Good Math, Bad Math

I came across this while looking through the referrals to GM/BM. This is an incredibly cool video of a strange phenomenon called the Kaye effect. It includes high speed video of the effect, and a demonstration of their mathematical analysis of the effect, and their prediction and verification of the effect.

The Kaye effect is an incredibly bizarre phenomenon. Basically, if you take a substance like liquid shampoo, and allow a thin stream of it to pour down from a height onto a smooth surface, the stream will periodically “bounce”, producing a stream leaping up from the point of contact. Watch it – it’s seriously cool.

Comments

  1. #1 Jon
    April 17, 2007

    That jetting effect reminds me of a solar flare.

  2. #2 archgoon
    April 18, 2007

    Fluids are whack.

  3. #3 Matthew
    April 18, 2007

    Ok, this is totally awesome.

    I have shampoo all over my bathroom sink now though.

  4. #4 Chris M
    April 18, 2007

    Wow! That is seriously cool. I also just tried this with some shampoo and it works. It’s a little hard to see the effect but you can see the result of effect…ie: the little streamers of shampoo left by the effect.

    Hmm… wonder if it would be hard to rig up the stable version in the bathroom…

  5. #5 Vityok
    April 18, 2007

    It is really cool. Worth to try.

  6. #6 Mark Hudson
    April 18, 2007

    Surely you all must be aware that no *human* could stack shampoo this way. This is proof, if any more were needed – just look around you, that GOD loves us, and wants us to have shiny hair.

  7. #7 gg
    April 18, 2007

    Nice! This is a perfect example of why I like the physical sciences – occasionally, one can still find jaw-dropping phenomena that can be observed in your bathroom.

    Mark Hudson wrote: “This is proof, if any more were needed – just look around you, that GOD loves us, and wants us to have shiny hair.”

    I would argue, due to the noodle-ness of the stream, that the FSM loves us, and wants us to have shiny hair. I mean, look at the traditional representation of the Christian god – he’s got a wild tangle of unkempt white hair! No way he’s responsible… Q.E.D.

  8. #8 Torbjörn Larsson
    April 18, 2007

    Fluids seems simple, yet admits a lot of fun physics. This reminds me of the youtube movie (“youtubio” ?) where one see people run on top of a bath of certain liquids, but sinks when standing still. IIRC there it was abnormal viscosity behavior.

    Pouring has other effects as well. One can look for oscillations as a function of flow, which has its own physical model. Another cool effect is to set up a dynamical stability by letting a fairly massive stream catch and hold floating bottles and perhaps other objects. Preferentially for bottles it forces down and holds the neck for a certain range of flows.

    I haven’t seen any attempt of explanation of a water trap. But it seems to me the dividing stream presses down the surrounding liquid and forces the bottle to stay. Drift in one direction would mean less of a stream which would give less of a dimple, forcing the bottle back to the symmetrical position.

    Or perhaps there is a better explanation. Why not give it a try and come back with observations? It is a good reason to empty a coke bottle, and it looks cool when the bottles becomes trapped under a tap. Just remember to throttle back the water before the sink overflows. ;-)

    (If anyone wants to make the effort in coming up with a testable model, please check thoroughly for previous work first, don’t take my word for it.)

  9. #9 andy.s
    April 18, 2007

    this is TOTALLY science fair material.

  10. #10 Amos
    April 18, 2007

    Torbjörn Larsson,

    I’ve seen that video as well. The video description says it’s a non-Newtonian fluid made from cornstarch and water. I’ve heard people have tried making bullet-proof vests based on the same principle, but none have worked well enough to make it to market. Very cool if one every does.

  11. #11 Dave Andersen
    April 18, 2007

    Torbjörn wrote: “I’ve heard people have tried making bullet-proof vests [out of non-newtonian fluds]”.

    In fact, a company called Spyder makes
    body armor for skiing based on exactly this principle. They protect the shins and forearms using it, and they claim it’s quite effective. No personal experience with it myself.

  12. #12 mollishka
    April 18, 2007

    Er, I think I need to invest in cheaper shampoo now …

  13. #13 Torbjörn Larsson
    April 19, 2007

    a non-Newtonian fluid

    Right, unconventional (‘non-liquid’) answer to stress due to unconventional viscosity behavior.

    Thanks for the info!

    Torbjörn wrote: “I’ve heard people have tried making bullet-proof vests [out of non-newtonian fluds]”.

    No, Amos deserves the credit for that.

    The body protection application was new to me. Though I am still dreaming of having a collision bag collar instead of a helmet for head (and back) protection on bicycles. (With a lot of issues about safety and activation, of course.)

    (Mandatory helmet regulation here – as if. ;-) I have nordic thin hair, so don’t wear head gear when it is avoidable.)

  14. #14 Julia
    April 22, 2007

    I need to invest in some biodegradable shampoo to try this at a Burn event. Whee!

  15. #15 Norm Breyfogle
    April 22, 2007

    God’s cleanliness agenda or even the FSM’s? Nah, this video is due to shampoo companies’ sales dreams!

    Btw, I wonder if spaghetti sales have risen in the last couple of years?

    That does it; I’m starting my own religion.

  16. #16 sideral
    March 18, 2008

    Whose music is this???? I love it! Can we find it somewere?
    and for the rest … it’s realy seriously cool !

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