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an interesting comic about maths, ideas etc. Co-written by a greek mathematician / writer and a Berkeley computer science professor, sold out in Greece and since its international release a couple of months ago is occupying the top selling comics lists of Amazon etc. also: http://www.logicomix.com/en/index.php?option=com_content&view=frontpage&Itemid=53

btw I just ordered it from Amazon, so if you want after I finish it I can lend it

if you view the source code there's also an RSS feed

well, it seems we'll never be able to see the yes...!

so ooooooooooooold!!!!

A good example of how loosing perspective makes so-called "novel ways" actually "rubish ways"

here the paper: http://arxiv.org/abs/1104.1401 well spent defence funding ....

We're all here about inventiveness and creativity, so here you go... Story of a guy who's life's motto has been "Gold lies on the streets and you just need to dig it up with ideas. Ideas are like the shovel" Add to it Monte Carlo, Marlene Dietrich and, say, King Farouk and you get quite an amazing story... And most of all, after reading this you'll know the value of knowing how to ski.

nice story indeed ...

I was so shocked not to see Dario in the authors list!

still practically as an ACT paper ... the first author was the first RF of the team and the one who suggested Dario ...

Yeah I've figured it out from his CV at the end of the article after posting :)

smart!

anybody else?

"And according to his calculations, improvements in short-pulse laser systems could make this form of thruster more than 40 times as efficient as even the best of today's ionic propulsion systems that push spacecraft around. "

Dejan please have a look at this also ...

while the nuclear reaction seems to be sound at first view, I am not so sure how this would work: "Electromagnetic forces push the target and the alpha particles in the opposite directions, and the particles exit the spacecraft through a nozzle, providing the vehicle's thrust. "

"Application of scientific principals for improvement of quality of reduced-fat, reduced-salt cheese" As far as I know, fat and salt content in food correlates *positively* with the taste, so the project is against food quality...

:) so Technology Review wrote the article now, based on an arXiv paper uploaded only now, but actually the paper was already published in Nature last year: http://dx.doi.org/10.1038/nphys1636

Greenwich could lose its place at the centre of global time if a move to "atomic time" is voted in by the International Telecommunication Union in Geneva in January 2012.

Haha this is really a British article... Already since 1972 we don't use GMT but UTC, which is based on atomic clocks. However British continue to call it GMT... The question is to drop the leap second in UTC, and France is definitely for this change (for scientific motives of course...;) I don't see how this is connected to winter time however... And they shouldn't worry Greenwich is still the beginning of the world with 0 degree longitude !

"the end of GMT as an international standard could accelerate the move to keep British Summer Time into the winter, letting us have lighter evenings." As I understand it, if GMT looses its "prestigious" status, then it would be easier to push through all-year BST in UK.

"The BICEP2 data would eliminate about 90% of inflationary models, Andrei Linde, a cosmologist at Stanford University in California, told a packed auditorium at MIT the day after the BICEP2 announcement (see picture below). Many of those models do not produce gravitational waves at detectable levels, said Linde, who is one of the founders of inflation theory." Is there any hope for LISA now?

Of course - the data is more proof that GWs exist!!

so you don't expect any impact on the science objectives of Lisa at all?

Theoretized 80 years ago was Breit-Wheeler pair production in which two photons result in an electron-positron pair (via a virtual electron). It is a relatively simple Feynmann diagram, but the problem is/was how to produce in practice a high energy photon-photon collider... The collider experiment that the scientists have proposed involves two key steps. First, the scientists would use an extremely powerful high-intensity laser to speed up electrons to just below the speed of light. They would then fire these electrons into a slab of gold to create a beam of photons a billion times more energetic than visible light. The next stage of the experiment involves a tiny gold can called a hohlraum (German for 'empty room'). Scientists would fire a high-energy laser at the inner surface of this gold can, to create a thermal radiation field, generating light similar to the light emitted by stars. They would then direct the photon beam from the first stage of the experiment through the centre of the can, causing the photons from the two sources to collide and form electrons and positrons. It would then be possible to detect the formation of the electrons and positrons when they exited the can. Now this is a good experiment... :)

True, but isnt it E2=(pc)^2 + (m0c^2)^2 such that for photons E\propto{pc} and for mass E\propto{mc^2}. I agree it will take a lot of energy, but this assumes that that wont be the problem at least. The question therefore is whether the mass flow of the photon rocket (fuel consumed to create photons, eg fission/fusion) is higher/lower than the mass flow for e-p creation. You are probably right that the low e-p cross-section will favour direct use of photons to create low thrust for long periods of time, but with significant power available the ISP might be higher for e-p pair creation.

In essence the equation tells you that for photons with zero rest mass m0 all the energy will be converted to momentum of the particles. If you want to accelerate e-p then you first spend part of the energy on creating them (~511 keV each) and you can only use the remaining energy to accelerate them. In this case the equation gives you a lower particle momentum which leads to lower thrust (even when assuming 100% acceleration efficiency). ISP is a tricky concept in this case because there are different definitions which clash in the relativistic context (due to the concept of mass flow). R. Tinder gets to a I_SP = c (speed of light) for a photon rocket (using the relativistic mass of the photons) which is the maximum possible relativistic I_SP: http://goo.gl/Zz5gyC .

Whether society embraces face recognition on a larger scale will ultimately depend on how legislators, companies and consumers resolve the argument about its singularity. Is faceprinting as innocuous as photography, an activity that people may freely perform? Or is a faceprint a unique indicator, like a fingerprint or a DNA sequence, that should require a person's active consent before it can be collected, matched, shared or sold?

Dr. Atick is firmly in the second camp.

Actually these sort of things are also quite easy to exploit. Print a picture of Osama bin Laden on your t-shirt and have the entire police force scared out of their wits.

I saw so many bin laden t-shirts already ... they must have better filters than this

The problem is that the light cone angle has a limit - all particles with high momentum (mass x velocity) generate light cones with the same angle. Hence, these particles are indistinguishable. Now Chalmers researcher Philippe Tassin and his colleagues at the Free University of Brussels have designed a material that manipulates the Cherenkov cone so that also particles with high momentum get a distinct light cone angle too. The work is on the cover of this week's issue of the journal Physical Review Letters ("Controlling Cherenkov Radiation with Transformation-Optical Metamaterials").

Other possible study: get a textbook example of an image of a pen, evolve it just enough so NN can't recognize it anymore, while minimizing the distance between the original and evolved images. EDIT: Its been done already: http://cs.nyu.edu/~zaremba/docs/understanding.pdf

Of course, you can't really use them to extrapolate. The unknown unknown is always the trickiest :P They should just make another class "random bullshit", really and dump all of this stuff in there. I think there's a potential paper right there

Our friends from NASA have come out with a plan to the human exploration of Venus in the time that everyone is speaking about Mars.

Love the concept acronym, which pretty much says it all... Not sure which astronaut would fancy floating around in an atmosphere where clouds are made of sulphuric acid. Besides I don't see the point of a manned mission if one can't reach the surface.. tele-operation would be easy and so much cheaper.

maybe we can use some neural networks to do animal "speech" recognition? :P

NASA validates the EmDrive (http://emdrive.com/) technology for converting electrical energy into thrust. (from the website: "Thrust is produced by the amplification of the radiation pressure of an electromagnetic wave propagated through a resonant waveguide assembly.")

I have to join the skeptics on this one ...

The unspoken reality is that the U.S. patent system creates a market so constricted by high transaction costs and legal risks that it excludes the vast majority of small and mid-sized businesses and prevents literally 95 percent of all patented discoveries from ever being put to use to create new products and services, new jobs, and new economic growth.