Archive for solar system
compression artifacts
Posted in Books, Kids, Travel with tags because it's Friday, comics, solar system, space, space exploration, video compresion, Voyager, xkcd on January 22, 2021 by xi'ansize matters
Posted in Statistics with tags astronomy, black holes, M87, scale, solar system, xkcd on May 27, 2019 by xi'anbye, Cassini!
Posted in Kids, pictures, Travel, University life with tags Cassini, NASA, Saturn, solar system, space probe on September 15, 2017 by xi'anit’s only an eclipse, for heavens sake!
Posted in Statistics with tags astronomy, eclipse, rationalism, religions, secularism, solar system on September 2, 2017 by xi'anI have been amazed and utterly baffled by the number of commentaries about the solar eclipse of last week that involved metaphysics and religious aspects. An eclipse is a most natural [and beautiful] phenomenon of one astronomical object getting in front of another one in a very predictable way: no reason to invoke deities or spirits in the process!
Bayesian program synthesis
Posted in Books, pictures, Statistics, University life with tags David Blei, deep learning, Gamelon, machine learning, neural network, principles of uncertainty, probabilistic programming, Science & Vie, solar system on April 7, 2017 by xi'anLast week, I—along with Jean-Michel Marin—got an email from a journalist working for Science & Vie, a French sciences journal that published a few years ago a special issue on Bayes’ theorem. (With the insane title of “the formula that deciphers the World!”) The reason for this call was the preparation of a paper on Gamalon, a new AI company that relies on (Bayesian) probabilistic programming to devise predictive tools. And spent an hour skyping with him about Bayesian inference, probabilistic programming and machine-learning, at the general level since we had not heard previously of this company or of its central tool.
“the Gamalon BPS system learns from only a few examples, not millions. It can learn using a tablet processor, not hundreds of servers. It learns right away while we play with it, not over weeks or months. And it learns from just one person, not from thousands.”
Gamalon claims to do much better than deep learning at those tasks. Not that I have reasons to doubt that claim, quite the opposite, an obvious reason being that incorporating rules and probabilistic models in the predictor is going to help if these rule and models are even moderately realistic, another major one being that handling uncertainty and learning by Bayesian tools is usually a good idea (!), and yet another significant one being that David Blei is a member of their advisory committee. But it is hard to get a feeling for such claims when the only element in the open is the use of probabilistic programming, which is an advanced and efficient manner of conducting model building and updating and handling (posterior) distributions as objects, but which does not enjoy higher predictives abilities by default. Unless I live with a restricted definition of what probabilistic programming stands for! In any case, the video provided by Gamalon and the presentation given by its CEO do not help in my understanding of the principles behind this massive gain in efficiency. Which makes sense given that the company would not want to give up their edge on the competition.
Incidentally, the video in this presentation comparing the predictive abilities of the four major astronomical explanations of the solar system is great. If not particularly connected with the difference between deep learning and Bayesian probabilistic programming.