The American Institute of Physics 4 страница
HIGHLY OPTIMIZED TOLERANCE. Many natural and man-made systems exhibit power-law statistics. That is, when you plot the likelihood of an event (e.g. sizes of forest fires, power outrages, and web file transfers, or losses due to hurricanes, floods, earthquakes, and man-made disasters) as a function of size the resulting graph will fall off proportionally to the size of the event raised to some exponent. Interactions or phenomena at many size scales (from very small to very large) contribute to the overall state of these systems. One theory, which tries to explain all this, is “self organized criticality”. Jean Carlson of UC Santa Barbara ([email protected]) and John Doyle of Caltech ([email protected]) now propose another theory, called highly optimized tolerance (HOT), which they believe does a better job of accounting for the tendency in interconnected systems to gain a measure of robustness against common and designed-for uncertainties and yet be hypersensitive to design flaws or rare events. For example, organisms and ecosystems exhibit remarkable robustness to large variations in temperature, moisture, nutrients, and predation, but can be catastrophically sensitive to tiny perturbations, such as a genetic mutation, an exotic species, or a novel virus. Engineers deliberately design systems to be robust to common uncertainties. Costs and performance tradeoffs force an acceptance of some hypersensitivity to (one hopes) rare perturbations. In evolved or designed systems, this tradeoff leads to the “robust, yet fragile” characteristic of complexity, one feature of which is power laws. Doyle and Carlson have been exploring the application of their theory to a number of biological and engineering problems with the help of experts in those fields. (Physical Review Letters, 13 March 2000; Select Article; a longer version appears in Physical Review E, August 1999.)
16 CONSECUTIVE MONTHS OF RECORD HIGH TEMPERATURES (global mean temperature, during 1997 and 1998) suggest to Thomas Karl (director of the National Climate Data Center, NCDC) that a human-induced global warming trend, and not merely the kind of natural temperature fluctuations one expects to see in the climate record, is under way.
According to Karl, the last quarter-century of data is characterized by a temperature gradient of two degrees Celsius per century. The 16-month streak is unmatched in temperature records dating back to the nineteenth century. (Thomas Karl in Geophysical Research Letters, 1 March 2000; [email protected], 828-271-4476.)
ANAMORPHIC IMAGES are those in which the painted image of an object has been distorted in such a way that the object becomes recognizable only by viewing it at an oblique angle or in some curved reflecting surface.
Anyone who has visited the National Gallery in London might have seen Hans Holbein’s painting “The Ambassadors,” in which an odd shape at the bottom of the canvas is seen to be a skull when viewed almost edge-on.
Anamorphic images were something of a rage in the Renaissance, and Leonardo and Durer tried the technique as part of their studies of perspective. An eighteenth century innovation was to create anamorphs of paintings by famous artists. A seventeenth century book by Jean-Francois Niceron worked out the geometrical algorithms for producing anamorphic art (the planar and conical cases are pretty easy but cylinders are quite challenging), but this mathematical connection was lost through the centuries. Now, scientists at Guelph University (Ontario, Canada) have re-derived the transform equations needed for producing anamorphs. (Hunt, Nickel, Gigault, American Journal of Physics, March 2000; Select Articles; James Hunt, [email protected], 519-824-4120, x3993; Bernie Nickel, [email protected]; images at http://physics.uoguelph.ca/)
ATMOSPHERIC INFRASOUND. Humans hear sounds in the 20-20,000 Hz frequency range. Ultrasound, waves above 20,000 Hz, is used for things such as medical imaging and can be sensed by animals such as bats and dogs. But how about infrasound, sound at frequencies less than 20 Hz?
Humans can sometimes feel (even if they can’t quite hear) infrasound in the form audio systems with the bass turned way up. The monitoring of infrasound may contribute practical benefits in a number of areas: determining the location and nature of avalanches, tornadoes, and meteor strikes, volcanoes, and nuclear weapons tests. (Physics Today, March 2000.)
Appendix 2
US wades into Colombia’s dirty war
Clinton’s drive against cocaine trade will worsen
violence, human rights groups say
Martin Hodgson in Bogot
Wednesday August 30, 2000
President Clinton arrives in Colombia today amid tight security for a visit that will underline a deepening US commitment to a messy civil war involving government forces, paramilitary death squads, leftist rebels and 90% of the world’s cocaine.
In the first trip to the country by a US president in a decade, Mr Clinton will throw his weight behind Plan Colombia, an ambitious strategy which the Colombian government hopes will put an end to the drugs trade and bring peace after nearly 40 years of fighting.
Visiting the capital, Bogot, was deemed too risky, so Mr Clinton will meet the Colombian president, Andres Pastrana, in the resort of Cartagena, on the Caribbean coast, guarded by 5,000 Colombian troops and 350 US agents.
“Colombia’s success is profoundly in the interest of the United States a peaceful, democratic and economically prosperous Colombia will help promote democracy and stability throughout the hemisphere,” Mr Clinton said earlier this month.
Acknowledging both Colombia’s strategic importance and its growing instability, Mr Clinton has supported Plan Colombia from its inception, and pledged $1.3bn (J867m) towards the scheme. But critics of the aid package fear the money will only cause the fighting to escalate, and may even spread political and drug-related violence throughout the region.
Human rights
While some US aid will go to development programmes and an overhaul of Colombia’s legal system, most will be spent on equipment and training for security forces, despite persistent concerns over the military’s human rights record.
Monitoring groups regularly accuse the Colombian army of standing by while rightwing paramilitaries massacre unarmed civilians they accuse of helping leftist rebels.
Last week Mr Clinton waived strict human rights conditions imposed by Congress and authorized the aid package, arguing that Colombia’s situation was a matter of US national security. But a White House memorandum justifying the decision acknowledged that “there remain disturbing, credible allegations that individual Colombian military officers continue to collaborate with paramilitaries”.
The waiver provoked criticism from human rights groups. “It gives a clear message that from the US point of view, human rights are not important. What matters for them is the war on drugs,” said Jorge Rojas of the Consultancy for Human Rights and Displacement, a Bogot-based monitoring group.
There are signs that US aid has already led to an escalation of Colombia’s civil war. In March, the country’s largest guerrilla group, the Revolutionary Armed Forces of Colombia (Farc) said it would step up kidnapping for ransom in order to raise funds equal to the US military aid.
The guerillas have also increased their attacks against isolated police stations, part of a long-term strategy to strengthen their control of rural Colombia. Although they have been involved in peace talks since last year, no ceasefire has been signed and, since January, the rebels have attacked 50 such stations. Sixty officers and dozens of civilians have been killed.
“Farc is accelerating its plans for territorial control, but the guerrillas are not the only ones getting stronger. State forces are improving, as are the paramilitaries. Inevitably there will be an escalation,” said defence analyst Alfredo Rangel.
In early August, 83 US Green Berets arrived in the country to train the second of three counter-narcotics battalions contemplated in Plan Colombia. These units will lead a campaign into the rebel-dominated southern jungles of Colombia, where most of the world’s cocaine is made.
“Our aid is strictly limited to anti-narcotic activities. It is not directly towards supporting counter-insurgent operations,” Mr Clinton told the Colombian magazine Cambio this week. But Colombian military commanders recognize that a push in the region will inevitably bring troops into combat with several thousand Farc guerillas who protect drug installations in return for “wax taxes”.
Attack
“We will attack anyone in the drugs trade – Farc, paramilitaries or whoever,” said General Mario Montoya, commander of the army’s southern task force.
It is still unclear how a military strike against drug plantations will tally with the second component of Plan Colombia: a package of social development to help wean locals from growing drug crops.
According to Mr Pastrana, investment in education, infrastructure and services will play a key part in establishing the rule of law in the southern regions of Putumayo and Caqueta. Traditionally, Colombian governments have paid little attention to these remote Amazon regions, allowing both rebel columns and drug plantations to grow unchecked.
In the past, Colombia has focused on spending “to prevent drugs reaching the streets of the US, instead of investing in education, sewage systems, housing”, said Mr Pastrana. “We want to work hand in hand with the communities, instead of concentrating on the policing aspect”.
But finding for social development programmes remains in doubt. At a conference in Madrid last month, European countries failed to pledge the $1bn (J667m) Mr Pastrana had hoped for.
Meanwhile, Farc is reported to be giving weapons training to peasants in Putumayo, and refugee groups fear that up to 200,000 people will flee their homes if widespread fighting breaks out.
Neighboring countries have expressed concern that the plan may cause Colombia’s civil war to spill across its borders. Ecuador and Brazil have reinforced security along their jungle frontiers. Peru’s president, Alberto Fujimori, said last week that an anti-narcotics drive threaten the stability of the entire region.
“How can you strengthen democracy in the midst of a war?” said Mr Rojas. His organization and 36 more Colombian human rights, Indian and development groups have said they will not participate in projects funded under the plan.
Farc chiefs say Mr Clinton’s approval of Plan Colombia was timed to coincide with the US election campaign. Speaking from a stronghold in southern Colombia, Commander Andres Paris said: “They want to spill Colombian blood to help their presidential candidates.”
Years of Conflict
948Assassination of popular liberal politician leads to rural unrest which claims 300,000 lives over next decade
1953-57 Military seize power, before returning it to coalition rule by liberal and conservative parties
1964 Colombian military launch US-backed Operation Laso, to destroy leftist guerrillas. It fails and marks foundation of the Revolutionary Armed Forces of Colombia (Farc), a communist guerilla movement
1966 Creation of rival, smaller guerrilla group, Army of National Liberation (ELN)
1980s Emergence of right-wing narco-paramilitaries who target guerrilla groups and their supporters. Farc’s political wing loses 4,000 people killed by drug-traffickers
1990 US president George Bush announces war on drugs
1992 US says it will stop aid to Colombian army amid claims that the army used the cash to fight Marxist rebels
1993 Medellin drug baron Pablo Escobar is shot dead by Colombian police after a US-backed search
1994Allegations that Colombian president-elect Ernesto Samper’s election campaign was funded by $6m from a Cali drug cartel lead to him losing his US travel visa.
1997 First US civilian pilot, working under a state department contract, is killed on a drug crop fumigation flight in south-east Colombia
1998 Farc is granted a 15,000 square mile demilitarized zone to encourage peace talks
June 2000 US Senate gives final approval to record $1.3bn package of military aid to help fight drugs and Marxist guerrillas
Why Sierra Leone’s war is far from won
The rebels may be in retreat, but renegades pose new threat
Chris McGreal in Freetown
Wednesday August 30, 2000
The Guardian
Study a map of Sierra Leone and you might find it difficult to imagine that the Revolutionary United Front is losing its war.
Four months ago, the government’s authority barely extended beyond the capital and the last means of escape, the international airport disturbingly far across the Sierra river. Beyond that, RUF rebels were largely in charge except in a few city enclaves vulnerable to attack.
The rebels are no longer such a threat. Freetown is more secure than at any time for years, and the RUF’s hopes of seizing power have been dashed. Their founder, Foday Sankoh, is in prison and his force is increasingly factionalised. The diamond mines that have funded its war will not be such an assert if an international agreement to permit only the sale of government-certified gems works, as it should.
But that does not mean the government’s remit has been extended much further than Freetown and the other enclaves. Territory newly liberated by the British-backed Sierra Leone army has not so much fallen under government control as fallen into a new form of chaos where groups such as the West Side Boys, who abducted 11 British soldiers on Friday, are free to rob, rape and kill.
This was not part of the British plan to galvanise the government, its army and the UN into confronting the RUF instead of backing down in the face of its attacks and breaches of last year’s peace accords.
The original intent was to build a single force using experienced troops from the old Sierra Leone military, militias such as the West Side Boys, and thousands of soldiers newly trained by the British.
This new army was to be thrown into battle against the RUF while a strengthened UN peacekeeping force secured the captured territory and freed up Sierra Leone’s army to continue advancing. The strategy had the added advantage of bringing the West Side Boys and other groups of young fighters, often high on drugs or drunk, under government command.
To some extent, it has worked. The army is beginning to look like a credible force and has won several important battle against the rebels. The RUF is generally in retreat and its attacks in the west are not as frequent or sustained. Some of its soldiers have surrendered, others show a reluctance to keep up the fight. Above all, there is no real prospect of the rebels seizing power as there was in May when Britain sent more than 1,000 troops to defend Freetown.
But neither the government nor the UN can offer even a reasonable guarantee of security more than about 30 miles beyond Freetown, even on the long, looping main road to the airport on which the West Side Boys seized the British troops.
And while the West Side Boys are relatively small and desperate militia, another private army is a much greater threat to security in what is claimed to be government territory. The civil defence force, more popularly known as the Kamajors, are a major force in southern cities such as Kenema and Bo where some residents describe them as imposing a reign of terror. They control large parts of the major highways south where young fighters regularly extort bribes, rape and sometimes murder those on the road.
Like the West Side Boys, the Kamajors rely on copious amounts of alcohol and drugs to fight, and they believe that charms and mirrors ward off bullets. And like the West Side Boys, the Kamajors are supposed to have fallen under government command but remain a renegade force.
Their leader, Sam Hinga Norman, who is also Sierra Leone’s deputy defence minister, flew to Kenema a fortnight ago to tell his men to end their lawlessness. They took little notice.
The situation will not be helped by the impact of diamond certification, as Kamajors, rebels and others mining the valuable gems try to unload their wares for fear of not being able to sell them in future.
Part of the problem lies with the UN. While its peacekeepers are more willing to fight the RUF to defend certain towns, they remain essentially passive when it comes to ensuring the security of liberated areas. UN soldiers do not touch the Kamajors’ roadblocks and do little to help the victims who are caught at them.
One UN official said the abduction of the 11 British soldiers by the West Side Boys clearly demonstrated that “it is a jungle out there and the idea that we can control things is completely wrong.”
That is a vacuum the RUF might just galvanise itself to step back into. To counter the threat, the UN secretary-general, Kofi Annan, wants to boost the peacekeeping force to 20,500 men. He told the Security Council on Friday that the RUF still poses a threat that “should not be underestimated”.
“The RUF is believed to have a strength of several thousand fighters. It is relatively well-equipped and, in spite of divisions between some groups, maintains a relatively well established system of command and control,” he said.
Bungled UN aid operation slows East Timor’s recovery
A year ago today its people voted for independence from Indonesia, but the fledgling democracy faces a hard future
John Aglionby in Maliana
Wednesday August 30, 2000
The Guardian
The growing mountain of freshly-made pupils’ desks and teachers’ tables stacked haphazardly outside Joao Evangelino’s rudimentary carpentry workshop in the town of Maliana neatly encapsulates the current state of East Timor, one year after it voted overwhelmingly for independence from Indonesia.
It is undeniable evidence that reconstruction in this United Nations-run territory, which was systematically destroyed by the Indonesian army and its local militias following the referendum last August 30, is at last gathering momentum and allowing the East Timorose the chance to participate in their own nation-building. But the fact that it is there at all, starting to gather dust, it undeniable evidence that there is still a long way to go before this former Portuguese colony can claim to have completed its phoenix-like rise from the ashes of last year’s devastation. Just last night, UN troops and militias exchanged gunfire near Maliana.
“The UN says it has nowhere to put it,” said Mr Evangelino, gesturing towards the furniture. “They haven’t decided which schools are going to reopen, let alone rebuilt them. And the school holiday ends next month.”
That Mr Evangelino endured a tortuous ordeal to see his workshop become a reality is a further microcosm of the nation’s acute growing pains.
“I put in my proposal on January 1 and got the money on May 30th,” said the mini-entrepreneur who, like thousands of East Timorese, spent weeks hiding from the militia until the UN established a presence in October. “I was told little except that the process takes a long time and that I had to be patient.”
UN officials accept that reconstruction has been slow but blame the delays on factors beyond their control. “The situation in East Timor was exceptional,” explained the UN’s transitional administrator, Sergio Vieria de Mello. “Unlike when we arrived in Kosovo, there was nothing here. Everything had either been destroyed or stolen. We had to start from scratch.”
That was undoubtedly the case, but the army of foreign administrators, donors and developers went about reconstruction in the wrong way. The most prominent first signs of change visible on the streets of the capital Dili were a fleet of thousands of brand-new four-wheel-drive vehicles, a 500-room floating hotel shipped in from Singapore for the international staff, and the growing number of cafes catering to their cappuccino craving.
These visible manifestations of the new neo-colonialism might not have been so bad if there had been decent interaction with the locals, many of whom had lost literally everything. But, for the most part, the foreigners were taught practically nothing about East Timor before arriving and when they landed they received little guidance from their superiors.
“I did not arrive in East Timor with a full knowledge of the situation here or the psychology of the East Timorese,” Mr Vieira de Mello admitted. “It took me six months to understand.”
As if afraid to learn or take any initiative, many UN staff drove round from meeting to meeting with their windows up, appearing not to acknowledge the destitution and suffering around them. “After work people would not go out and speak to the East Timorese, to find out what they wanted,” one UN staffer said. “They went and checked their email.”
Compounding the problems were the over-optimistic expectations of the East Timorese. “There was a widespread feeling that we were going to come in and solve their problems overnight,” said Gianni Deligia, the UN district administrator in Maliana. “The reality is that we are more a like a supermarket. We have this and that on offer and they have to choose.”
Crisis point came at the end of April. Demonstrations outside the headquarters of the UN Transitional Administration in East Timor (Untaet) were a daily part of life in Dili. To the East Timorese it seemed as if there was lots of show but little substance. Not atypical, according to one aid worker, was an education project where “only 18% of the budget went on pens, paper and stuff for the kids. There was so much bureaucratic waste.”
Frustration
Local leaders are more blunt. “There was a sense of frustration, a lack of faith in Unteat,” said Jose Ramos Horta, a vice president of the East Timorese political umbrella group, the National Council of East Timorese Resistance (CNRT), and a Nobel Peace Prize winner. “[This was] because of their inability to involve the East Timorese, their inability to come forward with a roadmap, a plan. We saw time going by and no Timorese administration, no civil servants being recruited, no jobs being created.”
So in May Mr Horta and the CNRT president, Jose Alexandre “Xanana” Gusmao, “did a lot of shock therapy with the UN”, Mr Horta says, and within days a difference was noticeable. In June four of the eight cabinet posts in the transitional administration were given to East Timorese and the size of the local consultation council was doubled. “Now we are in a much more cordial, fruitful partnership between the UN and CNRT,” Mr Horta said. “There are less demonstrations, people are getting jobs and also enough to eat.”
There is also a roadmap of the path towards transition to full independence. The CNRT is currently holding its first proper congress where the goal is to empower the constituent political parties, both those that existed before Jakarta invaded in 1975 and the new ones. The first general election is timetabled for the second half of next year.
Of much greater concern are the faltering processes of reconstruction and developing a sustainable economy. The World Bank, in charge of stimulating small and medium-sized enterprises, “has never worked quicker in its existence since the second world war then it has here,” according to its spokesman in Dili, Malcolm Ehrenpries. But, he adds, there are numerous hurdles still to overcome before a proper development strategy can be implemented. “We do not even know how many people live in East Timor.”
The population was about 800,000 before the vote. But a proportion of these were Indonesians who left and more than 250,000 people fled or were forced into West Timor by the militias. Well over 100,000 are thought still to be in virtual imprisonment in refugee camps there.
Coffee is the only current significant foreign currency earner – to the tune of about J12m last year – although East Timor and Australia are exploring the sea between them for oil and natural gas. No one knows for certain how big a windfall might come East Timor’s way; people are hoping for billions but the most realistic estimates are in the range of tens of millions of dollars a year.
The lack of income-generating opportunities is reflected in the national budget which, for the sake of not wanting to create a massive debt burden, has been limited to a paltry $60m.
“We can’t yet see if the economy will ever be really sustainable,” said Arsenio Barno, the executive director of the East Timor Non-Governmental Organization Forum. “We’re concentrating on developing the capacity of our human resources but our worry is that we will end up like Cambodia. Seven years after the UN went in the country is still very dependent on foreign aid.”
The struggle to create a functioning judicial system is typical of East Timor’s human resources crisis, according to Mr Vieira de Mello. “What we had here were Timorese students with law degrees from Indonesian universities, none of whom had the slightest court experience,” he said. “Well, we appointed them, we trained them and if you visit the Dili court you will see that we now have a credible, independent Timorese judiciary.”
What Mr Vieira de Mello did not say was that while the system might be functioning it is unable to cope with the flood of work and, like all facets of the embryonic administration, will take years to develop enough strength in depth.
With the future not looking exactly rosy, most people are putting their faith in Mr Gusmao. This former resistance leader who spent seven years in Indonesian jails is by far the most popular man in the territory and is widely expected to become the first president of independent East Timor.
“I don’t see any serious alternative candidate to Xanana becoming president,” Mr Horta says. “Just like with Mandela, he is an exceptional individual that everybody just follows.”
But Mr Gusmao is not exactly brimming with confidence about East Timor’s prospects. “It’s difficult to rebuild this country,” he said. “We’re building anew and need a new mentality to go with it. I can’t tell you my priority because everything is still a priority.”
Fisherman find man’s head in belly of a cod