Group items tagged

To determine the mass of an exoplanet using transmission spectroscopy, de Wit relied on the effect that a planet's mass has on its atmosphere, as transmission spectra give information on a planet's atmospheric properties. To do that, he worked from a standard equation describing the effect of a planet's temperature, gravitational force, and atmospheric density on its atmospheric pressure profile-the extent to which pressure changes throughout its atmosphere.

The European Space Agency has unveiled plans to "take 3D printing into the metal age" by building parts for jets, spacecraft and fusion projects.

Metal Age sounds like some epic good time...

If you've ever found your iPhone taking control of your life, there may be a good reason. It may think it has free will. That may not be quite as far-fetched as it sounds. Today, one leading scientist outlines a 'Turing Test' for free will and says that while simple devices such as thermostats cannot pass, more complex ones like iPhones might.

I don't know the inventor of that nonsense that the free will should be the result of QM. It's about the only point I agree with the author of the paper: QM is not necessary and doesn't help. What I meant: all these thought experiments done by typical ultra-naive realists (or ultra-naive physicalists, if you prefer) that cultivate the university departments of physics, computer science etc. are put the cart before the horse. First one has to clarify the role of physical theories and its concepts (e.g. causality) and then one can start to ask how "free will" could perhaps be seen in these theories. More than 200 years ago there existed a famous philosopher named Kant who had some interesting thoughts about this. But authors like Lloyd behave as if he never existed, in fact is view of the world is even pre-Platonic!

Henry Kissinger How I'm missing yer And wishing you were here

A theory-SuperDense quantum teleportation-posed by Hampshire College physics professor Herbert Bernstein will be tested on the International Space Station. Theoretical physicist Bernstein devised the SuperDense scheme more than a decade ago in his investigations of different ways to send a quantum state from one part of a laboratory to a remote station.

Anna could you have a closer look into this - we should at least know what they are up to, be able to explain if anybody asks ... I also somehow missed this one in the NIAC study descriptions ... maybe a good moment to have another look at these "This is the second NASA grant for SuperDense quantum teleportation. A grant awarded in 2010 through NASA Innovative Advanced Concepts (NIAC) investigated the viability of the theory and produced the world's first experimental demonstration. Surprising or seminal experiments have marked Bernstein's research career. This is the fourth time a major proposal has become reality; two of his experiments helped found new sub-fields of physics (neutron interferometry and entanglement for quantum information)."

Looks like the genetic evidence for the interbreding of homo sapiens and homo neanderthalensis becomes significant.

"Humans and Neanderthals interbred" - isn't that a bit weird since we call the result of the interbreeding "Humans" as well? This is a bit like saying "Ligers and Tigers interbred".

Need some Graphene? Use your blender!

The habitable zones of single stars are larger and wider as the temperatures increase. Although hotter stars have the widest regions where water can lie on the surface, they also have short lifetimes that limit the ability of life to evolve. Moons in close binary solar systems have a better chance of hosting life than those in single-star systems, new research has shown.

looks like the study Aurélie wanted to do ...

What is the best (wisest) size for a group of individuals? Couzin and Kao put together a series of mathematical models that included correlation and several cues. In one model, for example, a group of animals had to choose between two options-think of two places to find food. But the cues for each choice were not equally reliable, nor were they equally correlated. The scientists found that in these models, a group was more likely to choose the superior option than an individual. Common experience will make us expect that the bigger the group got, the wiser it would become. But they found something very different. Small groups did better than individuals. But bigger groups did not do better than small groups. In fact, they did worse. A group of 5 to 20 individuals made better decisions than an infinitely large crowd. The problem with big groups is this: a faction of the group will follow correlated cues-in other words, the cues that look the same to many individuals. If a correlated cue is misleading, it may cause the whole faction to cast the wrong vote. Couzin and Kao found that this faction can drown out the diversity of information coming from the uncorrelated cue. And this problem only gets worse as the group gets bigger.

Couzin research was the starting point that co-inspired PaGMO from the very beginning. We invited him (and he came) at a formation flying conference for a plenary here in ESTEC. You can see PaGMO as a collective problem solving simulation. In that respect, we learned already that the size of the group and its internal structure (topology) counts and cannot be too large or too random. One of the project the ACT is running (and currently seeking for new ideas/actors) is briefly described here (http://esa.github.io/pygmo/examples/example2.html) and attempts answering the question :"How is collective decision making influenced by the information flow through the group?" by looking at complex simulations of large 'archipelagos'.

Apr 30, Physics/General Physics A large pile of sand accumulates in front of the sledge when this is pulled over dry sand (left). On the wet sand (right) this does not happen.

study on the environmental effects of graphene. related article http://gizmodo.com/graphene-might-be-way-worse-for-the-environment-than-we-1568823876

An amazing video.. while science is still puzzled what actually happened

There's one very simple explanation I can think of...

Can our thoughts be deciphered?

Lets capture a star, shall we?

Amazing renderings.

wow, amazing pictures !

nice

At the link below you find additional information about the projects: Education: Ten weeks to save the world http://www.nature.com/news/2010/100915/full/467266a.html

well, most good ideas probably take only a second to be formulated, it's the details that take years :-)

I do not think the point of the SU is to formulate new ideas (infact there is nothing new in the projects chosen). Their mission is to build and maintain a network of contacts among who they believe will be the 'future leaders' of space ... very similar to our beloved ISU.

A nice GPU-based framework that is basically an emulator of the brain of the fruit fly. If you need a fruit fly brain - here it comes!

YEEHA! looks like there is hope for me after all! :)

> looks like there is hope for me after all! Not really, if you believe ScienceDaily headlines...

Here we go: we might not need liquid water after all on mars to get some nice flowering plants there! ... and terraform ? :-) Thirsty plants can extract water from the crystalline structure of gypsum, a rock-forming mineral found in soil on Earth and Mars.

Some plants grow on gypsum outcrops and remain active even during dry summer months, despite having shallow roots that cannot reach the water table. Sara Palacio of the Pyrenean Institute of Ecology in Jaca, Spain, and her colleagues compared the isotopic composition of sap from one such plant, called Helianthemum squamatum (pictured), with gypsum crystallization water and water found free in the soil. The team found that up to 90% of the plant's summer water supply came from gypsum.

The study has implications for the search for life in extreme environments on this planet and others.

Nature Commun 5, 4660 (2014)

Very interesting indeed. Attention is to be put on the form of calcium sulfate that is found on Mars. If it is hydrated (gypsum Ca(SO4)*2(H2O)) it works, but if it is dehydrated there is no water for the roots to take in. The Curiosity Rover tries to find out, but has uncertainty in recognising the hydrogen presence in the mineral: Copying : "(...) 3.2 Hydration state of calcium sulfates Calcium sulfates occur as a non-hydrated phase (anhydrite, CaSO4) or as one of two hydrated phases (bassanite, CaSO4.1/2H2O, which can contain a somewhat variable water content, and gypsum, CaSO4.2H2O). ChemCam identifies the presence of hydrogen at 656 nm, as already found in soils and dust [Meslin et al., 2013] and within fluvial conglomerates [Williams et al., 2013]. However, the quantification of H is strongly affected by matrix effects [Schröder et al., 2013], i.e. effects including major or even minor element chemistry, optical and mechanical properties, that can result in variations of emission lines unrelated to actual quantitative variations of the element in question in the sample. Due to these effects, discriminating between bassanite and gypsum is difficult. (...)"

forgot the reference http://www.msl-chemcam.com/doc/documents/577/Nachon%20et%20al%20Calcium%20sulfate%20veins%20characterized%20by%20ChemCam%20Curiosity%20at%20Gale%20Crater%20Mars_2013.pdf

Physicists have devised a way to take pictures using light that has not interacted with the object being photographed. This form of imaging uses pairs of photons, twins that are 'entangled' in such a way that the quantum state of one is inextricably linked to the other.

The actual article: http://www.nature.com/nature/journal/v512/n7515/full/nature13586.html ScienceDaily version: "Scientists photograph the Schrödinger's cat for the first time!"