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Thijs Versloot

Folding batteries - 1 views

phys.org/...ries-areal-energy-density.html

technology battery origami

shared by Thijs Versloot on 11 Oct 13 - No Cached
  • Thijs Versloot on 11 Oct 13
     
    They are cheating however as they fold a paper of 6x7cm to 1.6cm2 and then say the capacity has increased. But the interesting point here is that planar paper-batteries are very cheap to manufacture in roll-2-roll, plus there are many folding techniques thanks to the Japanese
johannessimon81

Evolutionary strategy: song birds search food in morning, go eat it in afternoon - 0 views

www.bbc.co.uk/24458583

BIO

shared by johannessimon81 on 11 Oct 13 - No Cached
  • johannessimon81 on 11 Oct 13
     
    Song birds don't eat in the morning because the added weight makes them slow and easy prey for other birds. They look for good food places during the early day and come back to eat as late as possible. Correlation of this behavior with the number of predators has been found as well...
LeopoldS

Brown Recluse Spider's Silk Is Strong and Really Strange - Wired Science - 0 views

www.wired.com/...brown-recluse-silk

Bio biomimetic silk

shared by LeopoldS on 12 Oct 13 - No Cached
  • LeopoldS on 12 Oct 13
     
    Fascinating! New type of spider silk?
Tom Gheysens

New theory of synapse formation in the brain - 2 views

www.sciencedaily.com/...131010205325.htm

Bio science AI brain

shared by Tom Gheysens on 14 Oct 13 - No Cached
  • Tom Gheysens on 14 Oct 13
     
    I have no idea if an algorithm based on this already exists, but it would certainly be a good one for autonomous AI, I think. I think an algorithm based on this should be able to select his own input parameters and reject them if they are not stimulated any further or integrate them in the algorithm if they are continiously stimulated... this could enable self learning, etc.
  • johannessimon81 on 14 Oct 13
     
    By steering the neuron's back to an intermediate activity level the mechanism probably optimizes their efficiency within the network (after all a neuron that fires all the time is just as useless as one that never fires).
Thijs Versloot

Infinite phase velocity in zero permittivity #metamaterial achieved - 2 views

phys.org/...sible-infinite-wavelength.html

light nano metamaterials

shared by Thijs Versloot on 14 Oct 13 - No Cached
  • johannessimon81 on 14 Oct 13
     
    Damn... At Leiden University I worked on transmission of light through Ag nano-layers. This could have been an easy experiment. I wonder about the evanescence of the wave as visible light is usually attenuated to <5% within 250nm of silver.
Thijs Versloot

Taking the internet underwater - 0 views

phys.org/...13-10-internet-underwater.html

technology

shared by Thijs Versloot on 15 Oct 13 - No Cached
  • Thijs Versloot on 15 Oct 13
     
    University at Buffalo researchers are developing a deep-sea Internet. The technological breakthrough could lead to improvements in tsunami detection, offshore oil and natural gas exploration, surveillance, pollution monitoring...
Nicholas Lan

amines found to be far more important than cosmic rays in cloud formation - 0 views

www.nature.com/...nature12663.html

science atmospheric biology

shared by Nicholas Lan on 15 Oct 13 - No Cached
  • Nicholas Lan on 15 Oct 13
     
    relationship between living organisms and cloud formation seems interesting
Zivile Dalikaite

Amaze project aims to take 3D printing 'into metal age' - 1 views

www.bbc.co.uk/...science-environment-24528306

technology

shared by Zivile Dalikaite on 16 Oct 13 - No Cached
  • Zivile Dalikaite on 16 Oct 13
     
    The European Space Agency has unveiled plans to "take 3D printing into the metal age" by building parts for jets, spacecraft and fusion projects.
  • Marcus Maertens on 16 Oct 13
     
    Metal Age sounds like some epic good time...
annaheffernan

Cool new analytical solutions to Maxwells equations - 5 views

physicsworld.com/...hysicists-tie-light-into-knots

shared by annaheffernan on 17 Oct 13 - No Cached
  • annaheffernan on 17 Oct 13
     
    The solutions show light tied in knots
  • johannessimon81 on 17 Oct 13
     
    Really cool topic. Here a link to a paper from Leiden's quantum optics group from 2008 about knotted light (I was in that group at the time): http://www.nature.com/nphys/journal/v4/n9/abs/nphys1056.html
  • LeopoldS on 27 Oct 13
     
    knot theory ... any volunteers?
johannessimon81

Big Data challenge at NASA - 2 views

www.nasa.gov/...spitzer20131017.html

technology big_data

shared by johannessimon81 on 19 Oct 13 - No Cached
LeopoldS liked it
  • johannessimon81 on 19 Oct 13
     
    Relevant to our recent discussion on big data at ESA?
  • LeopoldS on 19 Oct 13
     
    relevant yes, though the article gives little information on the "how"
johannessimon81

Bill Nye - The Science Guy on Jupiter and the Juno spacecraft - 0 views

www.youtube.com/watch

science education

shared by johannessimon81 on 19 Oct 13 - No Cached
  • johannessimon81 on 19 Oct 13
     
    Great explanations of space stuff for people who are not experts (for example children) :-)
Thijs Versloot

Quantum #teleportation theory to be tested on the #ISS - 8 views

phys.org/...eleportation-theory-space.html

science quantum ISS

shared by Thijs Versloot on 22 Oct 13 - No Cached
  • Thijs Versloot on 22 Oct 13
     
    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.
  • LeopoldS on 27 Oct 13
     
    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)."
Thijs Versloot

Does your iPhone have free will? #arXiv - 3 views

medium.com/...1e223b77e60

technology behavior

shared by Thijs Versloot on 22 Oct 13 - No Cached
  • Thijs Versloot on 22 Oct 13
     
    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.
  • ...3 more comments...
  • Luzi Bergamin on 22 Oct 13
     
    An interesting paper about how you should *NOT* think about free will...
  • johannessimon81 on 23 Oct 13
     
    I must say that the fact that the outcome of a thought process is not evident to myself in advance sounds like a more plausible explanation than 'free will' being the product of quantum mechanics. The later would not only produce unpredictable decisions but probably also irrational ones...
  • Paul N on 24 Oct 13
     
    Even if it were the product of quantum mechanics, it's still the result of external interference and not the result of 'free' will. It doesn't matter if the external input is deterministic or random, it's still external and it's not "YOU" that decided stuff.
  • Luzi Bergamin on 24 Oct 13
     
    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!
  • LeopoldS on 27 Oct 13
     
    Henry Kissinger How I'm missing yer And wishing you were here
Thijs Versloot

Dolphin inspired radar #biomimicry - 2 views

phys.org/...-10-dolphins-radar-device.html

tech bio radar

shared by Thijs Versloot on 23 Oct 13 - No Cached
  • Thijs Versloot on 23 Oct 13
     
    The device, like dolphins, sends out two pulses in quick succession to allow for a targeted search for semiconductor devices, cancelling any background "noise",
  • ...1 more comment...
  • Athanasia Nikolaou on 30 Oct 13
     
    and it sends out two pulses of opposite polarity, in succession, such that a semiconductor changes the negative to a positive one, amplifying the returning signal. Very interesting. Maybe we can combine different frequencies for identifying a single variable in earth observation. We already use more that one frequencies but for identifying one variable each.
  • Thijs Versloot on 31 Oct 13
     
    Could it be used to measure ocean acidification? I found a study that links sound wave propagation with ocean acidity. Maybe we are able to do such measurement from space even? "Their paper, "Unanticipated consequences of ocean acidification: A noisier ocean at lower pH," published last week in the journal Geophysical Research Letters, found that fossil fuels are turning up the ocean's volume. Since the beginning of the Industrial Revolution, the overall pH of the world's oceans has dropped by about 0.1 units, with more of the changes concentrated closer to the poles. The authors found that sound absorption has decreased by 15 percent in parts of the North Atlantic and by 10 percent throughout the Atlantic and Pacific"
  • Athanasia Nikolaou on 31 Oct 13
     
    The last time I asked an oceanographer for the use of acoustic waves, she said it is still a bit problematic method to take into account its data, but we were referring to measuring ocean circulation. It may be more conclusive for PH measurements, though. The truth is that there is a whole underwater network with pulse emmitters/receivers covering the North Atlantic basin, remnant infrastructure for spying activities in the WW2 and in the cold war, that stays unexploited. We should look more into this idea
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.
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