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Showing posts from September, 2014

O Conceito Tempo

Ao abrir um frasco de perfume, liberta o seu aroma no espaço envolvente. A transição do odor líquido para o ar perfumado é irreversível: as moléculas disseminadas do perfume não regressam espontaneamente ao frasco para reconstituir o líquido. A evaporação e a difusão do perfume é um exemplo da assimetria entre passado e futuro . No entanto, o perfume evapora-se e dispersa-se sob o impacto de biliões de bombardeamentos moleculares: as moléculas de ar atingem as moléculas de perfume aleatoriamente até que ambas fiquem inextricavelmente misturadas. Duas moléculas aproximam-se, chocam e afastam-se; e inversamente, aproximam-se, chocam e afastam-se. Ou seja, toda a colisão molecular individual é reversível e o Tempo simétrico.  Não existe qualquer inconsistência entre a simetria a nível molecular e a assimetria a nível macroscópio, são apenas dois níveis distintos de descrição de Tempo. Suspeita-se portanto que o Tempo de modo nenhum flui; tudo se passa simplesmente na mente. [God and the


The greatest shortcoming of the human race  is our inability to understand the exponential function. -   Albert Bartlett Maxwell recognized that the foundations of the physical world are imperceptible to our senses. All we know about them, possibly all we can ever know, are their mathematical relationships to things we can feel and touch. He stressed Kant's proposition that all human knowledge is of relations rather than of things . Algoristas vs Abacistas (1504)

New Words

When writing up his researches on electrochemistry, Faraday was faced with a difficulty: he was trying to describe physical processes that nobody had described, or perhaps even though of, before. As his ideas grew, language itself became part of his thinking. He sought precision and faced a particular problem with words that were in common use but had misleading theoretical connotations; the prime example was current, which implied that electricity was a fluid. New words were needed not for their own sake but because existing ones carried theoretical baggage that could constrain one’s thinking. [Faraday, Maxwell, and the Electromagnetic Field: How Two Men Revolutionized Physics (2014), Nancy Forbes, Basil Mahon]

Less is More

A population needs to be small if it is to incorporate any substantial innovation, genetic or cultural; large and dense populations simply have too much genetic inertia to be nudged consistently in any direction. Our own species, the Homo sapiens, was born out of such an event 200,000 years ago, when climate change repeatedly led to fragmentation of hominin populations, creating small groups in which genetic and cultural novelties were rapidly cemented, accelerating speciation. About 100,00 years later an African isolate of our species acquired the ability to use symbols; it was almost certainly this unique symbolic cognition that made it possible to eliminate all hominin competition in little time. -