Fourmilog: None Dare Call It Reason

Reading List: What If?

Sunday, November 15, 2015 21:50

Munroe, Randall. What If? New York: Houghton Mifflin, 2014. ISBN 978-0-544-27299-6.
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, readers began to ask him the kinds of questions he'd mused about himself. He began a feature on “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 Titanium 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.

  • 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?

Main belt asteroid 4942 Munroe 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 Kindle Unlimited subscribers.


Reading List: Farside

Monday, November 2, 2015 22:24

Chiles, Patrick. Farside. Seattle: Amazon Digital Services, 2015. ASIN B010WAE080.
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 the future.

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 its communications?

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 of 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.


Reading List: Concrete Planet

Sunday, October 25, 2015 23:30

Courland, Robert. Concrete Planet. Amherst, NY: Prometheus Books, 2011. ISBN 978-1-61614-481-4.
Visitors to Rome are often stunned when they see the Pantheon and 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 reinforced concrete allowed structures impossible to build with pure concrete. In 1903, the 16-story Ingalls Building 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 concrete.

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 construction.

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 in Egypt”).

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.


Reading List: The Road to Relativity

Monday, October 19, 2015 22:11

Einstein, Albert, Hanock Gutfreund, and Jürgen Renn. The Road to Relativity. Princeton: Princeton University Press, 2015. ISBN 978-0-691-16253-9.
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 geodesics, the 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 orbit.

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. Black holes, gravitational lensing, cosmology and the large-scale structure of the universe, gravitomagnetism, 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 Riemann's generalised multidimensional geometry and the tensor language in which it is expressed. The balance of the paper is written in this notation, which can be forbidding until one becomes comfortable with it.

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) within it.

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.


Reading List: Sweeter than Wine

Tuesday, October 13, 2015 22:52

Smith, L. Neil. Sweeter than Wine. Rockville, MD: Phoenix Pick, 2011. ISBN 978-1-60450-483-5.
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 things.

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.