mar 2007 / greg goebel
* Entries include: power grid infrastructure, a short history of life, future cellphones, RFID tagging luggage, Chinese sweatshop practices, Boeing versus Airbus, ethanol in Latin America, the Earth's fading magnetic field, cheating with online scoring systems, using the internet in Baghdad, improved geothermal energy technology, modular home construction, the art of bribery, space pen myth.
* INFRASTRUCTURE -- THE POWER GRID (8): There are a number of other interesting details to be observed at a power substation:
All the gear in a substation is heavily grounded, since if it weren't a worker touching a transformer case might end up being the connection to ground instead. Even the fencing is heavily grounded, and the chain-link fence around the site may be strung through with wires to keep it from building up an induced charge from the strong electric fields permeating the site.
Other items worthy of comment at substations may be plastic plates or baskets over the lines coming into or going out of the substation. Squirrels like to walk on power lines, and if they get into the substation it may be bad for their health and for the operation of the substation. There may be sets of fiberglass poles or "hot sticks" stacked inside the substation: they're used by service workers to clear debris from or otherwise interact with "hot" gear in the substation. [TO BE CONTINUED]
* FUTURE PHONES: Cellphones have evolved in ways that would have been hard to predict decades ago, demonstrating that the prediction game is dodgy. However, as reported in THE ECONOMIST ("The Phone Of The Future", 2 December 2006), considerable effort has been put into imagining where the cellphone will be decades from now.
Even in the present, the cellphone is no longer strictly a tool for voice communications. Cellphones often incorporate digital cameras and digital music players. Games and video entertainment are catching on a bit, as are location systems, and in the Far East cellphones with short-range RF interfaces are starting to be used as "electronic wallets" for performing small purchases. Digital messaging and networked transaction systems are making inroads as well. Where will it end? According to Bruce Sterling, a science-fiction writer turned "futurist", the phone will become the "remote control for life."
Cellphone processing power and memory are increasing rapidly, and the capabilities of the cellphone of tomorrow will likely match or even exceed that of the laptop computers of today. It is also very plausible that the cellphone of tomorrow won't look like a cellphone. Cellphone manufacturers have come to the conclusion that building a cellphone to do absolutely everything leads to an clunky and overly expensive product -- "flexibility is the key to uselessness" as the old saying goes -- and it may be attractive to modularly break up the functionality. We already have BlueTooth sets that fit into the ear; displays in the form of glasses are being developed, and research is under way on schemes to read the vibrations of the larynx to provide a form of voice input.
There is no obstacle but investment to turn the cellphone of today into an enhanced networking tool that would allow a user to control a home. With increasing use of RFID in products, a cellphone could be even used to find some object, eyeglasses maybe, misplaced in the house. Of course, predictions of the future are always dodgy, particularly in terms of the social changes, both good and bad, they can lead to. Technological visionaries aren't the only ones considering the implications of new technology. So are crooks -- and they are very quick to exploit new opportunities.
* LUGGAGE RFID: According to an article on WIRED Online ("Never Lose Luggage Again" by Dave Demerjian), RFID systems promise to make lost luggage from an airplane trip a rarity instead of a common complaint -- if the cash-strapped airlines can be persuaded to use them.
These days, the normal scheme for tracking luggage is a barcoded luggage tag with a 10-digit identifier, which is read by laser scanners connected to a central database as the luggage is shunted along conveyors. Unfortunately, the tags get crushed, dirty, or lost, and so even new barcode scanners don't read the tags correctly more than 90% of the time. As the scanners age, the ratio of good reads drops. In 2005, there were 3.5 million lost-baggage complaints, and the number for 2006 is expected to be bigger. The costs of tracking down lost luggage run to several billion USD a year.
Luggage tags with disposable passive electronic RFID systems would be a much better technical solution than barcodes. RFID doesn't need a clear line of sight to the tag, and dirt does little to degrade reading of the tag. RFID tags are not much damaged by weather, and adapting the baggage-handling system to RFID readers should be straightforward. Best of all, RFID scanners have a successful read rate of better than 99%. This would reduce the problem of lost luggage to a fraction of what it is now.
The problem is that while a barcode tag might costs about 2 cents, an RFID tag might cost up to 20 cents. With a large airline like Delta handling over a hundred million bags a year, that cost adds up, and airlines are reluctant to take the plunge.
However, McCarran International Airport in Las Vegas now has an RFID-based baggage handling system. With 70,000 bags going through the airport each day, a 90% read rate means 7,000 lost bags a day. A read rate of better than 99% means a much more manageable situation. The McCarran system includes 300 readers set up at check-in stations and another 70 readers distributed along the internal baggage distribution system. Passenger data is entered into a database at check-in time, with the baggage handling system referencing the RFID tags to the database to make sure the luggage is correctly routed. Right now, barcode tags are used along with the RFID tags, but soon combination tags will be available. The use of both systems means that the scheme will work even if not all airports and airlines used RFID luggage tags, allowing the scheme to be introduced gradually.
Hong Kong International Airport also has an RFID baggage handling system, which has the additional interesting security measure of flagging any luggage stowed on an aircraft for removal if the owner hasn't boarded. There were some problems with the system at first, since RFID tags can't be read if they're lying on a metal surface, but this was fixed with some minor changes to the conveyor system. The readers also sometimes picked up the wrong tags, but this problem was addressed by reducing the reader power and range.
Several airlines are committing to RFID schemes. The International Air Transportation Association (IATA) has come up with a global RFID tag specification to ensure that a tag attached at one airport can be read at another. Compared to the costs of lost baggage, going RFID would seem to be a no-brainer, but not all the airlines are convinced they'll come out ahead -- the Hong Kong International system cost $50 million USD, which was not pocket change. It's by no means certain that RFID will be universal in baggage handling systems any time soon
However, some advocates are convinced that RFID is the way of the future for the airlines, with tags also tracking luggage bins, catering trolleys, and even passengers. Says an enthusiast: "Embed a tag in their boarding pass or give them a bracelet, and it would be quite easy to locate passengers who were late boarding their flights." Those who have suggested that RFID is literally the work of the devil might not like the idea of being tagged like a wild bear -- but given how paranoid airports are, it's not an implausible vision of the future by any means.
* SWEATSHOP SLEIGHT OF HAND: These days, global corporations like Nike and Wal-Mart are very careful about dealing with subcontractors in countries like China where protection of worker's rights are weak. No big company wants to be accused of supporting worker exploitation, and so the companies have guidelines for their subcontractors, performing audits on the subcontractors to ensure compliance.
As reported by BUSINESS WEEK, a Chinese supplier of pens, mechanical pencils, and highlighters was under the gun from Wal-Mart, having flunked three audits for paying under minimum wage and violating overtime rules. The company was faced with a fourth audit that would be the last if things hadn't changed -- when the management got a cold-call from an official named Lai Mingwei with a firm with the seemingly innocent name of the Shanghai Corporate Responsibility Management & Consulting Company. Mr. Lai promised them that, for a fee, he could make sure they passed the audit. They hired him.
Lai's angle on "corporate responsibility management" was focused on "management" at the cost of "corporate responsibility". He showed the client company how to cook up a set of fake books to give to the auditors, how to spot troublemaking workers and send them home for the day of the audit, and briefed managers on what to say to the auditors. It all worked perfectly, the company passing the audit easily -- without having otherwise changed their business practices in the slightest. Ex-workers from various Chinese companies have been blowing the whistle. BUSINESS WEEK reporters talked with Lai's clients, who deny wrongdoing; Lai was willing to talk with reporters, saying his consulting activities were perfectly legitimate, focused on rectifying problems and not just covering them up.
There does seem to a lot of cheating on the system, and it's all but inevitable. Chinese labor laws and enforcement of such laws as do exist are weak, and suppliers are under relentless price pressure from clients such as Wal-Mart. Even as the suppliers are being squeezed on prices, they are being held to compliance on work rules that make it more difficult to stay in business. In other words, the system is arranged to give strong incentives to cheat, and also tends to implicitly shift part of the blame on the corporations, not just the subcontractors. One corporate compliance manager believes that only about 20% of Chinese subcontractors comply with wage rules, while only 5% comply with overtime rules. An owner of a Hong Kong factory flatly says: "These goals are a fantasy. Maybe in two or three decades we can meet them." Even some workers are inclined to cheat the rules: faced with the choice of working extra hours for the same pay when the alternative is no extra pay at all, they choose the extra pay.
To compound the difficulty, the auditing industry is a big business, not only involving large auditing operations inside major corporations, but bringing in global auditing agencies such Cal Safety Compliance, SGS of Switzerland, and Bureau Veritas of France. A single subcontractor may have several clients who are insisting on different sets of rules, with auditors visiting almost daily. Auret van Heerden, head of the Fair Labor Association, a compliance group of 20 corporations including Nike, Adidas, and Nordstrom, admits to the chaos: "McDonald's, Walt Disney, and Wal-Mart are doing thousands of audits a year that are not harmonized." Given such a torrent of inspection, even factory managers who want to be conscientious start to fall prey to "audit fatigue".
Some corporations, such as Nike, are becoming more involved in the operations of subcontractors, helping them to streamline their processes to raise their profit margins without having to break the rules. Other corporations have tried to establish better communications with suppliers, listening to them when they say they are having troubles complying with the rules, instead of simply making demands and driving the problems underground. Corporations have also established a "Fair Factories Clearinghouse" to allow them to compare notes on suppliers and also set more consistent rules. However, getting the system to work, particularly in the face of China's lax labor laws, promises to be an uphill struggle for a long time to come.
* A SHORT HISTORY OF LIFE (11): The Triassic and Jurassic periods, beginning 240 million and 205 million years ago respectively, were the first two of the three great ages of reptiles. Two major families of "dinosaurs" would become established during the Triassic:
It is a popular misunderstanding to believe that all the exotic reptiles of this era were dinosaurs, but many were nothing of the sort: the "plesioaurs", the classic "Loch Ness monster" marine reptiles, and the dolphinlike reptilian "ichthyosaurs" emerged in the Jurassic, as did the flying "pterosaurs", the only reptiles to be capable of true flight. Crocodilians and turtles also emerged in this era; lizards grew to monstrous size in the form of the "mosasaurs", which were like oversized ocean-going monitor lizards.
While the scenery might have been dominated by reptiles, they weren't the only creatures in the game: "ammonites", shelled cephalopods, were common, as well as frogs and salamanders. Birds, in the form of the toothed archaeopteryx, as well as primitive mammals -- creatures not so different from modern shrews -- emerged in the late Triassic.
No birds have teeth any longer, but relics of the early days of mammals survive, in the form of the "monotremes" of New Zealand like the platypus that lay eggs but give milk to their young. In the case of the platypus, however, except for its inclination to lay eggs it cannot be considered a "living fossil" in any way, instead being a highly evolved animal, sporting webbed feet, poison spurs, and an ultrasensitive "duckbill" for hunting worms and the like in brackish water. The age of dinosaurs also saw the introduction of the other two branches of the family of mammals, the "marsupials" like the kangaroo and opossom -- which give birth to young in a near-embryonic state after a short and convenient gestation period -- and the "placental" mammals, which give birth to generally developed young after a long gestation period.
* The Cretaceous period, beginning 135 million years ago, was the last of the great ages of dinosaurs. In terms of the beasts of the lands, the Cretaceous was different in degree but not in kind, with the carnosaurs reaching their peak in the "tyranosaurus rex" and acquiring some movie-monster notoriety (in the modern era) through the introduction of the "velociraptor". The pterosaurs also reached a peak of sorts, represented by the huge "Quexactolus", the size of a sailplane. There were sea turtles twice the dimensions of modern sea turtles.
The real innovation of the Cretaceous was somewhat less spectacular: flowering plants, and the pollinating insects such as bees to go along with them. Before the Cretaceous the world had no flowers; by the end of the era, the "angiosperms" would be the rulers of the plant worlds.
The Cretaceous came to an abrupt end 65 million years ago. The general consensus for some years was that a giant meteor impact that hit in what is now the Yucatan peninsula causes a wave of burning, followed by a long winter and a climatic shift. That hasn't been ruled out, but now researchers are not so sure. [TO BE CONTINUED]
* INFRASTRUCTURE -- THE POWER GRID (7): Towns always have power substations where the high-voltage trunks terminate and the electricity is distributed for local use. A substation is a fenced-off site cluttered with mysterious equipment, with a high-voltage line coming in and low-voltage lines going out. The site is crisscrossed with sets of "bus bars", usually long aluminum tubes, to shuffle the electricity around. The bars are held up by a scaffolding system, of course connected through porcelain insulator strings to prevent them from shorting out. Longer bus bars may be interrupted and jumped by a metal braid to compensate for thermal expansion.
The biggest objects in the substation are the transformers, which look like boxes with electrical connections coming in on one side and out on the other, filled with big transformer coils. (For a triple-phase line, there will be a set of three transformers, possibly with all three in the same box.) The high-voltage input generally has heftier "bushings" -- they look like insulating strings but conduct electricity down the center -- than the output or outputs. Although transformers are efficient, they still dissipate a bit of power, and so there are fins and banks of fans on them to get rid of the heat.
Oil circulates inside the transformer box to transport the heat from the interior. There may be an oil tank or tanks on top of the transformer to make sure there's adequate oil. Sensor systems built into the transformer check the state of the oil, checking for hydrogen bubbles that could indicate shorting inside the coils. A substation site is usually laid out with a barrier around the perimeter to ensure that oil will not drain off and contaminate the soil if a transformer springs a leak or blows out.
The amount of voltage pulled off the output side of a transformer can be varied simply by moving the "tap" connection off the output coil. This needs to be done at times to make sure the output voltage remains constant. The "tap-changer" on the side of the transformer housing use to have a hefty manual lever on it, but these days it's all done by remote control and there's nothing to see but a closed box on the side of the transformer. Very often the transformer has to be shut down before the tap can be changed.
* Shutting down the flow of electricity means a switch, but not too surprisingly the switches at a power substation are more formidable than those in your house. A typical high-voltage switch looks like a box or cylinder with two bushings on top to connect to inputs and outputs. The switch is full of oil, same stuff as inside the transformer box; when the switch contacts are opened, they tend to arc across (as described earlier) and the vaporized oil tends to shut down or "quench" the arc quickly.
A switch can look like a transformer, but there are clear differences. In the first place, a switch doesn't dissipate power whether its open or closed, and so a switch has no cooling fins or fans. In the second place, a transformer has a circuit in and a circuit out, meaning at least two insulator strings on each side. A switch is in line with a circuit, meaning that they may have one insulator string in and one insulator string out. For three-phase power, three switches are ganged together.
There are variations on switch technology. "Air-blast" switches, as their name implies, use a blast of high-pressure air to quench the arc. They lack the big tank of oil switches and may have a tee-shaped structure. The advantage of an air-blast switch is that there's no oil to deal with. The disadvantage is that they make a loud BANG when they're actuated, and they are not well suited for use in areas where neighbors can complain. In Europe, "metalclad" switches are filled with sulfur hexafluoride, which is a heavy gas that its very efficient at quenching arcs. It is also very expensive.
Switches can be actuated manually -- at least in the sense of someone pressing a button, though a switch actually gets the command by remote control -- or by automated systems that determine network faults, in which case the switch acts as a "circuit breaker", conceptually similar to those in a home. Since network faults tend to be transients, a circuit breaker thrown open will automatically reclose after a second or two; if the fault persists after a number of retries, the breaker stays open and service workers have to deal with the problem.
A substation has to designed carefully as part of a network to ensure reliability. There is generally a degree of redundancy to make sure that power gets to the end users even when part of the system goes down. [TO BE CONTINUED]
* GIMMICKS & GADGETS: BUSINESS WEEK reported on an interesting wind-power gimmick proposed by an American designer, Mark Obserholzer. His idea is to put vertical wind turbines in the barrier between the lanes of a freeway. with the turbines driven by traffic roaring past. One further concept would be to run an electric light rail down the midline, running on the power generated by the turbines.
* Britain is sometimes regarded as the world homeland for security cameras, a notion reinforced by a test exercise in Plymouth in which 250 police officers are wearing helmets fitted with a small color video camera. The cameras document an officer's actions and record details of incidents. Initial results of the trial show a 40% increase in the number of crimes being detected and a 20% increase in the conversion of a violent incident into an official crime.
* According to CNET Online, researchers at Purdue University have developed a "tactical biorefinery" for the US Army -- a portable generator that extracts energy from trash.
The biorefinery is about the size of a small moving van and can process a range of trash, including paper, plastic, styrofoam, cardboard, woodchips and food waste. Two different processes are used: food material is dumped into a bioreactor to be fermented by yeasts into ethanol, while the other materials -- paper cups, plastic forks, and so on -- are crushed into pellets and then burned to produce a mixed gas consisting of propane gas, methane, and hydrogen. The ethanol and the gas is used to drive a diesel / multifuel electric generator to drive the biorefinery and provide external power. The generator can be run on conventional diesel fuel until its conversion processes are up to speed.
The Army is interested in the system not merely because of the service's public mandate for environmental responsibility, but because it reduces the level of trash needed to be handled in field operations.
* Users of the latest Microsoft Internet Explorer 7 (IE7) may have noticed an interesting feature: get into a site like Paypal and the URL bar of the browser turns green. The feature, intended to defeat "phishing" online scams, is based on an "extended validation (EV) certificate" associated with Paypal or other properly registered sites. Security certification are not new, being associated with the "https" or "secure http" pages often used to ask for credit card information and the like, but the EV certificate is much more robust and harder to fake. That makes it more expensive, with a cost of hundreds instead of tens of dollars, and small businesses complain it is burdensome for their needs -- though it is the big operators like Paypal that are the primary focus of scams. Other browser makers are considering implementing the scheme.
* THE WOLF BITES BACK: In the business world, there are some sets of competitors whose relationship goes beyond even intense rivalry to bitter hatred. The acid relationship between Microsoft and its rivals, particularly Apple, seems subdued these days, but the emnity between world's two biggest jetliner manufacturers, Boeing of the USA and Airbus Industries of Europe, continues in full force.
Boeing had dominated the world jetliner market and was contemptuously dismissive of upstart Airbus at first, Boeing officials publicly stating that Airbus was just another European boondoggle that would sell a handful of aircraft and then be forgotten. When Airbus finally landed a US deal using what might be tactfully called "imaginative financing", Boeing's reaction was loud and angry, leading a senior Airbus official to sneer that "the Big Bad Wolf is screaming because Little Red Riding Hood has bitten him in the ass."
Only a few years back, Airbus could finally boast of a year of orders that exceeded those of Boeing, and was moving full speed ahead on the new A380 "super jumbo" airliner. Boeing seemed to be stalled, unwilling to accept the challenge, and then the company was hit with scandals that led to the successive resignations of two CEOs, as well as the imposition of US government penalties. It didn't take a mind reader to sense the satisfaction that Airbus took in the distress of its rival.
Now, as discussed in an article in BUSINESS WEEK ("The Secret Weapon At Boeing" by Stanley Holmes, 8 January 2007), the shoe is on the other foot. When Boeing announced the advanced twinjet 787 Dreamliner, Airbus officials were quick to criticise its "excessive" reliance on composite construction, but this was merely a classic exercise in spreading "fear, uncertainty, and doubt (FUD)" among potential customers that fizzled. The 787 was the right product at the right time: airlines were looking to replace aging air fleets, and with high fuel prices the fuel-economical 787 was exactly what they wanted. Airbus gave up the FUD campaign and responded with a competing "A350" design, which even at best would not be delivered to customers until several years after the 787 was in service. Design waffling in the face of customer inputs put it even further behind.
Airbus hoped the A380 would not only be a market leader as a passenger liner, but it would also be able to take on Boeing's continued domination of the air freightliner market, mostly through to freighter versions of the classic Boeing 747 jumbo jet. Unfortunately for Airbus, the A380 has run into technical problems with its vast wiring system and has been delayed. Boeing is working to release an improved 777 freightliner in 2008, and then the "747-8" freightliner in 2009. The 747-8 is the latest incarnation of the 747; it will be stretched for more capacity and range; feature new, highly efficient engines and wings; and have advanced avionics leveraged from the 787 program -- hence the "-8" suffix.
The air freight business is booming, particularly as trade from Asia increases. Boeing's traditional proportion of freightliner sales to total business is about 10%; for the moment it's up to 17%. Overall orders have zoomed back ahead of Airbus. Even when Airbus gets the A380 flying right, the 747-8 will be highly competitive in terms of capability and operating economy -- and with the dollar being weak at this time, relatively cheap to buy as well. Customers who had planned to buy A380 freighters are now cancelling orders and lining up to get the 747-8, to such an extent that industry observers are suggesting that the A380 freightliner may be cancelled. Airbus is now restructuring and performing layoffs.
The delay in the A380 program also helps Boeing in other ways. It means that more old 747 jetliners are being kept in service, instead of being converted to freightliners, and so there is a better new-buy market for freightliners. It also opens a window of opportunity for Boeing to sell 747-8 passenger liners. Airbus had mocked the announcement of 747-8 passenger liner versions, calling the 747 design in effect "old news", but with the A380 program delayed the 747-8 passenger liner just keeps looking better and better. Boeing can respond in all truth to the "old news" jab that, unlike the A380, the 747 is a well-proven and trustworthy design, and that with the latest improvements the 747-8 is a match for the A380 as far as cost-effectiveness is concerned.
Boeing has not demonstrated much inclination to publicly gloat over the distress of Airbus; Boeing's own recent troubles ensured that company officials aren't in a comfortable position to crow, and the message seems to have soaked in that the customers and the aerospace industry in general are sick of listening to the petty-minded sniping and bickering between the two companies. However, once again it hardly takes a mind-reader to suspect that there's a lot of gloating going on in private.
* LATIN ETHANOL: US President George W. Bush recently conducted a Latin American tour in hopes of mending tattered fences, and as it turned out one of the big items on the agenda was biofuel production. According to an article in THE ECONOMIST ("Fuel For Friendship", 3 March 2007), the matter is an important one to Mr. Bush, who has stated that the US will become increasingly reliant on biofuels in the near future, and to his first host on the tour, Brazilian President Luiz Inacio Lula da Silva.
Biofuels have been a bit of a sore point between the US and Brazil. The US has been pushing corn-based ethanol, with corn regarded as an expensive feedstock and the ethanol produced from it suffering from a number of drawbacks; Brazil uses sugar cane as a feedstock, still not perfect but grown in great quantity and, best of all, more easily converted into ethanol than corn: cornstarch has to be broken down into sugars first, sugar cane is mostly sugar to begin with. That means that Brazilian ethanol is about 75% the price of American ethanol -- and in today's oil market, cost-competitive even without subsidies. To keep American farmers happy, the US government has slapped import duties of 54 cents per US gallon (14.25 cents per liter) on most foreign ethanol.
This trade protectionism runs head-on into Brazil's biofuel ambitions. New ethanol production is coming online at a fast clip, with projections that Brazil will have 412 distilleries pouring out 36 billion liters (9.5 billion US gallons) of ethanol. Brazil would like trade barriers with the US (and with Europe, which similarly shuts out Brazilian ethanol) to fall, with projections showing that a fair trade regime would boost the country's current exports of 3 billion liters (790 million US gallons) per year to 200 billion liters (53 billion US gallons) by 2025. To put that in perspective, that would replace 10% of the world's gasoline consumption. That's not just an economic opportunity -- it's a bid for global power.
Other Latin American nations are jumping on the biofuel bandwagon as well, with their interest partly boosted by the fact that sugar cane is a common crop throughout the region. Colombia is building a number of plants, with government regulations ensuring there will be a market: by 2009, filling stations will be required to sell a 10% ethanol / 90% gasoline mix, with the proportion of ethanol rising to 25% in time. Costa Rica has implemented much the same policy, and Panama is considering it. Studies have encouraged Mexico to come on board, and a number of Caribbean nations see ethanol as a tempting way to boost their lagging sugar industry.
What these countries would like is access to the US market. Some of the smaller players in the game, such as Peru, already have it, the import duty having been waivered by trade concessions. A pipeline is being built in Peru to pump the ethanol to tankers for seaborne delivery to the USA and elsewhere. The Peruvians see exports of 120 million liters (32 million US gallons) by 2010 -- a drop in the bucket compared to what Brazil is capable of, but a substantial sum in itself.
The US has many good reasons to promote the biofuel industry in Latin America. For one, there is no way that the US can meet the targets for biofuel use stated by the Bush II Administration on its own. Imports from Latin America wouldn't constitute "energy independence", but ethanol from "friendlies" like Brazil and Colombia is much preferable to oil from "hostiles" like Iran and Venezuela. Buying Latin American ethanol would also help economic development in the region, reduce the flow of illegal immigrants, and polish America's somewhat tarnished reputation south of the border.
Outgoing Florida Governor Jeb Bush, the president's brother, set up an InterAmerican Ethanol Commission to promote a hemispheric biofuel effort and wrote the White House to suggest that the Federal government similarly devise "a comprehensive ethanol strategy" involving the USA and America's neighbors. On his Brazil stop, Presidents Bush and Lula da Silva signed a cooperative agreement on biofuels that was played up in the news media. The tariff still remains in effect, however, at least until it lapses in 2009.
* A SHORT HISTORY OF LIFE (10): The Permian period, beginning 290 million years ago, moved the scene of most interesting developments to land. Amphibians continued to thrive, including species that looked like snakes, or looked like crocodiles, or had big crescent-shaped heads.
However, the reptiles were beginning to come into their own. There are three main lines of reptiles, distinguished by distinctly different skull structures with differing numbers of holes behind the eye socket:
The synapsids are the "signature" creatures of the Permian, divided into two main groups: the well-known "pelycosaurs", with their wild "sails" on the back -- they're sometimes called "sailback dinosaurs" though they're really not dinosaurs at all -- and the "therapsids", which generally tended to be stumpy, squat beasts and which were the more or less direct ancestors of the mammals. There were herbivorous and carnivorous forms among both groups. Incidentally, nobody has any clear idea what the pelycosaur sail was form, one popular idea being that it was for thermal regulation.
The Permian period was the end of the Paleozoic era, and the end was not a subtle event, the biggest mass extinction in the history of life. The trilobites died out completely, losses of many families of marine invertebrates exceeded 90%. Others did not fare quite so badly, but all suffered. Nobody knows what happened; large eruptions and shifting continental masses, which rammed into each other to form the supercontinent "Pangea", may well have shifted the climate. Some suggest that the seas all went brackish in rising heat, with sulfur-metabolizing microorganisms taking over and filling up the atmosphere with toxic hydrogen sulfide gas. Whatever the cause, the world in the new Mesosoic era would look very different: the age of dinosaurs had arrived. [TO BE CONTINUED]
* INFRASTRUCTURE -- THE POWER GRID (6): A high voltage line has such an intense electric field around it that it can ionize the air molecules in its vicinity. The ionization and recombination of the molecules results in a faint sizzling sound, a faint glow visible on dark nights, and radio noise -- which is why AM radios tend to be lost in noise when a car drives under a power line. This is "corona", mentioned in an earlier installment.
Corona is not particularly noticeable in lines running at 100 kV or less, but at 345 kV or above it can waste a lot of power. Its radio emissions are subject to regulations as well, and the ionization can produce ozone and nitrous oxides, both air pollutants. As a result, power companies try to minimize it. One way is to control the geometry of electrical gear: a pointed element concentrates charge and increases electric field strength, while a flat element provides the minimal electric field. High voltage electrical gear features gentle curves, rounded corners, and smooth surfaces. Corona is harder to deal with in wet weather, but not as might be supposed because the air is more conductive: the reason is that water droplets on the line form into little spikes that produce lots of corona.
Increasing the diameter of a conductor reduces corona. "Expanded" conductors are steel-core conductors with a sheath of nonconductive fibers between the core and the current-carrying aluminum strands. The "bundled" conductor schemes mentioned earlier -- two, three, or four conductors in parallel -- produce an effect in which the electric fields of the multiple conductors merge to make the bundle look like one big fat conductor. Corona tends to be nasty at the connection from a conductor to an insulator, so this connection often features a ring called a "corona ring" or "corona shield" that distributes the electric field, reducing corona.
Incidentally, in principle small birds can land on a high voltage line and not get electrocuted, since there's no connection to ground and no current can flow. However, they can feel the corona and won't get near one.
* Power line insulators are usually stacks of glass or porcelain, clamped to a conductor on one end and pivoting freely from the power tower on the other. Little or no current will flow through the insulator itself, but it can leak over the exterior of the insulator, a phenomenon known as "surface creep". It gets worse when the insulator is wet or dirty. The insulator is made slick to shed contaminants, and the disks have ridges or the like to increase the length of the creep path, increasing the resistance and reducing the losses. The problem is worse in polluted areas; in such places, insulators may be greased or hosed off every now and then.
While the simplest arrangement is a single insulator string from the tower to the conductor, "vee" arrangements of two strings linked from the power pylon to a single conductor are sometimes used to reduce swaying. Arrangements of insulators can become even more complicated. Insulator disks used to be brown or black, with porcelain disks sometimes a pretty dark red color. These days they're usually an unobtrusive neutral gray.
* Lightning is a hazard to power lines. The towers usually have a hefty ground strap connected to a rod pounded into the ground, giving the lightning bolt a path to drain off into the earth. The conductors can't be grounded, of course, so to protect them there "aerial wires" strung at the top of the line assembly. They are electrically connected to the power towers, giving the lightning a way to drain off to ground. Incidentally, birds will perch on the aerial wires.
Lightning can still hit conductors, so the power system has defenses at its terminal ends -- circuit breakers and the like, more on this later. With lines operating at 500 kilovolts or more, circuit breakers have to be specially designed, not just to handle the higher voltages but to open more slowly. As mentioned, break the circuit to an inductor and the voltages will skyrocket, sparking across the open circuit gap. Abruptly throw open a very high voltage line, which has a degree of inductance, and the results can be disastrous.
* There have been concerns that people living near or under high-voltage lines are prone to cancers and other ailments. However, the increase in vulnerability to such is marginal and there are suspicions the seeming increase is just statistical noise -- all the more so because the incidence of such afflictions doesn't seem to change with level of exposure to electric fields, which makes no sense from a biomedical point of view.
The electric field is certainly perceptible, however. Try going under a high voltage line at night with a fluorescent light tube; it may well flicker and glow. Just don't take a long tube and don't wave it over your head.
* As a final footnote to high-voltage lines, consider the issue of maintaining them. It's difficult to shut them down, so generally maintenance has to be performing by linemen working on hot lines. The surprising part is that they do it bare-handed, more or less. A lineman is brought up to the line on an insulated cherry-picker and neutralizes the difference in potential with a pole. He has to wear a conductive suit to prevent from being zapped by the simple gradient in electric field. It is said that right up to the line, one hears a buzzing sound like being in a hive of bees. [TO BE CONTINUED]
* A FADING COMPASS? It has been known for a long time that the Earth's magnetic field is highly variable. According to an article in IEEE SPECTRUM ("The Case of Earth's Incredible Shrinking Field" by Justin Mullins, November 2006), Karl Friedrich Gauss figured out how to measure the Earth's magnetic field in the 1830s -- with the unit of magnetic field strength being measured in "gauss" in his honor for the feat -- and since that time the magnetic field has been shrinking at a rate of about 5% a century. The question this poses is: for how long has it been doing that? Now a team of British geophysicists led by David Gubbins of the University of Leeds has obtained an answer, from an indirect source: the logbooks of sailing ships from the 16th, 17th, and 18th centuries.
It is possible to obtain evidence of past magnetic field strength and direction frozen in lava flows, with a record now available of "paleointensities" from 315 sites covering the era from 1590 to 1840. However, measuring the paleointensities is tricky, with errors of about 10% -- which happens to be about the same as the range of change under investigation. Gubbins realized that he could do better if he knew what the magnetic field direction was for each sample. It turns out that old maritime logbooks have very exacting measurements of the direction of the Earth's magnetic field relative to Sun position. As Gubbins says: "Mariners made extremely accurate measurements, because their lives depended on it."
Investigation showed that the records of the British East India Company alone includes 50,000 measurements. His graduate students canvassed every measurement they could get their hands on, and armed with this data Gubbins has concluded that the Earth's magnetic field was stable or close to it for the period from 1590 to 1840. The change after that time seems to have been due to localized reversals of the magnetic field that appeared in the southern hemisphere in the late 18th century, with the reversals due to thermal changes in the Earth's core.
Long-range studies show that the Earth's magnetic field intensity has dropped about 40% over the last 2,500 years, which gives a slow rate of decline of about 1.6% per century. Says Gubbins: "It's just coincidence that today's period of rapid change began at about the time we became able to measure it."
* WHO CAN YOU TRUST? Anybody who has ever used online reviews quickly realizes that they are often exploited by people with a vested interest in praising their own products or in low-balling a competitor. According to an article on WIRED NEWS Online ("Herding The Mob" by Annalee Newitz), the same sort of trickery is now being applied to online feedback scores.
Those who use eBay or Amazon peer-to-peer sales knows the scheme: you buy something from somebody, you score them on how well they follow through with the transaction. Now scammers, spammers, and thieves are trying to "crowdhack" scoring systems in order to boost sales, increase website traffic, or simply steal.
The eBay ratings scheme was a pioneer scoring system, with the firm initially offering the scheme in 1996. Under the rules, only those involved in a transaction can rate the transaction, and there's no way to change the scores or remarks once posted. It became the model for online scoring systems. It might seem fairly hard to cheat given the rules, but that would be underestimating the resourcefulness of cheats.
A typical eBay scam is simple: the scammer sells a lot of small items to build up a positive profile -- then moves up to big-ticket items, sells them off in a burst, and leaves town with the money. Arizona police say that in 2003 a woman named Nancy Drexler sold a stream of CDs and DVDs, acquired a good rating, and then sold off $100,000 USD worth of expensive items that didn't exist, ripping off about 500 buyers. Arizona authorities haven't pressed fraud charges against her yet, but the state of Nevada has in a separate case.
John Morgan, a professor at the Haas School of Business of the University of California at Berkeley, has researched eBay fraud and says it is not only common, it is also blatant. The usual game is to set up networks of "buyers" and "sellers" that perform dummy purchases from one another, the usual price of a sale being a penny or so, to build up positive profiles. One of the "hot" items in this trade was a booklet explaining the scam, with the booklet to be resold by the purchaser to keep the scam rolling. Says Morgan: "We saw a number of sellers who used sham transactions to build reputation, laid low for a period of time, and then reentered high-value markets as apparently 'reputable' sellers."
The scams are not being ignored by eBay. A company spokesman says that the online system includes software to spot patterns of dubious transactions. The details are secret to prevent scammers from getting wise. However, other commerce sites don't have such protection. Yahoo Shopping, for example, lets anyone post a review, allowing the same people to log in using multiple email addresses and post glowing reviews over and over again. This tactic has long been known on internet forums, with individuals pretending to be multiple people to "gang up" on opponents, the game being called a "sock puppet show".
A Brooklyn-based company named PriceRitePhoto got superb Yahoo ratings despite many negative reports. Those who posted criticisms were harassed by the shop's owner. Yahoo threw PriceRitePhoto off the system, but it came back a few months later as Barclays-Photo. It got thrown off again after a series of complaints, but it's still operating on eBay -- with suspiciously high ratings.
* The "crowdhacking" phenomenon is also penetrating link-community sites like Digg. These sites bring together networks of users who tip off each other to interesting links on the web, with statistics kept and the most popular links listed on the site's front page. This potentially means a lot of traffic to sites that reach the top of the list.
The method of choice for manipulating Digg is called a "Sybil attack", after the tale of the woman with 16 different personalities. It's another "sock puppet show" trick, with one person opening multiple accounts and recommending the same link with all the accounts. There are other ways to cheat on votes: one enterprising soul set up a site named "User/Submitter" to promote websites on Digg for a fee; once paid off, User/Submitter paid Digg users 50 cents if they voted for three articles promoted by User/Submitter. Some companies also contact top Digg users and pay them to promote specified sites. Then there is "Spike the Vote", which is something like a pyramid scheme in which Digg users vote up each other's pet links. Like eBay, Digg has software to spot bogus voting patterns. For example, the software will sound an alarm if a number of accounts are created in a short period of time and all vote for the same links, or if people vote for a link without checking out the link first.
The arms race continues. Some are optimistic that the white hats will win, simply because scoring systems will be destroyed if nobody can trust the tallies, and those who own the systems have a vested long-term interest in making sure the game is honest. However, there are plenty of black hats with a short-term interest in making a killing, damn the long run -- and they can be very ingenious.
* STAYING ALIVE IN BAGHDAD: Intelligence is always a necessity in war. According to an article on BBC WORLD Online ("Iraqis Use Internet To Survive War" by Andrew North), Iraqi civilians have been finding the internet a valuable tool to enhance their chances for survival.
The popular Iraq League site, for example, suggests that people download satellite images of their neighborhoods to determine where death squads might enter the area, and to identify escape routes. Of course, the death squads are sure to be using them as well to plan their attacks.
The Iraq League site, which is actually hosted in the UK, is in principle nonpartisan, but is more of a reference for Sunnis than Shiites. It offers grim advice. Don't let the police arrest you, for example, since they are likely to torture and kill you. "If they tell you we just have a few questions and you will be back in an hour, don't believe them. You will be dead in an hour or disappear for months."
The site continues that everyone needs to be trained and vigilant, quick to call in local guard forces if intruders arrive. People should vary their routes from day to day, and Iraqis with names common among Sunnis -- like Abu Bakr or Omar -- should get new ID cards with less dangerous names. Devout Sunnis often have long beards; Shias wear short beards, and so it's safer to keep beards trimmed. Other websites suggest that Sunni shopkeepers hang up pictures of Shiite Grand Ayatollah Ali Sistani, or Imam Hussein, grandson of the Prophet and the great martyr of Shiite faith.
The Iraq League also maintains a section containing messages from people, both Sunnis and Shiites, trying to find missing family members and friends. The messages make the tragedies of war painfully apparent: "Please help me to find my husband who was kidnapped travelling from Baghdad to Amman. Gunmen seized him because he is a Shia, but they left my brother and his family because they are Sunni. Please help me." The message is months old and unanswered.
Sometimes the results are less discouraging. Help was offered to a girl who suffered an eye injury during a mortar attack on her school early in the year: "We can provide medical treatment outside Iraq." The fact that people are still willing to try to help each other is encouraging, but for the time being the real objective is just to stay alive.
* A SHORT HISTORY OF LIFE (9): The Carboniferious period, beginning 360 million years ago, was the first era of forests. They weren't much like forests we know today, being dominated by tree ferns, plus a wide range of other trees that haven't survived, at least in the form of trees, to the present. Some forms of "lycopod" trees appear particularly bizarre by modern standards. They have been referred to as "green scaly telephone poles"; they grew straight up without branches to terminate in one or more "pompoms" of long, whiplike leaves. They had sprawling root systems and very thick, scaly bark to support their height, since they weren't woody plants and were pulpy inside.
A forest of such lycopods could be compared to a grove of giant pipe cleaners. Other forms featured sets of branches that grew up into a canopy. They reproduced using cones, but the cones contained spores, not seeds. Other trees of the era were not so bizarre -- the pteridosperms looked like tree ferns, but they reproduced using seeds, not spores.
The amphibians thrived in the era, and led to the next generation of animals, the "amniotes", which reproduced using the "amniote egg", a neatly packaged environment for their offspring to grow through their larval stage and then hatch as little replicas of adults. No more going back to the water to spawn tadpoles. The first amniotes were the reptiles, which emerged later in the period. They were not so different from amphibians, the major distinction being that they hatched from their eggs fully formed, if of course not adult-sized, and without gills.
The Carboniferous also saw the introduction of flying insects. The best-known survivor from those days is the dragonfly, with its somewhat awkward wings. (The wings are also not all that aerodynamically efficient, as demonstrated by the noisy way dragonflies fly.) However, modern dragonflies are dwarfs compared to the biggest Carboniferous species, which had wingspans of up to 60 centimeters (2 feet). There are even more startling remains from the late Carboniferous of something that looked like a millipede but was 1.8 meters (6 feet) long, and scorpions bigger than 60 centimeters (2 feet). Why did bugs get so big? Different climate? Lack of competition? Nobody really knows.
Although some types of fossils are hard to come by, we are economically dependent on fossils from the Carboniferous era. The lush vegetation of the era accumulated in great beds; the beds would be buried and turn into coal and oil. Some big lumps of coal can be carefully broken open to reveal well-preserved plant fossils. We tank up our cars on the remains of Carboniferous forests. [TO BE CONTINUED]
* INFRASTRUCTURE -- THE POWER GRID (5): The last installment in this series mentioned power-line conductors but basically took them for granted. They are actually an interesting subject in themselves.
The most conductive metal is silver, but due to the obvious expense it is rarely used in electrical systems. Copper is next-best and gets plenty of use, but aluminum, the third-best, is cheap and light, so it is the conductor metal of choice in power lines: it works as well as copper if the conductor is made thicker.
The conductor wire in a power cable for, say, a vacuum cleaner is maybe about as big around as a pencil lead. The heavy-duty cable used with a clothes dryer has maybe the diameter of a crayon. The cable used in a high-power line can have a diameter up to about that of a baseball bat. It's not a solid length of aluminum, of course, which would make it somewhat hard to coil up, instead being a bundle of small, flexible strands. Oddly, aluminum cable configurations are named after flowers: the common 61-strand cable, capable of handling 1,100 amperes, is a "narcissus", with others named "snapdragon", "lupine", and "bluebonnet" -- the last being the heftiest standard cable, with a capacity of more than 2,000 amperes.
Some conductors have aluminum strands wrapped around a steel core. Steel is a middling conductor, but it adds strength. Such conductors are named after birds -- for example, a "starling" has 26 aluminum strands braided around seven finer steel strands. Conductors can be so strong that there are cases when they pulled down towers after ice storms -- not the desired effect, since it's much easier to fix a broken conductor than a tower. As mentioned earlier, high voltage lines will have two conductors, with the really high voltage lines having three or four -- with the conductors separated by spacers.
Conductors are delivered on big wooden spools. Once the conductor from one spool has been strung up, it has to be spliced to a conductor from another. The splice is performed with an aluminum sleeve, with the two conductors inserted and the sleeve then compressed to snug them together. The splicing procedure is performed by either a hydraulic ram unit or, believe it or not, special shaped explosive charges. Of course, the splicing is performed on the ground and the spliced cable then strung up.
Although residential line conductors are wrapped in insulation, high voltage line conductors are not. Insulation simply doesn't work: the voltages are so high that they would zap right through it.
Conductors often have puzzling elements attached to them, for example little dumbbells. They are vibration dampers, intended to prevent the conductor from vibrating and weakening itself. The dumbbells are called "Stockbridge dampers", for George Stockbridge, an American engineer who invented them in the 1920s. Other dampers included spirals of heavy wiring wrapped around the conductor or (common in my own locality little diamond-shaped bent metal "kites" that are fixed to the bottom of the conductor. Extra strands of wire are also wrapped around a conductor where it is clamped through an insulator to a power pole, with such "armor bars" reducing the potential for damage from vibration.
Conductors may be strung with brightly colored balls to make them more visible where they could be a hazard to navigation, near airports or when they're strung across rivers. In Europe, lights are hung from conductors to ensure that they are visible at night; the lights don't have a power supply, they get all the juice they need from the electric field around the conductor. In the US West, large raptors such as eagles and ospreys will often try to build nests on the top of power pylons, and the birds are big enough to short out the lines if they touch two conductors whilst flying down to roost. Shooing the birds off isn't practical, so platforms are built well above the original top of the tower to allow the birds to nest safely. It also wins the power company legitimate points on wildlife conservation. [TO BE CONTINUED]
* IMPROVING GEOTHERMAL: Geothermal power -- the idea of tapping steam from the Earth to drive electrical power turbines -- is not a new concept. In fact, it wasn't all that new an idea when it was promoted as an alternative power source during the 1970s energy crisis, and it hasn't been promoted much during the current energy crisis, partly because the 1970s hype about geothermal proved overblown. In the first place, it can only be used in locales that have geothermal activity, and in the second place it's a tricky engineering problem, with geothermal sources tending to be inconstant and plant gear suffering from fouling and corrosion.
One of the issues is the temperature of the steam obtained from the Earth. If the steam is much cooler than about 150 degrees Celsius, it will condense before it can be driven through a turbine; if it's hotter than 400 degrees Celsius, it is hard to handle. However, work is being performed to extend geothermal power outside these limits.
The waters at Chena hot springs in Alaska are pleasantly warm for bathers, but even the 74 degree Celsius temperature of the water down in the wells of the hot spring is on the cool side for power generation. It can still be done: a closed-loop system pumps a refrigerant known as R134A down into the well, where it is vaporized and comes back up to drive a turbine. The R134A is cooled down to liquid again by a local river, and sent back down the wells.
This isn't basically all that new an idea, either, the problem with it being that traditionally the cost of the system was prohibitive. The builders of the system at Chena have been able to reduce costs by using off-the-shelf air-conditioning components, and claim that their technology is cost-effective for any site where there is a difference in temperature of at least 50 degrees Celsius between the heat source and the cold sink. Some oil wells achieve that much and could be used to generate power.
Iceland is the world center for geothermal power; existing geothermal sites are well developed, and so there is an urge there to drill deeper to reach new, more potent geothermal sources. The "Iceland Deep Drilling Project" intends to extend the reach of current geothermal wells from about two kilometers (about 6,600 feet) to twice that depth or more, where the steam temperatures will run about 600 degrees Celsius. There's no one magic trick to handling such hot steam, it's just a question of engineering to handle the higher temperatures and pressures.
A deep-well geothermal power plant might cost three times as much as an shallow-well plant -- but it will produce ten times as much power. Industries are already locating to Iceland to take advantage of cheap electrical power, and deep-well plants will only enhance the country's industrial game plan. Icelanders are also exporting their technology to countries where active volcanic systems are common.
* PLUG-TOGETHER HOUSE: Prefabricated housing is nothing new, being represented in the US by the "factory homes" plugged into trailer parks, but they represent the low end of the housing market and aren't all that convenient in many ways, with a fixed configuration and still requiring a fair amount of fussing to get into operation.
According to an article in POPULAR SCIENCE ("Building Blocks" by Don Stover, November 2006), Kent Larson, a professor of architecture at the Massachusetts Institute of Technology (MIT), thinks that prefab homes are the way of the future, that the traditional approach to housebuilding is archaic and inefficient: "Every product except homes has become more sophisticated, with higher quality at lower cost. Homes are just the opposite." Very few people can afford a custom home built to their specifications, but even homes built to a standard are effectively custom in construction, put together piece-by-piece just as are the true custom homes. In his earlier life as a commercial architect in New York City, he was appalled by the indifferent and piecework way houses were built, and when he went to MIT in 1996 he began work on a scheme to change things.
Larson envisions a modular approach to building a house, with components built in a factory that are easy to update or replace. Buyers should be able to configure a design online to precisely fit their needs. His concept involves a rugged central "chassis" that could last for centuries, which would be fitted or refitted with a roof, walls, siding, and electronics as desired. Larson calls the concept the "open source building".
The problem is one of specifications and standards. A personal computer is reconfigurable because of the standard interfaces it supports, and Larson's reconfigurable house will need comparable standards to make sure the parts all work together. Larson is now working with a New Hampshire builder named Tedd Benson to construct four prototype houses, the first of which will be completed in the summer of 2007. The project is a pilot for MIT's Open Source Building Alliance (OSBA), a group of manufacturers with an interest in the concept. Larson wants to make sure industry is definitely on board the concept, since he knows it will have no chance of working if it's just passed down from on high from an academic institution.
Tedd Benson did not need to be converted to the vision, in fact he was maybe a bit ahead of Larson in the concept. His construction firm, Bensonwood Homes, had been putting together modular assemblies for the homes built by the firm, but they still needed considerable work to put together on the building site. Like Larson, Benson found the whole scheme absurdly backward and inefficient. Unlike most home builders, Benson had a scholarly bent, and in the early 1990s he discovered the writings of Dutch architect N. John Habraken, who proposed that a building's support structure should be separate from its "infill" -- interior elements such as partitions, wiring, plumbing, and cabinets. Habraken was a pioneer in the concept of "open building", which would evolve into Larson's "open source building". Habraken had been working at MIT and Benson invited him to New Hampshire to talk with the staff of Bensonwood Homes.
Then Benson discovered a book published in 1994 by Stewart Brand, best known for his WHOLE EARTH CATALOG series, titled HOW BUILDINGS LEARN. Brand's book divided buildings into six systems or "layers", each with a different lifespan: site, structure, skin, space plan, services, and "stuff":
In response to these ideas, Benson developed a modular scheme he calls "Open-Built", which involves modules attached to a timber-frame skeleton. However, he was still trapped by the "entanglement" problem, the need to wire and route systems on site. That's when he and Larson joined forces.
The pilot house is named "Open_1" and is part of a rehabilitation facility for brain injury patients in Greenfield, New Hampshire. It is a three-story timber-frame house, built in 40 prefab sections, including an elevator system, that were put into place with a crane. The sections were all completely finished, and the building was assembled in less than a month. The total amount of trash resulting from the construction filled up about two barrels.
The electrical links between sections were established using snap-together connectors. Wiring that might need to be updated was run through easily accessible raceways. The ceilings are made of removeable panels that allow easy access to light fixtures. The next prototype will have moveable interior walls. Larson, Benson, and others involved in the project believe that the open source building scheme will revolutionize construction, not only reducing costs but providing more flexibility and even improved quality.
* ED: I live next to a trailer park and factory homes seem like a fairly decent thing, nothing special but a clear step up from the tinny trailers they are gradually replacing, and seemingly cozy once various accessories like a porch and a garage are attached. I had elderly uncle and aunt who had been living in a "developed community" house, which like many such structures had two floors; when they got too old to handle the stairs, they moved to a double-wide factory home, which was much more convenient because it was all on a single level.
Still, factory homes are nothing more than setpiece boxes, and the open source building concept is light-years beyond such structures. What is particularly interesting about open source building is that there are contractors who are pushing the idea. I grew up in a construction family and the idea that guys with saws and hammers could even be interested in academic notions is a real surprise: they are not at all as a rule bookish people. I have a feeling that if open source building can be made to work, traditional house builders are going to have real problems adjusting to technologies that will blow their doors off in cost, quality, and customer appeal.
* In related news, WIRED Online had a short article on a "high style" factory home, the "Glassic Soho", designed by San Francisco architect and designer Christopher Deam, which is along the lines of a sleek, modern glass-fronted summer home. It has 37.2 square meters (400 feet) of floor space. The Glassic is manufactured by the Breckenridge company. Base price is only $59,000 USD, not counting installation. Three floor plans are available: one-bedroom, two-bedroom (no kitchen), or studio.
* THE ART OF BRIBERY: Utopian social schemes have a nasty tendency to founder on certain aspects of human cussedness, one of the more prominent being corruption. Although much worse in some places than in others, it exists everywhere, and no culture has been ever able to stamp it out completely.
An article in THE ECONOMIST ("How To Grease A Palm", 23 December 2006), took a close-up of the phenomenon of bribery. In Uganda, bribes account for 8% of the cost of running a business. Hospital supplies in Buenos Aires, Argentina, are 15% more expensive than they need to be, due to the overhead of paying bribes. Bribery is an obvious and generally unproductive drain on a country's economy, and World Bank boss Paul Wolfowitz is pushing an effort to fight corruption. For most of the people who have to deal with bribery on a daily basis, however, the concern is much less for the drain on GDP than for the nuisance and humiliation of having to make payoffs all the time.
There is actually a fairly elaborate set of rituals for bribery that are surprisingly constant all over the world. It is rare, crass, and clumsy for someone to simply come out and demand money; the process is almost always disguised as a proper sort of transaction. This is not done merely to avoid prosecution for a crime, since there are places where nobody is ever punished for taking bribes; the indirection also allows bribe-takers to at least tell themselves they're not doing anything wrong, and reduce if not eliminate the humiliation to the bribe-giver.
Petty officials in nations where corruption is common, for example, are fond of coming up with elaborate regulations that seem to change with the wind and time of day, which may require "fees", or lead to "fines" when they are, of course, violated. Border officials are fond of asking for "expediting fees", which is actually not all that much of a euphenism, the message being that people in a hurry can pay the fee and pass through with little hassle -- or put up with all the inspections and bureaucracy that can be exercised. In India, government inspectors can be given "speed money" to ensure that business permits are issued more quickly. In Eastern Europe, dealing with a privatized company usually means hiring a "consultant" for a large "fee", who then makes sure that all the proper officials are paid off while taking his own cut.
In many cases, the camouflage is a fiction that the bribe-taker is just asking for a little favor. In North Africa, they ask for "une petit cadeau" or "a little gift". Mexican police will ask for a "refresco", or soft drink; in Angola and Mozambique petty officials make the same request, though they use the Portugese term, "gazoso". Corruption is blatant in Iraq, but officials will still ask for "good coffee"; in Kenya, the term "chai" conveniently means both "tea" and "bribe". Of course, the Middle-Eastern term "baksheesh" is widely understood, though surprisingly it's of Persian, not Arabic, origin; the literal translation is more along the likes of a "tip" or "alms".
Along with the evasive language comes an inclination towards evasive ways of making payouts. Once again the habit persists even in places where bribery is regarded as normal and few fear any punishment for it. A bribe to a border guard may be hidden inside a passport. In many countries, bribes are simply called "envelopes", since envelopes are a common way to pass over money in a concealed fashion.
* The daily hassles over bribery in corrupt countries are aggravating to the locals, but they at least understand that a policeman who's getting little or sometimes no pay is just trying to survive. It is the big-time corruption of the people at the top that is really infuriating.
Visitors, on the other hand, are usually not as aware of the high-end corruption as of the petty bribery, and in fact tend to get it worse than the locals. Foreigners don't know the rules, and they're often assumed to be rich anyway. Journalists are particular targets, since they are generally trying to make their way into offices not generally open to the public. Of course, journalists are often given bribes as well. In Nigeria, they are given hundreds of dollars -- in discreet brown envelopes -- to attend press conferences and dutifully report the official line.
Although Nigeria is notoriously corrupt, as anyone getting email from Nigerian email scammers might imagine, even in the USA journalists end up getting their palms greased, though the means are subtler. One conservative columnist and talk-show host was found to have taken $240,000 USD from the US Department of Education to say nice things about an education-reform bill. This example suggests that bribery is not always a clearly-defined concept. A New York businessman may not have to pay bribes as a matter of course as does a businessman in Africa or suchlike, but he won't think twice about bribing his way into a fancy restaurant without a reservation with a fifty-dollar bill.
Indeed, ordinary practices of the US Congress verge on the corrupt. Lobbyists make large campaign contributions and get preferential treatment in return. As long as there's no legally identifiable link between the cause and effect, it's within the law, and it's very hard to prove any such link. Lobbyists generally know better than to make a pitch and then hand over money, or even mention it; the money's handed off discreetly at some other time and under an appropriate guise -- generally a contribution to a campaign fund, which is legal in itself. Going over the line into blatant bribery can be asking for trouble, the most entertaining recent case being Congressman Randy Cunningham, a Vietnam-era jet ace who got a Rolls-Royce from defense contractors, along with other impressively sparkly goodies.
* Still, the US and Western Europe are much cleaner than elsewhere. Very few citizens encounter bribery on even an occasional basis there. Even orderly, industrious Japan is much more corrupt, at least at the higher level -- Japanese cops generally don't take bribes, but ministers of parliament and government ministry officials will.
However, for really serious corruption, one must go to the poorer countries. Poverty and bribery generally go together. Bribery is not only correlated with poverty and illiteracy, but also linked to the level of state control over the media and the amount of government red tape it takes to get things done. Socialist and recently socialist countries, with high levels of red tape, tend to be more corrupt than others. The more bottlenecks in a society, the more the police and petty officials can abuse their power. Authoritarian states, despite their heavy-handed concepts of law along with inclination towards rough policing and harsh punishments, seem particularly prone to corruption -- authoritariasm being closely linked with a lack of accountability.
It is characteristic of bureaucracies to keep piling up rules to make sure things are done right, but in the end the result may be to have so many rules that nobody can do anything without breaking some of them. As a result, the laws are no longer taken very seriously. Too much of the rule of law, it seems, tends to lead to a land where the law no longer rules.
* A SHORT HISTORY OF LIFE (8): The Devonian period, beginning 410 million years ago saw the introduction of fish that we would unambiguously perceive as fish. Cartiligous fishes -- with a skeletal structure of soft cartilage instead of hard bone -- made their appearance in the form of sharks. We tend to think of sharks as fearsome, and with good reason, but the real terrors of the era were the "placoderms", which could run to up to 15 meters (50 feet) in length and had jawbones with bladed edges and fangs. Their fossils are often found during excavations of shale deposits in the city parks of Cleveland, Ohio. By late in the Devonian, true bony fish were available as well.
Trilobites were still around in the Devonian, but their wild diversity of forms suggest that they were having a much harder time of it. Some could roll up into an armored ball; others had extensive networks of spines; still others had eyestalks, which they could have used as "periscopes" to allow them to see what was going on while hiding under the seafloor.
The invasion of land accelerated during the Devonian. Ferns and horsetails populated the dry earth, to be joined by "progymnosperms" -- the first real trees, with wooden trunks and fan-shaped leaves. Seeds were finally "invented", providing a more reliable means of reproduction than spores or branching off runners. Land vegetation was no longer sparse and puny, and some paleontologists like to speak of a "Devonian explosion" of land plant forms, along the lines of the Cambrian explosion of marine invertebrates.
Centipedes, millipedes, and flightless insects wandered through the primitive forests. Late in Devonian, the first land vertebrates -- amphibians known as "tetrapods" -- were crawling up on the land. They weren't so much different from modern salamanders, equipped with some features of fish, in particular gills. They also didn't lay hard-shell eggs and had to go back to the water to spawn, with the eggs emerging as larva -- in exactly the same way a modern frog spawns its eggs in water that then emerge into tadpoles. The tetrapods were clearly an outgrowth of the "lobe-finned fishes", or fishes with muscular belly fins, similar to the modern coelocanth -- another "living fossil", in fact thought extinct for hundreds of millions of years until a number were caught from deep waters in the Indian Ocean during the 20th century.
Obviously some lobe-finned fish picked up the trick of being able to crawl out onto land for short periods -- a scheme hinted at by the modern "mudskipper" of Southeast Asia, which is a fish with frog eyes that can crawl around on the land for a surprising length of time. Another modern hint is the "lungfish", which can't go onto land, but which can surface and breathe in air -- a useful trick for a creature that lives in brackish water.
Where the lungfish of the past got the lungs is another interesting question. The cartiligous fishes don't have any means of maintaining neutral buoyancy and tend to sink; this isn't a problem with rays and mudsharks, which live on the bottom anyway, but other sharks have to keep moving at all times to stay afloat using underwater "lift". The bony fishes improved on this scheme by obtaining a "swim bladder" that could be filled with air or deflated to maintain constant buoyancy. The swim bladder led in turn to lungs. [TO BE CONTINUED]
* INFRASTRUCTURE -- THE POWER GRID (4): The electrical power system for the US and Canada is in the form of a "grid" consisting of multipoint networks that ensure power continues to flow even if a plant goes down. The grid is divided into two primary "zones" or "interconnections", with the dividing line between the two zones running roughly along the eastern side of the Rockies. There are also two secondary zones, one for Quebec, one for Texas, except for most of the Texas Panhandle. Within each zone, the AC power generation is kept precisely in lockstep: if it weren't, phase changes between different plants would result in wildly varying voltages over the power lines. Power transferred between zones is converted to DC and then back to AC to prevent phase mismatches.
The "feeder" lines of the grid of course feature power towers, and as a general rule, the bigger the tower, the higher the voltage, and the longer the feeder line. Short-haul lines, running maybe 80 kilometers (50 miles) operate at 115 or 138 kilovolts. Longer feeder lines use higher voltages, though the voltages vary by region. Along the West Coast, in the Mid-Atlantic States, and the Southeast, most long feeder lines use 230 or 500 kilovolts. In New England, New York, and the Midwest, most run at 345 kilovolts -- with a few high-capacity lines running at 735 or 765 kilovolts.
Since higher voltages translate to higher efficiencies, it's not surprising that the voltages get higher as the power being carried increases. The question, then, is why not build all feeders to operate at the highest voltages? In fact, why not run them at megavolts? The answer was basically given above: the higher the voltage, the more robust and expensive the power towers and distribution system. Since resistive losses in the wiring -- the "conductors" -- increase with distance, high voltages are absolutely needed for the long-distance lines, but the losses are acceptable over shorter lines and so there's no need to spend so much money. In addition, higher voltages mean greater losses through a leakage process known as "corona", of which more is said later.
It's difficult to tell what kind of voltages are being sent over a particular powerline just by looking at a power tower, but it is possible to get some clues. The spacing between conductors on a 735 or 765 kilovolt line will be 15 meters (50 feet) or more, with the spacing on a 345 kilovolt line running about half that. The spacing for lines running at 200 kilovolts or less will be maybe 5 meters (15 feet) or so. In addition, instead of three separate conductors, high voltage lines will have three loose "bundles" of conductors, with two, three, or four individual conductors linked together in the bundle using spacers.
The best-known form of a powerline tower is a latticework of trusses using lightweight metal members. This approach is sturdy, lightweight, not much disturbed by wind, and can be easily transported in sections to be assembled on site. Single-pylon designs, like street lamp-posts but with multiple arms or "boughs" to carry the cables, are also common. They are harder to set up and require a more robust foundation than a latticework tower. In addition, the conductors have to be strung vertically on the boughs, and since regulations demand minimum heights and spacing of powerlines, that means a taller tower. However, pylon towers have a smaller footprint, making them better suited to urban areas.
A twin-pylon arrangement, usually with wooden pylons, allows the three conductors to be strung horizontally. X-shaped and Y-shaped towers are also used. The power substation into Disney World in Florida has a tower in the shape of Mickey Mouse's head. Towers set up where the line changes direction are always more robust than the rest, because they have to handle more unbalanced forces; large towers may also be needed to span a river or canyon.
Two feeders are often run on the same line of towers, with six conductors run from tower to tower, reducing costs; multiple feeder lines from primary power stations may follow the same right-of-way for the same reason, at least until they branch off to their ultimate destinations.
There are a number of factors to consider in the design of a power line. One is that the length of the conductors will change with the weather, expanding in the summer and contracting in the winter. A longer conductor has greater resistance, so the limit of power that can be transferred is greater in the summer. Another factor is that there is a subtle electromagnetic interaction between the three conductors, resulting in the middle conductor in a three-phase triplet having slightly different electrical properties than the two on the sides. Over long distances, this difference will "unbalance" the line, so every here and there the power line has a special tower that swaps the conductors around.
* By the way, after all the arm-waving about why DC is no good for long-range power transmission, it must be added that there are many long-distance DC power lines, running at 500 kilovolts or so. It doesn't contradict what was said before, it just involves a layer of trickery. AC power is stepped up through transformers to a high voltage as before -- to then be converted to DC for transmission over the line. At the remote end, the DC is converted back into AC and then run through a stepdown transformer. From the endpoints, it still looks like an AC line.
Why bother? Mainly because it reduces the number of conductors from three to two, which means a cost saving over long distance -- two-thirds the wiring and lighter towers. Another advantage is that there's no need to ensure phase synchronization between the source of the power and the end users, with the back-conversion system ensuring the phase match. DC lines are often used to transfer power between zones.
The AC/DC conversion is performed by a set of high-power switches. When DC long-distance lines were introduced, back in the 1960s, the switches were "mercury-arc" valves, like an old vacuum tube except that they were filled with mercury vapor, were as long as one's arm, and had to be water-cooled. Modern converters use a solid-state switch called a "thyristor": it's also pretty hefty, though not in the same league as the old mercury-arc valves, and demands aggressive cooling. [TO BE CONTINUED]
* SPACE PEN MYTH: SCIENTIFIC AMERICAN Online recently had an interesting little article about a technology "urban legend" involving "space pens". According to the legend, the US National Aeronautics & Space Administration spent millions to design a pen whose ink would flow in space -- while the sensible Soviets simply used pencils.
As the article explains, like many urban legends, there's enough truth in the story to see how it got started, but it's still bogus in the end. In the early days of manned space flight, both NASA and the Soviets used pencils, but they left something to be desired: the graphite leads could break and float around, becoming a nuisance and possibly even a hazard -- suppose a fragment got into the seal of a pressure suit? NASA also got into a fiasco in 1965 when it became public that the agency had ordered 34 mechanical pencils from an engineering firm that cost well over $100 USD each. Apparently the pencils had to meet special specs, and since they were built in such low volume they ended up being very expensive. A different solution was required.
Paul C. Fisher and his company, the Fisher Pen Company, invested their own funds to design a better solution, the "space pen". Fisher patented this device in 1965; it could write upside-down and keep on writing in arctic or roasting conditions -- or even underwater. It achieved this feat with ink that was driven to a tungsten carbide ballpoint by pressurized nitrogen gas. The ink was in the form of a gel, with the rotation of the ballpoint turning it into a liquid.
The space pen was a marvel of technology. NASA was cautious at first, having been burned on the mechanical pencils, but investigated the device and became enthusiastic, ordering 400 in early 1968. The next year, the USSR ordered 100 for their own space program. Both only paid $2.39 per pen -- expensive for a ballpoint pen, particularly in those days, but these were no ordinary ballpoint pens. They worked very well, and in fact the Apollo 11 astronauts used a space pen to fix a broken switch.
Fisher is still in the space pen business, continuing to sell improved models to NASA and Russia. Fisher will sell the pens to anyone who wants to buy them, no questions asked. It's not like they're secret weapons -- but most people don't want to pay $100 USD for a ballpoint pen, even one that's vastly superior to any ballpoint pen they could get at a supermarket.