Reading List: The Road to Relativity
Monday, October 19, 2015 22:11
Reading List: Sweeter than Wine
Tuesday, October 13, 2015 22:52
Sunday, November 15, 2015 21:50
- Munroe, Randall.
New York: Houghton Mifflin, 2014.
As a child, the author would constantly ask his parents odd
questions. They indulged and encouraged him, setting him on
a lifetime path of curiosity, using the mathematics and physics
he learned in the course of obtaining a degree in physics
and working in robotics at NASA to answer whatever popped into
his head. After creating the tremendously successful Web comic
xkcd.com, readers began to ask him
the kinds of questions he'd mused about himself. He began a
feature on xkcd.com: “What
If?” to explore answers to these questions. This book is
a collection of these questions, some previously published on-line
(where you can continue to read them at the previous link), and
some only published here. The answers to questions are interspersed
with “Weird (and Worrying) Questions from the What If? Inbox”,
some of which are reminiscent of my own
Cranium mailbox. The book abounds with the author's
delightful illustrations. Here is a sample of the questions
dealt with. I've linked the first to the online article to give
you a taste of what's in store for you in the book.
Main belt asteroid
is named after the author.
While the hardcover edition is expensive for material most of which
can be read on the Web for free, the
Kindle edition is free to
- Is it possible to build a
jetpack using downward firing machine guns?
- What would happen if you tried to hit a baseball pitched at
90% the speed of light?
- In the movie 300 they shoot arrows up into the
sky and they seemingly blot out the sun. Is this possible, and
how many arrows would it take?
- How high can a human throw something?
- If every person on Earth aimed a laser pointer at the Moon at
the same time, would it change color?
- How much Force power can Yoda output?
- How fast can you hit a speed bump while driving and live?
Monday, November 2, 2015 22:24
- Chiles, Patrick.
Seattle: Amazon Digital Services, 2015.
Several years after the events chronicled in
Perigee (August 2012),
Arthur Hammond's Polaris AeroSpace Lines is operating routine
point-to-point suborbital passenger and freight service with
its Clippers, has expanded into orbital service with
Block II Clippers, and is on the threshold of opening up
service to the Moon with its “cycler” spacecraft
which loop continuously between the Earth and Moon. Clippers
rendezvous with the cyclers as they approach the Earth, transferring
crew, passengers, cargo, and consumables. Initial flights will be
limited to lunar orbit, but landing missions are envisioned for
In the first orbital mission, chartered to perform resource
exploration from lunar orbit, cycler Shepard is
planning to enter orbit with a burn which will, by the necessities
of orbital mechanics, have to occur on the far side of the Moon,
out of radio contact with the Earth. At Polaris mission control
in Denver, there is the usual tension as the clock ticks down toward
the time when Shepard is expected to emerge from behind
the Moon, safely in orbit. (If the burn did not occur, the ship would
appear before this time, still on a trajectory which would return it
to the Earth.) When the acquisition of signal time comes and goes
with no reply to calls and no telemetry, tension gives way to
anxiety. Did Shepard burn too long and crash on the
far side of the Moon? Did its engine explode and destroy the
ship? Did some type of total system failure completely disable
On board Shepard, Captain Simon Poole is struggling to
survive after the disastrous events which occurred just moments after
the start of the lunar orbit insertion burn. Having taken refuge in
the small airlock after the expandable habitation module has deflated,
he has only meagre emergency rations to sustain him until a rescue
mission might reach him. And no way to signal Earth that he is alive.
What seems a terrible situation rapidly gets worse and more
enigmatic when an arrogant agent from Homeland Security
barges into Polaris and demands information about the passenger
and cargo manifest for the flight, Hammond is visited at home
by an unlikely caller, and a jarhead/special operator type
named Quinn shows them some darker than black intelligence
about their ship and “invites” them to NORAD
headquarters to be briefed in on an above top secret project.
So begins a nearish future techno-thriller in which the situations
are realistic, the characters interesting, the perils harrowing, and
the stakes could not be higher. The technologies are all plausible
extrapolations of those available at present, with no magic.
Government agencies behave as they do in the real world, which is to
say with usually good intentions leavened with mediocrity, incompetence,
scheming ambition, envy, and counter-productive secrecy and arrogance.
This novel is not going to be nominated for any awards by the
social justice warriors who have infiltrated the
science fiction writer and fan communities: the author understands
precisely who the enemies of civilisation and human destiny are,
forthrightly embodies them in his villains, and explains why
seemingly incompatible ideologies make common cause against the
values which have built the modern world. The story is one of problem
solving, adventure, survival, improvisation, and includes one of the
most unusual episodes of space combat in all of science fiction. It
would make a terrific movie.
For the most part, the author gets the details right. There are a few
outright goofs, such as seeing the Earth from the lunar far side (where it
is always below the horizon—that's why it's the far side);
some errors in orbital mechanics which will grate on players
Kerbal Space Program;
the deployed B-1B bomber is Mach 1.25, not Mach 2;
and I don't think there's any way the ships in
the story could have had sufficient delta-v to rendezvous with
a comet so far out the plane of the ecliptic. But I'm not going to
belabour these quibbles in what is a rip-roaring read. There is
a glossary of aerospace terms and acronyms at the end. Also included is
a teaser chapter for a forthcoming novel which I can't wait to read.
Sunday, October 25, 2015 23:30
- Courland, Robert.
Amherst, NY: Prometheus Books, 2011.
Visitors to Rome are often stunned when they see the
learn it was built almost 19 centuries ago, during the reign
of the emperor Hadrian. From the front, the building has a
classical style echoed in neo-classical government buildings
around the world, but as visitors walk inside, it is the amazing
dome which causes them to gasp. At 43.3 metres in diameter, it was the
largest dome ever built in its time, and no larger dome has, in all the centuries
since, ever been built in the same way. The dome of the Pantheon is a monolithic
structure of concrete, whose beauty and antiquity attests to the
versatility and durability of this building material which has become
a ubiquitous part of the modern world.
To the ancients, who built from mud, stone, and later brick, it must have
seemed like a miracle to discover a material which, mixed with water, could
be moulded into any form and would harden into stone. Nobody knows how or where
it was discovered that by heating natural limestone to a high temperature it
could be transformed into
quicklime (calcium oxide),
a corrosive substance which reacts exothermically with water, solidifying into
a hard substance. The author speculates that the transformation of limestone
into quicklime due to lightning strikes may have been discovered in Turkey and
applied to production of quicklime by a kilning process, but the evidence for this
is sketchy. But from the neolithic period, humans discovered how to make
floors from quicklime and a binder, and this technology remained in use until
the 19th century.
All of these early lime-based mortars could not set underwater and were
vulnerable to attack by caustic chemicals. It was the Romans who discovered
that by mixing volcanic ash
(pozzolan), which was
available to them in abundance from the vicinity of Mt. Vesuvius, it was possible
to create a “hydraulic cement” which could set underwater and
was resistant to attack from the elements. In addition to structures like the
Pantheon, the Colosseum, roads, and viaducts, Roman concrete was used to build
the artificial harbour at
Caesarea in Judea,
the largest application of hydraulic concrete before the 20th century.
Jane Jacobs has
written that the central aspect of a dark age is not that specific things
have been forgotten, but that a society has forgotten what it has
forgotten. It is indicative of the dark age which followed the fall of
the Roman empire that even with the works of the Roman engineers remaining
for all to see, the technology of Roman concrete used to build
them, hardly a secret, was largely forgotten until the 18th century, when a few
buildings were constructed from similar formulations.
It wasn't until the middle of the 19th century that the precursors of modern
cement and concrete construction emerged. The adoption of this technology
might have been much more straightforward had it not been the case that a
central player in it was
William Aspdin, a
world-class scoundrel whose own crookedness repeatedly torpedoed ventures
in which he was involved which, had he simply been honest and straightforward
in his dealings, would have made him a fortune beyond the dreams of avarice.
Even with the rediscovery of waterproof concrete, its adoption was slow in
the 19th century. The building of the
Thames Tunnel by
the great engineers
Marc Brunel and his son
Isambard Kingdom Brunel
was a milestone in the use of concrete, albeit one achieved only after
a long series of setbacks and mishaps over a period of 18 years.
Ever since antiquity, and despite numerous formulations, concrete had one
common structural property: it was very strong in compression (it resisted
forces which tried to crush it), but had relatively little tensile
strength (if you tried to pull it apart, it would easily fracture). This
meant that concrete structures had to be carefully designed so that the
concrete was always kept in compression, which made it difficult to build
cantilevered structures or others requiring tensile strength, such as many
bridge designs employing iron or steel. In the latter half of the 19th century,
a number of engineers and builders around the world realised that by
embedding iron or steel reinforcement within concrete, its
tensile strength could be greatly increased. The advent of
concrete allowed structures impossible to build with pure concrete. In
1903, the 16-story
in Cincinnati became the first reinforced concrete skyscraper, and the
tallest building today, the
Burj Khalifa in
Dubai, is built from reinforced concrete.
The ability to create structures with the solidity of stone, the strength
of steel, in almost any shape a designer can imagine, and at low cost
inspired many in the 20th century and beyond, with varying degrees of
success. Thomas Edison saw in concrete a way to provide affordable houses
to the masses, complete with concrete furniture. It was one of his less
successful ventures. Frank Lloyd Wright quickly grasped the potential
of reinforced concrete, and used it in many of his iconic buildings. The
Panama Canal made extensive use of reinforced concrete, and the Hoover Dam
demonstrated that there was essentially no limit to the size of a structure
which could be built of it (the concrete of the dam is still curing to
this day). The Sydney Opera House illustrated (albeit after large schedule
slips, cost overruns, and acrimony between the architect and customer) that
just about anything an architect can imagine could be built of reinforced
To see the Pantheon or Colosseum is to think “concrete is eternal”
(although the Colosseum is not in its original condition, this is mostly
due to its having been mined for building materials over the
centuries). But those structures were built with unreinforced Roman
concrete. Just how long can we expect our current structures, built from
a different kind of concrete and steel reinforcing bars to last?
Well, that's…interesting. Steel is mostly composed of iron, and iron
is highly reactive in the presence of water and oxygen: it rusts. You'll
observe that water and oxygen are abundant on Earth, so unprotected steel
can be expected to eventually crumble into rust, losing its structural
strength. This is why steel bridges, for example, must be regularly
stripped and repainted to provide a barrier which protects the steel
against the elements. In reinforced concrete, it is the concrete itself
which protects the steel reinforcement, initially by providing an alkali
environment which inhibits rust and then, after the concrete cures, by
physically excluding water and the atmosphere from the reinforcement. But,
as builders say, “If it ain't cracked, it ain't concrete.”
Inevitably, cracks will allow air and water to reach the reinforcement,
which will begin to rust. As it rusts, it loses its structural strength
and, in addition, expands, which further cracks the concrete and allows
more air and moisture to enter. Eventually you'll see the kind of
crumbling used to illustrate deteriorating bridges and other infrastructure.
How long will reinforced concrete last? That depends upon the details. Port
and harbour facilities in contact with salt water have failed in less than
fifty years. Structures in less hostile environments are estimated to have a life
of between 100 and 200 years. Now, this may seem like a long time compared
to the budget cycle of the construction industry, but eternity it ain't, and
when you consider the cost of demolition and replacement of structures such as
dams and skyscrapers, it's something to think about. But obviously, if the
Romans could build concrete structures which have lasted millennia, so can we.
The author discusses alternative formulations of concrete and different kinds
of reinforcing which may dramatically increase the life of reinforced concrete
This is an interesting and informative book, but I found the author's style
a bit off-putting. In the absence of fact, which is usually the case when
discussing antiquity, the author simply speculates. Speculation is always
clearly identified, but rather than telling a story about a shaman discovering
where lightning struck limestone and spinning it unto a legend about the
discovery of manufacture of quicklime, it might be better to say, “nobody
really knows how it happened”. Eleven pages are spent discussing the
thoroughly discredited theory that the Egyptian pyramids were made of concrete,
coming to the conclusion that the theory is bogus. So why mention it?
There are a number of typographical errors and a few factual errors (no, the
Mesoamericans did not build pyramids “a few of which would equal those
Still, if you're interested in the origin of the material which surrounds us
in the modern world, how it was developed by the ancients, largely forgotten,
and then recently rediscovered and used to revolutionise construction, this is
a worthwhile read.
Monday, October 19, 2015 22:11
- Einstein, Albert, Hanock Gutfreund, and Jürgen Renn.
The Road to Relativity.
Princeton: Princeton University Press, 2015.
One hundred years ago, in 1915, Albert Einstein published the final
version of his general theory of relativity, which extended his 1905
special theory to encompass accelerated motion and gravitation. It
replaced the Newtonian concept of a “gravitational force”
acting instantaneously at a distance through an unspecified mechanism
with the most elegant of concepts: particles not under the influence
of an external force move along spacetime
generalisation of straight lines, but the presence of mass-energy
curves spacetime, which causes those geodesics to depart from straight
lines when observed at a large scale.
For example, in Newton's conception of gravity, the Earth orbits the Sun
because the Sun exerts a gravitational force upon the Earth which pulls it
inward and causes its motion to depart from a straight line. (The Earth also
exerts a gravitational force upon the Sun, but because the Sun is so much
more massive, this can be neglected to a first approximation.) In general
relativity there is no gravitational force. The Earth is moving in a straight
line in spacetime, but because the Sun curves spacetime in its vicinity this
geodesic traces out a helix in spacetime which we perceive as the Earth's
Now, if this were a purely qualitative description, one could dismiss it
as philosophical babble, but Einstein's theory provided a precise description
of the gravitational field and the motion of objects within it and, when
the field strength is strong or objects are moving very rapidly, makes
different predictions than Newton's theory. In particular, Einstein's theory
predicted that the perihelion of the orbit of Mercury would rotate around the
Sun more rapidly than Newton's theory could account for, that light propagating
near the limb of the Sun or other massive bodies would be bent through twice the
angle Newton's theory predicted, and that light from the Sun or other
massive stars would be red-shifted when observed from a distance. In due
course all of these tests have been found to agree with the predictions of
general relativity. The theory has since been put to many more precise
tests and no discrepancy with experiment has been found.
For a theory which is, once you get past the cumbersome
mathematical notation in which it is expressed, simple and elegant, its
implications are profound and still being explored a century later.
cosmology and the large-scale
structure of the universe,
and gravitational radiation
are all implicit in Einstein's equations, and exploring them are among
the frontiers of science a century hence.
Unlike Einstein's original 1905
paper on special
relativity, the 1915 paper, titled
“Die Grundlage der allgemeinen
Relativitätstheorie” (“The Foundation of General
Relativity”) is famously difficult to comprehend and baffled many
contemporary physicists when it was published. Almost half is a tutorial
for physicists in
multidimensional geometry and the
in which it is expressed. The balance of the paper is written in this
notation, which can be forbidding until one becomes comfortable with
That said, general relativity can be understood intuitively the same way
Einstein began to think about it: through thought experiments. First,
imagine a person in a stationary elevator in the Earth's gravitational
field. If the elevator cable were cut, while the elevator was in free
fall (and before the sudden stop), no experiment done within the elevator
could distinguish between the state of free fall within Earth's gravity
and being in deep space free of gravitational fields. (Conversely, no
experiment done in a sufficiently small closed laboratory can distinguish
it being in Earth's gravitational field from being in deep space accelerating
under the influence of a rocket with the same acceleration as Earth's gravity.)
(The “sufficiently small” qualifier is to eliminate the effects
of tides, which we can neglect at this level.)
The second thought experiment is a bit more subtle. Imagine an observer
at the centre of a stationary circular disc. If the observer uses rigid
rods to measure the radius and circumference of the disc, he will find
the circumference divided by the radius to be 2π, as expected from
the Euclidean geometry of a plane. Now set the disc rotating and repeat
the experiment. When the observer measures the radius, it will be as
before, but at the circumference the measuring rod will be contracted
due to its motion according to special relativity, and the circumference,
measured by the rigid rod, will be seen to be larger. Now, when the circumference
is divided by the radius, a ratio greater than 2π will be found, indicating
that the space being measured is no longer Euclidean: it is curved. But
the only difference between a stationary disc and one which is rotating is
that the latter is in acceleration, and from the reasoning of the first
thought experiment there is no difference between acceleration and gravity.
Hence, gravity must bend spacetime and affect the paths of objects (geodesics)
Now, it's one thing to have these kinds of insights, and quite another to
puzzle out the details and make all of the mathematics work, and this
process occupied Einstein for the decade between 1905 and 1915, with many
blind alleys. He eventually came to understand that it was necessary to
entirely discard the notion of any fixed space and time, and express the
equations of physics in a way which was completely independent of any
co-ordinate system. Only this permitted the metric structure of
spacetime to be completely determined by the mass and energy within it.
This book contains a facsimile reproduction of Einstein's original
manuscript, now in the collection of the Hebrew University of Jerusalem.
The manuscript is in Einstein's handwriting which, if you read German,
you'll have no difficulty reading. Einstein made many edits to the
manuscript before submitting it for publication, and you can see them all
here. Some of the hand-drawn figures in the manuscript have been cut
out by the publisher to be sent to an illustrator for preparation of
figures for the journal publication. Parallel to the manuscript, the
editors describe the content and the historical evolution of the concepts
discussed therein. There is a 36 page introduction which describes the
background of the theory and Einstein's quest to discover it and the
history of the manuscript. An afterword provides an overview of
general relativity after Einstein and brief biographies of principal
figures involved in the development and elaboration of the theory.
The book concludes with a complete English translation of Einstein's
two papers given in the manuscript.
This is not the book to read if you're interested in learning general
relativity; over the last century there have been great advances in
mathematical notation and pedagogy, and a modern text is the best
resource. But, in this centennial year, this book allows you to
go back to the source and understand the theory as Einstein presented it,
after struggling for so many years to comprehend it. The supplemental
material explains the structure of the paper, the essentials of the
theory, and how Einstein came to develop it.
Tuesday, October 13, 2015 22:52
- Smith, L. Neil.
Sweeter than Wine.
Rockville, MD: Phoenix Pick, 2011.
A couple of weeks after D-Day, Second Lieutenant J Gifford found
himself separated from his unit and alone in a small French village which,
minutes later, was overrun by Germans. Not wishing to spend the rest of the
war as a POW, he took refuge in an abandoned house, hiding out
in the wine cellar to escape capture until the Allies took the village. There,
in the dark, dank cellar, he encounters Surica, a young woman also hiding from the
Germans—and the most attractive woman he has ever seen. Nature
takes its course, repeatedly.
By the time the Germans are driven out by the Allied advance, Gifford
has begun to notice changes in himself. He can see in the dark. His
hearing is preternaturally sensitive. His canine teeth are growing.
He cannot tolerate sunlight. And he has a thirst for blood.
By the second decade of the twenty-first century, Gifford has established
himself as a private investigator in the town of New Prospect, Colorado,
near Denver. He is talented in his profession, considered rigorously
ethical, and has a good working relationship with the local police. Apart
from the whole business about not going out in daytime without extensive
precautions, being a vampire has its advantages in the gumshoe game: he
never falls ill, recovers quickly even from severe injuries, doesn't age,
has extraordinary vision and hearing, and has a Jedi-like power of suggestion
over the minds of people which extends to causing them to selectively forget
But how can a vampire, who requires human blood to survive, be ethical?
That is the conundrum Gifford has had to face ever since that day in the
wine cellar in France and, given the prospect of immortality, will have to
cope with for all eternity. As the novel develops, we learn how he has
met this challenge.
Meanwhile, Gifford's friends and business associates, some of whom
know or suspect his nature, have been receiving queries which seem to
indicate someone is on to him and trying to dig up evidence against
him. At the same time, a series of vicious murders, all seemingly
unrelated except for their victims having all been drained of blood, are
being committed, starting in Charleston, South Carolina and proceeding
westward across the U.S.
These threads converge into a tense conflict pitting Gifford's ethics
against the amoral ferocity of an Old One (and you will learn just how
Old in chapter 26, in one of the scariest lines I've encountered in
any vampire tale).
I'm not usually much interested in vampire or zombie stories because they
are just so implausible, except as a metaphor for something else. Here,
however, the author develops a believable explanation of the vampire phenomenon
which invokes nothing supernatural. Sure, there aren't really
vampires, but if there were this is probably how it would work. As
with all of the author's fiction, there are many funny passages and turns of
phrase. For a novel about a vampire detective and a serial killer, the
tone is light and the characters engaging, with a romance interwoven with
the mystery and action. L. Neil Smith wrote this book in one month: November, 2009,
as part of the
National Novel Writing Month, but other than
being relatively short (150 pages), there's nothing about it which
seems rushed; the plotting is intricate, the characters well-developed,
and detail is abundant.