Redes Sociais: a era da partilha digital

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The People Still Waiting

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Fiction · technology · Portugal, 2033 The People Still Waiting Portugal, 2033. Across nineteen countries, an emergency network reports that recovery is almost complete. A mother’s phone tells her otherwise. This is fiction. Its people, organisations and future events are invented. The closing note separates the evidence discussed in this series from the catastrophe imagined here.
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A Field Guide to Breaking In

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Security mechanisms · Field guide A Field Guide to Breaking In How data becomes an instruction, a credential becomes authority, and a small failure becomes a larger breach. A server receives a request. A database looks up a customer. A browser displays a comment. A developer installs a dependency. Nothing in that list sounds like an intrusion. Each action is ordinary work. The danger begins when ordinary work carries something across a boundary it was supposed to respect: a value becomes part of a command; a packet changes where a processor goes next; a stolen cookie stands in for a person; a trusted update delivers hostile code. “The attacker gained access” hides these differences. Access to what? With whose permissions? Can they read records, change records, make network requests, execute JavaScript in a browser, or run a program on a server? Those are different achievements, and the distance between them matters. This guide follows eight attack families through those transiti...
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Penrose: When the Future Points Inward

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A black hole is usually imagined as a place: a dark region somewhere in space, surrounded by a boundary beyond which nothing can escape. But one of the most unsettling ways to understand it is through time. In the simplest description of a black hole, crossing the event horizon changes what your future can contain. Outside, you may approach the hole or move away. Inside, every possible future leads deeper inward. Escaping would require more than a powerful engine. It would require a direction that the geometry no longer permits. Roger Penrose’s great achievement was to show that gravitational collapse could produce a breakdown of spacetime without the perfect symmetry on which earlier models depended. His paper, published on 18 January 1965, helped transform black holes from a disturbing mathematical possibility into a serious physical prediction. Penrose’s original paper . To appreciate why this mattered, we have to return to a time when physicists had good reasons to distrust what th...
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Entre a pedrinha e o caminho

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Ao longo da minha vida, houve sempre uma tensão entre a contemplação e a ação. Enquanto me demorava numa pergunta, havia alguma coisa por fazer. Enquanto fazia, havia alguma coisa que gostaria de compreender melhor. Ambas reclamavam tempo, e o tempo que dava a uma já não estava disponível para a outra. A minha curiosidade levou-me a mudar frequentemente de objeto de estudo. Biologia, física, gestão, história, engenharia: cada domínio abria um mundo, com as suas perguntas, os seus instrumentos e as suas maneiras de olhar. Entrar num deles era descobrir quanto havia ainda para aprender. Entretanto, outro começava a chamar por mim. Reconheço-me nesta passagem de Um, ninguém e cem mil , de Luigi Pirandello: Não é que, atenção, a minha vontade se opusesse a seguir as vias para as quais o meu pai me encaminhava. Seguia-as todas. Mas, avançar por elas, não avançava. Detinha-me a cada p...
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