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Motor Made From Liquid Film

KentuckyFC writes "Last year, a group of Iranian physicists made a puzzling discovery. They placed a thin film of water in a small cell and bathed it in two perpendicular electric fields. To their surprise this caused the water to rotate. They called their device a liquid film motor and posted on the web a cool set of movies showing the phenomenon. The puzzle is this: the electric fields are static, so what's driving the motor? Now another group of physicists has the answer: a complex interaction between the electric field, the cell container and the liquid causes water to move along the cell wall. Crucially, it moves in opposite directions on opposite sides of the cell and so sets up a circular flow. The phenomenon works only when friction and surface tension are significant forces so the effect is entirely scale dependent. That's probably why we haven't seen it before and also why it could have important implications for microfluidic devices such as lab-on-a-chip."

9 of 241 comments (clear)

  1. Re:Where does the energy come from ? by mbone · · Score: 4, Informative

    OK, having read the "real" article, the best response is that this may explain the observed effects. The major differences

    - the depth of the film is an important parameter, but that isn't known for the original experiments, so they can't compare results to theory in a detailed fashion.

    - the theoretical work leads to at most one steady vortex in a container, but the experimental results show both one and two. The two vortex results may, of course, be transient.

    - the theoretical results have flow speeds largest at the outer boundary. The experimental results have it increasing towards the center. This may be explainable by other effects, such as surface tension, but it is a discrepancy.

    And the article says nothing directly about where the energy is coming from, but, reading it, it must be the electric field.

  2. good for iran by circletimessquare · · Score: 5, Interesting

    the ayatollah has made science a high priority:

    Ali Khamenei has been supportive of scientific progress in Iran. He was among the first Islamic clerics to allow stem cell research and therapeutic cloning.[27] In 2004, Khamenei said that the country's progress is dependent on investment in the field of science and technology. He also said that attaching a high status to scholars and scientists in society would help talents to flourish and science and technology to become domesticated, thus ensuring the country's progress and development.[28]

    http://en.wikipedia.org/wiki/Ali_Khamenei

    he recongizes the truth: iran will be a second rate power unless it leads in the field of science, through which it retains its independence and preeminence. this is why attacking iran's nuclear pursuits is hopeless, since iran attaches so much pride in iranian science and technology exploits. they just launched a satellite too. but all of these advances came from science and technology stolen or borrowed from other countries

    but the history of persian science is a rich one, and there is no reason its future shouldn't be bright as well, if only the ayatollah would also realize that the preeminence of the west in science came only after the enlightenment

    what else happened in the west during the enlightenment? religion was questioned. this is not a mistake or a coincidence: the questioning of religion is inseperable from being a strong scientific thinker. the probing mind of a scientist must be able to question everything, no taboos, in order to do the best science one can. you train young minds to question everything, and in this way, you make great scientists

    so dear ayatollah: i celebrate your desire to reassert persia at the forefront of science and technology. so why don't you further this great goal along by relaxing the stifling theocratic censorship of your society, ensuring bright young minds are trained to their utmost? in order to ensure that persian civilization flowers again, let little discoveries like this thin film motor not by isolated gems, but instead be the beginning of a rich tapestry of persian thought

    do that, by relaxing your fundamentalist stranglehold on the mind of the young iranian

    --
    intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
  3. This is an act of war!!! by alta · · Score: 4, Funny

    By posting links to MOVIES hosted in IRAN you have used the /. effect to saturate that entire country's available bandwidth. This is terrorism sponsored by the capitalist west! You have fired the first shot, but I ran WILL retaliate. You knew we had nukes, now we will prove it to the doubters. Kiss your precious Israel goodbye!

    It'll take us a while to get the nukes into launch position though. The servos are these really cool little motors made out of water and electricity. They have to be really small, so we have a whole lot of them working together.

    --
    Do not meddle in the affairs of sysadmins, for they are subtle, and quick to anger.
  4. Re:at least something by N1AK · · Score: 4, Insightful

    Nice to see at least something coming out of that region of the world nowadays that has no relation to terrorists or nukes.

    It is nice to see something that isn't negative about Iran getting into western news. Iran has a population around that of the United Kingdom so I have no doubt that numerous beneficial scientific discoveries are made there.

  5. Re:Where does the energy come from ? by Anonymous Coward · · Score: 5, Funny

    From the will of Allah, you insensitive infidel.

  6. Re:What a weasel sentence by ad0n · · Score: 5, Insightful

    What is worse? N1AK suggesting that out of a population of X size, you might get Y innovations (where X:Y has a common ration across various countries), or your post that suggests N1AK is an unscientific proponent of religious zealots?

    I'm left wondering if you would make the same claim if we were talking about a (say..) South American country rather than Iran.

  7. Re:absolutely wrong by dargaud · · Score: 4, Insightful

    you SHOULD earn a pittance as a university researcher [...] however, when you DO find something of value, guess what: you cash out and become a millionaire

    No. That will lead to people only working in fields where they can 'make it big' and leave all the rest which, as history has taught us again and again, is where the discoveries of tomorrow are to be made. Basically it would push technology and drop fundamental research. You think like a bean counter.

    Disclaimer, I work in research. And not everybody who does 'discovers' things. I design instrumentation; as such I'll never 'discover' anything and I'm rarely associated in publications. So for you it means I should earn a pittance with no hope of anything better.

    Well, if that's any consolation for you, I do earn a pittance already.

    --
    Non-Linux Penguins ?
  8. well said by circletimessquare · · Score: 5, Insightful

    pride has an upside and a downside, and one downside of pride is you would rather retain your identity even though it also means being in a weaker position

    the muslim world sees elements of the west that alternately repel and attract. unfortunately, some of those elements of the west aren't things unique to the west, but are actually more accurately described as elements of simple humanity. such that a lot of the fighting of westernization that goes on in the name of pride in the middle east are actually wars against humanization

    for example: women's rights. when you fight that, because it's "western", you are actually retarding the development of your own societies on a human level. if the west never existed, one can imagine the fight for women's rights continuing in the middle east, because such a fight does not depend upon the west as some sort of example, but is a fight valid within itself in islamic societies. that is, the fight for women's rights is not some sort of decadent western influence betraying traditional identity, but is instead a humanist, organic struggle native to the middle east. but humanist struggles always entail a bit of the strange and unknown, to breakway from traditional ways, and so it is easy to confuse two sources of conflict: westernization and humanization. and so, in the name of fighting the west, muslim societies subjugate their own women, and wind up hobbling the development of half their societies. for doing that, the middle east can never hope to be as powerful and as influential as the west, with half their population treated like cattle

    there's plenty of things the islamic world says it hates about the west that are shared by the west and, for example, the far east. such that to describe these concepts they say threatens the middle east as some sort of western thing is false: they are human concepts. the islamic world, in the name of retaining an identity distinct from the west, are embracing agendas that are not really anti-western, but are actually anti-human

    --
    intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
  9. Re:What a weasel sentence by Rei · · Score: 5, Interesting

    Just as another example of Iranian research: ridiculously strong concrete. High strength concrete generally has a compressive strength of 3,000 PSI or so. The person who wrote in about the situation had created concrete for the competition that was 16,000 PSI. 10,000 PSI is considered hard rock, and granite is 30,000 PSI. The Iranian concrete was *50,000-60,000* PSI. When it shattered, it damaged the testing equipment. They pulled it off using what appeared to be a quartz aggregate (160,000 PSI) and steel fibers. And this was at 28 days; concrete gets stronger over time.

    Naturally, Wired spins it into the context of bunkers and nuclear weapons, like we do with everything that comes out of Iran. How long until this thin-film motor gets portrayed as something nefarious?

    "Next on Fox: An Iranian art student paints a prize-winning portrait of a sunflower. Is it really a secret code for transferring nuclear secrets? Find out after the break."

    Iran is trying their damndest not to be seen as an intellectual backwater. And while they're not up to western standards, nor are western stereotypes of Iranian academic achievement generally justified. There are now six times as many university students in Iran today as there were in 1979 when the Shah was overthrown -- largely because tuition, room, and board are paid for by the government, which is trying to improve their education standards. Here's a fair summary of the situation today. They're no shining star when it comes to education, but they're not backwoods yokels either.

    Another way to put it: Iran has two of the top 500 universities in the world, as ranked by QS. That puts them tied for 42nd in terms of top-500 universities, with . 140 countries don't have any top-ranking universities at all. There's not a single country in the Carribean with a top-500 university, only two countries in all of Africa (Egypt=1, South Africa=4), and so on. The lion's share are in the US -- 123, followed by the UK (50), Germany (42), France (38), and Japan (36). Iran ranks better than Lithuania, Saudi Arabia, Uruguay, Egypt, Slovenia, Colombia, Peru, UAE, Romania, Sri Lanka, and Bangladesh (1 each), but below Mexico (3) and Poland, Portugal, Pakistan, Denmark, Israel, Norway, South Africa, Chile, Phillipines, Czech Republic, and Argentina (4 each).

    --
    Are there any deer in the theater tonight? Get 'em up against the wall.