Paulipod 0 #1 November 3, 2004 Having seen the budding scientists among you in the 'Weight / Mass' thread.... Here's a little poser for you.... What makes water go the direction it does down the plughole? Bodyflight Bedford www.bodyflight.co.uk Quote Share this post Link to post Share on other sites
mnealtx 0 #3 November 3, 2004 Coreolis (spelling?) effect.... and if you're below the equator, it runs the other way...Mike I love you, Shannon and Jim. POPS 9708 , SCR 14706 Quote Share this post Link to post Share on other sites
Paulipod 0 #4 November 3, 2004 FAIL - Next answers please Bodyflight Bedford www.bodyflight.co.uk Quote Share this post Link to post Share on other sites
yoink 321 #5 November 3, 2004 Quote FAIL - Next answers please I told you.... magic. Quote Share this post Link to post Share on other sites
Paulipod 0 #6 November 3, 2004 lol.. I'll reserve judgement on that one til I run out of other suggestions Bodyflight Bedford www.bodyflight.co.uk Quote Share this post Link to post Share on other sites
Patkat 0 #7 November 3, 2004 Gravity, and the fact that water is a fluid, allow it to flow down the drain. All other things being equal, the spin the water takes on is caused by the coreolis effect, imparted by the earth's rotation. It's clockwise in the northern hemisphere, and anti-clockwise in the southern. You can get it to spin the other way with a vigorous swirl of the hand, or with that device featured in the Simpsons episode where Bart placed that expensive call to Australia.Patkat gotta exercise my demons! Quote Share this post Link to post Share on other sites
Paulipod 0 #8 November 3, 2004 lol... I wondered how many people based their knowledge on the simpsons However... FAIL - Coriolis is NOT the right answer... but a commonly misunderstood myth. Bodyflight Bedford www.bodyflight.co.uk Quote Share this post Link to post Share on other sites
mnealtx 0 #9 November 3, 2004 So my old physics book was wrong? Damn....Mike I love you, Shannon and Jim. POPS 9708 , SCR 14706 Quote Share this post Link to post Share on other sites
Paulipod 0 #10 November 3, 2004 Fraid so... if they said that your household plughole is affected by Coriolis.... I'll hold on for correct answers Bodyflight Bedford www.bodyflight.co.uk Quote Share this post Link to post Share on other sites
Cajun 0 #11 November 3, 2004 Frame-dragging ? Quote Share this post Link to post Share on other sites
Guest #12 November 3, 2004 QuoteHaving seen the budding scientists among you in the 'Weight / Mass' thread.... Here's a little poser for you.... What makes water go the direction it does down the plughole? IIRC, there have been some new findings which have debunked the Coriolis Effect wrt the "swirly direction", but I can't recall what they are and I don't have the findings in front of me. Care to illuminate us there, Hawking? mh . Quote Share this post Link to post Share on other sites
yoink 321 #13 November 3, 2004 Chaos Theory.... or magic. One of the two anyway... probably. Quote Share this post Link to post Share on other sites
BeattheDrums 0 #14 November 3, 2004 I'm thinking it might have something to do with the design of the plughole.... Did I win? A thunder of jets in a clear blue sky, a streak of gray and a cheerful "Hi" Quote Share this post Link to post Share on other sites
Paulipod 0 #15 November 3, 2004 Ok Ok... certainly the closest... Its really down to the shape and imperfections of the bowl.. So - Lisa Simpson, youre not so smart after all! I have three basins in my house for example - 2 go clockwise - 1 goes anticlockwise Bodyflight Bedford www.bodyflight.co.uk Quote Share this post Link to post Share on other sites
yoink 321 #16 November 3, 2004 and nobody's noticed this before????? Quote Share this post Link to post Share on other sites
Patkat 0 #17 November 3, 2004 Quotelol... I wondered how many people based their knowledge on the simpsons However... FAIL - Coriolis is NOT the right answer... but a commonly misunderstood myth. Too bad Malcolm in the Middle hasn't addressed this problem - I'm sure that kid knows the right answer. And anyway, I'm an English major. I don't know much, but at least I cite my sources I'll stick with my basic answer - that gravity and water's fluidity enable it to flow down the drain, and postulate that the spinning effect is caused by the fact that the drain is round and that water tends to adhere to surfaces. The spinning effect is the most efficient manifestation of the water's tendency to flow down the sides of the drian pipe. I just made all that up on the spot. [takes break for a quick education in fluid dynamics.] http://www.physics.ohio-state.edu/~dvandom/Edu/newcor.html http://www.sciam.com/askexpert_question.cfm?articleID=00069EE7-6D24-1C71-9EB7809EC588F2D7&catID=3 These two sources suggest that it really is just residual motion left over from the filling of the sink, or other motion imparted while it was filled. Coriolis effect can be measured under verrrry controlled circumstances, but is negligible in real life. Guess I overthought it.Patkat gotta exercise my demons! Quote Share this post Link to post Share on other sites
pilotdave 0 #18 November 3, 2004 Snopes agrees with ya: http://www.snopes.com/science/coriolis.htm Dave Quote Share this post Link to post Share on other sites
Patkat 0 #19 November 3, 2004 Wait! What am I doing? I am definitely taking a shower and putting on some clothes - right this instant! Patkat gotta exercise my demons! Quote Share this post Link to post Share on other sites
unformed 0 #20 November 3, 2004 cool ... i just learned something today .... i always thought it was the coriolis effect ..This ad space for sale. Quote Share this post Link to post Share on other sites
mccurley 0 #21 November 3, 2004 I was told by my physics teacher in highschool that as one side of the hole was closer to the equator it was traveling trough space faster then the other side, due to the distance of the equator. (Imagine the travel trough space as a straight line) This minute difference in the realative speed of north and south sides of the hole impart the spin into the water as it drops, or changes vector through space. (Imagine two bodies exiting seperate airplanes flying beside each other at slightly different speeds and each holding on to opposite ends of the same rope. One is trown forward faster then the other) That's what he told us anyway back in about 1969. Hell I'm impressed I can remember that!!!Watch my video Fat Women http://www.youtube.com/watch?v=eRWkEky8GoI Quote Share this post Link to post Share on other sites
JohnMitchell 14 #22 November 3, 2004 High School science classes are full of misinformation. The Coriolis effect requires large distances to have an effect. I've read that the Coriollis effect in a bathtub would produce one revolution per day, hardly a large factor in which way the water drains. However, I've read that a 15 mile artillery round will displace up to 100 yards due to the Coriollis effect, depending on latitiude and direction of the shot. Any artillery officers out there with more info? High School Science also tells us that it's only Bernoulli making all airplanes fly, another science myth. Quote Share this post Link to post Share on other sites
mccurley 0 #23 November 3, 2004 Agreed the scale was incorrect but the lesson was an analogie relating to the larger scales involved in physics. Along with gravitational influances and proximity to large masses. Things get scaled down to fit into our tiny highschool brains. So analogy fundmentally correct, in the context of larger scales. IE: assume the rope the jumpers are hanging on to being hundreds of miles long? Theoretical of courseand assume on mass or drag effect on the rope itself.Watch my video Fat Women http://www.youtube.com/watch?v=eRWkEky8GoI Quote Share this post Link to post Share on other sites
SpeedRacer 1 #24 November 3, 2004 coriolis effect does not have a significant effect on bodies of water as small as your sink or toilet. It has to do with the shape of the drain, initial motion of the water when it was put in, etc. Speed Racer -------------------------------------------------- Quote Share this post Link to post Share on other sites
kallend 1,646 #25 November 3, 2004 QuoteHaving seen the budding scientists among you in the 'Weight / Mass' thread.... Here's a little poser for you.... What makes water go the direction it does down the plughole? Coriolis effect is tiny over the dimensions of a bathtub, and random turbulence in the water easily overcomes it. HOWEVER, some 30 years ago some physicists did an experiment with a tub of water that they let stand, covered, for a week (so any intial motions would die out) before draining it through a hole in the center, using, I believe, a valve some way down the drain so that opening the valve didn't create any effect in the tub. Apparently under these conditions the rotation direction was quite consistent with Coriolis. So the real answer to your question is - conservation of angular momentum (which always works).... The only sure way to survive a canopy collision is not to have one. Quote Share this post Link to post Share on other sites
