28 February 2008
23 February 2008
Ceea ce zice despre ultimatum game nu e chiar adevarat. Oferta nu e in jur de 50 la suta, ci in jur de 40 la suta. De asemenea, nu exista practic nici o diferenta culturala intre cati bani sunt oferiti (in toate tarile se ofera in jur de 40% +/-10%), insa exista diferente culturale foarte mari in ceea ce priveste acceptarea banilor. Cu alte cuvinte se pare ca ar exista o diferenta culturala in privinta tolerantei fata de egoismul altora, insa nu exista diferente culturale in materie de comportament egoist! Momentan, nimeni n-are nici cea mai mica idee despre ce anume sta la baza acestui tip de diferenta culturala, pentru ca tot ce ti-ar trece prin cap in prima instanta a fost infirmat experimental (factorii respectivi nu sunt corelati cu graficul raspunsului la ultimatum game). Eu am sugerat ca s-ar putea ca explicatia sa fie urmatoarea: cu cat intr-o tara este mai nesigur viitorul cu atat oamenii tind sa respinga mai des oferta facuta in ultimatum game. (Nu stiu sa fi fost verificata sau infirmata speculatia.) Rezultatele la ultimatum game in diferite tari (click to enlarge): Cat se ofera: Cat de des e respinsa oferta:
22 February 2008
Nathan Ensmenger (2008) The machine in America: a social history of technology - By Carroll W. Pursell, The Economic History Review 61 (1), 263–265 doi:10.1111/j.1468-0289.2007.00419_27.x:
Pursell describes this book as a ‘social history’ (p. xi) of technology, by which he means a history of technology focused not on machines and processes, but on the people who create, use, and make sense of them. For Pursell, technologies are best understood as social products, as the reflection of very particular times, places, and relationships. Thus Pursell looks beyond inventors, engineers, and capitalists to consumers, policy-makers, and everyone affected, directly or indirectly, by the creations of our technological society. His goal is to integrate the study of technology into the mainstream of American history. Citing his mentor A. Hunter Depree, he argues that the history of American science and technology, properly understood, is the history of America. The first few chapters of the book describe the migration of tools and techniques—first medieval agriculture technologies, and later textile and other industrial manufacturing machines—from the Old World to the New. Throughout the colonial and early Republican period, Americans begged, borrowed, and stole technologies from Europe, often transforming them significantly in the process. Although Pursell makes no claim to comprehensive coverage, which would be impossible in a single-volume survey, he covers all the traditional topics, including agricultural, manufacturing, transportation, and domestic technologies. Over the course of the nineteenth century, the US developed into a technological and industrial powerhouse in its own right. It is in his treatment of this important and formative period that the value of Pursell's social history approach becomes apparent. He ties together neatly what are often treated as separate or even contradictory histories: the rise of industrial manufacturing in the north-east, the opening of the agricultural heartland of the Great Plains regions, and the ‘winning of the west’ through mining and irrigation projects. In each of these cases, for reasons economic, social, and political, Americans developed a propensity for a certain kind of technological solution: large-scale, high-capital, and labour-saving, but also resource intensive. These solutions often had unintended consequences. The same technologies that enabled increased productivity for farmers, for example, also distanced them from their customers, and made them vulnerable to the monopolistic practices of intermediaries such as grain silos and railroads. One of the important themes of the book is the growing relationships among industry, science, and government. Despite the initial reluctance of the federal government to fund technological development (as in turnpikes and canals), by the middle of the nineteenth century the US government was committed to devoting its resources to the service of industry. The US Geological Survey was established in 1879, for example, in large part to subsidize essential research required by the mining industry. The Department of Agriculture served a similar purpose for the agricultural industry. By the early twentieth century, organizations such as the National Advisory Committee for Aeronautics, the National Bureau of Standards, and the National Resources Committee were unabashedly committing federal resources to ‘supplying the people with important scientific findings which they need for their private purposes’ (p. 232). The Second World War and the Cold War only accelerated this ongoing trend towards government-directed industrial research.
Dintr-un review de la Economic History Review la cartea lui Peter Hennock, The origin of the welfare state in England and Germany, 1850–1914: social policies compared:
In making his comparison, Hennock exposes the very different foundations of German and British state welfare and stresses the contrasting roles played by social insurance both at this time and in shaping subsequent developments. From its very inception, the British welfare state offered central government (and the Treasury) a more definitive role in the provision of welfare than did its German counterpart. Contrary to what we might assume, a more authoritarian regime thus created, arguably inadvertently, more space for local self-determination in this area than did a more liberal British state. Aided by earnings-related contributions and benefits, social insurance agencies in the Kaiserreich were less reliant on central government contributions than they were in Britain and exercised far greater autonomy as a result. In the long run, this explains why Nazis disliked social insurance for its potential to incubate political opposition and why, since 1945, the German nation has displayed continuously a preference for tackling social risk through this medium. In contrast, British social insurance schemes were subject to greater central direction and their agencies were far more vulnerable to state control. Today, British national insurance contributions are viewed as a tax and the social benefits available to contributors have all but disappeared. As this book argues, these very different historical trajectories owe their origins to legislation passed before 1914 (not post-1945). They are explained partly by contrasting powers of central government in the two countries. The new German Empire's legitimacy required its respect for long-established powers of the municipal and state authorities found within its borders. Tax-raising capacities being limited, self-funded insurance was an attractive option for providing welfare. In Britain, by contrast, such constitutional limitations were less evident and, in years of crisis for local government finance, central state subsidy and social insurance offered complementary solutions to the problem of poverty. In this sense, this book argues (correctly) that comparing national welfare states requires a comparison of the nature and remit of national state power. This offers a new dimension to already established arguments concerning the German preoccupation with the threat of social democracy and the British with the threat of pauperism that has dominated welfare comparisons between these two countries in this era to date. As this book demonstrates, the public sphere is not a common space. This perspective on the scope of state power reveals a major problem for comparisons of welfare states (alluded to in the introduction): where do their boundaries fall? The very notion of a ‘welfare state’ assumes a degree of commonality that offers historians a given body of legislation for comparative analysis. However, matters are not so neat. Should, for example, legislation on hours of work, minimum wages, and other aspects of labour law (governing industrial bargaining and the right to strike) be included? In Germany, where the suppression of free trades unionism accompanied the introduction of social insurance, the answer might be ‘yes’. In the UK, more liberal government separated industrial relations from state welfare, a feature that shaped subsequent historiography. (Noel Whiteside (2008), The origin of the welfare state in England and Germany, 1850-1914: social policies compared - By Peter Hennock. The Economic History Review 61 (1), 243–244 doi:10.1111/j.1468-0289.2007.00419_11.x)
21 February 2008
Putine lucruri mi se par mai obositoare decat discutiile epistemologice cu filosofi. Pozitia mea e radical empirista: orice afirmatie descriptiva care are sens (are un oarecare continut informational) are in mod necesar o anumita conectare la realitate, iar aceasta conectare la realitate poate fi folosita pentru a determina experimental (daca esti suficient de ingenios incat sa inventezi o retea potrivita de experimente - care sa se contranga unele pe altele si sa nu lase urme de interpretari alternative) daca propozitia respectiva e adevarata sau falsa. In practica, avem mult prea putine experimente pentru a determina in mod clar valoarea de adevar a propozitiilor, asa ca trebuie sa ne multumim cu judecati probabiliste, si pe masura ce avem mai multe experimente probabilitatea tot mai multor propozitii tinde la 0 sau la 1. Genul asta de pozitie pare complet absurda celor mai multi filosofi pe care i-am intalnit pentru ca ei au impresia ca intotdeauna poti avea interpretari alternative, sau chiar ca intotdeauna poti interpreta oricum vrei tu datele experimentale. Aceasta poveste cu "interpretarile" nu mi se pare ca sta in picioare pentru ca inventeaza un dualism inexistent intre "interpretari" si afirmatiile propriu-zise pe care le judeci. Interpretarea e la randul ei un set de premize. Asa ca la fel cum testezi empiric o afirmatie, tot la fel testezi si o interpretare. Prin urmare ideea asta ca intotdeauna poti interpreta datele cum vrei este de fapt credinta in existenta unor adevaruri sintetice a priori (acest gen de filosofi relativisti neaga in general existenta unor asemenea adevaruri, asta cred ca pe buna dreptate). Ceea ce este frustrat sunt exemplele care sunt aduse.
- De pilda un argument foarte popular pare sa fie: noi pur si simplu presupunem ca lumina merge in linie dreapta (pentru ca poate asta e cel mai simplu lucru de presupus) si toate impresiile noastre despre lume pleaca de la aceasta premiza imposibil de testat. Insa oricine a frunzarit o carte de optica (chiar si in manualul de liceu!) ar trebui sa stie ca faptul ca lumina merge in linie dreapta nu e deloc ceva luat de bun si cunoastem foarte bine in ce conditii lumina merge pe traiectorii curbe (refractie, difractie, interferenta, lentile gravitationale). De asemenea, stim inclusiv care ar fi consecintele experimentale ale neomogenitatii si neizotropiei spatiului (nu s-ar conserva impulsul si momentul cinetic).
- Un alt exemplu popular este faptul ca noi chipurile nu avem nici cea mai mica idee daca toti percepem culorile la fel; pur si simplu fiecare dintre noi a fost educat sa numesca "rosu" ceea ce fiecare percepe cand i se arata culoarea rosie etc. Acest argument ignora complet faptul ca nu exista decat 3 culori independente (de pilda rosu, verde, albastru), toate celelalte fiind combinatii de acestea. Din acest motiv este foarte usor sa-ti dai seama daca cineva are o vedere anormala. Daca eu as vedea invers sa zicem albastrul si rosu atunci ar trebui sa vad invers (si sa fi fost invatat invers) si turcoaz-ul si galben-ul si asa mai departe.
- Un alt exemplu este matematica. 2 + 2 fac 4 iar asta e ceva dat. Adevarul insa e ca 2 + 2 = 4 e o teorema care decurge din axiomele aritmeticii, iar faptul ca aceste axiome ale aritmeticii sunt utile la modelarea fenomenelor naturale este o concluzie stabilita empiric si nicidecum un adevar a priori.
- La 15 ani de la publicarea Consciousness Explained Dennett inca se mai chinuie sa le explice astora ca ideea de zombi e aberanta (Sweet Dreams incepe cu o discutie despre zombi).
- Searle inca bate campii cu camera chinezeasca.
- De 20+ de ani tot nu s-au saturat sa discute despre Mary cea crescuta in camera alb-negru (!).
The scientific method makes one assumption, and one assumption only: the Universe obeys a set of rules. That’s it. There is one corollary, and that is that if the Universe follows these rules, then those rules can be deduced by observing the way Universe behaves. This follows naturally; if it obeys the rules, then the rules must be revealed by that behavior. A simple example: we see objects going around the Sun. The motion appears to follow some rules: the orbits are conic sections (ellipses, circles, parabolas, hyperbolas), the objects move faster when they are closer to the Sun, if they move too quickly they can escape forever, and so on. From these observations we can apply mathematical equations to describe those motions, and then use that math to predict where a given object will be at some future date. Guess what? It works. It works so well that we can shoot probes at objects billions of kilometers away and still nail the target to phenomenal accuracy. This supports our conclusion that the math is correct. This in turn strongly implies that the Universe is following its own rules, and that we can figure them out. (Phil, Is science faith-based?)Sean explica super bine din ce cauza incertitudinea stiintifica exista la marginile teoriilor, acolo unde incercam sa le extindem dincolo de domeniul lor de valabilitate deja testat. Insa chiar daca descoperim vreo noua teorie revolutionara, acea teorie nu o sa dea peste cap toata baza de date experimentale deja adunata, dimpotriva, ea va trebui sa fie conforma cu ea.
The main point here is that, while there are certainly many things that modern science does not understand, there are also many things that it does understand, and those things simply do not allow for telekinesis, telepathy, etc. [...] If we can show that psychic phenomena are incompatible with the laws of physics we currently understand, then our task is to balance the relative plausibility of “some folks have fallen prey to sloppy research, unreliable testimony, confirmation bias, and wishful thinking” against “the laws of physics that have been tested by an enormous number of rigorous and high-precision experiments over the course of many years are plain wrong in some tangible macroscopic way, and nobody ever noticed.” The crucial concept here is that, in the modern framework of fundamental physics, not only do we know certain things, but we have a very precise understanding of the limits of our reliable knowledge. We understand, in other words, that while surprises will undoubtedly arise (as scientists, that’s what we all hope for), there are certain classes of experiments that are guaranteed not to give exciting results — essentially because the same or equivalent experiments have already been performed. [...] We are creatures of the universe, subject to the same laws of physics as everything else. As everyone knows, there are many things we don’t understand about biology and neuroscience, not to mention the ultimate laws of physics. But there are many things that we do understand, and only the most basic features of quantum field theory suffice to definitively rule out the idea that we can influence objects from a distance through the workings of pure thought. The simplest example is telekinesis, the ability to remotely move an object using only psychic powers. For definitiveness, let’s consider the power of spoon-bending. [...] Could either gravitation or electromagnetism be responsible for bending spoons? No. In the case of electromagnetism, it would be laughably easy to detect the kind of fields necessary to exert enough force to influence a spoon. Not to mention that the human brain is not constructed to generate or focus such fields. But the real point is that, if it were electromagnetic fields doing the spoon-bending, it would be very very noticeable. (And the focus would be on influencing magnets and circuits, not on bending spoons.) In the case of gravitation, the fields are just too weak. Gravity accumulates in proportion to the mass of the source, so the arrangement of particles inside your brain will have a much smaller gravitational effect than just the location of your head — and that’s far too feeble to move spoons around. A bowling ball would be more efficient, and most people would agree that moving a bowling ball past a spoon has a negligible effect. Could there be a new force, as yet undetected by modern science? Of course! I’ve proposed them myself. Physicists are by no means closed-minded about such possibilities; they are very excited by them. But they also take seriously the experimental limits. And those limits show unambiguously that any such new force must either be very short-range (less than a millimeter), or much weaker than gravity, which is an awfully weak force. The point is that such forces are characterized by three things: their range, their strength, and their source (what they couple to). As discussed above, we know what the possible sources are that are relevant to spoons: quarks, gluons, photons, electrons. So all we have to do is a set of experiments that look for forces between different combinations of those particles. And these experiments have been done! The answer is: any new forces that might be lurking out there are either (far) too short-range to effect everyday objects, or (far) too weak to have readily observable effects. [...] That’s it. We are done. The deep lesson is that, although science doesn’t know everything, it’s not “anything goes,” either. There are well-defined regimes of physical phenomena where we do know how things work, full stop. The place to look for new and surprising phenomena is outside those regimes. You don’t need to set up elaborate double-blind protocols to pass judgment on the abilities of purported psychics. Our knowledge of the laws of physics rules them out. Speculations to the contrary are not the provenance of bold visionaries, they are the dreams of crackpots. (Sean Caroll, Telekinesis and Quantum Field Theory)Articolul meu mai vechi despre diferenta dintre stinta si religie.
Uneori e nevoie de o anumita doza de cinism pentru a veni in intampinarea unor argumente precum:
The story begins in a village a few miles to the west of London. The government proposes to flatten Sipson in order to build a third runway for Heathrow airport. The public consultation is about to end, but no one doubts that the government has made up its mind. Its central case is that the economic benefits of building a third runway outweigh the economic costs. The extra capacity, the government says, will deliver a net benefit to the UK economy of £5bn. The climate change the runway will cause costs £4.8bn, but this is dwarfed by the profits to be made. [...] Consider the implications. On one side of the equation, human life is being costed. On the other side, the value of delays to passengers is being priced, and it rises according to their wealth. Convenience is weighed against human life. The richer you are, the more lives your time is worth. The people most likely to be killed by climate change do not live in this country. Most of them live in Africa and south Asia. Hardly any of the economic benefits of expanding Heathrow accrue to them. Yet the government has calculated the economic benefits to Britain, weighed them against the global costs of climate change and discovered that sacrificing foreigners - especially poor ones - is a sensible economic decision. I can accept that a unit of measurement that allows us to compare the human costs of different spending decisions is a useful tool. What I cannot accept is that it should be scrambled up with the price of eggs and prefixed with a dollar sign. Human life is not a commodity. It cannot be traded against profits or exchanged for convenience. We have no right to decide that others should die to make us richer. (George Monbiot, Juggle a few of these numbers, and it makes economic sense to kill people)Din Free Exchange de la The Economist:
Of course, valuations of human life are carried out in an explicit manner all the time. Insurance markets depend upon such valuations, as do court judgment in wrongful death cases. How is this different? [In cazul analizelor cost/benefit legate de incalzirea globala.] Qualitatively, answers Mr Monbiot. In the case of the Heathrow runway, we are setting the lives of dead Bangladeshis against a few minutes saved by wealthy London businessmen. The affront to justice is only worsened by the fact that the rich are judged to have more valuable lives than the poor. If we cannot place a monetary value on life, we're stuck with an insoluble equation. We're left to conclude that any life is too dear to sacrifice, and so all activities contributing to global warming--or any other potentially fatal economic process--should be halted. Mr Monbiot doesn't want this, but the placement of any monetary value on life, no matter how high, essentially values that life in terms of consumption. If a life is worth $10 million and a burger worth $1, then we cannot avoid saying that a life is worth 10 million burgers, unappealing as that sounds. The larger failure in this argument, however, is a lack of recognition that material progress contributes to material welfare, including reduced mortality. The capitalistic push for ever more consumption has done wonders for global economic output, allowing the earth to sustain billions more people than it could a century ago at a higher standard of living than ever before. We don't set the value of life against income because income is more precious than life. We set life against income because income sustains life. The things we do that encourage economic growth improve living standards around the world. Curtailing those activities will reduce those improvements, generating loss of life relative to the alternative. When we try to determine how to respond to warming we have to balance the life cost of reduced growth against the life cost of warming. We have to work in similar metrics on both sides of the equation, and monetary values are the easiest way to do this.
08 February 2008
Echipa lui Lluís Quintana-Murci de la Institutul Pasteur a analizat 2.8 milioane de "polimorfisme uni-nucleotida" - mutatii genetice care implica schimbarea unei singure "litere" (baze azotate) din ADN - care sunt probabil de data recenta si sunt un indiciu al diversificarii genetice recente a populatiilor umane.* Se poate masura cat de recente sunt variatiile genetice din cauza ca cea mai mare parte a ADN-ului, 80-90 la suta din el, nu are nici o functie (junk-DNA), ci este doar zgomot - o acumulare de mutatii fara sens. Neavand nici o functie, selectia naturala nu actioneaza deloc, nici pozitiv nici negativ, asupra lor. Prin urmare numarul de mutatii care apar in cadrul junk-DNA indica viteza cu care apar mutatiile in general; cu alte cuvinte cat de eficient functioneaza enzimele care corecteaza mutatiile. Comparand numarul de mutatii din cadrul junk-DNA cu numarul de mutatii din cadrul genelor (fragmentele de ADN care contin instructiunile pentru constructia unei anumite proteine) se poate deduce daca selectia naturala favorizeaza o modificare a proteinelor respective sau dimpotriva o conservare a lor. Cercetatorii au descoperit ca principalul factor care impiedica diversificarea genetica este faptul ca de obicei mutatiile cresc vulnerabilitatea fata de boli. Cum insa unele boli apar in special in anumite zone geografice (e.g. malaria) unele dintre mutatiile descoperite reflecta o variabilitate a vulnerabilitatii fata de aceste boli. Exista 55 de gene care s-au schimbat cel mai tare; cu alte cuvinte mutatiile in aceste regiuni ale ADN-ului au fost favorizate de selectia naturala: 30 dintre ele nu se stie ce functie au, iar restul controleaza culoarea pielii si cresterea parului, rezistenta fata de boli regionele (precum malaria), metabolismul si au de-a face cu diferentele de dieta ale oamenilor din diferite zone (acestea au impact si asupra unor conditii precum obezitatea, diabetul si hipertensiunea). Trecerea la agricultura a favorizat anumite schimbari genetice precum reglarea insulinei, metabolizarea zaharului, amidonului, alcoolului si zincului, si transportul grasimilor. Din cele 20,000-25,000 de gene umane, numai 582 par sa se fi schimbat in ultimii 60,000 de ani, ceea ce ofera sustinere suplimentara ideii ca nu exista decat o singura rasa umana. Cum s-a raspandit omul din Africa (click pentru detalii): --- *) Lluís Quintana-Murci et.al, Natural selection has driven population differentiation in modern humans, Nature Genetics, 3 February 2008