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Category Archives: Physics
Meeting with Aram Harrow, and my Lecture on Why Quantum Computers Cannot Work.
Last Friday, I gave a lecture at the quantum information seminar at MIT entitled “Why quantum computers cannot work and how.” It was a nice event with lovely participation during the talk, and a continued discussion after it. Many very … Continue reading
Symplectic Geometry, Quantization, and Quantum Noise
Over the last two meetings of our HU quantum computation seminar we heard two talks about symplectic geometry and its relations to quantum mechanics and quantum noise. Yael Karshon: Manifolds, symplectic manifolds, Newtonian mechanics, quantization, and the non squeezing theorem. … Continue reading
The Quantum FaultTolerance Debate Updates
In a couple of days, we will resume the debate between Aram Harrow and me regarding the possibility of universal quantum computers and quantum fault tolerance. The debate takes place over GLL (Godel’s Lost Letter and P=NP) blog. The Debate Where were … Continue reading
A Discussion and a Debate
Heavier than air flight of the 21 century? The very first post on this blog entitled “Combinatorics, Mathematics, Academics, Polemics, …” asked the question “Are mathematical debates possible?” We also had posts devoted to debates and to controversies. A few days ago, … Continue reading
Aaronson and Arkhipov’s Result on Hierarchy Collapse
Scott Aaronson gave a thoughtprovoking lecture in our Theory seminar three weeks ago. (Actually, this was eleven months ago.) The slides are here . The lecture discussed two results regarding the computational power of quantum computers. One result from this paper gives an … Continue reading
Octonions to the Rescue
Xavier Dahan and JeanPierre Tillich’s Octonionbased Ramanujan Graphs with High Girth. Update (February 2012): Non associative computations can be trickier than we expect. Unfortunately, the paper by Dahan and Tillich turned out to be incorrect. Update: There is more to … Continue reading
Benoît’s Fractals
Mandelbrot set Benoît Mandelbrot passed away a few dayes ago on October 14, 2010. Since 1987, Mandelbrot was a member of the Yale’s mathematics department. This chapterette from my book “Gina says: Adventures in the Blogosphere String War” about fractals is brought here on this … Continue reading
Posted in Geometry, Obituary, Physics, Probability
6 Comments
Itamar Pitowsky: Probability in Physics, Where does it Come From?
I came across a videotaped lecture by Itamar Pitowsky given at PITP some years ago on the question of probability in physics that we discussed in two earlier posts on randomness in nature (I, II). There are links below to … Continue reading
Posted in Obituary, Philosophy, Physics, Probability
Tagged Itamar Pitowsky, Philosophy of science, Physics, Probability
1 Comment
Randomness in Nature II
In a previous post we presented a MO question by Liza about randomness: What is the explanation of the apparent randomness of highlevel phenomena in nature? 1. Is it accepted that these phenomena are not really random, meaning that given enough … Continue reading
Posted in Philosophy, Physics, Probability
Tagged foundation of probability, Philosophy, Physics, Randomness
16 Comments
When Noise Accumulates
I wrote a short paper entitled “when noise accumulates” that contains the main conceptual points (described rather formally) of my work regarding noisy quantum computers. Here is the paper. (Update: Here is a new version, Dec 2010.) The new exciting innovation in computer … Continue reading