Coriolis Effect
Discussion
Had a real argument with some people over the week-end about this and the effect it has on water draining down a plug hole (the debate was fueled by copious amounts of alcohol so it was not conducted at a very intellectual level :).
Apparently, these people were given a demonstration at the equator (in Africa) a few weeks ago and it was shown to them how water drains in opposite directions depending on whether you are north or south of the equator. Now, even though the coriolis effect really does exist, it is far too weak to influence water draining out of a sink or a loo.
Has anyone ever seen this demo in person and were they convinced that what they saw really was due to coriolis?
Apparently, these people were given a demonstration at the equator (in Africa) a few weeks ago and it was shown to them how water drains in opposite directions depending on whether you are north or south of the equator. Now, even though the coriolis effect really does exist, it is far too weak to influence water draining out of a sink or a loo.
Has anyone ever seen this demo in person and were they convinced that what they saw really was due to coriolis?
Astonishingly, this is one way of working out where the equator is. Quite literally, if water is pouring out of a hole there will be a very slight clockwise or anti-clockwise rotation - even as much at 30 yards either side of the equator. I've seen it demonstrated a number of times, with something like a leaf foating on top of the water.
Snopes has the answer...
www.snopes.com/science/coriolis.htm
and this is some background...
www.ems.psu.edu/~fraser/Bad/BadCoriolis.html
>> Edited by FunkyGibbon on Tuesday 30th August 09:25
www.snopes.com/science/coriolis.htm
and this is some background...
www.ems.psu.edu/~fraser/Bad/BadCoriolis.html
>> Edited by FunkyGibbon on Tuesday 30th August 09:25
Saw a program on this last year, showing how the con artists made it look like the water spun in one direction or the other. They simply fill the container with there backs to the audience, then pick it up and turn round shaprly causing the water to swirl in whatever direction they like.
Saw this myself, the guys poured the water into different sides of the container either side of the line, what I noticed was that the container (metal) was slightly shaped to encourage the water to move in a given direction.
Basic circus trick I'm afraid, put on for the tourists.
On a topical note, if you think about it hurricanes do not form/start to spin until the airmass have moved some distance from the equator, also you do not get hurricanes on the equator itself.
Basic circus trick I'm afraid, put on for the tourists.
On a topical note, if you think about it hurricanes do not form/start to spin until the airmass have moved some distance from the equator, also you do not get hurricanes on the equator itself.
hmmm. well i saw this on one of Michael palin's jaunts around the globe and a chap gave a demo showing the different rotations using the same buckets. and then he placed the bucket on the equator and the stick didn't turn at all.
so 1) it must be true cos Michael palin could never lie and 2) i don't care if its not true cos it looked cool.
ps not that this helps, but it looks like you and i are equally sad cos i was arguing about just this yesterday whilst drunk. though, i was arguing with the voices in my head.
so 1) it must be true cos Michael palin could never lie and 2) i don't care if its not true cos it looked cool.
ps not that this helps, but it looks like you and i are equally sad cos i was arguing about just this yesterday whilst drunk. though, i was arguing with the voices in my head.
nervous said:
hmmm. well i saw this on one of Michael palin's jaunts around the globe and a chap gave a demo showing the different rotations using the same buckets. and then he placed the bucket on the equator and the stick didn't turn at all.
so 1) it must be true cos Michael palin could never lie and 2) i don't care if its not true cos it looked cool.
I saw this as well the other day, it was on his Pole To Pole trek. Did look good
For those who think it’s a con, please explain how when placed exactly on the equator the water did not rotate either way.
You must have defective sinks Eric. Mine give a fulsome swirl and the bath gives great whirlpool (and tremendous sucking noise
) But it is proper 30s plumbing - all pipes made of angle iron etc.
I've seen film of Australian sinks giving reverse swing...I mean swirl, so it must be true.
So that's settled then
) But it is proper 30s plumbing - all pipes made of angle iron etc. I've seen film of Australian sinks giving reverse swing...I mean swirl, so it must be true.
So that's settled then
JonRB said:
The Snopes article specifically mentions Palin actually.
Anyway, would you trust any man who is associated with an organisation that spreads lies and deceipt about cars and speeding? (Palin is the chairman of Transport2000)
oh, poo. really? well, in that case, I'm taking down the shrine right now.
trust me to cite the most hated man in the world on a car enthusiasts website as the basis of some weak gag/ scientific proof. still, at least Ive started as i mean to go on. consistent as ever.
cotty said:
I saw this as well the other day, it was on his Pole To Pole trek. Did look good
For those who think it’s a con, please explain how when placed exactly on the equator the water did not rotate either way.
When he does the demo directly over the equator he does not turn to swirl the water, just puts it down so the water will not turn.
I recomend this book, sets a lot of mis-conceptions straight.
[url]www.amazon.com/exec/obidos/tg/detail/-/0471409766/ref=ase_badastronomy/002-2653388-0828049?v=glance&s=books[/url]
It is a con - aimed at gullible tourists. In fact the individual who demonstrated the "trick" to my friends was the same chap who demonstrated it to Palin.
Coriolis is a real effect - but is works at a very subtle level and will not affect sinks, toilets, bidets, bed pans or any other bathroom receptacles.
Coriolis is a real effect - but is works at a very subtle level and will not affect sinks, toilets, bidets, bed pans or any other bathroom receptacles.
Eric Mc said:
It is a con - aimed at gullible tourists. In fact the individual who demonstrated the "trick" to my friends was the same chap who demonstrated it to Palin.
Coriolis is a real effect - but is works at a very subtle level and will not affect sinks, toilets, bidets, bed pans or any other bathroom receptacles.
Actaully it does, it's just that you need to be sufficiently far from the equator, so standing just 1m either side of it won't work. But the whole water swirling different ways in UK vs Aus is true. Oh and it's what causes Hurricanes to form/ spin Btw.
Physicists have actually performed experiments using house hold sinks. They found the sink would need to sit still for 3 weeks so that any random currents would die off enough to see the Coriolis effect. Not only that, you would have to drain the sink one drip at a time.
Also, toilets are made to swirl the water around, to remove those more stubborn stains.....
>> Edited by fazz81 on Tuesday 30th August 10:56
Also, toilets are made to swirl the water around, to remove those more stubborn stains.....
>> Edited by fazz81 on Tuesday 30th August 10:56
fazz81 said:
Physicists have actually performed experiments using house hold sinks.]They fond the sink would need to sit still for 3 weeks so that any random currents would die off enough to see the Coriolis effect. Not only that, you would have to drain the sink one drip at a time.
I suppose otherwise as soon as you pulled the plug that would be an influence on the water
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