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LeopoldS

Phys. Rev. Lett. 105, 211303 (2010): Model for Gravity at Large Distances - 2 views

prl.aps.org/...e211303

phy science astronomy pioneer anomaly

shared by LeopoldS on 18 Nov 10 - No Cached
  • LeopoldS on 18 Nov 10
     
    Sante have a look at this ... Daniel is the TU researcher who did the study I was sending you a few years ago with Luzi - very nice and smart guy .... Luzi: now you will have difficulties in shooting :-)
andreiaries

Upping the Anti: CERN Physicists Trap Antimatter Atoms for the First Time: Scientific A... - 0 views

www.scientificamerican.com/article.cfm

science phy

shared by andreiaries on 22 Nov 10 - No Cached
  • andreiaries on 22 Nov 10
     
    Not really the first time, but they seem to be much closer to be being able to study them. Apparently, they had 38 atoms trapped for miliseconds. Now it's time to prove it behaves just like matter.
Dario Izzo

Probabilistic Logic Allows Computer Chip to Run Faster - 3 views

www.azonano.com/news.asp

INF MAD probabilistic computing AI

shared by Dario Izzo on 07 Dec 09 - Cached
  • Dario Izzo on 07 Dec 09
     
    Francesco pointed out this research one year ago, we dropped it as noone was really considering it ... but in space a low CPU power consumption is crucial!! Maybe we should look back into this?
  • ...6 more comments...
  • Ma Ru on 07 Dec 09
     
    Q1: For the time being, for what purposes computers are mainly used on-board?
  • Dario Izzo on 07 Dec 09
     
    for navigation, control, data handling and so on .... why?
  • Ma Ru on 07 Dec 09
     
    Well, because the point is to identify an application in which such computers would do the job... That could be either an existing application which can be done sufficiently well by such computers or a completely new application which is not already there for instance because of some power consumption constraints... Q2 would be then: for which of these purposes strict determinism of the results is not crucial? As the answer to this may not be obvious, a potential study could address this very issue. For instance one can consider on-board navigation systems with limited accuracy... I may be talking bullshit now, but perhaps in some applications it doesn't matter whether a satellite flies on the exact route but +/-10km to the left/right? ...and so on for the other systems. Another thing is understanding what exactly this probabilistic computing is, and what can be achieved using it (like the result is probabilistic but falls within a defined range of precision), etc. Did they build a complete chip or at least a sub-circiut, or still only logic gates...
  • Dario Izzo on 07 Dec 09
     
    Satellites use old CPUs also because with the trend of going for higher power modern CPUs are not very convenient from a system design point of view (TBC)... as a consequence the constraints put on on-board algorithms can be demanding. I agree with you that double precision might just not be necessary for a number of applications (navigation also), but I guess we are not talking about 10km as an absolute value, rather to a relative error that can be tolerated at level of (say) 10^-6. All in all you are right a first study should assess what application this would be useful at all.. and at what precision / power levels
  • Joris _ on 07 Dec 09
     
    The interest of this can be a high fault tolerance for some math operations, ... which would have for effect to simplify the job of coders! I don't think this is a good idea regarding power consumption for CPU (strictly speaking). The reason we use old chip is just a matter of qualification for space, not power. For instance a LEON Sparc (e.g. use on some platform for ESA) consumes something like 5mW/MHz so it is definitely not were an engineer will look for some power saving considering a usual 10-15kW spacecraft
  • Dario Izzo on 07 Dec 09
     
    What about speed then? Seven time faster could allow some real time navigation at higher speed (e.g. velocity of a terminal guidance for an asteroid impactor is limited to 10 km/s ... would a higher velocity be possible with faster processors?) Another issue is the radiation tolerance of the technology ... if the PCMOS are more tolerant to radiation they could get more easily space qualified.....
  • Joris _ on 08 Dec 09
     
    I don't remember what is the speed factor, but I guess this might do it! Although, I remember when using an IMU that you cannot have the data above a given rate (e.g. 20Hz even though the ADC samples the sensor at a little faster rate), so somehow it is not just the CPU that must be re-thought. When I say qualification I also imply the "hardened" phase.
  • Francesco Biscani on 08 Dec 09
     
    I don't know if the (promised) one-order-of-magnitude improvements in power efficiency and performance are enough to justify looking into this. For once, it is not clear to me what embracing this technology would mean from an engineering point of view: does this technology need an entirely new software/hardware stack? If that were the case, in my opinion any potential benefit would be nullified. Also, is it realistic to build an entire self-sufficient chip on this technology? While the precision of floating point computations may be degraded and still be useful, how does all this play with integer arithmetic? Keep in mind that, e.g., in the Linux kernel code floating-point calculations are not even allowed/available... It is probably possible to integrate an "accelerated" low-accuracy floating-point unit together with a traditional CPU, but then again you have more implementation overhead creeping in. Finally, recent processors by Intel (e.g., the Atom) and especially ARM boast really low power-consumption levels, at the same time offering performance-boosting features such as multi-core and vectorization capabilities. Don't such efforts have more potential, if anything because of economical/industrial inertia?
pacome delva

Quantum dots boost solar cell efficiencies - 2 views

physicsworld.com/...38046

phy solar_cells quantum_dots

shared by pacome delva on 15 Dec 09 - No Cached
  • pacome delva on 15 Dec 09
     
    Apparently there is a project going on in ESA on this topic led by TEC-EP, the contact person is Evelyne Simon. I really would like to do some research on these topics to see if we can find something interesting that would not have been considered in this study.
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?"
Nina Nadine Ridder

'This Planet Tastes Funny,' According to Spitzer - 2 views

www.physorg.com/news191080885.html

exoplanets spectra GJ436b Spitzer

shared by Nina Nadine Ridder on 22 Apr 10 - Cached
  • Nina Nadine Ridder on 22 Apr 10
     
    Spectra of the atmosphere of the planet GJ436b in the constellation Loe show evidence for carbon monoxide. Theoretical studies using numerical models however predicted that this planet's carbon inventory should be stored in the form of methane rather than CO as its temperature is estimated to be 800K. Where this inaccuracy of atmospheric models comes from is not known and has to be investigated further.
Juxi Leitner

Networked Networks Are Prone to Epic Failure | Wired Science | Wired.com - 1 views

www.wired.com/...networked-networks

tech networks failure

shared by Juxi Leitner on 27 Apr 10 - Cached
  • The interconnections fueled a cascading effect, with the failures coursing back and forth. A damaged node in the first network would pull down nodes in the second, which crashed nodes in the first, which brought down more in the second, and so on. And when they looked at data from a 2003 Italian power blackout, in which the electrical grid was linked to the computer network that controlled it, the patterns matched their models’ math.
  • Juxi Leitner on 27 Apr 10
     
    that would be an interesting "Systems of Systems" study for once ...
LeopoldS

Why Humans Have Sex | The New York Academy of Sciences - 4 views

www.nyas.org/...PodcastDetail.aspx

behaviour psychology

shared by LeopoldS on 04 May 10 - Cached
  • LeopoldS on 04 May 10
     
    nice podcast ... ESTEC YGT community might be an interesting study pool ....
  • Juxi Leitner on 06 May 10
     
    haha ;) I dunno what the general idea of the YGTs here at ESTEC is ;)
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 ?
Luís F. Simões

Shell energy scenarios to 2050 - 6 views

www.shell.com/...shell_energy_scenarios_2050

energy future forecast politics economy climate_change

shared by Luís F. Simões on 09 Mar 11 - No Cached
  • Luís F. Simões on 09 Mar 11
     
    just in case you were feeling happy and optimistic
  • ...7 more comments...
  • Francesco Biscani on 09 Mar 11
     
    An energy scenario published by an oil company? Allow me to be sceptical...
  • Joris _ on 10 Mar 11
     
    Indeed, Shell is an energy company, not just oil, for some time now ... The two scenarii are, in their approach, dependant of economic and political situation, which is right now impossible to forecast. Reference to Kyoto is surprising, almost out-dated! But overall, I find it rather optimistic at some stages, and probably the timeline (p37-39) is unlikely with recent events.
  • Luís F. Simões on 10 Mar 11
     
    the report was published in 2008, which explains the reference to Kyoto, as the follow-up to it was much more uncertain at that point. The Blueprint scenario is indeed optimistic, but also quite unlikely I'd say. I don't see humanity suddenly becoming so wise and coordinated. Sadly, I see something closer to the Scramble scenario as much more likely to occur.
  • LeopoldS on 12 Mar 11
     
    not an oil company??? please have a look at the percentage of their revenues coming from oil and gas and then compare this with all their other energy activities together and you will see very quickly that it is only window dressing ... they are an oil and gas company ... and nothing more
  • Joris _ on 14 Mar 11
     
    not JUST oil. From a description: "Shell is a global group of energy and petrochemical companies." Of course revenues coming from oil are the biggest, the investment turnover on other energy sources is small for now. Knowing that most of their revenues is from an expendable source, to guarantee their future, they invest elsewhere. They have invested >1b$ in renewable energy, including biofuels. They had the largest wind power business among so-called "oil" companies. Oil only defines what they do "best". As a comparison, some time ago, Apple were selling only computers and now they sell phones. But I would not say Apple is just a phone company.
  • LeopoldS on 14 Mar 11
     
    window dressing only ... e.g. Net cash from operating activities (pre-tax) in 2008: 70 Billion$ net income in 2008: 26 Billion revenues in 2008: 88 Billion Their investments and revenues in renewables don't even show up in their annual financial reports since probably they are under the heading of "marketing" which is already 1.7 Billion $ ... this is what they report on their investments: Capital investment, portfolio actions and business development Capital investment in 2009 was $24 billion. This represents a 26% decrease from 2008, which included over $8 billion in acquisitions, primarily relating to Duvernay Oil Corp. Capital investment included exploration expenditure of $4.5 billion (2008: $11.0 billion). In Abu Dhabi, Shell signed an agreement with Abu Dhabi National Oil Company to extend the GASCO joint venture for a further 20 years. In Australia, Shell and its partners took the final investment decision (FID) for the Gorgon LNG project (Shell share 25%). Gorgon will supply global gas markets to at least 2050, with a capacity of 15 million tonnes (100% basis) of LNG per year and a major carbon capture and storage scheme. Shell has announced a front-end engineering and design study for a floating LNG (FLNG) project, with the potential to deploy these facilities at the Prelude offshore gas discovery in Australia (Shell share 100%). In Australia, Shell confirmed that it has accepted Woodside Petroleum Ltd.'s entitlement offer of new shares at a total cost of $0.8 billion, maintaining its 34.27% share in the company; $0.4 billion was paid in 2009 with the remainder paid in 2010. In Bolivia and Brazil, Shell sold its share in a gas pipeline and in a thermoelectric power plant and its related assets for a total of around $100 million. In Canada, the Government of Alberta and the national government jointly announced their intent to contribute $0.8 billion of funding towards the Quest carbon capture and sequestration project. Quest, which is at the f
  • Joris _ on 14 Mar 11
     
    thanks for the info :) They still have their 50% share in the wind farm in Noordzee (you can see it from ESTEC on a clear day). Look for Shell International Renewables, other subsidiaries and joint-ventures. I guess, the report is about the oil branch. http://sustainabilityreport.shell.com/2009/servicepages/downloads/files/all_shell_sr09.pdf http://www.noordzeewind.nl/
  • LeopoldS on 16 Mar 11
     
    no - its about Shell globally - all Shell .. these participations are just peanuts please read the intro of the CEO in the pdf you linked to: he does not even mention renewables! their entire sustainability strategy is about oil and gas - just making it (look) nicer and environmentally friendlier
  • Joris _ on 16 Mar 11
     
    Fair enough, for me even peanuts are worthy and I am not able to judge. Not all big-profit companies, like Shell, are evil :( Look in the pdf what is in the upstream and downstream you mentionned above. Non-shell sources for examples and more objectivity: http://www.nuon.com/company/Innovative-projects/noordzeewind.jsp http://www.e-energymarket.com/news/single-news/article/ferrari-tops-bahrain-gp-using-shell-biofuel.html thanks.
nikolas smyrlakis

Why We Love to Hate Awards - Freakonomics Blog - NYTimes.com - 0 views

freakonomics.blogs.nytimes.com/...why-we-love-to-hate-awards

nytimes freakonomics CMS obama wine

shared by nikolas smyrlakis on 20 Oct 09 - Cached
  • nikolas smyrlakis on 20 Oct 09
     
    [spam] Obama expressed his disappointment recently when rapper Kanye West stormed the stage at the MTV Video Music Awards to protest singer Taylor Swift's win of the "Best Female Video" trophy. Soon after, Obama himself was Swifted by critics who felt he was undeserving of his Nobel Prize win. It is obviously connected to the study of the Journal of Wine Economics that wine gold awards are given randomly http://www.wine-economics.org/journal/content/Volume4/number1/Full%20Texts/1_wine%20economics_vol%204_1_Robert%20Hodgson.pdf which also raised some controversy
nikolas smyrlakis

Global Warming To Bring More Rain To Taiwan - Science News - redOrbit - 2 views

www.redorbit.com/...g_to_bring_more_rain_to_taiwan

climate change global warming rainfall

shared by nikolas smyrlakis on 26 Oct 09 - No Cached
  • nikolas smyrlakis on 26 Oct 09
     
    An interesting aspect of global warming..Was thinking of that today and apparently there are some studies but very limited.Involves a lot of satellite data to measure also moisture etc. in the atmoshpere
pacome delva

Grandma Plays Favorites -- Balter 2009 (1028): 1 -- ScienceNOW - 1 views

sciencenow.sciencemag.org/...1

bio evolutionary_biology

shared by pacome delva on 29 Oct 09 - Cached
  • A new study finds support for the "grandmother hypothesis," the idea that older women spread their genes most effectively by helping their daughters take care of their children.
  • Thus paternal grandmothers were most beneficial to the survival of their granddaughters and least beneficial to the survival of their grandsons, while maternal grandmothers showed an intermediate effectiveness. Experts are thrilled by the findings. "Wow, very interesting," says Hawkes. "The consistent results across seven populations ... seem to clarify previously inconsistent results." Lorena Madrigal, an anthropologist at the University of South Florida in Tampa, calls the study "an important contribution to a topic of great interest to evolutionary biologists."
jmlloren

Experimental verification of the feasibility of a quantum channel between space and Earth - 0 views

www.iop.org/...njp8_3_033038.html

NAN MAD technology

shared by jmlloren on 14 Jul 09 - Cached
  • jmlloren on 14 Jul 09
     
    Extending quantum communication to space environments would enable us to perform fundamental experiments on quantum physics as well as applications of quantum information at planetary and interplanetary scales. Here, we report on the first experimental study of the conditions for the implementation of the single-photon exchange between a satellite and an Earth-based station. We built an experiment that mimics a single photon source on a satellite, exploiting the telescope at the Matera Laser Ranging Observatory of the Italian Space Agency to detect the transmitted photons. Weak laser pulses, emitted by the ground-based station, are directed toward a satellite equipped with cube-corner retroreflectors. These reflect a small portion of the pulse, with an average of less-than-one photon per pulse directed to our receiver, as required for faint-pulse quantum communication. We were able to detect returns from satellite Ajisai, a low-Earth orbit geodetic satellite, whose orbit has a perigee height of 1485 km.
  • pacome delva on 16 Jul 09
     
    hello Jose! Interesting it was proposed to do the same with the ISS as part of the ACES experiment. I don't remember the paper but i can look if you're interested
Tobias Seidl

The Cochrane Collaboration - Welcome first-time visitors! - 0 views

www.cochrane.org/index_newcomers.htm

BIO health ACT

shared by Tobias Seidl on 22 Jul 09 - Cached
  • Tobias Seidl on 22 Jul 09
     
    This is an idependent organisation reviewing healthcare studies and basically judging the results. Something like the ACT for international medicine. Sounds interesting in the approach. Their suggestion for swine-flu prevention: wash your hands frequently. Nothing helps better.
Nicolas Weiss

Fliegender Holländer: Tüftel-Student fliegt nur mit Muskelkraft - SPIEGEL ONL... - 0 views

www.spiegel.de/...0,1518,641805,00.html

Flying (Crazy) Dutchman

shared by Nicolas Weiss on 12 Aug 09 - Cached
  • Nicolas Weiss on 12 Aug 09
     
    The guy is studying Aeronautics in Delft and has been working on his flying bike since he was 16. He manage to fly 1.5 m high and 10 m long! A bit higher and the bike helm is not going to be of so much help!
LeopoldS

A new angle on clinging in geckos: incline, not substrate, triggers the deployment of t... - 0 views

rspb.royalsocietypublishing.org/...rspb.2009.0946.abstract

BIO biomimetics NAN

shared by LeopoldS on 07 Aug 09 - Cached
  • LeopoldS on 07 Aug 09
     
    Tobias - have a look at this one ... am surprised to see this "new" paper since thought to remember that in our study they presented something quite similar ....
nikolas smyrlakis

Men lose their minds speaking to pretty women - Telegraph - 0 views

www.telegraph.co.uk/...-speaking-to-pretty-women.html

science Health research Gender News Psychology

shared by nikolas smyrlakis on 10 Sep 09 - Cached
  • nikolas smyrlakis on 10 Sep 09
     
    a study from a dutch university
  • LeopoldS on 12 Sep 09
     
    I knew it --- we have to fire Fairouz, Nina and Friederike!!! your sheer presence is impacting the performance of the male researchers in the team!!!
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