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Did you know about this Weather Modification Office? Promising or dodgy?

Yes. In China it happens apparently quite often that weather is regionally modified, e.g. in order to have good weather conditions during certain events (like olympics in Beijing). But also in other countries weather modification is applied, for reasons of agriculture, pollution, skiing, etc. Obviously, one wonders on the environmental impact of such an artificial cloud feeding process with silver iodide. I just googled, stumbling upon this report http://www.weathermodification.org/AGI_toxicity.pdf which published the result: no environmentally harmful effects...

and w.r.t. ur question: I mean different weather conditions which we experience locally (like droughts or other extreme weather events) are (often) due to large-scale/global climatic changes. Hence, cloud seeding just describes a local, short-term mitigation of these events. However, there is a geoengineering proposal (so climate modification) which also suggests to seed clouds above the sea (i.e. increase cloud coverage, e.g. by using seaspray as cloud condesation nuclei), thereby increasing the planetary albedo (Earth reflectance) and reducing the energy reaching the Earth surface. If this idea is promising or not, I couldn't judge upon, but for sure it is worthwhile to take a closer look at.

"Yammer is a tool for making companies and organizations more productive through the exchange of short frequent answers to one simple question: What are you working on?" Have you tried it yet?

additional info: http://en.wikipedia.org/wiki/Himba_people#Exceptional_color_perception

Yeah that's interesting stuff... We have one prof in the lab who used to do some research related exactly to this (http://www.tech.plym.ac.uk/socce/staff/tonybelpaeme/research.html). Similar question (i.e. if/how language is involved in the formation of a concept) is also valid for numbers, see for instance this recent story: http://www.newscientist.com/article/dn20095-without-language-numbers-make-no-sense.html

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.

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 .

Interdisciplinary teams of handpicked individuals chosen for their field-leading expertise and innovative mind combine humanitarian questions with state of the art science, cutting-edge technology and endless fantasy. Organised by THE Port Association, hosted by CERN (IdeaSquare tbc) and with partners from other non-governmental organisations, a three-day problem solving workshop hackathon will be devoted to humanitarian, social and public interest topics. Interdisciplinary teams of selected participants will work together in the fields of: communication - transport - health - science - learning - work - culture - data

I mainly see neural networks in this... maybe some evolutionary stuff :))

An exhaustive overview of all possible advanced rocket concepts, eg.. "As an example, consider a photon rocket with its launching mass, say, 1000 ton moving with a constant acceleration a =0.1 g=0.98 m/s2. The flux of photons with E γ=0.5 MeV needed to produce this acceleration is ~1027/s, which corresponds to the efflux power of 1014 W and the rate of annihilation events N'a~5×1026 s−1 [47]. This annihilation rate in ambiplasma l -l ann corresponds to the value of current ~108 A and linear density N ~2×1018 m−1 thus any hope for non-relativistic relative velocity of electrons and positrons in ambiplasma is groundless." And also, even if it would work, then one of the major issues is going to be heat dispersal: "For example, if the temperature of radiator is chosen T=1500 K, the emitting area should be not less than 1000 m2 for Pb=1 GW, not less than 1 km2 for Pb=1 TW, and ~100 km2 for Pb=100 TW, assuming ε=0.5 and δ=0.2. Lower temperature would require even larger radiator area to maintain the outer temperature of the engine section stable for a given thermal power of the reactor."

The problem is not achieving a high energy density, that we can already do with nuclear fission, the question however is how to confine or harness this power with relatively high efficiency, low waste heat and at not too crazy specific mass. I see magnetic confinement as a possibility, yet still decades away and also an all-or-nothing method as we cannot easily scale this up from a test experiment to a full-scale system. It might be possible to extract power from such a plasma, but definitely well below breakeven so an additional power supply is needed. The fission fragments circumvent these issues by a more brute force approach, thereby wasting a lot of energy for sure but at the end probably providing more ISP and thrust.

Sure. However, the annihilation based photon rocket concept unifies almost all relevant drawbacks if we speak about solar system scales, making itself obsolete...it is just an academic testcase.

First peer review study about he criticality of rare-earth metals. It can be read "They found that supply limits for many metals critical in the emerging electronics sector (including gallium and selenium) are the result of supply risks. The environmental implications of mining and processing present the greatest challenges with platinum-group metals, gold, and mercury. For steel alloying elements (including chromium and niobium) and elements used in high-temperature alloys (tungsten and molybdenum), the greatest vulnerabilities are associated with supply restrictions" Questions about estimation apart, this can be a valuable market for asteroid mining.. (ot just more market for Infinium-like companies http://www.technologyreview.com/news/527526/a-cleaner-cheaper-way-to-make-metals/).

In the wake of the financial crisis, many started questioning different aspects of the economic formalism. Here a mathematical "dynamic" alternative to economic utility theory (which has also been the target of some famous recent attacks, see prospect theory) is developed and applied to the St. Petersburg coin tossing paradox. A good read at http://scitation.aip.org/content/aip/journal/chaos/26/2/10.1063/1.4940236

Simulating the economic state of the Galaxy after the resistance has blown up the Death Stars. See the paper here: http://arxiv.org/pdf/1511.09054.pdf

Love this type of friday afternoon research questions. There is also a now famous scene in the movie Clerks discussing the loss of independent contractors lives as the Death Star was being build.. https://www.youtube.com/watch?v=iQdDRrcAOjA

That analysis is quite crappy and is easily demolished in the video's comments.

any papers or insights on methods available?

Couldn't find a paper for Alibaba's results but Microsoft Research's performance on this dataset was very close. The paper is here: https://www.microsoft.com/en-us/research/wp-content/uploads/2017/05/r-net.pdf Btw the 'reading test' is a publicly available dataset called 'Stanford Question Answering Dataset (SQuAD)'. Their website shows a leaderboard: https://rajpurkar.github.io/SQuAD-explorer/

Some people answering the question 'What's cooler than blasting space debris with lasers...?'.

If it fires in both directions, can we align it such that it deorbits two debris with one shot?

:) the idea of having this method for debris removal is actually an ACT one from Claudio Bombardelli (ACT RF in MAD https://en.wikipedia.org/wiki/Ion-beam_shepherd). This is just a technological device to implement it so that the system on board is simplified (i.e. instead of two engines, you get away with one and a weird nozzle) Marcus, you cannot align it to get rid of two debris as you need to keep the spacecraft close to the debris as this is a long duration acion. One of the two would drift away (can only follow one!)

first science results reported in Nature (as far as I know) from the Yutu-2 and Chang'e mission .... and they look very good!

Sure they are very useful! It will be even better if they manage to fit the data to modeled circulation of the lunar magma ocean that was formed posterior to the "Theia" body collision with Earth. The collision was the cause of the magma ocean in the first place. The question now is how this circulation pattern of the lava-moon "froze" in time upon phase transition to solid. Because, what crystallizes last in sequence, is more rich in "incompatible" with the crystal structure, elements, we might combine data+models to predict their location. Those incompatible tracers are mainly radioactively decaying elements that produce heat (google publications about lunar KREEP elements (potassium (K), rare earth elements(REE), and phosphorus(P)). By knowing where the KREEP is: - we know where to dig for them mining (if they are useful for something, eg. Phosphorus for plants to be grown on the Moon) - we avoid planning to build the future human colony on top of radioactives, of course. The hope is that the Moon, due to lack of plate tectonics, has preserved this "signature of the freezing sequence". Let's see.

thanks Nasia! very interesting comment

Fascinating insight into the question of how networks learn.

Let's keep a eye on this... Animals use odor cues to navigate through their environments, helping them locate targets and assess danger. Much of how animal brains organize, read out, and respond to odor stimuli across spatial and temporal scales is not well understood. To tackle these questions, Odor2Action uses a highly interdisciplinary team science approach. Our work uses fruit fly, honeybee, and mouse models to determine how neural representations of odor are generated, reformatted, and translated to generate useful behaviors that guide how animals interact with their environment.

reminds me of the methan smelling source finding study we did ...