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Thijs Versloot

Time 'Emerges' from #Quantum Entanglement #arXiv - 1 views

medium.com/...d5d3dc850933

science quantum relativity

shared by Thijs Versloot on 23 Oct 13 - No Cached
  • Thijs Versloot on 23 Oct 13
     
    Time is an emergent phenomenon that is a side effect of quantum entanglement, say physicists. And they have the first exprimental results to prove it
  • ...5 more comments...
  • johannessimon81 on 23 Oct 13
     
    I always feel like people make too big a deal out of entanglement. In my opinion it is just a combination of a conserved quantity and an initial lack of knowledge. Imagine that I had a machine that always creates one blue and one red ping-pong ball at the same time (|b > and |r > respectively). The machine now puts both balls into identical packages (so I cannot observe them) and one of the packages is sent to Tokio. I did not know which ball was sent to Tokio and which stayed with me - they are in a superposition (|br >+|rb >), meaning that either the blue ball is with me and the red one in Tokio or vice versa - they are entangled. So far no magic has happened. Now I call my friend in Tokio who got the ball: "What color was the ball you received in that package?" He replies: "The ball that I got was blue. Why did you send me ball in the first place?" Now, the fact that he told me makes the superpositon wavefunction collapse (yes, that is what the Copenhagen interpretation would tell us). As a result I know without opening my box that it contains a red ball. But this is really because there is an underlying conservation law and because now I know the other state. I don't see how just looking at the conserved quantity I am in a timeless state outside of the 'universe' - this is just one way of interpreting it. By the way, the wave function for my box with the undetermined ball does not collapse when the other ball is observed by my friend in Tokio. Only when he tells me does the wavefunction collapse - he did not even know that I had a complementary ball. On the other hand if he knew about the way the experiment was conducted then he would have known that I had to have a red ball - the wavefunction collapses as soon as he observed his ball. For him it is determined that my ball must be red. For me however the superposition is intact until he tells me. ;-)
  • Luzi Bergamin on 24 Oct 13
     
    Sorry, Johannes, you just develop a simple hidden-parameters theory and it's experimentally proven that these don't work. Entangeled states are neither the blue nor the red ball they are really bluered (or redblue) till the point the measurement is done.
  • Luzi Bergamin on 24 Oct 13
     
    Hm, to me this looks like a bad joke... The "emergent time" concept used is still the old proposal by Page and Whotters where time emerges from something fundamentally unobservable (the wave function of the Universe). That's as good as claiming that time emerges from God. If I understand correctly, the paper now deals with the situation where a finite system is taken as "Mini-Universe" and the experimentalist in the lab can play "God of the Mini-Universe". This works, of course, but it doesn't really tell us anything about emergent time, does it?
  • johannessimon81 on 24 Oct 13
     
    Actually, it has not been proven conclusively that hidden variable theories don' work - although this is the opinion of most physicists these days. But a non-local hidden variable would still be allowed - I don't see why that could not be equivalent to a conserved quantity within the system. As far as the two balls go it is fine to say they are undetermined instead of saying they are in bluered or redblue state - for all intents and purposes it does not affect us (because if it would the wavefunction would have collapsed) so we can't say anything about it in the first place.
  • Luzi Bergamin on 24 Oct 13
     
    Non-local hidden variables may work, but in my opinion they don't add anything to the picture. The (at least to non-physicists) contraintuitive fact that there cannot be a variable that determines ab initio the color of the ball going to Tokio will remain (in your example this may not even be true since the example is too simple...).
  • johannessimon81 on 24 Oct 13
     
    I guess I tentatively agree with you on both points. In the end there might anyway be surprisingly little overlap between the way that we describe what nature does and HOW it does it... :-D
  • Luzi Bergamin on 24 Oct 13
     
    Congratulations! 100% agree.
Ma Ru

I know at least *some* of you will like it... - 13 views

www.nerdtests.com/ft_nq.php

fun inf phy science

shared by Ma Ru on 29 Mar 10 - Cached
LeopoldS liked it
  • Ma Ru on 29 Mar 10
     
  • ...9 more comments...
  • Luzi Bergamin on 29 Mar 10
     
    Shit!! I only got 79, should have lied better...
  • Ma Ru on 29 Mar 10
     
    My score was obtained with *sincere* answers, don't cheat!
  • pacome delva on 30 Mar 10
     
    ouah, 80...! didn't think i was so nerd...!
  • Ma Ru on 30 Mar 10
     
    Dario, Francesco, we're waiting for your scores... are you afraid of the truth??
  • nikolas smyrlakis on 31 Mar 10
     
    hmm "Low Ranking Nerd. Definitely a nerd but low on the totem pole of nerds." , as of a score of 66
  • LeopoldS on 02 Apr 10
  • Dario Izzo on 02 Apr 10
     
    I am disappointed!!!!! Shame on me.......
  • Francesco Biscani on 02 Apr 10
     
    Sigh
  • LeopoldS on 02 Apr 10
     
    wow!
  • Francesco Biscani on 02 Apr 10
     
    My girlfriend... She must be an archaeological nerd...
  • Ma Ru on 03 Apr 10
     
    Great Scott, Leo! Honest answers?? I was kinda expecting Francesco's score, but this...
Alexander Wittig

SpaceX founder files with government to provide Internet service from space - 0 views

www.washingtonpost.com/...5-a0dc-2b6f404ff5cf_story.html

technology space

shared by Alexander Wittig on 11 Jun 15 - No Cached
LeopoldS liked it
  • Alexander Wittig on 11 Jun 15
     
    Elon Musk is moving forward with space based internet service...
  • ...3 more comments...
  • Alexander Wittig on 11 Jun 15
  • LeopoldS on 11 Jun 15
     
    reading the qz article, it is not clear to me that google dropped out as one of the main investors in SpaceX? did I miss something?
  • jcunha on 12 Jun 15
     
    I attended a presentation by H. Hemmati, formerly at NASA's JPL, now at Facebook working to "connect the unconnected" during a panel session of the Workshop "Shining light on future space optical communications". I gather that they are targeting a combined strategy of HAP (with solar powered planes at 20-25 km), balloons and satellites. The rationale behind is that each solution is best suited for different population density zones, i.e. satellites while expensive (total cost of 100MUSD after Hemmati) are the only way to provide internet in remote zones, while balloons seem to be one inexpensive solution for densely populated areas. Funfact: he mentioned that the main drawback will be some crashes of HAP elements...
  • jcunha on 31 Jul 15
     
    Facebook announced they are ready to test of of their High Altitude Platform element, a drone of the size of a Boeing 737. See the new here http://phys.org/news/2015-07-facebook-ready-giant-drone-internet.html?utm_source=nwletter&utm_medium=email&utm_content=ctgr-item&utm_campaign=daily-nwletter. It seemed interesting for me that they are developing also a reliable optical communication between this element and scattered ground stations.
  • Thijs Versloot on 31 Jul 15
     
    Nice link, that thing is huge and I would love to see a drone that size fly. Also, Facebook's Aerospace Team? :)
Francesco Biscani

Apple's Mistake - 5 views

www.paulgraham.com/apple.html

shared by Francesco Biscani on 16 Jun 10 - Cached
LeopoldS liked it
  • Francesco Biscani on 16 Jun 10
     
    Nice opinion piece.
  • LeopoldS on 16 Jun 10
     
    nice indeed .... especially like: "They make such great stuff, but they're such assholes. Do I really want to support this company? Should Apple care what people like me think? What difference does it make if they alienate a small minority of their users? There are a couple reasons they should care. One is that these users are the people they want as employees. If your company seems evil, the best programmers won't work for you. That hurt Microsoft a lot starting in the 90s. Programmers started to feel sheepish about working there. It seemed like selling out. When people from Microsoft were talking to other programmers and they mentioned where they worked, there were a lot of self-deprecating jokes about having gone over to the dark side. But the real problem for Microsoft wasn't the embarrassment of the people they hired. It was the people they never got. And you know who got them? Google and Apple. If Microsoft was the Empire, they were the Rebel Alliance. And it's largely because they got more of the best people that Google and Apple are doing so much better than Microsoft today. Why are programmers so fussy about their employers' morals? Partly because they can afford to be. The best programmers can work wherever they want. They don't have to work for a company they have qualms about. But the other reason programmers are fussy, I think, is that evil begets stupidity. An organization that wins by exercising power starts to lose the ability to win by doing better work. And it's not fun for a smart person to work in a place where the best ideas aren't the ones that win."
  • Ma Ru on 16 Jun 10
     
    Poor programmers can complain, but they will keep developing applications for iPhone as long as their bosses will tell them to do so... From my experience in mobile software development I assure you it's not the pain of the programmer that dictates what is done, but the customer's demand. Even though like this the quality of applications is somewhat worse than it could be, clients won't complain as they have no reference point. And things will stay as they are: apple censoring the applications, clients paying for stuff that "sometimes just does not work" (it's normal, isn't it??), and programmers complaining, but obediently making iPhone apps...
duncan barker

Challenging Existence of 'Absolute Time' - 3 views

www.21stcenturysciencetech.com/...time.html

phy

shared by duncan barker on 12 Aug 10 - Cached
  • Luzi Bergamin on 12 Aug 10
     
    I doubt that Shnoll is really the first one making such experiments, but perhaps they are more complete than any others done before. Similar things are very popular in the context of Psychology and more exotic fields. If I remember correctly someone ran long experiments with random number generators... Mostly the stories died after a short time, since the experiments are not reproducable. Anyway, why do these guys always have to claim that their work is somehow fundamentally changing our view of physics, notoriously referring to Einstein-Bohr debates and this stuff. That's nonsense! If these effects exist the first explanation is always much simpler. There is somewhere something that influences physics on Earth in a defined way. But this influence depends on the relative position or whatever of the Earth to that whatever-it-is. No problem with absolute time and all that sh...
  • LeopoldS on 12 Aug 10
     
    Two years ago, nearly unnoticed in the West, the Russian biophysicist S.E. Shnoll published a paper in the prominent Russian physics journal Uspekhi Fisicheskikh Nauk ..... ah then ...
  • Luzi Bergamin on 12 Aug 10
     
    You are right, Leo, they are mostly Russians that publish in some unspellable Journals nobody knows.... or then they are supported by Templeton Foundation.
Tobias Seidl

Rules for Biologically Inspired Adaptive Network Design -- Tero et al. 327 (5964): 439 ... - 4 views

www.sciencemag.org/...439

BIO AI robot navigation paper

shared by Tobias Seidl on 22 Jan 10 - Cached
  • Tobias Seidl on 22 Jan 10
     
    Navigation for robtos. That's how we should have done the hybrid controller study.
  • ...3 more comments...
  • LeopoldS on 23 Jan 10
     
    and why didnt we?
  • Tobias Seidl on 25 Jan 10
     
    Because I have no clue about fungi. They are no animals. (Neither they are plants, of which I also don't have a clue.)
  • LeopoldS on 25 Jan 10
     
    so what are they then? ... and don't tell me "fungi" now ..
  • Tobias Seidl on 25 Jan 10
     
    Well, it has always been a long discussion. Fungi are according to the most recent findings definitely no plants. Since they have always been in botanic textbooks, I would assume that they were never considered animals.No fauna, no flora, no stones. Maybe they are extraterrestrials. But that wouldn't solve the questions. Maybe they are just "fungi"?
  • LeopoldS on 25 Jan 10
     
    what about then: "can we use them for space?"
Luís F. Simões

Boeing probes international market for human spacecraft - 1 views

spaceflightnow.com/...10cst100

human spaceflight commercial spaceflight

shared by Luís F. Simões on 11 Feb 11 - No Cached
  • The aerospace powerhouse is designing and testing systems for its CST-100 space capsule, a craft the company says could begin flying astronauts to low Earth orbit by 2015. It will launch on existing rockets to lessen development risk and costs.
  • "The spacecraft that we're designing is rocket-agnostic. It would be possible to sell this like a commercial airplane to countries who perhaps have a launch vehicle who would like to launch it in their own country."
  • Luís F. Simões on 11 Feb 11
     
    ...and hitting the news in the same day: A Rocket Built from U.S. and European Parts "A new rocket that would combine parts from NASA's canceled Ares I rocket as well as the Ariane 5 , a well-proven European satellite launcher, could provide a low-cost option for taking crew and cargo to the space station. The rocket proposal was announced this week by ATK, an aerospace and defense company that manufactures the solid rocket motors for NASA's space shuttles, and Astrium, the European company that makes the Ariane 5. They say the rocket, called Liberty, would be ready for flight by 2015." "Other commercial companies, including Boeing and Orbital Sciences Corporation, are looking to use low-end versions of the Atlas V to carry the capsules they are building. Liberty could carry any capsule at a cost less than that of the Atlas V, according to ATK." Look! Competition! :)
Ma Ru

Dark Matter or Black Hole Propulsion? - 1 views

www.newscientist.com/...s-for-interstellar-travel.html

NRG propulsion star travel space PHY

shared by Ma Ru on 25 Nov 09 - Cached
  • Ma Ru on 25 Nov 09
     
    Anyone out there still doing propulsion stuff? Two more papers just waiting to get busted... http://arxiv.org/abs/0908.1429v1 http://arxiv.org/abs/0908.1803
  • ...5 more comments...
  • Luzi Bergamin on 26 Nov 09
     
    What an awful bunch of complete nonsense!!! But I don't think anybody wants to hear MY opinion on this...
  • pacome delva on 26 Nov 09
     
    wow, is this serious at all...!?
  • Luzi Bergamin on 26 Nov 09
     
    Are you joking?? The BH drive propses a BH with a lifetime of about an year, just 10^7 tons, peanuts!! Then you have to produce it, better not on Earth, so you do this in space, with a laser that produces an equivalent of 10^9 tons highly foucussed, even more peanuts!! Reasonable losses in the production process (probably 99,999%) are not yet taken into account. Engineering problems... :-) The DM drive is even better, they want to collect DM and compress it in a propulsion chamber. Very easy to collect and compress a gas of particles that traverse the Earth without any interaction. Perhaps if the walls of the chamber are made of artificial BHs?? Who knows??
  • LeopoldS on 26 Nov 09
     
    WRONG!!! we are all just WAITING for your opinion on this ....!!!
  • pacome delva on 27 Nov 09
     
    well, yes my remark was ironic... I'm surprised they did a magazine on these concepts...! But the press is always waiting for sensational. They do not even wait for the work to be peer-reviewed now to make an article on it ! This is one of the bad sides of arxiv in my opinion. It's like a journalist that make an article with a copy-paste in wikipedia ! Anyway, this is of course complete bullsh..., and I would have laughed if I had read this in a sci-fi book... but in a "serious" article i'm crying... For the DM i do not agree with your remark Luzi. It's not dark energy they want to use. The DM is baryonic, it's dark just because it's cold so we don't see it by usual means. If you believe the in the standard model of cosmology, then the DM should be somewhere around the galaxies. But it's of course not uniformly distributed, so a DM engine would work (if at all...) only in the periphery of galaxies. It's already impossible to get there...
  • Luzi Bergamin on 27 Nov 09
     
    One reply to Pacome, though the discussion exceeds by far the relevance of the topic already. Baryonic DM is strictly limited by cosomology, if one believes in these models, of course. Anyway, even though most DM is cold, we are constantly bombarded by some DM particles that come together with cosmic radiation, solar wind etc. etc. If DM easily interacted with normal matter, we would have found it long ago. In the paper they consider DM as neutralinos, which are neither baryonic nor strongly or electromagnetically interacting.
  • pacome delva on 27 Nov 09
     
    well then I agree, how the fu.. they want to collect them !!!
LeopoldS

Software to Rate How Drastically Photos Are Retouched - NYTimes.com - 1 views

www.nytimes.com/...ally-photos-are-retouched.html

shared by LeopoldS on 01 Dec 11 - No Cached
  • LeopoldS on 01 Dec 11
     
    good to see that we are not fooled that easy ...
  • Ma Ru on 01 Dec 11
     
    I think you misunderstood: the whole point of this research is that we *are* fooled, all too easily...
santecarloni

First flat lens focuses light without distortion - physicsworld.com - 0 views

physicsworld.com/...cuses-light-without-distortion

light lens PHY science

shared by santecarloni on 24 Sep 12 - No Cached
LeopoldS liked it
  • santecarloni on 24 Sep 12
     
    Physicists in the US have made the first ultrathin flat lens. Thanks to its flatness, the device eliminates optical aberrations that occur in conventional lenses with spherical surfaces. As a result, the focusing power of the lens also approaches the ultimate physical limit set by the laws of diffraction.
  • LeopoldS on 24 Sep 12
     
    Really nice indeed! The new flat ultrathin lens is different in that it is a nanostructured "metasurface" made of optically thin beam-shaping elements called optical antennas, which are separated by distances shorter than the wavelength of the light they are designed to focus. These antennas are wavelength-scale metallic elements that introduce a slight phase delay in a light ray that scatters off them. The metasurface can be tuned for specific wavelengths of light by simply changing the size, angle and spacing between the nanoantennas. "The antenna is nothing more than a resonator that stores light and then releases it after a short time delay," Capasso says. "This delay changes the direction of the light in the same way that a thick glass lens would." The lens surface is patterned with antennas of different shapes and sizes that are oriented in different directions. This causes the phase delays to be radially distributed around the lens so that light rays are increasingly refracted further away from the centre, something that has the effect of focusing the incident light to a precise point.
Tom Gheysens

Cheap battery stores energy for a rainy day : Nature News & Comment - 0 views

www.nature.com/...energy-for-a-rainy-day-1.14486

energy battery science phy nature

shared by Tom Gheysens on 16 Jan 14 - No Cached
  • Tom Gheysens on 16 Jan 14
     
    Thijs interested? quinones are my field
  • Thijs Versloot on 20 Jan 14
     
    I think the major benefit of this system is the low cost of the products involved compared to standard flow batteries. However, two issues still remain, corrosion and size. I think these things need to be big right due to the volumetric storage using quinones? Nevertheless, it is interesting to see where this development will lead to. "The system is far from perfect, however: bromine and hydrobromic acid are corrosive, and could cause serious pollution if they leaked. "The bromine is, right now, the Achilles heel of this particular battery," Aziz says. The answer could be to go completely organic, he adds: "We are working on replacing the bromine with a different quinone." Are there quinones which would not be corrosive but retain good volumetric performance?
johannessimon81

A Different Form of Color Vision in Mantis Shrimp - 4 views

www.sciencemag.org/...411.full

technology BIO biomimetics science

shared by johannessimon81 on 28 Jan 14 - No Cached
  • johannessimon81 on 28 Jan 14
     
    Mantis shrimp seem to have 12 types of photo-receptive sensors - but this does not really improve their ability to discriminate between colors. Speculation is that they serve as a form of pre-processing for visual information: the brain does not need to decode full color information from just a few channels which would would allow for a smaller brain. I guess technologically the two extremes of light detection would be RGB cameras which are like our eyes and offer good spatial resolution, and spectrometers which have a large amount of color channels but at the cost of spatial resolution. It seems the mantis shrimp uses something that is somewhere between RGB cameras and spectrometers. Could there be a use for this in space?
  • Ma Ru on 31 Jan 14
     
    > RGB cameras which are like our eyes ...apart from the fact that the spectral response of the eyes is completely different from "RGB" cameras (http://en.wikipedia.org/wiki/File:Cones_SMJ2_E.svg) ... and that the eyes have 4 types of light-sensitive cells, not three (http://en.wikipedia.org/wiki/File:Cone-response.svg) ... and that, unlike cameras, human eye is precise only in a very narrow centre region (http://en.wikipedia.org/wiki/Fovea) ...hmm, apart from relying on tri-stimulus colour perception it seems human eyes are in fact completely different from "RGB cameras" :-) OK sorry for picking on this - that's just the colour science geek in me :-) Now seriously, on one hand the article abstract sounds very interesting, but on the other the statement "Why use 12 color channels when three or four are sufficient for fine color discrimination?" reveals so much ignorance to the very basics of colour science that I'm completely puzzled - in the end, it's a Science article so it should be reasonably scientifically sound, right? Pity I can't access full text... the interesting thing is that more channels mean more information and therefore should require *more* power to process - which is exactly opposite to their theory (as far as I can tell it from the abstract...). So the key is to understand *what* information about light these mantises are collecting and why - definitely it's not "colour" in the sense of human perceptual experience. But in any case - yes, spectrometry has its uses in space :-)
Francesco Biscani

STLport: An Interview with A. Stepanov - 2 views

www.stlport.org/...StepanovUSA.html

computer science

shared by Francesco Biscani on 23 Mar 10 - Cached
  • Generic programming is a programming method that is based in finding the most abstract representations of efficient algorithms.
  • I spent several months programming in Java.
  • for the first time in my life programming in a new language did not bring me new insights
  • ...2 more annotations...
  • it has no intellectual value whatsoever
  • Java is clearly an example of a money oriented programming (MOP).
  • Francesco Biscani on 23 Mar 10
     
    One of the authors of the STL (C++'s Standard Template Library) explains generic programming and slams Java.
  • ...6 more comments...
  • Ma Ru on 24 Mar 10
     
    "Java is clearly an example of a money oriented programming (MOP)." Exactly. And for the industry it's the money that matters. Whatever mathematicians think about it.
  • Joris _ on 24 Mar 10
     
    It is actually a good thing that it is "MOP" (even though I do not agree with this term): that is what makes it inter-operable, light and easy to learn. There is no point in writing fancy codes, if it does not bring anything to the end-user, but only for geeks to discuss incomprehensible things in forums. Anyway, I am pretty sure we can find a Java guy slamming C++ ;)
  • Francesco Biscani on 24 Mar 10
     
    Personally, I never understood what the point of Java is, given that: 1) I do not know of any developer (maybe Marek?) that uses it for intellectual pleasure/curiosity/fun whatever, given the possibility of choice - this to me speaks loudly on the objective qualities of the language more than any industrial-corporate marketing bullshit (for the record, I argue that Python is more interoperable, lighter and easier to learn than Java - which is why, e.g., Google is using it heavily); 2) I have used a software developed in Java maybe a total of 5 times on any computer/laptop I owned over 15 years. I cannot name of one single Java project that I find necessary or even useful; for my usage of computers, Java could disappear overnight without even noticing. Then of course one can argue as much as one wants about the "industry choosing Java", to which I would counterargue with examples of industry doing stupid things and making absurd choices. But I suppose it would be a kind of pointless discussion, so I'll just stop here :)
  • Joris _ on 24 Mar 10
     
    "At Google, python is one of the 3 "official languages" alongside with C++ and Java". Java runs everywhere (the byte code itself) that is I think the only reason it became famous. Python, I guess, is more heavy if it were to run on your web browser! I think every language has its pros and cons, but I agree Java is not the answer to everything... Java is used in MATLAB, some web applications, mobile phones apps, ... I would be a bit in trouble if it were to disappear today :(
  • Dario Izzo on 24 Mar 10
     
    I personally do not believe in interoperability :)
  • Ma Ru on 24 Mar 10
     
    Well, I bet you'd notice an overnight disappearance of java, because half of the internet would vanish... J2EE technologies are just omnipresent there... I'd rather not even *think* about developing a web application/webservice/web-whatever in standard C++... is it actually possible?? Perhaps with some weird Microsoft solutions... I bet your bank online services are written in Java. Certainly not in PHP+MySQL :) Industry has chosen Java not because of industrial-corporate marketing bullshit, but because of economics... it enables you develop robustly, reliably, error-prone, modular, well integrated etc... software. And the costs? Well, using java technologies you can set-up enterprise-quality web application servers, get a fully featured development environment (which is better than ANY C/C++/whatever development environment I've EVER seen) at the cost of exactly 0 (zero!) USD/GBP/EUR... Since many years now, the central issue in software development is not implementing algorithms, it's building applications. And that's where Java outperforms many other technologies. The final remark, because I may be mistakenly taken for an apostle of Java or something... I love the idea of generic programming, C++ is my favourite programming language (and I used to read Stroustroup before sleep), at leisure time I write programs in Python... But if I were to start a software development company, then, apart from some very niche applications like computer games, it most probably would use Java as main technology.
  • Francesco Biscani on 24 Mar 10
     
    "I'd rather not even *think* about developing a web application/webservice/web-whatever in standard C++... is it actually possible?? Perhaps with some weird Microsoft solutions... I bet your bank online services are written in Java. Certainly not in PHP+MySQL :)" Doing in C++ would be awesomely crazy, I agree :) But as I see it there are lots of huge websites that operate on PHP, see for instance Facebook. For the banks and the enterprise market, as a general rule I tend to take with a grain of salt whatever spin comes out from them; in the end behind every corporate IT decision there is a little smurf just trying to survive and have the back covered :) As they used to say in the old times, "No one ever got fired for buying IBM". "Industry has chosen Java not because of industrial-corporate marketing bullshit, but because of economics... it enables you develop robustly, reliably, error-prone, modular, well integrated etc... software. And the costs? Well, using java technologies you can set-up enterprise-quality web application servers, get a fully featured development environment (which is better than ANY C/C++/whatever development environment I've EVER seen) at the cost of exactly 0 (zero!) USD/GBP/EUR... Since many years now, the central issue in software development is not implementing algorithms, it's building applications. And that's where Java outperforms many other technologies." Apart from the IDE considerations (on which I cannot comment, since I'm not a IDE user myself), I do not see how Java beats the competition in this regard (again, Python and the huge software ecosystem surrounding it). My impression is that Java's success is mostly due to Sun pushing it like there is no tomorrow and bundling it with their hardware business.
  • Joris _ on 24 Mar 10
     
    OK, I think there is a bit of everything, wrong and right, but you have to acknowledge that Python is not always the simplest. For info, Facebook uses Java (if you upload picture for instance), and PHP is very limited. So definitely, in company, engineers like you and me select the language, it is not a marketing or political thing. And in the case of fb, they come up with the conclusion that PHP, and Java don't do everything but complement each other. As you say Python as many things around, but it might be too much for simple applications. Otherwise, I would seriously be interested by a study of how to implement a Python-like system on-board spacecrafts and what are the advantages over mixing C, Ada and Java.
Luís F. Simões

Seminar: You and Your Research, Dr. Richard W. Hamming (March 7, 1986) - 10 views

www.chris-lott.org/...kaiser.html

science research Methods methodology Nobel Bell Labs Los Alamos

shared by Luís F. Simões on 07 Jan 11 - Cached
LeopoldS liked it
  • This talk centered on Hamming's observations and research on the question "Why do so few scientists make significant contributions and so many are forgotten in the long run?" From his more than forty years of experience, thirty of which were at Bell Laboratories, he has made a number of direct observations, asked very pointed questions of scientists about what, how, and why they did things, studied the lives of great scientists and great contributions, and has done introspection and studied theories of creativity. The talk is about what he has learned in terms of the properties of the individual scientists, their abilities, traits, working habits, attitudes, and philosophy.
  • Luís F. Simões on 07 Jan 11
     
    Here's the link related to one of the lunch time discussions. I recommend it to every single one of you. I promise it will be worth your time. If you're lazy, you have a summary here (good stuff also in the references, have a look at them):      Erren TC, Cullen P, Erren M, Bourne PE (2007) Ten Simple Rules for Doing Your Best Research, According to Hamming. PLoS Comput Biol 3(10): e213.
  • ...3 more comments...
  • pacome delva on 11 Jan 11
     
    I'm also pretty sure that the ones who are remembered are not the ones who tried to be... so why all these rules !? I think it's bullshit...
  • Luís F. Simões on 11 Jan 11
     
    The seminar is not a manual on how to achieve fame, but rather an analysis on how others were able to perform very significant work. The two things are in some cases related, but the seminar's focus is on the second.
  • pacome delva on 12 Jan 11
     
    Then read a good book on the life of Copernic, it's the anti-manual of Hamming... he breaks all the rules !
  • LeopoldS on 12 Jan 11
     
    honestly I think that some of these rules actually make sense indeed ... but I am always curious to get a good book recommendation (which book of Copernic would you recommend?) btw Pacome: we are in Paris ... in case you have some time ...
  • pacome delva on 12 Jan 11
     
    I warmly recommend this book, a bit old but fascinating: The sleepwalkers from Arthur Koestler. It shows that progress in science is not straight and do not obey any rule... It is not as rational as most of people seem to believe today. http://www.amazon.com/Sleepwalkers-History-Changing-Universe-Compass/dp/0140192468/ref=sr_1_1?ie=UTF8&qid=1294835558&sr=8-1 Otherwise yes I have some time ! my phone number: 0699428926 We live around Denfert-Rochereau and Montparnasse. We could go for a beer this evening ?
LeopoldS

physicists explain what AI researchers are actually doing - 5 views

arxiv.org/1410.3831

AI PHY

shared by LeopoldS on 07 Dec 14 - No Cached
  • LeopoldS on 07 Dec 14
     
    love this one ... it seems to take physicist to explain to the AI crowd what they are actually doing ... Deep learning is a broad set of techniques that uses multiple layers of representation to automatically learn relevant features directly from structured data. Recently, such techniques have yielded record-breaking results on a diverse set of difficult machine learning tasks in computer vision, speech recognition, and natural language processing. Despite the enormous success of deep learning, relatively little is understood theoretically about why these techniques are so successful at feature learning and compression. Here, we show that deep learning is intimately related to one of the most important and successful techniques in theoretical physics, the renormalization group (RG). RG is an iterative coarse-graining scheme that allows for the extraction of relevant features (i.e. operators) as a physical system is examined at different length scales. We construct an exact mapping from the variational renormalization group, first introduced by Kadanoff, and deep learning architectures based on Restricted Boltzmann Machines (RBMs). We illustrate these ideas using the nearest-neighbor Ising Model in one and two-dimensions. Our results suggests that deep learning algorithms may be employing a generalized RG-like scheme to learn relevant features from data.
Dario Izzo

Dmitry Medvedev reveals aliens are among us - 6 views

www.telegraph.co.uk/...-Vladimir-Putins-lateness.html

shared by Dario Izzo on 08 Dec 12 - No Cached
LeopoldS liked it
  • Dario Izzo on 08 Dec 12
     
    I Knew!!! I Knew!!! They are all around. I always though Marek was one :) "I believe in Father Frost. But not too deeply. But anyway, you know, I'm not one of those people who are able to tell the kids that Father Frost does not exist"
  • johannessimon81 on 09 Dec 12
     
    His rival putin on the other hand... He got into an ultra-light aircraft to guide birds during their migration - from the video it seems that only very few birds think he is credible (as a guide). --> http://www.telegraph.co.uk/news/worldnews/vladimir-putin/9524900/Flying-Vladimir-Putin-leads-birds-on-first-ever-migration-in-latest-publicity-stunt.html
  • Ma Ru on 10 Dec 12
     
    Yup. My structural perfection is matched only by my hostility.
LeopoldS

Association for the Advancement of Artificial Intelligence - 2 views

www.aaai.org/home.html

AI

shared by LeopoldS on 18 Jan 13 - Cached
  • LeopoldS on 18 Jan 13
     
    does any of you know the value/standing of this association?
  • Juxi Leitner on 19 Jan 13
     
    quite well-reputed, they were founded as the American Association for AI (and only recently cahnged it to be more international). They are partly organizing IJCAI and the AAAI conferences (mostly in the US), which are quite good. Symposia around specific topics are also done and at those mostly professors and researchers with high impact are going.
  • LeopoldS on 19 Jan 13
     
    Thanks Juxi. was contacted by one of the organisers for the Berlin edition of it in 2 years. looking at your answer, it seems having the ACT associated to it is not a bad idea. will check with the team. Would you yourself be interested?
LeopoldS

[1305.3913] Indication of anomalous heat energy production in a reactor device - 5 views

arxiv.org/1305.3913

shared by LeopoldS on 23 May 13 - No Cached
  • LeopoldS on 23 May 13
     
    looks like some backwind for all the cold fusion believers ...
  • ...1 more comment...
  • johannessimon81 on 24 May 13
     
    Actually Sante and me just reviewed their paper. Although (some of) the scientists in the paper seem to have good track records their experimental techniques are by far not the best to determine the excess amount of energy produced. Even though their methods may introduce fairly large errors they would not be able to negate the cited power output - so they either are super-sloppy (i.e. they lie) or there is TRULY new physics involved... A big problem is that they are basically verifying somebody else's experiment - however because this guy is paranoid he does not tell them exactly what he did. In fact they went to his lab and used a setup that HE put together. All they do is do a measurement on it and it seems like they try to be thorough. There is quite a chance that the guy behind it all (Rossi) is setting them up - personally I would think >95%. However, the implications of this being new physics are so big that I think further research should be conducted.
  • LeopoldS on 24 May 13
     
    I just answered something very similar to Franco, except the conclusions: I don't think that there is a good reason for us or anybody else in ESA to get involved at this stage.
  • johannessimon81 on 24 May 13
     
    I agree - if this device would work it there would be other interest groups (like the energy sector) with a much more concrete stake in the technology.
LeopoldS

Meteorite Crashes In Russia, Panic Spreads (Updating) - 5 views

gizmodo.com/...rashes-in-russia-panic-spreads

shared by LeopoldS on 15 Feb 13 - No Cached
  • Joris _ on 15 Feb 13
     
    Latest update: the European Space Agency says their experts "confirm there is no link between the meteor incidents in Russia and asteroid 2012DA14 flyby tonight". How did they find this? As they did not see this one coming, how could they come to that conclusion that early!
  • ...5 more comments...
  • johannessimon81 on 15 Feb 13
     
    As you can see from the videos of this meteorite it is coming in from an east to south-east direction (i.e. the direction of the sunrise, more or less). 2012DA14 is coming from due south as you can see here: http://www.wired.com/wiredscience/2013/02/how-to-watch-asteroid-2012-da14/ So the two objects seem to be coming from different directions - at least that would be my explanation.
  • Joris _ on 15 Feb 13
     
    My point is, that if you want to come to such a conclusion (that it is not rubble) you need to be able to construct back the orbits of both objects. 2012DA14 has been observed for one year only, but it is well enough. When the meteor has been observed for the first time, such that we knew its orbit? has it been observed before? if yes, why the impact has not been predicted?
  • johannessimon81 on 15 Feb 13
     
    If you can show that they come from different directions you know that they are not associated, even if you don't reconstruct their orbits.
  • Joris _ on 15 Feb 13
     
    I don't think so. If both objects were part of the same, they would be on different but intersecting orbits anyway, hence different directions. Anyway, I am not knowledgeable in atmospheric entry ... But, with so few information about the object, I am surprised they are 100% certain it is not related to DA14. I think science requires more cautions ... With only the direction they are 100% sure, while the probability of such event is itself extremely small, I am amazed... They can't even predict with 100% certainty where a space debris will fall... plus, nobody consider the object being part of a bigger one that broke up during early entry (which has not been observed) ... so many uncertainties and possible hypothesis... and i am not the only one :) http://www.infowars.com/russian-meteor-linked-to-da14-asteroid/
  • LeopoldS on 17 Feb 13
     
    was not that evident to me also but apparently with the right understanding it was quite clear; was amazed also how quickly NASA has published the likely trajectory of the russian object - have a look at it: quite evident that these are not coming from the same body
  • Joris _ on 17 Feb 13
     
    yes, now i get my 100% certainty with the reconstructed orbits nothing else (http://wiki.nasa.gov/cm/blog/Watch%20the%20Skies/posts/post_1361037562855.html) ... I still think that esa anouncemement was highly premature but with a high probability of being right...
  • Ma Ru on 26 Feb 13
     
    Some more results on the topic (link to an arxiv article inside): http://www.bbc.co.uk/news/science-environment-21579422
Luís F. Simões

Zeitgeist 2012 - Google - 2 views

www.google.com/...2012

google zeitgeist 2012

shared by Luís F. Simões on 13 Dec 12 - No Cached
LeopoldS liked it
  • 1.2 trillion searches. 146 languages. What did the world search for in 2012?
  • Luís F. Simões on 13 Dec 12
     
    this is a gold mine :D Portugal, a bankrupt country in crisis where the Most Searched How to... is "Como emagrecer" (how to lose weight?). Netherlands, where the Most Searched How to... is "Hoe overleef ik" (how do I survive?) UK where the most Trending What is... is "What is love?" and Italians... please explain how come the top Trending How to... are 1. Come fare Sesso 2. Come fare un Clistere !?!? Respect for Austria though, where the top trending What is... are: 1. Was ist ACTA 2. Was ist SOPA any other interesting finds?
  • Ma Ru on 14 Dec 12
     
    From Ghana "What is...?": What is a Constitution What is Government [edit] Some top Science searches in the US: Hemorrhoid, Pregnancy Syndroms. Any potential for Ariadna? [edit] ... and finally, for the sake of my shield, top search from Poland in the Music category
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