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Science

The Weird Science of Tossing Stones Into a Lake 89

Posted by kdawson
from the no-skipping-allowed dept.
Interoperable writes "Researchers in Spain and the Netherlands add another piece to a centuries-old puzzle in physics: the dynamics of an object falling into water. This common occurrence has a complex anatomy that includes a thin 'crown splash' around the perimeter of the impact, a deep cavity of air following the impactor, and a high, narrow jet of water that results from the collapse of the cavity. The new research, recently published in Physical Review Letters, demonstrates that airflow through the neck of the collapsing cavity reaches supersonic speeds despite low relative pressures between the air in the cavity and ambient pressure. Such an effect has no analogue in aerospace engineering or other sciences because of the highly dynamic nature of the collapsing nozzle structure." It's funny that the APS wants to charge non-subscribers $25 to download what is available for free on the arXiv.
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The Weird Science of Tossing Stones Into a Lake

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  • by creimer (824291) on Monday January 18, 2010 @07:15PM (#30814590) Homepage
    The only way to appreciate the science of tossing stones into a lake is to be stoned yourself.
    • Personally I'd suggest getting high on marihuana; I've never been a fan of playing the Lottery.

      • by trb (8509)
        I guess most slashdot readers never read that story.
    • by u38cg (607297)
      An old bridge engineer's trick is to chuck a large stone into water. If it goes 'splash', it's shallow. If it swallows it with a 'gloop', it's too deep for a person.
  • by Anonymous Coward

    Slashdot has officially jumped the shark with this splashing story. Really, who gives a toss?

    • by JWSmythe (446288)

      Ummmm, it jumped the shark a few years ago. We just hang out here out of morbid curiosity. Kinda like watching the last few years of the Cosby show. Oh wait, that one bit it on the pilot. We only watched for one reason [youtube.com] (warning, video acid trip).

    • I do, really I'm quite fascinated by stuff like this.

  • by djupedal (584558) on Monday January 18, 2010 @07:27PM (#30814690)
    If you promise not to mess with the nature of my nozzle's highly dynamic collapsing nozzle-structure, I won't mess with yours - unless you want me to, of course, in which case I would expect to be able to count on reciprocity.

    I think that's only fair, I mean, especially given that we just met and all. Let's just hope your nozzle hasn't been anywhere unseemly lately. I hate unseemly nozzles and I have no use for any with a rather static collapsing nozzle-structure, as I'm sure most people do. yuck....
  • by Trepidity (597) <delirium-slashdot@@@hackish...org> on Monday January 18, 2010 @07:32PM (#30814722)

    Imagine what the U.S.'s technology leadership could've been like if we had put a President in the White House who truly understood [youtube.com] this kind of cutting-edge science.

    • by kandela (835710)
      Yeah, he made quite a splash!
    • Re: (Score:3, Insightful)

      by phantomfive (622387)
      Wow, you posted the link to a youtube video and now slashdotters are starting to post over there. Check out this comment for example, made about an hour ago:

      Wait, what? Some "people" will spend $15 to $20 for the tickets to sit through 'Butterfly Effect,' 'The Hitchhiker's Guide to the Galaxy' and 'Shrek' but still make themselves known to Big Brother as unclear on such a plain and simple concept as we have in this video? OK, put the cell phone down and step away from the 'candy.'

      Notice these signs:

      * The implication that all other people are stupider than the poster.
      * Talking about geeky movies
      * Vastly over-estimating the value of a movie ticket, showing this person never actually goes to the theater, because he has no friends and just downloads all the movies he or she watches.
      * Totally out of place comment
      * Exaggerated,

      • Not the poster but in Australia movie tickets cost $15 for a standard ticket - more ritzier set-ups go as high as $30. What is the cost in the US and elsewhere? Are we getting ripped off?
        • I expect to spend about $10 USD when I go to the theater. Don't know how that relates to the Australian dollar, but I know the exchange rates have been fluctuating a lot lately.
        • by NitroWolf (72977)

          Not the poster but in Australia movie tickets cost $15 for a standard ticket - more ritzier set-ups go as high as $30. What is the cost in the US and elsewhere? Are we getting ripped off?

          It depends on what theater you go to...

          Standard tickets are $5 - $7 for matinee, then you have prime time which usually runs $7 - $10. We are starting to see a lot more premium theaters that have suites and recliners, restaurants, etc... and those tickets are $15 - $20 each. I pay for the suites which are $20 a piece because, well, it's worth it and they give you "free" $7.50 in food, so the ticket is really only $12.50 if you plan on ordering something anyway... and no one under 18 is allowed. It's much

        • by pjt33 (739471)

          I saw Avatar in 3D in Spain for a bit less than the equivalent of 15 AUD. Normal tickets are about 75% of that.

      • by aug24 (38229)

        I like the way he quoted the word people. What are they really? I suggest that he or she must be on some kind of drugs. Possibly Ritalin.

  • by denmarkw00t (892627) on Monday January 18, 2010 @07:32PM (#30814724) Homepage Journal

    Neat! I want to see what that cone looks like as it develops, in super-slow motion.

    Offtopic: I can't reply to the Racist Facial thread - all the Reply buttons are missing in both Camino and Firefox, and obviously I can post this thread. What gives?

    • Re: (Score:3, Interesting)

      by shams42 (562402)

      Offtopic: I can't reply to the Racist Facial thread - all the Reply buttons are missing in both Camino and Firefox, and obviously I can post this thread. What gives?

      You must not be of Slashdot's preferred race...

    • It's probably because the story is old.
  • by imsabbel (611519) on Monday January 18, 2010 @07:36PM (#30814748)

    Just some pieces of info for people who might not know:

    Nowadays, all the major publishers dont have an issue if you post a prepring on arxiv, prl included.
    If you want to get a preprint out, the procedure is as follows:

    1) You put something on arxiv and submit it to PRL.
    2) After a few weeks/months, you get your referee reports.
    3) Then you revise it, and update your arxiv version.
    4) Paper gets accepted. Paper is entering the editorial process, and you get proofs.
      -> at this point, APS has contributed to the paper. The specific version proofed by PRL can no longer be uploaded to ARXIV /etc.
    5) Final corrections, ready to print.

    Nowadays, the proof and setting part is relatively minor. Most likely you will have written it in RevTex, and have PDF figures, so its an no issue.
    But they still allow you to send them the text in word and the figures in phyical form (ink drawing, whatever), if you are really interested in it not getting published quickly.

    So for most issues, a paper on Arxiv might be 99.9% identical to the final published paper, and only diiffer by the editorial issues. But you cannot know it. It might also represent a state from before the peer review.

    • Re: (Score:3, Insightful)

      by skine (1524819)

      My impression of the system is:

      1) Hey, respectable journal! Here's my paper. You own it now. Please publish it?

      2) Journal either publishes it, or doesn't. Either way, they own your paper and pay you nothing.

      3) You want to spread the information, so you post it for free on the internet. This is a breach of copyright, but the Journal doesn't really care because the same number of people will buy the magazines regardless.

      • Re: (Score:2, Insightful)

        by Krahar (1655029)
        In my experience you only hand over copyright AFTER the paper has been accepted for publication, and you ARE allowed to post preprints on the internet. What you are not allowed to do is to take the final PDF that the paper prints and distribute it, even if it is word-for-word identical other than editorial changes.
        • Re: (Score:3, Insightful)

          I think that's correct. You can generate a pdf of the exact article that the journal has and distribute it freely because you retain the rights to the content. The exact formatting, however, is copyrighted exclusively by the journal so you can't distribute the pdf you get from their website.
      • by khallow (566160)
        I agree with the other replier. When I published [scientificcommons.org] some physics papers with my PhD adviser, we wrote the papers first, put them on the Arxiv, then looked for a place to publish the papers. We didn't actually hand over copyright till the papers were accepted.
      • Re: (Score:3, Interesting)

        No, copyright transfer is very odd for journals. The author retains the right to print the article for personal distribution (you can always find a pdf on the author's website) and distribution of pre-prints is fine. I believe that the journal does hold the copyright, but certain exceptions are included in the transfer paperwork so there's no breach of copyright. Furthermore, images can be usually copied with consent of the author, not the journal (except art supplied by the journal, such as covers).

        You can

      • by tsa (15680)

        Don't forget the journal usually charges you 100 US$ per page for publishing it.

    • by jschen (1249578) on Monday January 18, 2010 @10:27PM (#30815778)

      Nowadays, all the major publishers dont have an issue if you post a prepring on arxiv, prl included.

      True in some fields, but not all. The two biggest chemistry journals, Angewandte Chemie and Journal of the American Chemical Society, both do not allow submission of communications for which preprints have been released. One also can't submit it elsewhere at the same time. (One can, though, submit a paper to either journal after another journal has already declined to publish it.) As for the major multidisplinary journals, Nature allows publication of preprints. Science does not.

    • by prograde (1425683)

      There's a quicktime movie showing the reversal of the air stream [aps.org] in the Supplemental Material of the PRL site.

      It's pretty cool, and I couldn't find it on arxiv. Boy, I love being a student again and having free access to journal subscriptions!

  • PT Barnum (Score:3, Insightful)

    by v1 (525388) on Monday January 18, 2010 @07:43PM (#30814810) Homepage Journal

    It's funny that the APS wants to charge non-subscribers $25 to download what is available for free on the arXiv.

    If there's somebody stupid enough to pay for it, there's always somebody smart enough to charge for it.

    Economic Darwinism hard at work, parting fools from their money since before 5,000 BC.

    • by LihTox (754597)

      They charge $25/paper so that university libraries will continue to pay for full access for their users. If the papers were free, libraries could stop subscribing to the journals and the funding would dry up. As it is, I doubt that very many people pay the $25; at least I hope not. If any are, I suggest becoming acquainted with the nearest university library (and if you're a scholar, even an unemployed/underemployed one, try to become affiliated with the appropriate department of a local college or unive

      • Usually a trip to the author's website will serve to get you pdf generated from the same source sent to the journal. If not, e-mail the author; they love it when people read their work.
  • $25 (Score:1, Interesting)

    by Anonymous Coward

    It's funny that the APS wants to charge non-subscribers $25 to download what is available for free on the arXiv.

    It's not that funny - the version subscribers can download from the APS has, amongst other things, a guarantee that it has had at least one cursory review. While it is true that the arxiv also filters out almost all spam and quite a few of the crackpot submissions, it is still chock-full of total bullshit. Say what you like about APS being the "accepts anyone" whore of the scientific community, th

    • you can hopefully see that the APS is not trying to rip people off or make everyone miserable.
      What I guess they are doing is trying to drive people to subscribe rather than buying single articles by making the single article price stupidly high.

      Subscriptions have a number of advantages for a publisher

      1: it provides a more steady stream of income. In general stability is good especially for a smaller buisness or a nonprofit.
      2: people may keep paying even if they no longer really need the subscription. People

  • by KneelBeforeZod (1527235) on Monday January 18, 2010 @07:47PM (#30814848)

    I'd love to see the testing process for this.

    Tries 1 - 100

    1. Plop
    2. Plunk
    3. Plunk
    4. Bloop
    5. Plunk ....

    Give me a grant!

  • by Tisha_AH (600987) <Tisha.Hayes@gmail.com> on Monday January 18, 2010 @07:56PM (#30814914) Journal

    My younger brother discovered a key principle of the viscosity of fluids when he was 12 years old. He and his friend decided to drop a gigantic boulder down the center hole of an outhouse, they were standing over the "opening" to see the effect.

    I imagine the sound was much "deeper" but their screams were really high.

    It was a 2 mile walk to the nearest running water for them, our camping trips were never the same after that.

    • by mikael (484) on Tuesday January 19, 2010 @12:14AM (#30816268)

      A similar event happened during the construction of the London flood barrier. For some reason, a large amount of material had to be dumped into the river Thames. This might have been cement or just rubble for part of the underground foundations. It was anticipated that this process might generate some sort of pressure wave that would travel at high speed through the water. Thus a warning was given not to be in the river or close any storm drains at this time. Unfortunately, this warning was not received by a particular tenant of an old apartment block which had one end of their combined storm drain/sewer overflow submerged in the river. Minutes after the construction process had begun there was a complaint through the telephone lines that the tenant in question had just stood up in their bathroom, when the toilet had erupted in a geyser that went everywhere.

      This was from the same construction company that attempted to fill in a deep hole in the River Thames with liquid cement, only to find that they had filled in someone's basement / underground car park.

    • by squidfood (149212)
      Teachable moments are so rare.
  • I read the title as "The weird Science of Tossing Salad"
  • Cool technique. I wonder if they played "Smoke on the water" in the background ;P~~~

  • How Profound:The high air speeds are shown to result from the "nozzle" being a liquid cavity shrinking rapidly in time.

    • Remember, the cavity is closing up in 3 dimensions while the air has only one direction in which to escape. Rather than profound, it is an interesting phenomenon, and can possibly have some practical usage.

  • by Hurricane78 (562437) <deleted@slashd o t .org> on Monday January 18, 2010 @10:05PM (#30815638)

    For anyone who cares: Her name was: Amélie Poulain.

    ___
    *Waiting for the about 3 french female geeks who get it* ;)

  • Designed for mere mortals to read, should really have been included by the OP. http://physics.aps.org/viewpoint-for/10.1103/PhysRevLett.104.024501 [aps.org]
  • 1.) When the ball reaches the fluid it momentarily stops
    2.) Just as the balls is completely below the fluid line it appears to stop again
    3.) As the ball travels through the fluid, the INNER wall of separated fluid remains surprisingly straight for a surprisingly long period of time, yet the OUTER wall appears to be in constant motion
    4.) Just before the ejected column of fluid collapses, a bright flash (a bubble perhaps) appears within the 'dome' of the ejection. This appears to change in intensity, be
  • So, the big question is: when will the first computer game that features realistic water splashes be released?
  • Lottery in June. Corn come soon....

  • This explains the "Kerplunk" sound of a softball or slightly larger sized rock dropped into water. It's the initial splash "Ker" and the collapsing cone "Plunk".

Let's organize this thing and take all the fun out of it.

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