October 09, 2001
The Fifty Nine Story Crisis
In 1978, William J. LeMessurier
, one of the nation's leading structural engineers, received a phone call from an engineering student in New Jersey. The young man was tasked with writing a paper about the unique design of the Citicorp tower
in New York. The building's dramatic design was necessitated by the placement of a church. Rather than tear down the church, the designers, Hugh Stubbins and Bill LeMessurier, set their fifty-nine-story tower on four massive, nine-story-high stilts
, and positioned them at the center of each side
rather than at each corner. This daring scheme allowed the designers to cantilever the building's four corners, allowing room for the church beneath the northwest side.
Thanks to the prodding of the student (whose name was lost in the swirl of subsequent events), LeMessurier discovered
a subtle conceptual error in the design of the building's wind braces; they were unusually sensitive to certain kinds of winds known as quartering winds. This alone wasn't cause for worry, as the wind braces would absorb the extra load under normal circumstances. But the circumstances were not normal
. Apparently, there had been a crucial change during their manufacture (the braces were fastened together with bolts instead of welds, as welds are generally considered to be stronger than necessary and overly expensive; furthermore the contractors had interpreted the New York building code in such a way as to exempt many of the tower's diagonal braces from loadbearing calculations, so they had used far too few bolts
.) which multiplied the strain produced by quartering winds. Statistically, the possibility of a storm severe enough to tear the joint apart was once every sixteen years
(what meteorologists call a sixteen year storm). This was alarmingly frequent. To further complicate matters, hurricane season was fast approaching.
The potential for a complete catastrophic failure was there, and because the building was located in Manhattan, the danger applied to nearly the entire city. The fall of the Citicorp building would likely cause a domino effect
, wreaking a devestating toll of destruction in New York.
The story of this oversight, though amazing, is dwarfed by the series of events that led to the building's eventual structural integrity. To avert disaster, LeMessurier quickly and bravely blew the whistle - on himself
. LeMessurier and other experts immediately drew up a plan in which workers would reinforce the joints by welding heavy steel plates over them.
Astonishingly, just after Citicorp issued a bland and uninformative press release, all of the major newspapers in New York went on strike. This fortuitous turn of events allowed Citicorp to save face and avoid any potential embarrassment. Construction began immediately, with builders and welders working from 5 p.m. until 4 a.m. to apply the steel "band-aids" to the ailing joints. They build plywood boxes around the joints, so as not to disturb the tenants, who remained largely oblivious to the seriousness of the problem.
Instead of lawsuits and public panic, the Citicorp crisis
was met with efficient teamwork and a swift solution. In the end, LeMessurier's reputation was enhanced for his courageous honesty, and the story of Citicorp's building is now a textbook example of how to respond to a high-profile, potentially disastrous problem.
Most of this information came from a New Yorker
article by Joe Morgenstern (published May 29, 1995) . It's a fascinating story, and I found myself thinking about it during the tragedies of September 11. What if those towers had toppled over in Manhattan? Fortunately, the WTC towers were extremely well designed - they didn't even noticeably rock when the planes hit - and when they did come down, they collapsed in on themselves. They would still be standing today too, if it wasn't for the intense heat that weakened the steel supports.
Posted by Mark at 08:04 AM
September 27, 2001
Do minds play dice?
Unpredictability may be built into our brains.
Neurophysiologists have found that clusters of nerve cells respond to the same stimulus differently each time, as randomly as heads or tails. The implications of this are far reaching, but I can't say I'm all that suprised. It makes evolutionary sense, in that you can evade (or even launch) attacks better by jumping from side to side. It makes sociological sense, in that a person's environment and upbringing do not necessarily dictate how they will act in the future (the most glaring examples are criminals; surely, their childhood must have been traumatic in order for them to commit such heinous acts). It even makes sense creatively, in that "randomness results in new kinds of behaviour and combinations of ideas, which are essential to the process of discovery".
Posted by Mark at 06:56 PM
July 05, 2001
Probabilities in the Game of Monopoly
has all the numbers you could ever possibly need to play Monopoly
more efficiently; most probable squares, how long it takes for investments to pay off, which properties are better to mortgage, where to build hotels, which squares get landed on first.
The railroads are excellent investments, particularly when owned together, although in absolute income terms they don't keep up with heavily built on properties later in the game. The best return on investment to be found is from putting a third house on New York Avenue. In fact, the third house has the fastest payoff of any building on almost all of the properties. The square most landed on other than Jail is Illinois Avenue, and in fact a hotel there will bring the most income other than a hotel on Boardwalk. By far the worst individual investment is to buy Medeterranean Avenue without first owning Baltic. That's not to say that you shouldn't buy it, but it's not going to make you much money without quite a bit of construction. The properties between the Jail square and the Go To Jail square are landed on the most, because of the jump caused by landing on Go To Jail. The Orange ones have the biggest bang for the buck as far as building goes.
All the probabilities were conducted with a long term computer simulation. I suppose this whole thing may seem excessive, but it is quite interesting and nice to know that the orange properties are the best to own and build on. The simulations do not, however, take into account all the shady dealings between players (I'll trade you St. Charles Place, which will give you a monopoly, for Baltic Ave. and 5 free passes on any of your properties
) that can be ever-so-crucial to the outcome of the game. [via Bifurcated Rivets
Posted by Mark at 01:01 PM
June 22, 2001
Out of This World
Scientific American's Steve Mirsky shows a sense of humor in his story about the drop-off in UFO reports
, giving several flippant explanations for the lack of sightings. Some claim that the aliens have completed their survey of Earth, but Mirsky believes the idea that they could complete their survey of Earth in a mere 50 years is both ludicrous and insulting and reasons that they must have run out of their alien government funding. My favourite explanation:
The aliens have finally perfected their cloaking technology. After all, evidence of absence is not absence of evidence (which is, of course, not evidence of absence). Just because we no longer see the aliens doesn't mean they're not there. Actually, they are there; the skies are lousy with them, they're coco-butting one another's bald, veined, throbbing, giant heads over the best orbits. But until they drop the cloak because they've got some beaming to do, we won't see them.
I love the description "bald, veined, throbbing, giant heads". [via Follow Me Here
Posted by Mark at 01:16 PM
June 19, 2001
How Science Ignores the Natural World
Where the Buffalo Roam - How Science Ignores the Natural World
: An interview with Vine Deloria, one of the most important living Native American writers. Central to Deloria's critique of Western culture is the understanding that, by subduing nature, we have become slaves to technology and its underlying belief system.
"...Indians experience and relate to a living universe, whereas Western people - especially scientists - reduce all things, living or not, to objects. The implications of this are immense. If you see the world around you as a collection of objects for you to manipulate and exploit, you will inevitably destroy the world while attempting to control it. Not only that, but by perceiving the world as lifeless, you rob yourself of the richness, beauty, and wisdom to be found by participating in its larger design."
"Science insists, at a great price in understanding, that the observer be as detached as possible from the event he or she is observing. Contrast that with the attitude of indigenous people, who recognize that humans must participate in events, not isolate themselves."
This is the sort of thing you don't hear very often and its very interesting. Deloria makes some great points (along with some I don't particularly agree with, but are interesting nonetheless), especially about science and how it attempts to reduce everything to a paradigm. Doing so certainly has its value, but much like every other version of reality that is forwarded, science is not completely satisfactory.
"...the point is to ask the questions, and keep asking them."
Right on. [via liquid gnome
Posted by Mark at 11:49 AM
May 21, 2001
Bending Time and Space with Light
: New Scientist reports that a professor of theoretical physics, Ronald Mallett, thinks he has found a practical way to make a time machine. Unlike other "time travel" solutions, such as wormholes
, Mallett's solution relies heavily on light, a much more down to earth ingredient when compared to the "negative energy" matter used to open wormholes
. Even though light doesn't have mass
, it does have the quirky ability to bend space-time. Last year, Mallett published a paper describing how a circulating beam of laser light would create a vortex in space within its circle (Physics Letters A, vol 269, p 214).
To twist time into a loop, Mallett worked out that he would have to add a second light beam, circulating in the opposite direction. Then if you increase the intensity of the light enough, space and time swap roles: inside the circulating light beam, time runs round and round, while what to an outsider looks like time becomes like an ordinary dimension of space.
The energy needed to twist time into a loop is enormous, but Mallet saw that the effect of circulating light depends on its velocity: the slower the light, the stronger the distortion in space-time. Light gains inertia as it is slowed down, so "Increasing its inertia increases its energy, and this increases the effect," Mallett says. There is still a lot of work to do to make this process a reality, and it probably won't happen for some "time", but the concept of plausible time travel in our time is intriguing, if only because of the moral and paradoxical issues it raises. The most famous paradox
, of course, is going back in time to kill your grandparents, effectively negating your very own existence - but then you wouldn't be able to go back in time, would you? My favourite solution to said paradoxes is the Terminator
or Bill and Ted
version of time travel in which what you've done in the past has already influenced your present (and future). [via ArsTechnica
Posted by Mark at 09:35 AM
May 01, 2001
The Earthquake Rose
Earthquakes are generally considered to be nasty, rather destructive events, but after a recent earthquake in Seattle, someone noticed some interesting patterns
produced by a sand tracing pendulum (or Foucault Pendulum
). The entire pattern resembles an eye (some say Poseidon's eye, for the god of the sea is also the god of earthquakes), but the pupil of said eye, the part of the pattern created by the earthquake, looks very much like a rose (and thus, it is called an Earthquake Rose). It is really quite pretty, and it's fascinating that "such a massive and very destructive release of energy can also contain such delicate artistry within its chaos." [found somewhere I don't remember the name of].
Posted by Mark at 12:22 PM
April 23, 2001
: A 300-story supertall building originally proposed for Hong Kong is now being considered by China's leaders for Shanghai. Its European designers describe it as a "vertical city". It would house 100,000 people and contain hotels, offices, cinemas and hospitals, effectively making it possible (not necissarily preferable) to live an entire life in one building. "Dwarfing Kuala Lumpur's twin Petronas Towers, the world's tallest buildings at 1,483ft high, it would be set in a gigantic, wheel-shaped base incorporating shopping malls and car parks." The designers have devised a root-like system of foundations that would descend 656ft, surrounded by an artificial lake to absorb vibrations caused by any earth tremors. Amazing stuff; it reminds me of the gigantic cities of The Caves of Steel
, where cities spanned hundreds of miles and were ultimately self-contained (which caused a nasty fear of open spaces). Such an undertaking is an engineering nightmare. If attempted, it could quite possibly fail miserably - there are so many factors and pitfalls to be avoided, that there are bound to be some unforeseen consequences...[via /.
If this venture is successful, however, it seems like it would be the world's first successful arcology. From the Arcologies egroup discussion
Arcology is Paolo Soleri's concept of cities which embody the fusion of architecture with ecology. The arcology concept proposes a highly integrated and compact three-dimensional urban form that is the opposite of urban sprawl with its inherently wasteful consumption of land, energy, time and human resources. An arcology would need about two percent as much land as a typical city of similar population. Arcology eliminates the automobile from inside the city and reserves it for use outside the city. Walking would be the main form of transportation inside an arcology. The miniaturization of the city enables radical conservation of land, energy and resources. Arcology would rely as much as possible on the sun, the wind and other renewable energy so as to reduce pollution and dependence on fossil fuels. Arcology needs less energy per capita thus making recycling and the use of solar energy more feasible than in present cities.
Posted by Mark at 09:42 AM