| Friday, December 21st, 2012 |
| 12:01 am |
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| Friday, February 5th, 2010 |
| 11:36 pm |
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| Monday, February 1st, 2010 |
| 6:10 am |
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| Thursday, January 28th, 2010 |
| 2:41 pm |
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| Sunday, January 24th, 2010 |
| 7:06 pm |
By Ilya Bernstein DownstreamDownstream from all this spilled blood Will they find new ways to love the past? Will they conclude just as we conclude That the past is worth a backward glance When it overflows like a bleeding wound? Downstream from this fine-grained dust That flies in our faces and in our eyes Will they recall as we recall All that fire has refused to burn? Will they find new ways to love the past? continue reading |
| Monday, December 28th, 2009 |
| 4:38 pm |
Ray Solomonoff; lattices vs. categories; Witten and path integrals
Ray Solomonoff died 3 weeks ago in Cambridge. Among other things, he was the first person who discovered what we now call Kolmogorov complexity. Очень необычный человек, даже визуально, он был весь светящийся, в полном соответствии со своим именем, как на фотографии на своем сайте. ( via )Lattices vs. categories. Ретах опубликовал короткие воспоминания об И.М.Гельфанде, которые заканчиваются описанием того, как Гельфанд читал доклад о теории решёток на заседании пямяти Бирхгофа в Гарварде во время знаменитой первоапрельской метели в 1997-ом году. Ретах говорит, что после доклада Гельфанд сказал ему: "А знаете почему я согласился выступить? Бирхгоф тут не при чем, надо искать замену теории категорий, слишком она жесткая. Может быть, решетки подойдут". ( Read more... )Witten and Feynman integrals. Интересное обсуждение с центральной идеей, что деятельность Witten'а основывается не на физической интуиции, а на интуиции фейнмановских интегралов (если это так, то это проливает довольно много света на то, что там происходит): ( Read more... )I'll be happy to translate Russian parts into English upon request (in comments). |
| Tuesday, December 1st, 2009 |
| 4:06 pm |
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| Friday, November 20th, 2009 |
| 7:54 pm |
Firefox add-ons: WebPredict, TooManyTabs
I'd like to review a couple of Firefox add-ons I am using every day: our own WebPredict, and TooManyTabs. Both are intended for people who browse a lot. WebPredict allows user to rate some Web pages, and based on those ratings predicts the quality of other Web pages. We made a beta-release of this add-on recently, and this beta-release prompted me to write this review. ( Read more... )TooManyTabs allows user who has too many tabs to save tabs, so that they don't eat memory and don't slow down the browser. ( Read more... ) |
| Friday, November 6th, 2009 |
| 11:18 pm |
t
The strangest impression from my October trip to Moscow was mainstreaming of Pelevin. The ads for his new novel, "t", were on subway escalators, the book itself was featured prominently in airport book kiosks. ( Read more... )Since I started to talk about "t", I want to write a bit about treatment of time in the "Quantum Gravity" book I mentioned in the previous post. The most interesting is his "Thermal time hypothesis", a conjecture that time is on its fundamental level induced by the thermodynamic considerations. ( Read more... ) |
| Monday, October 12th, 2009 |
| 12:01 am |
Carlo Rovelli, "Quantum Gravity"
'(Newtonian) space was the "sensorium" of God, the World as perceived by God.' ( online reference )This is the only textbook on loop quantum gravity and it can actually be partially understood by non-physicists. For example, in mid-90s I was trying to imagine how one could have discrete space at the quantum scale, but so that it still appears continuous at the macroscopic level. All variants I could come up with were pretty ugly. This book contains a very neat construction of that. ( Read more... ) |
| Monday, September 21st, 2009 |
| 10:09 pm |
More on perception of conscious will
The perception of conscious will is an inference. Daniel Wegner demonstrated a while ago, that it is easy to create experimental setups, where the subject has illusion of freely causing events, which are completely independent of his actions or intentions. cognitivedaily is reporting on an experiment, which sheds some extra light on the inference of conscious will: http://scienceblogs.com/cognitivedaily/2009/09/free_choice_may_not_be_as_free.phpHere, the subject presses the button, and the beep sounds as a result, but a random delay is added between pressing the button and the resulting beep sound. Then the subject is asked to pinpoint the moment of time, when the decision to press the button was made. It turns out that subjects on average estimate that moment as approximately 130 milliseconds before the beep sound (and that the estimate depends very weekly on the actual time when the subject pressed the button). ( a bit of discussion ) |
| Friday, September 4th, 2009 |
| 6:08 pm |
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| Thursday, August 27th, 2009 |
| 12:06 am |
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| Wednesday, August 5th, 2009 |
| 11:30 am |
Duality between metric and logical viewpoints
The metric viewpoint: how far two objects are from each other. The logical viewpoint: to what degree two objects overlap. Fuzzy mathematics is traditionally done from the logical viewpoint, so the first step in introducing fuzzy metrics is often the transformation f(x,y) = exp(-d(x,y)).( Read more... )However, this seems to be a rather superficial duality: basically two equivalent ways to write the same things using different notation. The question is whether there is also a natural deeper duality here (of a contravariant nature, where function arrows would reverse direction when one switches between these two viewpoints). |
| Tuesday, July 28th, 2009 |
| 7:39 pm |
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| Thursday, July 9th, 2009 |
| 4:47 pm |
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| Friday, May 29th, 2009 |
| 6:17 pm |
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| Wednesday, May 27th, 2009 |
| 4:58 pm |
Anti-angiogenesis drugs :-(
I still remember time when great hopes in anti-cancer therapy were raised in connection with drugs blocking formation of new blood vessels. And (as it is often the case) the results in mice were great.Then the hopes dimmed, and the controversial approval of Avastin by FDA in 2008 against the recommendation of its advisory panel underscored the fact that the advances were quite marginal (the panel objected because for that class of tumors Avastin only slowed tumor growth but failed to extend survival): http://en.wikipedia.org/wiki/BevacizumabHere is an article which seems to shed some light on why the "magic bullet" does not quite work: http://scienceblog.cancerresearchuk.org/2009/03/22/anti-angiogenesis-drugs/( summary ) |
| Tuesday, May 26th, 2009 |
| 7:56 pm |
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| Tuesday, May 5th, 2009 |
| 11:56 am |
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