Two years ago I wrote an article about The Myth of the Toilet Flush, comparing the angular rotation caused by the earth’s rotation to the typical rotation in experiments with garden hoses that make it easy to observe the Coriolis effect. There are several orders of magnitude in difference, and the effect can only be observed in an experiment done extremely carefully, not in the bathtub sink or toilet flush.
Now two awesome science geeks have finally done such a careful experiment – even a time-synchronized one, observing vortices on either hemisphere!
The effect has been demonstrated in a similarly careful experiment in 1908. It had been done on the Northern hemisphere only, but if it can attributed it to the Coriolis effect by ruling out other disturbances, the different senses of rotations are straight-forward.
Austrian physicist Ottokar Tumlirz had published a German paper called “New physical evidence on the axis of rotation of the earth”. I had created this ugly sketch of his setup:
A cylindrical vessel (not shown in my drawing) is filled with water, and two glass plates are placed into it. The bottom plate has a hole, as well as the vessel. Both holes are connected by a glass tube that has many small holes. The space between the two plates is filled with water and water slowly flows out – from the bulk of the vessel through the the tiny holes into the tube. These radial red lines are bent very slightly due to the Coriolis force, and the Tumlirz added a die to make them visible. He took a photo 24 hours after starting the experiment, and the water must not flow out faster than 1 mm per minute.
Ernst Mach has given an account of Tumlirz’ experiment, quoted in an article titled Inventors I Have Met – anecdotes by a physicist approached by ‘outsider scientists’, once called paradoxers, today often called crackpots. I learned about Ernst Mach’s article from the reference and re-print of the article on this history of physics website.
Mach refers to Tumlirz’ experiment as an example of an idea that seems to belong in the same category at first glance, but is actually correct:
To be sure, Professor Tumlirz has recently performed an experiment which, while externally similar to this, is correct. By this experiment the rotation of the earth can be imitated, if the utmost care is taken, by the direction of the current of water flowing axially out of a cylindrical vessel. Further details are to be found in an article by Tumlirz in the Sitzungsberichte der Wiener Akademie, Vol. 117, 1908. I happened to know the origin of the thought that gave rise to this invention. Tumlirz noticed that the water flowing somewhat unsymmetrically in a glass funnel assumed a swift rotation in the neck of the funnel so that it formed a whirl of air in the axis of the flowing jet. This put it in his mind to increase the slight angular velocity of the water at rest with reference to the earth, by contraction in the axis.
Comment on the German abstract: It seems one line or sentence got lost or mangled when processing the original as this does not make sense: so bendet sich das Wasser zwischen den beiden Glasscheiben [here something is missing] nach dem Rohrchen durch die kleinen Öffnungen.
I have not managed to find the full version of the old paper and the figures and photos online. I would be grateful for pointers.
Edit 2017: The link to the abstract used in 2015 is now dead, but I found a full-text version of the paper. Formulas are scrambled though.
Update added August 2016: C. Schiller quotes this historical experiment in vol. 1 of his free physics textbook Motion Mountain (p. 135):
Only in 1962, after several attempts by other researchers, Asher Shapiro was the first to verify that the Coriolis effect has a tiny influence on the direction of the vortex flowing out of the bathtub.
Ref: A. H. SHAPIRO, Bath-tub vortex, Nature 196, pp. 1080-1081, 1962
14 Comments Add yours
…and look. I missed this one too. This time I did not even read it.
I’ve been a bad blogger :-(
Reading through your piece I am reminded of just how badly popular media portrays science and, so, here in no particular order are the TEN annoying science NON-FACTS
1. Laws are theories that have been proven. To that I say, “Please read short articles on Karl Popper and Thomas Kuhn”
2. THE scientific method. There isn’t ONE scientific method, rather lots of procedures are, to varying extent, scientific.
3. The notion that scientists are necessarily:
– socially awkward or nutty
– dressed in lab coats
(for example you fit none of the above descriptions)
4. a version of Naive Realism that goes something like this: as time goes on we get closer and closer to “the truth.”
5. The AWFUL notion that there needs to be a zero-sum game played between the arts and the sciences. Actually if I had to pick the worst one I think this would be it.
6. Vaccines cause autism. Pure crap.
7. Humans have five senses. What about balance, spacial awareness, hunger and about ten others besides the common five?
8. Einstein was bad at math in school. Nonsense.
9. We only use 10% of our brain. Sure hahahahahaha!
10. Logical thought comes from the LS of the brain and the intuitive stuff from the right. Just no.
There are more, of course :-) Like the LIE I sometimes hear new teachers say”_____insert counter intuitive framework such as Newton’s 3rd here____ is easy. I can make it easy for you.” No you can’t. If you think, say, Newton’s 3rd is easy then you probably don’t get it yourself.
Oh and one more freebie–the notion that jet engines use work just like balloons that are expelling air. Again–hahahahahaha!
Wow – a complete 10 items list in a comment! This should be a blog post – thanks, Maurice :-)
I fully agree, and some more history of science would really help here. As you mention Einstein: My pet peeves are ‘inspirational’ quotes by famous scientists (most often by Einstein), quoted out of context.
ps love the new picture, just like England.
Thanks – Eastern Austria, close to the border to Hungary. Mainly vineyards :-)
I was fairly well convinced of the rotation of the earth when seeing Foucault’s pendulum at the Science Museum in London (don’t ask how many years ago that was !).
I was thinking of your old posts (this one, too! and the slinky!) this past week, and hoping you’d one day share more of your adventures through physics. Some of the reasons for wanting this are completely selfish, of course, and you are free to ignore them as possible hints for more.
Thanks, Michelle :-) Seems I have got the message already! The previous post is about heat pumps – but this time focussed on physics.
BTW, I just clicked on your G+ About page to confirm my theory about your cryptical comment :-) Kudos! An impressive change and unusual choice for a second degree!!
I couldn’t remember what I put there. :) Math, and the advisor suggested I consider additional concentration in physics, given that my best grades in the first degree seemed to be in philosophy classes and the English courses on literary theory. I probably would have avoided physics, except following your blog has shifted the anxiety to curiosity. We’ll see how it goes. I feel there is so much work I have to do just to remember what I’ve forgotten!
Wow – my blog has made an impact on somebody’s decisions :-) Thanks, Michelle, for letting me know :-)
Thanks for being curious enough to check up on my about page. :)
Fascinating, I am sucker for old papers like that.
Me, too :-)