sábado, 19 de dezembro de 2009

Ovo Estrelado dos Açores

Ovo Estrelado dos Açores


Cientistas portugueses descobriram perto dos Açores uma depressão do fundo do Oceano Atlântico que acreditam ter origem no impacto de um meteorito, noticiou hoje a estação britânica BBC News.

A cratera é relativamente circular, com uma cavidade com seis quilómetros de largura e possui uma ampla cúpula central, tendo sido denominada "Ovo Estrelado" devido à sua forma distintiva.

Caso se confirme que a sua origem resulta do impacto de um corpo exterior, estima-se que a colisão tenha provavelmente ocorrido nos últimos 17 milhões de anos, a provável idade máxima do fundo basáltico da rocha submarina onde está a cratera.

"Para ter a certeza, precisamos de retirar amostras e fazer um perfil das camadas sedimentares, para determinar se existe realmente uma elevação central decorrente de um impacto", explicou Frederico Dias, da Estrutura de Missão para a Extensão da Plataforma Continental Portuguesa (EMEPC).

"É também necessário analisar os sinais consistentes com um impacto a alta velocidade", pormenorizou, como a acumulação de materiais rochosos e a existência de fragmentos de rocha de forma cónica, que se formam a partir das altas pressões associadas a fenómenos vulcânicos e ao impacto de meteoritos.

O investigador descreveu este provável impacto no encontro de Outono da União Geofísica Norte-americana (AGU), a maior reunião anual de cientistas ligados às ciências da Terra, que termina hoje em São Francisco.

O "Ovo Estrelado" foi inicialmente identificado a partir de informação reunida numa investigação hidrográfica, em 2008. Uma nova acção, que decorreu entre Setembro e Novembro deste ano, confirmou a sua presença.

A depressão está localizada a dois quilómetros de profundidade e a certa de 150 quilómetros do arquipélago dos Açores.

A sua origem vulcânica parece improvável, pois os investigadores não conseguiram descobrir a presença de correntes de lava na estrutura ou nas suas imediações.

Uma terceira expedição à área vai avançar no início de 2010 e retirar amostras do solo oceânico para análise com o auxílio de um veículo operado remotamente.

A EMEPC foi criada em 2005 e é responsável pela realização dos estudos técnicos necessários à apresentação de uma proposta de extensão da plataforma continental de Portugal, para além das 200 milhas náuticas.

sexta-feira, 18 de dezembro de 2009

domingo, 13 de dezembro de 2009

quarta-feira, 9 de dezembro de 2009

terça-feira, 8 de dezembro de 2009

sábado, 5 de dezembro de 2009

O Povoador

O Padre Português que
não precisou de Viagra
Por Manuel Luciano da Silva, Médico

Portugal vai celebrar, em 2039, novecentos anos de Indipendência. Com uma história de quase mil anos, Portugal é um país com muitos acontecimentos históricos, desde os mais dramáticos aos mais heróicos.

Citamos este exemplo verídico histórico, arquivado na Torre do Tombo em Lisboa (Arquivo Nacional Português) porque relata as aventuras sexuais dum padre de Trancoso (Beira Alta, Norte de Portugal).

Foi pai de 244 crianças: sendo 143 raparigas e 98 rapazes. Engravidou 46 mulheres diferentes, incluindo a própria mãe!

Foi condenado à morte, mas o Rei D. João II (Príncipe Perfeito) perdou-lhe a sentença porque entendeu que "naquela região o país precisava de aumentar a população e portanto o padre fez os seus actos a bem para a sociedade".

Aqui está o referido documento histórico.

Trancoso foi o local do casamento entre o Rei, D. Dinis e a Rainha Santa Isabel, in 1283.

Faz hoje, 17 de Março de 2004, 517 anos que a sentença foi pronunciada pelo Rei D. João II.

SENTENÇA PROFERIDA EM 1487 CONTRA

O PRIOR DE TRANCOSO

( Quando forem a Trancoso, vão à casa onde
viveu este padre, que é agora o restaurante O MUSEU )

Do Arquivo Nacional da Torre do Tombo

Autos arquivados na Torre do Tombo, armário 5,maço 7:

"Padre Francisco da Costa, prior de Trancoso, de idade
de sessenta e dois anos, será degredado de suas ordens
e arrastado pelas ruas públicas nos rabos dos cavalos,
esquartejado o seu corpo e postos os quartos, cabeça e
mãos em diferentes distritos, pelo crime que foi
arguido e que ele mesmo não contrariou,

- sendo acusado de ter dormido:

- com vinte e nove afilhadas e tendo delas noventa e sete filhas e trinta e sete filhos;

- de cinco irmãs teve dezoito filhas;

- de nove comadres trinta e oito filhos e dezoito filhas;

- de sete amas teve vinte e nove filhos e cinco filhas;

- de duas escravas teve vinte e um filhos e sete filhas;

- dormiu com uma tia, chamada Ana da Cunha, de quem teve três filhas,

- da própria mãe teve dois filhos.


Total: duzentos e setenta e cinco, sendo cento e quarenta e oito do sexo feminino e cento e vinte e sete do sexo masculino, tendo concebido em cinquenta e quatro
mulheres".



"El-Rei D. João II lhe perdoou a morte e o mandou por
em liberdade aos dezassete dias do mês de Março de
1487, com o fundamento de ajudar a povoar aquela
região da Beira Alta, tão despovoada ao tempo e
guardar no Real Arquivo da Torre do Tombo esta
sentença, devassa e mais papéis que formaram o
processo".

Esta sentença ficará arquivada na Torre do Tombo, Lisboa, Portugal

terça-feira, 1 de dezembro de 2009

Ciência

Plato in Space

Charles T. Rubin

Anathem is a big book about a big topic: nothing less than the nature of the universe and of intelligence within it. The novel certainly has its share of action—but as befits its topic it is even more filled with argument. Neal Stephenson seems most interested in exploring a proposition that can be stated fairly simply: like the laws of nature it discovers, intelligence itself is the same throughout the universe. If Pythagoras discovers his theorem here, the equivalent insight will be found elsewhere. If we have Platonists, empiricists, and logical positivists, similar schools of thought will be found wherever there is intelligence. Most science fiction involving contact with aliens, which is indeed the device that moves the plot of Anathem, is implicitly premised on at least some weak form of this proposition, though none that come to mind explore the question with quite the philosophical depth of Anathem.

One important aspect of the novel is likely to be of particular interest to readers of this journal, for on Stephenson’s world of Arbre, the relationship among science, technology, and politics is, as the book opens, radically different from what prevails in our world today. Stephensonis, in this novel as always, a thoughtful and therefore thought-provoking author, and in presenting us with the arrangements on Arbre he allows us to reflect on how the motives that drive scientific and technological development relate to what can be done about the problems that arise therefrom, and on how dealing with such problems will be influenced by what we think about historical progress.

Some four millennia before Anathem’s story opens, Arbre was much like Earth today. Science and technology flourished together and in full cooperation with business, military, and government; on Arbre this period is called the Praxic Age. But then, following two great wars and a genocide (the “harbingers”), came “the Terrible Events,” a planetary catastrophe. Details are sketchy, but global climate change and the creation of a more unstable climate are certainly part of the picture. In response to what were taken to be the proven dangers of unfettered scientific research, scientists were segregated (or segregated themselves; the point is to some degree contested) from the rest of society and thenceforward live under monastic-like discipline in carefully controlled cloisters. These are known as “concents” and the natural philosophers who live within their walls are called “avout.”

(The obvious similarity to “convent” and “devout” is part of Stephenson’s effort to make this world understandable and to suggest playful parallels and similarities between it and our own. Revered scientists are given the title “Saunt”—but whereas our “Saint” implies holiness, “Saunt” is derived from “savant.” The non-scientists outside the walls of the concents are said to live in the “Sæcular” world. Moments of what we would call “insight” are called by the avout “upsight.” Many specific concepts and characters from the history of Western philosophy are given new names—so the Agora of Athens becomes the “Periklyne” on Arbre, and Occam’s razor becomes “Gardan’s steelyard.”)

The discipline of the concents limits what the avout can possess (no technology from the outside world, for example), what they can study and with what tools, what kinds of plants they can grow, and how much contact they can have with the outside world and indeed with each other. The concents of which we hear most are subdivided into “maths.” One math opens itself to information from the outside world and from other maths once a year, another every ten years, a third every hundred years, and a fourth every thousand years. Fraa (“brother”) Erasmas (known as Raz), the narrator-hero of the book, is a late teen living in a math of “Tenners.” As the book begins, it is preparing for its once-a-decade opening. So far as we know, the way of life in each math is essentially the same, built around rituals that are performed in common but with each math segregated from the others.

Men and women avout work and live together and may form various kinds of attachments. However, while the point is made repeatedly that the differences between avout and those who live in the outside world are more a matter of nurture than nature, the avout food supply contains a birth-control agent to prevent any accidental or deliberate effort to breed super-scientists. While some of the “avout” move up from one math to another when the opportunity presents itself, clearly the concents can only perpetuate themselves by bringing in people from the outside—foundlings, excess children, or by-blows of the upper class. The biggest challenge would seem to be keeping the Thousander maths going, but we eventually find that they live unusually long lives, and that abandoned infants are sometimes sent into their math so that they will not contaminate it with outside knowledge.

The Concent of Saunt Edhar on which the first sections of the book focus, like others we later learn of, is divided not only by the maths, but by a variety of sects within the maths based on philosophical divergences or different foci of study. Like our academics, these avout are relentless sectarians. A further division within the concents stems from the fact that the avout do not have any access to computer technology and Arbre’s equivalent of the Internet, so the concent has various mechanisms and tools that the avout cannot run or repair themselves; for that they are dependent on tech-savvy custodians called Ita.

Formally supervising the whole system are hierarchs, avout who have greater contact with the outside world, and over the local hierarchs stands an Inquisition that travels freely. Avout who break the rules are ordered as punishment to copy and memorize while in solitary confinement material “crafted and refined over many centuries to be nonsensical, maddening, and pointless.” Worse still, an avout could be subjected to “Anathem”—expelled entirely from the concent and “Thrown Back” into the Sæcular world. We know for certain that mathic discipline is imperfect and we have reason to suspect, particularly in relation to the rarely-seen Thousanders, that it might even be less perfect than we directly observe. Nonetheless, on the whole it seems to operate effectively.

The result of all these measures is to slow the accumulation of scientific data, and to sever the link between science and technology. So there is on Arbre no “big science” as we know it and, it would seem, little laboratory work. Over the centuries that follow the Terrible Events, various additional restrictions are placed on the mathic world, such as a ban on genetic engineering. These accommodations result from the concents being sacked when the Sæcular powers that be get too worried about what is going on inside them. However, the avout are still “on tap” for these Sæcular powers, which can call them out as necessary to solve problems that require their expertise. Raz and the other avout at Saunt Edhar’s mostly seem to study astronomy and cosmology; we are led to believe they are making observations that would have otherwise required huge particle accelerators. They have little to work with except telescopes, chalkboards, paper (from genetically engineered trees that produce paper leaves), and pen—and their own minds, which they systematically develop through memorizing and participating in various forms of more or less Socratic dialogue.

Assessing the effects of the segregation of science on the rest of the world is made difficult by the fact that we see the world beyond the concent walls through Raz’s eyes, and he is certainly a prejudiced observer to begin with—although he becomes less so as his experience widens. Still, the worst one might say is that it is in many respects a somewhat degraded version of our own world today. The intellectual level of the outside world is not high, despite the fact that the one-year maths serve as colleges for the upper classes. Commercially and militarily motivated technological change occurs, even though the artisan class is not interested in the newest technology but in being able to comprehend, develop, adapt, and repair its own existing tools. The artisans we come to know best would be very unhappy to be as dependent on anyone as the avout are on the Ita. Mass culture is somewhat lower than our own, literacy more rare, religion (which from the avout point of view is part of the “Sæcular” world) perhaps more powerful at least in some time periods. (On Arbre, science and religion share a common father, which allows Stephenson to present what is, for a work of science fiction, a highly nuanced picture of the role of religion in life and its relationship to science. But this topic would be a fit theme for discussion all on its own.) Despite the fact—or perhaps because of it?—that there is a chemical in the food supply that makes people outside the concents feel good, the social and political world does not seem very stable—although the appearance of instability may reflect the telescoping effect of the very long view of history taken by the avout. Still, when Raz is called upon to leave his concent and travel on the outside, he observes a good deal more decaying than being built up. He himself notes that this kind of ebb and flow is cyclical, like the unstable climate.

What we can say for sure is that this strong division between the mathic and the Sæcular world proves to be highly stable; the arrangement has been in existence for well over three thousand years. What is required to have that stability is cutting off scientists from the outside world and to some extent from each other, cutting them off from most kinds of useful technology and technological development from them, and having a non-scientific culture that is more or less hostile to them by default. The scientists must believe that on balance their isolation is for their own good, and there must be a way for them to exercise their inquisitive minds. If, however noteworthy the subtle likenesses between concent life and our system of higher learning, we find it hard to imagine that the system Stephenson lays out could possibly come to pass in our world, that may just be because in our world the burden of guilt for “Terrible Events” we are still mostly imagining—from disastrous climate change to nuclear holocaust—has not yet been assumed by, or shackled upon, scientific shoulders.

But this stable arrangement contains both the good news and the bad news of Arbre’s history compared with our own. The “harbingers” of the Terrible Events sound suspiciously like our twentieth century. Assuming even a rough equivalence between Earth and Arbre years, Arbre represents a rather distant human future. The bad news is that Arbre, with only a few notable exceptions, has certainly not achieved anything like the extraordinary developments that science and technology seem to promise us today, let alone what science fiction routinely expects of so distant a future. With few exceptions, there is no radical extension of the human lifespan or of human capabilities. Arbre has not colonized and environmentally engineered other planets. The fact that Sæcular culture three millennia on is a somewhat degraded version of our own might even suggest that it is stuck in a kind of dark age. The good news is that there seem to have been no further “terrible events,” and even the last, longest, and worst of the sacks ended over eight centuries before the book opens.

So the mathic system “works” in the sense that the restriction of scientific research and its separation from technology creates the most stable age in Arbre’s history, even if everything is not all sweetness and light. We should perhaps not be surprised that such stability has costs of its own. But for the avout these costs are perhaps not as high as we might think. It is true that the sacks exact a terrible cost, particularly the last one. It is true that some avout chafe at restrictions and are disciplined or expelled for breaking rules. But the avout who actually engage in research (not all do so; the less able are shunted off into useful work around the concent) do so with ingenuity heightened by their limited resources and the intense focus that follows from their lack of distraction. Their discipline produces orderly habits of thought and action, along with a fair degree of comradely devotion to their brothers and sisters, sects, maths, and concents. Within the broad limits imposed on them, they seem to have freedom to choose to study whatever inquiries interest them, unmolested by disapproving non-scientists, and uninfluenced by commercial motives or external funding streams (although there is politicking among the various sects). Finally, they have a patience that comes from having a very long-term perspective on the significanceof their own contributions within the larger mathic effort at understanding the world.

Stephenson seems to think that a certain kind of person, with a certain kind of education, will find ways to answer the questions that interest him whatever the circumstances; for example, without calculating machines the avout have developed the ability to model calculations using songs. The fact that Stephenson calls the avout “theors” is also significant—their intellectual efforts are far more like the ancient science that was akin to contemplation than Baconian science directed at conquest, doing and making for immediately useful even if charitable purposes. This difference between theors and our scientists is only highlighted by the fact that the theors are the guardians of Arbre’s philosophical heritage. The intellectual and historical underpinnings of their efforts are very much a living part of what they do as theors—they are not just “gen-ed” add-ons, as they are for so many of our scientists-in-training. So we are not surprised when one character remarks that the avout spend their lives learning how to learn; they specialize without becoming narrow specialists. In the scheme of things, that is unlikely to strike many of us as the worst of fates, and suggests how the mathic system preserves what is best in the spirit of scientific inquiry as we know it.

That is not to say that the mathic system represents a model we should attempt to emulate in order to avoid our own version of the Terrible Events. But neither should we assume that the three thousand years of relative stability on Arbre made possible by the mathic system, including its costs, are just an arbitrary exercise of Stephenson’s imagination. We can see it as a thought experiment if we compare it with our usual way of doing things. On those rare occasions when those of our intellectuals who think at all about restraining developments in science and technology do so, they unsurprisingly think first in terms of the accustomed tools of a liberal democratic order that seeks to be minimally invasive in such matters: government regulatory oversight, or ethics norms voluntarily developed by professional organizations and adhered to by their members—classic parchment barriers. Stephenson would certainly not be the first to wonder whether such kid-glove measures are proportionate to the dangers threatened by greatly increasing our powers over nature and each other. His more thought-provoking contribution is the suggestion that such measures also may not do justice to the deep and abiding motive behind such research and development: the desire to know. Aristotle may be correct that all men desire by nature to know, but surely the passion is more powerful and developed in some than in others. Can government paperwork and ethics codes really provide a serious bulwark against those for whom the desire to know is their master passion?

Speaking broadly, we know that one of the tendencies of modern political arrangements is to make ethical restraint a matter of individual choice, at least to the extent compatible with public order and safety. Although Tocqueville’s concerns about the tyranny of the majority cannot be dismissed out of hand, liberal democracies rightly pride themselves on their avoidance of the ruthless enforcement of beliefs and norms of the sort found in secular or religious totalitarianism. Still, we know from one of Stephenson’s previous books, The Diamond Age (1995), that he is aware of the potentially corrosive moral effects of the very democratic principle “let each do as he pleases.” There is a sense in which modern liberal political arrangements wish to have ethical citizens without having an ethos, a publicly prescribed way of life for those citizens. This project would have seemed paradoxical or impossible to the ancients, who believed that ethics needed the careful support and habituation of institutions “with teeth in them,” to use Leo Strauss’s memorable phrase. And such a system is just what the mathic order represents. The discipline of the avout is written in a book but does not just happen from reading that book; it is lived and reinforced moment to moment by the very structure of their days, their possessions, their activities. If even then the system is imperfect and some avout place their desire to know above the rules of the community, then how much less restraint can we expect from less stringent measures within the framework of a more individualistic culture, and one where the already powerful desire to know will be freely mixed with other powerful desires the avout are less subject to—say, for material goods or public influence?

If part of friendship is avoiding discussing the defects of one’s friends, some friends of liberal democracy may feel it is not polite to confront this dilemma. Everybody understands, they might say, that neither fettered nor unfettered scientific and technological development is a free lunch, and that the costs and benefits of either course of action will be distributed unevenly. Our rather mild regimes of restraint stem from the judgment that on balance less control has larger benefits because it leads to more progress, and that the way you solve the problems of any one stage of historical progress is to press beyond them to the next stage. Progress may open the door to “terrible events,” but that just means we have to make progress all the faster in order to avoid them.

Viewed this way, progress is an infinite historical task, without a clear goal or purpose towards which to advance; one might wonder, then, why we call it “progress” and not simply “change.” But that we live in and should want to live in a progressive world is a crucial element of our narrative about ourselves. At various points in the story, Anathem suggests that a life well lived requires some such story to make it meaningful, some sense of purpose. Historical progress is the story that makes us reluctant to limit developments in science and technology. Stephenson’s treatment of the relationship of religion and science on Arbre suggests that, while it is dangerous to have no story at all, it is also problematic if one adheres dogmatically to the sole truth of one’s own story. Anathem raises questions about whether or to what extent this thing called progress really exists.

Anathem is filled with cycles; the analemma on the book jacket is a well-chosen graphic element. With their long-range perspective, the avout see cycles everywhere. Polar ice expands and contracts, cities grow and shrink, empires and beliefs rise and fall. The avout cyclically open and close their maths to the outside world, and inside the concent walls their days are structured by repeating rituals performed around a huge (non-digital) clock. They are aware that it is harder than it seems for something new to arise under the sun. A sect among them, the Lorites, specializes in pointing out when apparently new ideas are really just repetitions of old and otherwise forgotten ideas, and Lorites seem to have no lack of work to do. The intensely sectarian structure within the maths is testimony to just how hard it is to get beyond certain fundamental assumptions or predispositions.

Yet against this cyclical view of events, the book ends on an apparently progressive note. In order to be better prepared for future visitations by potentially hostile aliens with superior technology, Sæcular and avout have agreed to govern Arbre as two Magisteria. But here a complex and ambiguous aspect of the story must be noted. For it is not impossible that elements among the avout themselves helped bring about this crisis and, with the cooperation of a shadowy group of quasi-avout operating in the Sæcular world, shaped its course. We know for a fact that the Thousanders can manipulate the course of events (although in the cosmology of the book that is not the right way to describe their ability) and that such manipulation is crucial at a critical moment in the story; there are alternate timelines in alternate universes that have less happy outcomes. Raz at least is willing to take seriously the possibility that this shadowy group of avouts engineered the crisis by summoning the aliens, all with the intention of bringing the mathic age of scientific segregation to a close.

Nobody speaks against this new world order and some are clearly excited by it. As the book closes, we see Raz establishing a new concent. Predicated on this new avout-Sæcular cooperation, it will not be closed off from the world in the old mathic way. Yet it will still have walls, and the walls are already being laid out with an eye to their defensibility and with arched openings that could readily be turned into the closed gates that had defined the mathic concents. Diarchies are notoriously unstable.

Beyond that problem, ought we not expect that avout and Sæcular working together to meet some unknown contingency will develop very dangerous technologies? The timeline-manipulating Thousanders and their allies may have a good deal of work ahead of them if this second age of science and technology is not to end as disastrously as the first one. For us, it should be a sobering lesson if such godlike power is what it would take to maintain stability and prevent a repetition of the Terrible Events. Without that godlike power, it would seem, we should just expect that old patterns will be repeated.

The overarching metaphysic and cosmology of Anathem may suggest that this seeming anti-progressivism is not the last word. Raz is a member of a quasi-Platonic sect that believes that our ideas are reflections of Ideas; he joins their ranks despite the fact that they are widely looked down upon for holding what seems to be a suspiciously religious point of view (in our terms: the realm of Ideas sounds too much like heaven). Yet events more and more seem to vindicate their perspective, eventually allowing speculation that the universe in which Arbre exists may be a cosmos “closer” to the ultimate world of Ideas than the alternative cosmi from which the aliens prove to have come. It might be tempting, then, to see the cycles of Arbre as moments in a larger ascending spiral moving towards some ultimate truth.

Even if that view were correct, it would already be distinguished from historical progress understood as an infinite task without settled purpose or direction. However, it is not clear that the book’s quasi-Platonism makes the ascending spiral the appropriate image. Towards the very end of the book, when Raz’s views of at least some of Arbre’s religions have softened, he speaks of one preacher’s “amazing, exasperating sermons, filled with wisdom and upsight and human truths, fettered to a cosmographical scheme that had been blown out of the water four thousand years ago.” Yet perhaps a good Platonist should not be amazed or exasperated. Even if it is simply a human possibility—that is, possible always and everywhere—to grasp the truth, to have “upsight” into some of the truth does not mean upsight into all of it. To use the favorite example of the book, the Pythagorean theorem is an Idea that is true always and everywhere, and may be grasped always and everywhere, without complete knowledge of the whole of which it is a part. “Progress” occurs, one might say, when one moves from not knowing it to knowing it, but that progress has nothing to do with time or historical development; indeed an enigmatic Thousander suggests that time does not even exist, which would leave historical progress an illusion within an illusion.

In themselves, these are just the sort of arcane speculations that are quite suitable for science fiction. But as was the case with the obviously impractical concents, they are speculations that can make us wonder whether there are not equally arcane speculations upon which our more accustomed ways of thinking are built. The important truism that “you can’t stop progress” is easy enough to say, but understanding what it actually means is another matter—as is the question of whether it is true.

Anathem presents us with a familiar unfamiliar world and in so doing opens a door to asking such questions. We think we know the best ways, if necessary, to limit developments of science and technology, but Stephenson makes us wonder whether our easygoing ethical individualism is adequate to both our growing power over nature and ourselves, and to the force and dignity of the impulse to know that stands behind our science. We think we know what historical progress means, but Anathem makes us wonder whether progress without truth is anything more than change, and whether truth does not render progress superfluous. Is not wonder the beginning of philosophy?

Charles T. Rubin, a New Atlantis contributing editor, is an associate professor of political science at Duquesne University.

Charles T. Rubin, "Plato in Space," The New Atlantis, Summer 2009, pp. 59-68.







http://www.thenewatlantis.com/

quinta-feira, 26 de novembro de 2009

walking man

terça-feira, 24 de novembro de 2009

Estátua viva

quinta-feira, 19 de novembro de 2009

Aphex Twin - Gwelly Mernans

quarta-feira, 18 de novembro de 2009

segunda-feira, 16 de novembro de 2009

domingo, 1 de novembro de 2009

Espaço-tempo

Einstein was right! Nasa Fermi telescope uncovers proof of famous space-time theory

By Daily Mail Reporter
Last updated at 1:44 AM on 01st November 2009


Racing across the Universe for the last 7.3-billion-years, two highly charged particles have arrived at Nasa's Fermi Gamma-ray Space Telescope within a second of one another. Excited scientists believe this could be evidence of Einstein's space-time theory.

The photons were launched on their marathon during a short gamma-ray burst, an outpouring of radiation likely generated by the collision of two neutron stars, the densest known objects in the Universe.

One of the photons possessed a million times more energy that the other but they arrived at almost the same time.
photons

In this illustration, one photon (purple) carries a million times the energy of another (yellow). Some theorists predict travel delays for higher-energy photons. Yet Fermi data failed to show this effect

In Einstein's vision of a unified space-time all forms of electromagnetic radiation, from gamma rays through to X-rays, are thought to travel through the vacuum of space at the same speed, no matter how much energy they have.

But in some new theories of gravity, space-time is considered to have a 'shifting, frothy structure' when viewed at a scale trillions of times smaller than an electron.

These new models of the Universe say this 'foamy texture' would slow down the higher-energy photon relative to the lower energy one.

The Fermi Telescope results showed this did not happen as scientists believe the nine-tenths of a second gap, when spread over more than seven billion years, is too small to be significant.

Professor Peter Michelson from Stanford University said: 'This measurement eliminates any approach to a new theory of gravity that predicts a strong energy-dependent change in the speed of light.'

The principal investigator for Fermi's Large Area Telescope (LAT) concluded: 'To one part in 100 million billion, these two photons traveled at the same speed. Einstein still rules.'

Professor Michelson's team has published a paper on the findings in the online version of the journal Nature.


More...

* Earliest star blast helps astronomers peer back to dawn of time

Physicists have yearned for years to develop a unifying theory of how the universe works. But no one has been able to come up with one that brings all four of the fundamental forces in the universe into one tent.

The Standard Model of particle physics is considered to have succeeded in unifying three of the four. These are the 'strong force' that holds nuclei together inside atoms and the 'weak force' that is responsible for radioactive decay and electromagnetism.

However gravity has always been the odd man out in this model. Though a host of theories have been advanced, none has been shown successful.

Albert Einstein's theories of relativity also fail to unify the four forces but the latest evidence suggests he was nearer to the truth than many modern theories.

Read more: http://www.dailymail.co.uk/sciencetech/article-1223853/Nasa-Fermi-telescope-uncovers-proof-Einsteins-space-time-theory.html?ITO=1490#ixzz0VbzlkcQ0

quinta-feira, 29 de outubro de 2009

Espaço

Um grupo internacional de astrofísicos detectou um corpo celeste que é o mais distante e o mais antigo registado até agora e confirmou que as estrelas já existiam quando o universo tinha apenas 600 milhões de anos.

Estas são algumas das conclusões de dois estudos publicados na revista cientifica Nature, que analisam a explosão de raios gama registada a 23 de Abril, que foi o mais distante observado até agora e que corresponde à explosão da estrela mais antiga e longínqua que se conhece.

Trata-se de uma estrela gigante que se apagou há 13 mil milhões de euros e cujo último esplendor chegou à Terra há apenas seis meses.


TSF

sexta-feira, 23 de outubro de 2009

Christian the lion - Full ending

quarta-feira, 21 de outubro de 2009

Design: Arquitecto português ganha Prémio do Público em concurso do Museu Guggenheim de Nova Iorque - dn - DN

Design: Arquitecto português ganha Prémio do Público em concurso do Museu Guggenheim de Nova Iorque - dn - DN

Futuro tentou sabotar o 'grande colisionador' - Ciência - DN

Futuro tentou sabotar o 'grande colisionador' - Ciência - DN

Investigadores portugueses caracterizam genoma inédito

Investigadores portugueses conseguiram fazer a primeira caracterização a nível mundial do genoma (transcriptoma) do mexilhão das fontes hidrotermais, permitindo criar a primeira base de dados sobre os genes deste animal, que vive no mar profundo.

«A criação desta base de dados, a primeira a nível mundial, é um grande salto evolutivo na investigação porque vai permitir perceber os mecanismos de adaptação do animal a condições extremas de sobrevivência», afirmou o investigador Raul Bettencourt, citado pela Lusa.

A investigação desenvolvida pelo Departamento de Oceanografia e Pescas (DOP) da Universidade dos Açores permitiu a aquisição de novos conhecimentos que podem vir a ter aplicação em áreas como a biotecnologia ou a medicina.

Em causa está a possível descoberta de genes com elevado valor biotecnológico ou de proteínas com propriedades anti-microbianas, que são utilizadas pelo animal para se defender dos microorganismos do meio ambiente em que vive.

No centro das atenções dos investigadores está o Bathymodiolus azoricus, um mexilhão que vive no campo hidrotermal Lucky Strike, a cerca de 1.700 metros de profundidade, na região da crista médio-atlântica, a 200 milhas a sudoeste do Faial.

domingo, 11 de outubro de 2009

Good Luck

Be lucky - it's an easy skill to learn

Those who think they're unlucky should change their outlook and discover how to generate good fortune, says Richard Wiseman


Prof Richard Wiseman
Psychology of luck: Prof Richard Wiseman has discovered the secret to good luck

A decade ago, I set out to investigate luck. I wanted to examine the impact on people's lives of chance opportunities, lucky breaks and being in the right place at the right time. After many experiments, I believe that I now understand why some people are luckier than others and that it is possible to become luckier.

To launch my study, I placed advertisements in national newspapers and magazines, asking for people who felt consistently lucky or unlucky to contact me. Over the years, 400 extraordinary men and women volunteered for my research from all walks of life: the youngest is an 18-year-old student, the oldest an 84-year-old retired accountant.

Jessica, a 42-year-old forensic scientist, is typical of the lucky group. As she explained: "I have my dream job, two wonderful children and a great guy whom I love very much. It's amazing; when I look back at my life, I realise I have been lucky in just about every area."

In contrast, Carolyn, a 34-year-old care assistant, is typical of the unlucky group. She is accident-prone. In one week, she twisted her ankle in a pothole, injured her back in another fall and reversed her car into a tree during a driving lesson. She was also unlucky in love and felt she was always in the wrong place at the wrong time.

Over the years, I interviewed these volunteers, asked them to complete diaries, questionnaires and intelligence tests, and invited them to participate in experiments. The findings have revealed that although unlucky people have almost no insight into the real causes of their good and bad luck, their thoughts and behaviour are responsible for much of their fortune.

Take the case of chance opportunities. Lucky people consistently encounter such opportunities, whereas unlucky people do not. I carried out a simple experiment to discover whether this was due to differences in their ability to spot such opportunities.

I gave both lucky and unlucky people a newspaper, and asked them to look through it and tell me how many photographs were inside. On average, the unlucky people took about two minutes to count the photographs, whereas the lucky people took just seconds. Why? Because the second page of the newspaper contained the message: "Stop counting. There are 43 photographs in this newspaper." This message took up half of the page and was written in type that was more than 2in high. It was staring everyone straight in the face, but the unlucky people tended to miss it and the lucky people tended to spot it.

For fun, I placed a second large message halfway through the newspaper: "Stop counting. Tell the experimenter you have seen this and win £250." Again, the unlucky people missed the opportunity because they were still too busy looking for photographs.

Personality tests revealed that unlucky people are generally much more tense than lucky people, and research has shown that anxiety disrupts people's ability to notice the unexpected. In one experiment, people were asked to watch a moving dot in the centre of a computer screen. Without warning, large dots would occasionally be flashed at the edges of the screen. Nearly all participants noticed these large dots.

The experiment was then repeated with a second group of people, who were offered a large financial reward for accurately watching the centre dot, creating more anxiety. They became focused on the centre dot and more than a third of them missed the large dots when they appeared on the screen. The harder they looked, the less they saw.

And so it is with luck - unlucky people miss chance opportunities because they are too focused on looking for something else. They go to parties intent on finding their perfect partner and so miss opportunities to make good friends. They look through newspapers determined to find certain types of job advertisements and as a result miss other types of jobs. Lucky people are more relaxed and open, and therefore see what is there rather than just what they are looking for.

My research revealed that lucky people generate good fortune via four basic principles. They are skilled at creating and noticing chance opportunities, make lucky decisions by listening to their intuition, create self-fulfilling prophesies via positive expectations, and adopt a resilient attitude that transforms bad luck into good.

I wondered whether these four principles could be used to increase the amount of good luck that people encounter in their lives. To find out, I created a "luck school" - a simple experiment that examined whether people's luck can be enhanced by getting them to think and behave like a lucky person.

I asked a group of lucky and unlucky volunteers to spend a month carrying out exercises designed to help them think and behave like a lucky person. These exercises helped them spot chance opportunities, listen to their intuition, expect to be lucky, and be more resilient to bad luck.

One month later, the volunteers returned and described what had happened. The results were dramatic: 80 per cent of people were now happier, more satisfied with their lives and, perhaps most important of all, luckier. While lucky people became luckier, the unlucky had become lucky. Take Carolyn, whom I introduced at the start of this article. After graduating from "luck school", she has passed her driving test after three years of trying, was no longer accident-prone and became more confident.

In the wake of these studies, I think there are three easy techniques that can help to maximise good fortune:

  • Unlucky people often fail to follow their intuition when making a choice, whereas lucky people tend to respect hunches. Lucky people are interested in how they both think and feel about the various options, rather than simply looking at the rational side of the situation. I think this helps them because gut feelings act as an alarm bell - a reason to consider a decision carefully.
  • Unlucky people tend to be creatures of routine. They tend to take the same route to and from work and talk to the same types of people at parties. In contrast, many lucky people try to introduce variety into their lives. For example, one person described how he thought of a colour before arriving at a party and then introduced himself to people wearing that colour. This kind of behaviour boosts the likelihood of chance opportunities by introducing variety.
  • Lucky people tend to see the positive side of their ill fortune. They imagine how things could have been worse. In one interview, a lucky volunteer arrived with his leg in a plaster cast and described how he had fallen down a flight of stairs. I asked him whether he still felt lucky and he cheerfully explained that he felt luckier than before. As he pointed out, he could have broken his neck.

quinta-feira, 1 de outubro de 2009

Hipopótamo

Pictured: The baby pygmy hippo who's barely bigger than a lettuce leaf

By Daily Mail Reporter

Hippos kill more humans than any other animal - but this little fellow doesn't look like he could do too much harm.

A newborn baby pygmy from Rotterdam's Blijdorp Zoo, he's dwarfed by lettuce leaves as he has a nibble with his mum.

Much tamer and shyer than their aggressive cousins, pygmy hippos are now critically endangered, with less than 3000 remaining in the wild.

pygmy hippopotamus A newly born pygmy hippopotamus has a nibble with its mother in Rotterdam's Blijdorp Zoo

They're indigenous to the tropical forests of West Africa, and their primary threat is the loss of their forest habitat due to the timber industry. They're also hunted extensively for their meat.

The aptly named pygmy grows to just over 3ft tall - just one fifth of the size of the common hippopotamus - and is the only other species of hippo in the world.

Reclusive and nocturnal, the mammals are semi-aquatic and need to live near water to keep their skin moisturised and their body cool.

They sometimes even mate and give birth in water, and they secrete oils known as 'blood-sweat' to keep their hide waterproof.

Pygmy hippos are plant-eating mammals, feeding on ferns, broad-leaved plants, grasses and fruits they find in the forest.

quinta-feira, 24 de setembro de 2009

Água na Lua

It's Official: Water Found on the Moon
SPACE.com

Andrea Thompson
Senior Writer
SPACE.com andrea Thompson


Since man first touched the moon and brought pieces of it back to Earth, scientists have thought that the lunar surface was bone dry. But new observations from three different spacecraft have put this notion to rest with what has been called "unambiguous evidence" of water across the surface of the moon.

The new findings, detailed in the Sept. 25 issue of the journal Science, come in the wake of further evidence of lunar polar water ice by NASA's Lunar Reconnaissance Orbiter and just weeks before the planned lunar impact of NASA's LCROSS satellite, which will hit one of the permanently shadowed craters at the moon's south pole in hope of churning up evidence of water ice deposits in the debris field.

The moon remains drier than any desert on Earth, but the water is said to exist on the moon in very small quantities. Finding water on the moon would be a boon to possible future lunar bases, acting as a potential source of drinking water and fuel.

Apollo turns up dry

When Apollo astronauts returned from the moon 40 years ago, they brought back several samples of lunar rocks.

The moon rocks were analyzed for signs of water bound to minerals present in the rocks; while trace amounts of water were detected, these were assumed to be contamination from Earth, because the containers the rocks came back in had leaked.

"The isotopes of oxygen that exist on the moon are the same as those that exist on Earth, so it was difficult if not impossible to tell the difference between water from the moon and water from Earth," said Larry Taylor of the University of Tennessee, Knoxville, who is a member of one of the NASA-built instrument teams for India's Chandrayaan-1 satellite and has studied the moon since the Apollo missions.

While scientists continued to suspect that water ice deposits could be found in the coldest spots of south pole craters that never saw sunlight, the consensus became that the rest of the moon was bone dry.

But new observations of the lunar surface made with Chandrayaan-1, NASA's Cassini spacecraft, and NASA's Deep Impact probe, are calling that consensus into question, with multiple detections of the spectral signal of either water or the hydroxyl group (an oxygen and hydrogen chemically bonded).

Three spacecraft

Chandrayaan-1, India's first-ever moon probe, was aimed at mapping the lunar surface and determining its mineral composition (the orbiter's mission ended 14 months prematurely in August after an abrupt malfunction). While the probe was still active, its NASA-built Moon Mineralogy Mapper (M3) detected wavelengths of light reflected off the surface that indicated the chemical bond between hydrogen and oxygen — the telltale sign of either water or hydroxyl.

Because M3 can only penetrate the top few millimeters of lunar regolith, the newly observed water seems to be at or near the lunar surface. M3's observations also showed that the water signal got stronger toward the polar regions.

Cassini, which passed by the moon in 1999 on its way to Saturn, provides confirmation of this signal with its own slightly stronger detection of the water/hydroxyl signal. The water would have to be absorbed or trapped in the glass and minerals at the lunar surface, wrote Roger Clark of the U.S. Geological Survey in the study detailing Cassini's findings.

The Cassini data shows a global distribution of the water signal, though it also appears stronger near the poles (and low in the lunar maria).

Finally, the Deep Impact spacecraft, as part of its extended EPOXI mission and at the request of the M3 team, made infrared detections of water and hydroxyl as part of a calibration exercise during several close approaches of the Earth-Moon system en route to its planned flyby of comet 103P/Hartley 2 in November 2010.

Deep Impact detected the signal at all latitudes above 10 degrees N, though once again, the poles showed the strongest signals. With its multiple passes, Deep Impact was able to observe the same regions at different times of the lunar day. At noon, when the sun's rays were strongest, the water feature was lowest, while in the morning, the feature was stronger.

"The Deep Impact observations of the Moon not only unequivocally confirm the presence of [water/hydroxyl] on the lunar surface, but also reveal that the entire lunar surface is hydrated during at least some portion of the lunar day," the authors wrote in their study.

The findings of all three spacecraft "provide unambiguous evidence for the presence of hydroxyl or water," said Paul Lacey of the University of Hawaii in an opinion essay accompanying the three studies. Lacey was not involved in any of the missions.

The new data "prompt a critical reexamination of the notion that the moon is dry. It is not," Lacey wrote.

Where the water comes from

Combined, the findings show that not only is the moon hydrated, the process that makes it so is a dynamic one that is driven by the daily changes in solar radiation hitting any given spot on the surface.

The sun might also have something to do with how the water got there.

There are potentially two types of water on the moon: that brought from outside sources, such as water-bearing comets striking the surface, or that that originates on the moon.

This second, endogenic, source is thought to possibly come from the interaction of the solar wind with moon rocks and soils.

The rocks and regolith that make up the lunar surface are about 45 percent oxygen (combined with other elements as mostly silicate minerals). The solar wind — the constant stream of charged particles emitted by the sun — are mostly protons, or positively charged hydrogen atoms.

If the charged hydrogens, which are traveling at one-third the speed of light, hit the lunar surface with enough force, they break apart oxygen bonds in soil materials, Taylor, the M3 team member suspects. Where free oxygen and hydrogen exist, there is a high chance that trace amounts of water will form.

The various study researchers also suggest that the daily dehydration and rehydration of the trace water across the surface could lead to the migration of hydroxyl and hydrogen towards the poles where it can accumulate in the cold traps of the permanently shadowed regions.

o povo votou outra vez

terça-feira, 22 de setembro de 2009

Weather Geeks Champion New Armageddon-Worthy Cloud

Weather Geeks Champion New Armageddon-Worthy Cloud

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Boston Dynamics Big Dog (new video March 2008)

BigDog has been developed by Boston Dynamics - a robotics company - in response to a request by the Defense Advanced Research Projects Agency to carry soldiers' equipment across rough terrain. BigDog has four legs allowing it to traverse areas that wheeled or tracked vehicles cannot move across and carries a laser gyroscope and stereo vision system. If the Skynet-like vision of a four-legged military robot tramping through woodland in the snow is not frightening enough, then the segment when BigDog is pushed off balance and staggers drunkenly sideways is surely one of the creepiest things ever to appear on YouTube.

http://www.telegraph.co.uk/

segunda-feira, 21 de setembro de 2009

Beagle Escape!!! (w/music)

domingo, 20 de setembro de 2009

Ovation TV | Jackson Pollock

Surrealismo

Surreal experiences


16 September 2009
Surreal experiences boost brain power
by Kate Melville

Psychologists at the University of California - Santa Barbara and the University of British Columbia have found that exposure to surrealism, by say, reading a book by Franz Kafka or watching a film by director David Lynch, enhances the cognitive mechanisms that oversee the implicit learning functions in the brain. The research was reported in the journal Psychological Science.

"The idea is that when you're exposed to a meaning threat - something that fundamentally does not make sense - your brain is going to respond by looking for some other kind of structure within your environment," said researcher Travis Proulx. "And, it turns out, that structure can be completely unrelated to the meaning threat."

Meaning, explains Proulx, is an expected association within one's environment. Fire, for example, is associated with extreme heat, and putting your hand in a flame and finding it icy cold would constitute a threat to that meaning.

In the study, the researchers asked a group of subjects to read an abridged and slightly edited version of Kafka's The Country Doctor, which involves a nonsensical - and in some ways disturbing - series of events. A second group read a different version of the same short story, one that had been rewritten so that the plot and literary elements made sense. The subjects were then asked to complete an artificial-grammar learning task in which they were exposed to hidden patterns in letter strings. They were asked to copy the individual letter strings and then to put a mark next to those that followed a similar pattern.

"People who read the nonsensical story checked off more letter strings - clearly they were motivated to find structure," said Proulx. "But what's more important is that they were actually more accurate than those who read the more normal version of the story. They really did learn the pattern better than the other participants did."

Importantly, the researchers have identified the beneficial effects of unusual experiences only in implicit pattern learning. It remains to be seen whether or not reading surreal literature would aid in the learning of studied material as well. "It's important to note that sitting down with a Kafka story before exam time probably wouldn't boost your performance on a test," noted Proulx.

He added that the element of surprise was critical. "If you expect that you'll encounter something strange or out of the ordinary, you won't experience the same sense of alienation. You may be disturbed by it, but you won't show the same learning ability. The key to our study is that our participants were surprised by the series of unexpected events, and they had no way to make sense of them. Hence, they strived to make sense of something else."

Related:
Striking differences between brains of rich and poor
The High Cost Of Intelligence
Brain Wired For Adventure
This Is Your Brain On Jazz

Source: University of California

It

It’s Better In Somalia

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quinta-feira, 17 de setembro de 2009

RTP - CONVERSA DE ESCRITORES

RTP - CONVERSA DE ESCRITORES

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Astronomia em português

A existência de vida noutros planetas.

Portugal tem astrónomos que participam em projectos internacionais que em breve confirmarão a suspeita. Tem outros que desenvolvem instrumentos para telescópios e sondas que vão cartografar a nossa galáxia, saber do que são feitos os astros.
Sabia que o ferro que lhe tinge o sangue é anterior a si, ao planeta? A maternidade? As estrelas. E já pensou que na nossa essência primitiva somos extra-terrenos, à procura de vida extra-terrestre?
Portugal também teve astrónomos que foram citados por Newton, reis que decretaram a construção de observatórios astronómicos e matemáticos que calcularam nos astros as rotas dos oceanos.
A astronomia faz universalmente parte de nós, da nossa história e cultura, desde o Neolítico.
É nesse tempo que começa a história dos ANOS-LUSOS contada à velocidade de 7 mil anos por hora.

quarta-feira, 16 de setembro de 2009

segunda-feira, 14 de setembro de 2009

Ilusões de óptica

http://www.ritsumei.ac.jp/~akitaoka/index-e.html

debate do js js

A Verdade da Política de Manuela Ferreira Leite

A cobra que faz rir




Snake that grew a foot out of its body Photo: CEN/Europics

Dean Qiongxiu, 66, said she discovered the reptile clinging to the wall of her bedroom with its talons in the middle of the night.

"I woke up and heard a strange scratching sound. I turned on the light and saw this monster working its way along the wall using his claw," said Mrs Duan of Suining, southwest China.

Mrs Duan said she was so scared she grabbed a shoe and beat the snake to death before preserving its body in a bottle of alcohol.

The snake – 16 inches long and the thickness of a little finger – is now being studied at the Life Sciences Department at China's West Normal University in Nanchang.

Snake expert Long Shuai said: "It is truly shocking but we won't know the cause until we've conducted an autopsy."

A more common mutation among snakes is the growth of a second head, which occurs in a similar way to the formation of Siamese twins in humans.

Such animals are often caught and preserved as lucky tokens but have very little chance of surviving in the wild anyway, especially as the heads have a tendency to attack each other.

sábado, 12 de setembro de 2009

Pink Floyd - Wish You Were Here

Astronomia



Um português na elite mundial da astronomia

por Alfredo Teixeira


Nuno Santos, professor e investigador do Centro de Astrofísica da Universidade do Porto, ganhou uma bolsa de quase um milhão de euros para encontrar planetas sósias da Terra.

Descobrir um planeta igual à Terra é o grande desafio de Nuno Santos, investigador do Centro de Astrofísica da Universidade do Porto, premiado com uma bolsa do European Research Council - ERC Starting Grant 2009. Um objectivo no qual, actualmente, está concentrada toda a comunidade científica mundial. Tanto a americana NASA como a europeia ESO (Observatório Europeu do Sul) desenvolvem projectos numa competição que faz lembrar os tempos da Guerra Fria pela conquista do espaço americano e soviético.

É nesta pesquisa que entra o investigador português a quem foi agora atribuída uma bolsa de quase um milhão de euros para desenvolver uma investigação de ponta que permita a detecção e estudo de outros planetas semelhantes à Terra a orbitar estrelas parecidas com o Sol.

Neste momento, Nuno Santos encontra-se no Chile, mais propriamente na localidade de La Silla, no deserto de Atacama, onde está instalado o telescópio HARPS do ESO, local onde habitualmente investigadores europeus fazem as suas pesquisas pelo universo e colocam em prática os estudos que cada um vai desenvolvendo nos seus países. Por isso, confessa Nuno Santos, "esta bolsa vai servir para reforçar e consolidar a equipa que existe no Centro de Astrofísica do Porto e desenvolver uma ciência que permitirá descobrir e estudar um planeta parecido com a Terra".

Ao mesmo tempo, abrirá caminho para o projecto Expresso (Echelle Spectrograph for Rocky Exoplanet and Stable Spectroscopic Observations) da Agência Espacial Europeia (ESO) e que tem também por objectivo detectar planetas parecidos com o nosso, capazes de albergar vida.

A bolsa foi atribuída pelo European Research Council (ERC) e Nuno Santos foi um dos 219 contemplados num universos de 2503 candidaturas. "Este dinheiro vai ainda permitir contratar investigadores internacionais para trabalharem no Porto e atribuir bolsas para estudantes portugueses desta área", explica o astrónomo. O trabalho desenvolvido nos últimos anos por Nuno Santos acaba assim por ser reconhecido, sendo de referir que a equipa do investigador, juntamente com astrónomos franceses e suíços, foi responsável, em Abril de 2007, por uma das maiores descobertas científicas dos últimos anos: o Gliese 581, uma estrela--anã vermelha em volta da qual orbita um planeta potencialmente habitável fora do sistema solar.

Desde logo, o Gliese 581 despertou a atenção mundial pela sua semelhança com a Terra. Apelidado pelos astrónomos de "Super-Terra", este planeta extra--solar possui um diâmetro 50% maior do que o da Terra e dista de nós 20,5 anos-luz.

"Era quase garantido lá existirem temperaturas amenas, faltava saber é se tinha água capaz de suportar vida", diz Nuno Santos. Meses depois, a esperança era desfeita. Afinal a "Super-Terra" não estava suficientemente longe da sua estrela para que a existência de gelo ou água fosse possível.

Nos últimos anos, outros três sósias da Terra foram encontrados na órbita desta estrela-anã vermelha. Mas estes planetas tinham características que tornavam impossível qualquer forma de vida semelhante à terrestre.

Para Nuno Santos, a bolsa agora atribuída "é um reconhecimento pelo trabalho e um estímulo para o futuro". O investigador prevê que este incentivo comece a dar resultados já a partir do próximo ano.

quinta-feira, 10 de setembro de 2009

sexta-feira, 28 de agosto de 2009

Did You Know?

sexta-feira, 21 de agosto de 2009

Ciência

Publicado na revista “Cell”


Português descobre gene crucial para transformar células adultas em estaminais embrionárias
20.08.2009 - 17h40 Teresa Firmino

José Silva anda às voltas com o mesmo gene há cinco anos e agora descobriu como é que esse gene consegue fazer com que células adultas, perfeitamente diferenciadas como as da pele, regressem a um passado distante – levando-as a transformar-se em células estaminais embrionárias.

O biólogo português, 35 anos, do Centro para a Investigação de Células Estaminais da Universidade de Cambridge, em Inglaterra, publica hoje a descoberta na edição online da revista norte-americana “Cell”.

O gene alvo de tantas atenções é o Nanog, que, em gaélico, remete para a expressão “terra dos sempre jovens”. Foi descoberto em 2003, por outro cientista, e no ano seguinte José Silva começou a dedicar-lhe atenção.

O que tem para contar inclui vários tipos de células. Ao contrário das células adultas, que já se diferenciaram, tornando-se pele ou coração, por exemplo, as estaminais dos embriões originam todos os tipos de células (mais de 200) de um organismo. Por essa razão, os cientistas querem aprender tudo sobre elas, para depois as transformar em qualquer tipo de célula e tratar as mais variadas doenças, como a Parkinson, Alzheimer ou diabetes.

Se a obtenção dessas células puder evitar a criação e destruição de embriões – produzindo estaminais a partir de células adultas –, contorna-se uma série de problemas éticos. Mais: podem-se gerar células compatíveis com qualquer doente a partir de células do seu corpo.

Em 2006, José Silva percebeu que o Nanog tem um papel importante na reprogramação das células adultas, pois faz com que voltem a ser estaminais embrionárias.

Nessa altura, o investigador procedeu à fusão de células diferenciadas (da pele e do timo) com células estaminais do cérebro (nos adultos também há células estaminais, mas têm alguma especialização; as células estaminais do sangue só já dão as várias células sanguíneas e nunca do coração, por exemplo).

Era a primeira vez que se identificava um gene específico envolvido na reprogramação das células. Mas faltava dar o grande passo: levar uma célula adulta, sem fusões, a transformar-se em estaminal.

Seria uma equipa japonesa a dar esse passo, em 2006, ao descobrir que é possível programar células adultas como estaminais embrionárias. Para tal, a equipa de Shinya Yamanaka, da Universidade de Quioto, usou quatro genes (nenhum era o Nanog) e mostrou que são essenciais para a reprogramação celular. Convertidas à força, por assim dizer, ficaram conhecidas como “células estaminais induzidas”. A equipa de Yamanaka mostrou que tal é possível fazendo nascer ratinhos criados com células adultas da pele.

No entanto, o que se passava durante essa conversão manteve-se às escuras, até agora. “A biologia desse processo era uma caixa negra. Os quatro genes são importantes para iniciar o processo que leva à geração das células estaminais induzidas, mas o que acontecia era um ponto de interrogação”, diz José Silva.

O biólogo suspeitava que o Nanog desempenharia um papel importante, talvez fosse até o protagonista. Foi ver se era mesmo assim.

Maestro de vários genes

Descobriu duas coisas, que publica agora na “Cell”. Primeiro, o Nanog é absolutamente necessário para reprogramar as células adultas em células estaminais induzidas, num pratinho de laboratório. Segundo, no próprio embrião, o Nanog é necessário para o seu desenvolvimento normal. Sem o gene, o embrião não consegue formar células estaminais, de onde surgirá todo o organismo, pelo que é inviável. As células do embrião ficam retidas num estádio intermédio, sem chegarem a estaminais.

O artigo de José Silva recentra a descoberta de Yamanaka, também entre os autores deste trabalho. Assim, os quatro genes parecem iniciar o processo de proliferação de células no embrião, ainda antes de aparecerem as estaminais (ao fim de cinco a seis dias de desenvolvimento do embrião humano). Só depois de entrarem em acção é que o Nanog surge em cena, como um maestro que conduz uma orquestra. Mas sem outros genes, a transição das células (tanto do embrião como das adultas) para estaminais não é possível.

“É o Nanog que faz com que as células pré-estaminais do embrião se tornem estaminais. Mas para exercer a sua função, o Nanog precisa de outros genes”, frisa José Silva.

No trabalho dos japoneses, além dos quatro genes, o Nanog entrou em acção sem que a equipa o soubesse. Se tivesse bloqueado a sua actividade, não se teria conseguido criar ratinhos a partir de células adultas. Os ratinhos que José Silva criou durante as suas experiências provam como o Nanog é essencial.

quarta-feira, 19 de agosto de 2009

terça-feira, 18 de agosto de 2009

Descoberto elemento crucial para formação de vida num cometa

Descoberto elemento crucial para formação de vida num cometa
Ontem

Cientistas da NASA descobriram glicina, um elemento fundamental para a formação de vida, em amostras do cometa Wild 2, trazidos para a Terra pela sonda Stardust, informou hoje, terça-feira, a agência espacial norte-americana.

A glicina é um aminoácido usado pelos organismos vivos para produzir proteínas e esta é a primeira vez que se encontra num cometa", afirmou Jamie Elsila, do Centro de Voos Espaciais da NASA.

"A nossa descoberta apoia a teoria de que alguns ingredientes da vida surgiram no espaço e chegaram à Terra através do impacto de meteoritos e cometas", refere um comunicado do Laboratório de Propulsão por Jacto (JLP) da NASA.

Carl Pilcher, director do Instituto de Astrobiologia da agência espacial, considera que a descoberta também confirma a hipótese de que os blocos básicos da vida abundam no espaço e de que a vida no Universo é mais comum do que se crê.

Os resultados da investigação foram apresentados numa reunião da Sociedade Química dos Estados Unidos realizada em Washington, no passado fim-de-semana, e serão publicados proximamente na revista Meteorites and Planetary Science, segundo o JPL.

A sonda Stardust passou através de uma densa nuvem e de gases que rodeavam o núcleo de gelo do Wild 2, em Janeiro de 2004.

O engenho espacial continha uma malha com uma substância absorvente que capturou esses pós e gases, que se desprendeu da sonda numa cápsula que regressou à Terra em Janeiro de 2006.

As análises revelaram imediatamente a presença de glicina nas amostras, mas como esse aminoácido existe também na vida terrestre, pensou-se inicialmente que a malha estaria contaminada.

No entanto, novas investigações em que foi usado o método de análise isotópica excluíram essa possibilidade.

A descoberta de aminoácidos nas amostras do cometa é assombrosa e profunda", descreveu Donald Brownlee, professor da Universidade de Seattle (Washington) e investigador principal do projecto.

JN

Gripe A

Um novo método de diagnóstico desenvolvido por investigadores brasileiros da Universidade Federal de Pernambuco detecta o vírus da nova gripe (H1N1) no tempo máximo de cinco minutos e poderá ser utilizado em larga escala a baixo custo.

"É uma técnica usada para fazer diagnóstico totalmente diferente das técnicas usuais", disse à Lusa o físico Celso Pinto de Melo, que lidera a investigação em Pernambuco.

"Apesar de uma grande sofisticação, esse procedimento demora de três a cinco minutos. É um teste rápido e barato. É possível aplicá-lo e dar a resposta ao paciente se ele está ou não infectado, adiantou.

Ainda em fase de testes de laboratório, o cientista acredita que este método democratizaria o diagnóstico e causaria um "impacto muito grande".

Apenas quatro laboratórios estão autorizados no Brasil a fazer os testes de diagnóstico da H1N1: o Adolfo Lutz em São Paulo, a Fiocruz no Rio de Janeiro, o Evandro Chagas no Pará e os laboratórios centrais Lacens do Paraná e Rio Grande do Sul.

No caso de pacientes do estado de Pernambuco, os exames são levados para o Pará e levam mais de dez dias para terem a confirmação do resultado.

"O tempo de dez dias é apenas útil para dados epidemiológicos. Não há muito a fazer: ou o paciente já foi medicado com tamiflu e melhorou ou evoluiu para óbito", argumentou.

Pinto de Melo explicou que a nova técnica consiste num trabalho com polímeros condutores com nanopartículas metálicas que apresentam intensa fluorescência.

A investigação teve início há três anos e meio, quando a equipa de cientistas viu a possibilidade de usar este método para algum tipo de diagnóstico.

"Vimos que, graças à enorme luminescência de material, poderiam ser feitos testes com fragmentos com vírus ou bactérias em pequenas concentrações e desde há dois anos que estamos a trabalhar com o diagnóstico da dengue e o HPV (papiloma vírus humano). E os testes foram muito positivos", destacou.

O grau de fiabilidade para o diagnóstico do HPV aproxima-se dos 100 por cento e da dengue supera os 70 por cento.

O teste consiste em recolher o material genético do paciente (secreção nasal ou sangue) e, numa lâmina, juntar a uma substância de composto metálico fluorescente. Para confirmar a doença, a lâmina fica a brilhar em contacto com o fragmento de RNA que transmite a carga genética do vírus.

"Se o paciente é suspeito de ter a doença, a lâmina fica brilhante e o teste é positivo", destacou, acrescentando: "Queremos fazer para o H1N1 o que já está a ser feito com a dengue e o HPV".

O laboratório da instituição já está em contacto com as autoridades públicas de Pernambuco para articular acções com vista a utilizar este método. Melo garantiu que é possível que, a partir da próxima semana, esta técnica já possa ser utilizada.

Mas, para ser implementado a nível nacional é necessário o cumprimento de uma série de exigências e protocolos de segurança do Ministério da Saúde e da Agência Nacional de Vigilância Sanitária (Anvisa).

Se os testes provarem fiabilidade, admitiu o investigador, o método será usado para uma larga gama de doenças como a leishmaniose e a hepatite. A possibilidade de salvar vidas também é maior, reconheceu.

Celso Pinto de Melo considerou viável implantar este sistema a nível nacional, até o final do ano, caso a Anvisa e o Ministério de Saúde manifestem interesse.

A grande vantagem seria a rapidez e a facilidade do diagnóstico que não ficaria restrito aos quatro laboratórios.

"Poderia ser feito em postos de saúde e hospitais com um preço de custo de dose a 75 centavos de real" (pouco mais de 28 cêntimos do euro), concluiu.

segunda-feira, 17 de agosto de 2009

domingo, 16 de agosto de 2009

Vaults


June 2009 Molecule of the Month by David Goodsell Previous Features
doi: 10.2210/rcsb_pdb/mom_2009_6
Vaults

Our cells are filled with compartments, each performing a specific function. Some of these compartments, such as mitochondria and lysozomes, are very large and enclose many different molecular machines. Other intracellular compartments are smaller, such as the transport vesicles that shuttle proteins from site to site inside the cell. Most of these compartments, including mitochondria, lysozomes and transport vesicles, are surrounded by membranes. However, in special cases, cells build smaller compartments surrounded by a protein shell. In our own cells, vaults are a spectacular example of these protein-enclosed compartments.
Symmetrical Shells

Vaults are composed of many copies of the major vault protein, which assembles to form a hollow football-shaped shell. The one shown here is from rat liver cells (PDB entries 2zuo, 2zv4, and 2zv5) and contains 78 copies of the protein. Inside cells, the vault also encloses a few other molecules, which were not seen in the crystal structure because they don't have a symmetrical structure inside the vault. These molecules include several small RNA molecules, a protein that binds to RNA, and an enzyme that adds nucleotides to proteins.
Mystery of the Vault

Vaults still pose great mysteries. Researchers have been struggling to find out what they do. They are found in many types of cells (each of our own cells contain about 100,000 of them) but some organisms, such as fruit flies and yeast cells, don't have them at all. They are often found in the cytoplasm, where they are transported rapidly from site to site. But, they are also found occasionally in the nucleus, and even more interestingly, they have been found in nuclear pores. These findings, along with lots of other observations, suggest that vaults may be used for transport. Definitive proof, however, still remains to be discovered.

http://www.rcsb.org/pdb/home/home.do

sábado, 8 de agosto de 2009

Raul Solnado - é da maternidade??

Raul Solnado.

Adeus Raul.

segunda-feira, 3 de agosto de 2009

Ser astronauta

Rui Curado Silva
11:56 Quarta-feira, 3 de Jun de 2009

Samantha Cristoforetti (Itália), Alexander Gerst (Alemanha), Andreas Mogensen (Dinamarca), Luca Parmitano (Itália), Timothy Peake (Grã-Bretanha) e Thomas Pesquet (França) são os seis novos astronautas europeus revelados pela ESA no passado 25 de Maio. O processo de selecção que durou cerca de um ano, compreendeu uma série de rigorosos testes aos conhecimentos técnicos e científicos dos candidatos, testes psicológicos, análises médicas e testes físicos. A primeira triagem começou por uma análise médica a vários parâmetros físicos dos candidatos a astronauta: análises ao sangue, ritmo cardíaco, visão, etc. Após estas análises a ESA deu como aptos 8413 candidatos de toda a Europa !

Os concursos para astronautas são muito raros. Este foi o primeiro concurso realizado pela Agência desde a adesão de Portugal à ESA, em Novembro de 2000. No entanto, apesar de ter sido a primeira oportunidade de candidatos de nacionalidade portuguesa poderem integrar o restrito corpo de astronautas da ESA, fomos 210 a passar as análises médicas, o que constitui um bom resultado para um país da nossa dimensão. Infelizmente, a partir desta fase existe um grande abismo entre os países que investem a sério nesta área e os que nada investem, que é o nosso caso. Há muita coisa a fazer para podermos aspirar a ter um dia um astronauta. Por exemplo em "Carnet de bord d'un Cosmonaute ", o cosmonauta francês Jean-Pierre Haigneré que participou em duas missões espaciais a bordo da estacção espacial Mir transmite uma boa ideia do extremo rigor do processo de selecção. Nesta obra o cosmonauta agradece várias vezes às equipas de médicos, psicólogos e preparadores físicos do CNES (Centre National d'Etudes Spaciales) que ele considera determinantes para a sua selecção. Em Portugal este apoio não existe, pelo que será muito improvável que possamos ter um astronauta se nada for feito para prepararmos os nossos candidatos.

Aqui ficam alguns conselhos para os que desejarem passear no espaço um dia envergando um fato de astronauta da ESA:

- Não fumar.Os fumadores não passam nas análises médicas;

- Aprender várias línguas para além do inglês, de preferência o russo e o francês;

- Estar em forma. Um bom ritmo cardíaco é um ponto forte. A musculação pode ser desvantajosa. Ser muito alto é também uma desvantagem. Problemas de visão pouco significativos não eliminam os candidatos;

- Praticar vários desportos e actividades físicas, em especial a corrida, a natação, o mergulho e alguns desportos radicais como o pára-quedismo, a escalada ou a espeleologia;

- Experiência em pilotagem de aviões. Não é obrigatório, mas é uma grande vantagem;

- Ter uma extraordinária capacidade de relacionamento com os colegas. Muito importante para as missões tripuladas de longa duração;

- Idade aconselhada entre os 27 e os 37;

- Obter diplomas em ciências exactas e em ciências da vida (ex: licenciatura em física e mestrado em psicologia);

- Carreira científica com trabalhos publicados em revistas da especialidade com arbitragem pelos pares;

- Destreza no manuseamento de dispositivos mecânicos, eléctricos e sensores.

Consultar aqui as biografias dos novos astronautas da ESA

Júpiter, o anjo da guarda

Dia 19 de Julho, quando um cometa atingiu Júpiter deixando sobre ele uma gigantesca marca, os astrónomos congratularam-se pela rara oportunidade de observar uma colisão de astros no sistema solar. Quinze anos atrás, tinham observado o impacto do cometa Shoemaker-Levy sobre o mesmo planeta. Ao contrário deste, que tinha sido previsto com antecedência, e sobre o qual telescópios de todo o mundo na altura se debruçaram, o impacto de 19 de Julho foi totalmente inesperado.

Quem pela primeira vez notou uma mancha nova sobre o planeta foi um astrónomo amador australiano, de nome Anthony Wesley. O achado foi confirmado pelos maiores observatórios do mundo, que estudaram a composição dos gases e partículas libertados, semelhantes aos que tinham sido ejectados pelo cometa Shoemaker-Levy. Com grande probabilidade, o objecto que caiu sobre Júpiter era um cometa.

Houve quem estranhasse que tivesse sido um amador a descobrir a rara ocorrência. Mas isso acontece frequentemente com eventos imprevistos. Os profissionais têm programas de estudo definidos e não vasculham os céus ao acaso, antes aproveitam os raros e dispendiosos momentos de acesso aos observatórios para efectuar estudos precisos e há muito programados. Os amadores têm, em geral, mais tempo para observar os astros sem propósito definido. Numa noite podem fotografar a Lua, observar a grande nebulosa de Orionte e deter-se ainda sobre Júpiter. Por essas razões, os grandes caçadores de cometas, que descobrem anualmente muitos desses astros, são quase sempre amadores.

Os cometas que inesperadamente aparecem nos céus são originados na chamada nuvem de Oort, que rodeia o nosso sistema planetário. É uma nuvem gigantesca e muito rarefeita, de objectos que remanescem da nébula primordial que originou o sistema solar. Entre as poeiras e objectos que aí existem há pedaços de gelo sujo que, ocasionalmente, por efeito da passagem por perto de uma estrela ou por outra perturbação gravítica, abandonam essa região e aproximam-se do Sol. Nessa altura, esses objectos começam a derreter-se e revelam-se como cometas, com cabeleiras e extensas caudas. Terá sido um desses cometas imprevistos que se abateu sobre Júpiter em 19 de Julho.

Ao registar este impacto, os astrónomos têm ainda um outro prazer. Confirmam uma ocorrência que, segundo todos os cálculos, nos tem protegido repetidamente de impactos cósmicos devastadores. Confirmam que Júpiter, assim como Saturno, tem actuado como barreira que impede muitos cometas de atingirem a Terra.

A vida sobre o nosso planeta tem sido permitida pelo facto de os grandes impactos cósmicos terem sido muito raros. Acredita-se que há cerca de 65 milhões de anos uma colisão precipitou o fim da era dos dinossáurios. Há 40 milhões de anos registou-se outra extinção de vida generalizada, possivelmente também devida à queda de cometas sobre a Terra. Mas os períodos tranquilos têm sido muito longos.

Esta semana ficou a saber-se mais sobre a nuvem de Oort devido a um trabalho de dois cientistas da Universidade de Washington publicado online pela "Science". De acordo com os seus cálculos, a frequência com que cometas caem sobre o nosso planeta é muito menor do que se pensava. Os cálculos apontam para órbitas de colisão mais precisas do que antes se imaginava, mas continuam a mostrar que os planetas gigantes são uma barreira protectora do nosso planeta. Como diriam os Romanos, o poderoso Júpiter protege-nos.


Nuno Crato

sexta-feira, 31 de julho de 2009

Rattray Marsh "Creek Circle"

terça-feira, 21 de julho de 2009