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Προβολή αναρτήσεων από Δεκέμβριος, 2013

On the Computing Spacetime

Fotini Markopoulou has published a paper entitled The Computing Spacetime . The first sentence of this paper is: That the Universe can be thought of as a giant computation is a straightforward corollary of the existence of a universal Turing machine . This is a very bold statement, to say the least. We have absolutely no idea what are the (ultimate) laws of the universe and yet we can immediately prove that it is a gigantic computer! Now let's see the proof: The laws of physics allow for a machine, the universal Turing machine, such that its possible motions correspond to all possible motions of all possible physical objects. That is, a universal quantum computer can simulate every physical entity and its behavior. This means that physics, the study of all possible physical systems, is isomorphic to the study of all programs that could run on a universal quantum computer. We can think of our universe as software running on a universal computer. First let me remark that Markopo

Fairytale Physics

Jim Baggot in his recent book that is entitled Farewell to Reality: How Fairytale Physics Betrays the Search for Scientific Truth   advocates the idea that modern physics is going in the wrong direction. In particular, he critically examines superstring theory and concludes that this theory cannot explain the existence of many things we know they exist! Similar ideas have been presented in Peter Woit's Not Even Wrong: The Failure of String Theory and the Continuing Challenge to Unify the Laws of Physics . Recently, the British newspaper The Guardian has published as debate between Baggot and string theorist Mike Duff. The later replied to Baggot's remark that "the positron was discovered in cosmic ray experiments just a couple of years after Dirac had agreed that this was what his theory predicted" as follows: Dirac did not assume the positron; he discovered it to be a consequence of an equation that described the well-established electron. Similarly, string