Water Down the Drain & the Coriolis Effect

LOOKS GOOD!

Masu

The effect that most people attribute to being the cause is called the coriolis effect and is related to the rotation of the Earth. Conventional scientific wisdom, however, states that coriolis has way to little effect to cause any rotation we and that any observed rotation is due to some sort of asymmetry in the drain, container or way the water enters.

Try:

The effect that most people attribute to being the cause is called the coriolis effect and is related to the rotation of the Earth. Conventional scientific wisdom, however, states that coriolis has way too little influence to cause any rotation, and that any observed rotation is due to some sort of asymmetry in the drain, container or way the water enters.

Dick

I have reworked paragraph two and think it makes batter sense now, have a look and see what you think.

Good, but...

When 'to' means excessive or excessively, it is spelled 'too'. Sorry to nitpick.

Dick

That being the only change you made, this would appear obvious and unworthy of comment, as did the initial misspelling.

Is that better?

In February I posted over 60,000 words in CR4 responses and at the current rate March's total is going to be close to 90,000 words, so the occasional error is bound to slip in.

added nothing to the subject

That's only because you missed the multitude of threads that talked about proper grammar. A little game that is being played so nothing gets too serious...:)

Wouldn't it be easier to just ask someone that is on a ship that crosses the equator to note their observation of the water going down the plug hole north and south of the line?

I did this years ago when I was in the navy and it was the same both sides of the equator. This may have been due to reasons like the design of the sink or the rolling of the ship at the critical moment as a flow pattern was being established.

A solid reliable answer would be nice. Count me in.

If you are that close to the equator, the Coriolis force is RRRReeeeaaaalllllyyyy small!

The ideal would be if we could find somebody in Punta Arenas, Chile and maybe Reykjavic, Iceland to try the apparatus we are going to make. I spent literally days experimenting with a bathtub in Santiago, Chile 40 years ago, and later here in the US, with no consistant results.

Dick

I have been thinking about this experiment in my free time. I think the key issue is the outlet nozzle. Any deviation of your funnel nozzle inside surface from its ideal conical shape is likely to influence the result. As the water is speeded up any slight iregularity in the nozzle can create a spin, and this can in turn influence the vortex at the entery to the nozzle. The only good way of ensuring that some such apparatus related effect is not corrupting the experiment is to use the same apparatus and setup; and repeat the experiment in both hemispheres. This is of course a bit expensive.

Count me in. How about takeing a two liter bottle (should be available anywhere in the world) put a small hole(1/8") in the bottom to let air in,fill with water with finger over hole,turn bottle upside down and watch for water spin as the water drains out. The vent hole would keep the air from glugging in the bottom and distroying any rotation that might occure.

hilltopper-your idea will give you a vortex BUT it would NOT be accurate. The bottom line is that we are going to have to use THE SAME MEASURING DEVICE around the globe. That would be the ONLY way we can be sure of no variations in the experiment. It looks like dkwarner in California, USA is going to make that testing device. MASU supplied me with the original specs. and I forwarded them to dkwarner. He has the necessary equipment to machine the testing rig. As MASU has said, this is going to be a FIRST for CR4 readers, LETS DO IT RIGHT!!! James

Let me try to put some numbers to this:

Assume:
Lossless system.
10-metre diameter bowl
Location - near poles (but not so near you need to heat the water)

=> "Stationary" velocity at edge of bowl is 30-metres/day (1.25-m/hour)
So the first difficulty is to ensure the water is stiller than this before you start to let it run. If you fill slowly through the central plug-hole, you could presumably guarantee that the movement was decaying from this initial value - but how long would you need to wait?

Regarding identical equipments - ensuring any slight tilt is identical between the various locations would make even this quite difficult.

I think, so far as ultra-precise experimental physics is concerned, I've done my bit - so count me out on this one. I'll stick with Foucault, for which you only need sealing wax*, string, and a bit of patience

Fyz

Foucault has nothing to do with flowing fluids; only proves and measures the rotation of the earth.

Our project is simply to prove or disprove the existence of an influence of the Coriolis effect on water going down the drain of sinks and the like. I have yet to see anyone with a 10 meter diameter sink, bathtub, or even swimming pool(10m in one dimension for a pool, yes, but not diameter)!

The system we will use for leveling will be as good or better than the methods used to level sinks etc. at installation, so I believe it will be valid.

I am considering a set of vanes that would be inserted briefly into the water after filling to reduce any circulating currents. After removal of the vanes, the water will still be required to sit undisturbed and covered (to prevent air circulation from affecting the water) for some time. My current thought is in the range of 8-12 hours of settling time, but I'm quite willing to accept advice on that value.

Dick

Obviously, I failed to make the point that the effects in a practical sized bowl are so small compared with what you usually see in practice that I wouldn't expect you to be able to observe them.

A minor point of detail: I think you will do better to fill the bowl through the outlet, and forget about any vanes. Then, assuming that the bowl is symmetric you know that the initial angular momentum will be small - i.e. rotating w.r.t. the earth about once a day. You therefore know that you only need to let it settle to (say) 1/10th of the original relative velocity to validate the experiment (and you can test the settling time with a separate fill using liquid that is visibly moving).

Now, assuming you have left the bowl long enough to settle, and only Coriolis is relevant, what happens when you let the water run out?

If the drainage hole is 1-cm in diameter and the bowl is 1-m in diameter (small and large respectively compared with the average round bowl), the rotation rate when the fluid from the edges reaches the edge of the drain will be 100-cycles/day. I.e. it will take nearly 15-minutes for each rotation. The problem as I perceive it is that, in order to be able to observe that the flow is not radial, you will have to let the water flow out quite slowly - and this will give enough time for viscosity to damp out any differential rotations.

Even if you make the drainage hole smaller, you won't see an improvement, because the viscosity-mass time constant of the fluid reduces with reducing size.

In short, at the scales you propose to work, you will require highly specialised equipment if you are to even observe any rotational movements due to the Coriolis effect.

That was the basis of my comment that the only modest-sized experiment known to me that could demonstrate the existence of Earthly rotation was Foucault's (it is technically a Coriolis experiment, but I agree that it takes a bit of physical insight to see the relationship with the effects on fluids.)

Fyz

Hi Fyz , Are you saying that Coriolis effect can be deduced from observing a Foucault pendulum ? It's twisting my mind so to speak - can you elaborate for me.

I'm already jittery over 'latitude' and the fact that the Earth is mapped on a Geoid (being a flattened sphere , bulging slightly below the equator ) - inferences being that g varies locally (with local radius affecting gravitation and centripetal force ) . I can't see how to calculate radius of rotation at a given point (even if it has no relevance to the proposed experiment ?) , since map latitude /sighting the pole star cannot help on their own .

I'm afraid these questions are easier to visualise for yourself than to explain fully. But I can give some visualisation guidelines:

Coriolis and the pendulum:

For simplicity. start at one of the poles. You can see that an ideal pendulum keeps a constant trajectory, while you go round it. That tells you that the Earth is rotating. If you examine the trajectory of your (long) pendulum very carefully (relative to distant stars), you will see that it is elliptical (because you start it with the Earth's surface velocity). The angular momentum of the pendulum as it passes round the centre of swing is the same as the angular momentum with which it started - but now you can see it is there, as the velocity is large compared with the rotation. That is no different to winds being pulled in towards a low pressure point - the Coriolis effect.

To convert to other latitudes, you need to resolve the forces. Personally, I find it more comfortable to use the polar direction as the reference coordinates and tilt the gravity (and surface forces for winds), but that is probably a matter of taste.

Regarding the radius of rotation at different latitudes - for these experiments it comes out in the wash, as it represents a fixed modification to effective gravitation. Historically, the only ways you could deduce your distance from the axis would have been:
i) Using optical measurements with respect to near and distant astronomical objects; or
ii) Measuring distances on the ground, and correlating that with latitude (departures from rotational symmetry could in principle be determined in the same way, and/or using top-end Chronometers); or
iii) Using sea levels and simple Newtonian theory as the reference line for general surveying

(Method iii is not bad, but assumes the Earth has uniform density. It would be possible to adjust this using local measurements of g, but I don't know that the data was available over wide enough areas to be useful)

SFIK, the first modern advance would have been using interferometric distance measurements from the moon. These days, it is much easier, as we can use satellite +time references (GPS, Glonass, etc)

BTW, I believe the pear-shaped bulge 'below' the equator is driven by variable density of the earth's constituents - low density -> reduced gravity -> increased bulge -> further reduced gravity. (Perhaps it is really middle earth spread, however)

Fyz

My reading suggested that the bulge is more 'spun-out' than density. However,

Thought experiment :

I stand in the garden at Etherville , with known latitude and measured local g. I am then placed on top of a tower many miles high . Now , the measured g is lower because (A) I am further from the earths c.o.g and (B) the centripetal force is less due to increased distance from the axis of earth rotation . If the height of this absurd ladder is not known , I can't calculate my new radius of rotation - the distant star has the same angle , and the change in g is a function of 2 different factors which are a function of sin latitude and cos latitude respectively. Remember the ladders height is not known.

Ah , I think the penny has dropped , I could work back from the mentioned change in g at the top of the ladder and work out a percentage cause by each effect. Yes I think the percentage changes would come out in the wash . I shall post this comment anyway , since the notion of these components to g causing a lop-sided force is curiously amusing.

Thanks for the info Fyz. Btw I think Foucault's pendulum was once tried in St Paul's Cathedral , London.

Kris (wobbly at 51^o)

That is true of the main bulge that would be at it's maximum on the equator. But not of the pear-shaped part* and other distortions from the theoretical oblate spheroid. Of course, there are also local contributions due to rigidity... The gravitational distortion (relative to the theoretical oblate spheroid) is known as the "Geoid height".

*bulges just south of the equator and north of the tropics, with complementary dips elsewhere - see for example http://en.wikipedia.org/wiki/Earth_radius

Fyz

Many thanks Fyz . You really shoud get involved in this project , your analytical skills would be a real boon I think . The private mail system works fine if you want original test data etc.

I've weakened (though that really should be reserved for week-end, pun intended), and exchanged data with Masu.

Fyz

Excellent . In England we're always reserved .

I eat my words - you can do better than the numbers above - though I don't know how much. Post number 70 outlines the principle.

Apologies

Fyz

Hy Fyz,

What we did with the shape of the container was to back track from the diameter of the hole that was controlling the flow rate. I carried out several hundred experiments with various diameters of hole and timed various volumes of water as they drained through the hole. From that I generated and equation that can be used to calculate the flow rate through a given diameter hole.

Since we know the flow rate through a given diameter hole we can calculate the velocity of the water as it flows through the hole. I then took that velocity and back tracked its velocity as it accelerated from zero. That gave me as series of distances above the flow controlling hole and velocities. From these I then calculated the ideal diameter that associated with the know flow rate and velocity at that position.

The result is the theoretical shape that a stream of water would form if it were to start from stationary and then accelerate under gravity so that it had the same diameter and flow rate as the hole allows. The theory behind it is that if the shape of the base of the container were to mimic the shape that the stream the water would form if in a free fall situation, then there would be minimal restriction of the flow. This would then eliminate any sudden changes in velocity and turbulence giving the coriolis effect the best chance of forming a vortex.

There are a couple of spread sheets and documents that detail the experimental results and calculations behind the shape that we ended up generating. If you would like a copy of them send me your email address via the CR4 mail system and I will mail them to you directly. Unfortunately the CR4 mail system dose not allow attachments so the technical drawings, written documents and spread sheets have been sent directly to the participants. Unfortunately that means you are not getting the full story by just reading this thread.

Hmm. In that case, it looks like I'm not going to see the background work - unless you can find a way to post it. So my comments are in ignorance of your background - apologies for duplication...

Yes, the smooth flow should help prevent eddies that would hide the desired phenomenon. What you want is fast flow initially, and slow flow at the end so you that radial flow does not disguise the Coriolis rotation. A segmented pipe will increase the loss of the desired flow, but might allow a more rapid overall flow before the onset of turbulence.

Doesn't the flow rate through the hole depend on the length of the pipe below the hole? You'd get the greatest flow for a given hole size with a 'pipe' that was nearly 10-m long and with an inverted funnel near the top (to widen it out so that viscosity did not contribute along the length, and Bernoulli did not limit the flow at the bottom). You might also wish to place the bottom of the pipe in a dish so the water escaped (slowly) upwards - to prevent air bubbling up and replacing water in the pipe.

Fyz

Hi Fyz,

If you are worried about your email being published you can send a private CR4 message by the link with your direct email address.

Hi James,

I agree with you when citate MASU :...LETS DO IT RIGHT.

Please, the original specs for testing rig? Thanks,Nic

p.s. We are making what said GALILEO in (1600 + x) years: numerare, misurare...[we have to count ..and to measure..]

Hi nicolaievlad-Thanks for your interest in the coriolis project! This was MASUs idea to experiment. If you search this blog, you will find a dkwarner in California. He is doing the actual building of the project. Contact MASU if you are interested in doing the experimenting with us, and he will provide the details. DKWARNER will provide specs. when he completes the model. James

(where are you from? We have people interested all around the world!)

Hello nicolaievlad

As james told you, I am building the apparatus. I'm doing it in my spare time, so it will probably still be 2-3 weeks before I finish. If you would like to see drawings of the proposed apparatus, send me (or MASU) your email address, and I'll send them to you. You are of course welcome to join the group!

Dick (dkwarner)

Hi masu

Since it appears that there are more "Northerners" than "Southerners" in the experiment so far, I'll join the Southern team!

An interesting aside, also to do with water: it is thought that the Coriolis force has some influence on the tidal currents in open seas, since there is always a significant north-south (or south-north) component in the currents. It causes rotating currents more or less like rotating air around low-pressure weather systems.

Regards, Jorrie

Jorrie,

My father asked me once: Isn't any kinetic energy grabber installed worldwide on a grand scale, going to influence the weather on a global scale?

I dismissed it at first (a question of scales), then thought about it, then noted that any kind of energy grabber on a global scale, would eventually have a global effect, sort of a domino effect, as this globe is quite a closed-system.

If this is a question of scales (e.g: Tidal kinetic grabber), it may sometimes be neglible, or out of practical range. But considering such intervention as an "initiating push" to chaotic systems such as weather patterns, this is worth extensive hydrodynamic research and simulation prior to application, even for feasibility studies. Just a note.

Hi Yuval, you wrote: "I dismissed it at first (a question of scales), then thought about it, then noted that any kind of energy grabber on a global scale, would eventually have a global effect, sort of a domino effect, as this globe is quite a closed-system."

This is slightly off-topic, but...

As Physicist pointed out in some previous thread of Masu's, a "Tidal kinetic grabber" could actually reduce the global effect of slow-down of Earth's rotation rate by our moon. This is because the most economical place to do it is in estuaries with fast flowing tidal currents, where the extraction of energy dampens the oscillations a bit.

Think about it - not all interventions are bad!

Regards, Jorrie

Tornados are more common in the US and Australia because the passing traffic provides seed vortices that develop into tornados. (LOL)

Interesting thought - Any source or proof?

Don't knock the idea I have heard this many times over the last 35 years or so. I saw a vortex form when two trucks passed and once triggered the heat from the bitumen just kept it building. Within seconds it was enormous and it started to meander about aimlessly until it struck a mini bus parked on the side of the road. The mini bus was nearly overturned, it was up on two wheels for a while before coming back down with a thump. Scared the crap out of occupants in the van, it was lucky they weren't moving at the time as the results could have been much worse. I lost site of it shortly after that but it was still spinning away and growing in size when it disappeared behind a hill.

I have also seen the wing tip vortices from an aircraft stir up some serious winds on the ground, up to a couple of minutes after the aircraft has flown nearby. Wing tip vortices linger in the atmosphere for a long time and spread out considerably.

It dose sound far fetched that two vehicles passing could trigger a tornado but I have certainly seen it trigger some serous whirlwinds, that are rotating in the correct direction for the coriolis effect to feed them. Stranger things have happened, nobody believed in global warming 30 years ago and look where we are now.

I believe that it is likely to make little difference to the observed number of tornadoes whether they or not they are being seeded in this particular way. You need suitable source of energy (temperature inversion) and a non-uniform motion to seed the tornado. I can't see why the size of the seed would affect whether it grows or not - but it will affect how long it will take to reach the level that would be recognised as a tornado.

I don't know what the numbers would really be, but I find it hard to imagine that the multiplier between a typical animal sticking it's head out of a burrow (or George B combing his hair) and two vehicles passing would be larger than that between the vehicles and the final tornado. That equates to taking the same time to grow from hair combing to the equivalent of the passing vehicles as it would from vehicles to tornadoes. So the only way that vehicles would trigger more tornadoes than other minor events is if the duration of suitable conditions was comparable with the time needed for the tornado to grow.

I believe that tornadoes (perhaps by other names) are not that uncommon in other regions where atmospheric conditions and lack of ground features permit - but perhaps they are not so well reported. BTW, we even get them in the UK, in spite of driving on the left and the relatively heavily featured landscape.

Fyz

Hi Fyz,

While we don't get anything like the scale of the tornadoes that you see in the USA we do get some pretty violent whirlwinds that spring up in the deserts. The thing with Australia is that nearly everybody lives near the coast so anything that happen in the heart of the continent can easily go unnoticed. There are very large tracts of land that have absolutely nothing in them and there is no weather radar covering much of the continent so I suppose you could actually miss something like a tornado completely.

MASU-We can get some nasty tornadoes here in North Carolina. (eastern USA) The worst ones are in whats called "tornado alley". That is the mid -west around the state of Texas and north. The cold fronts and warm fronts have to mach up just right to get that twisting action. When that happens-all *ell breaks loose! James

One thing that nobody so far has mentioned is that you need to let the apparatus sit quietly for a long period so that any residual vorticity can go away, and then take great care that whatever method that is used to start the flow does not introduce any vorticity.

You are correct on both points, although Masu has mentioned both in previous posts. The current idea is to use a motor-actuated ball valve at the bottom of a long tube under the 'sink'. Any better ideas? Dick

A couple factors for design that might rule out using a soda bottle:

1. You need a wide basin so that the water travels as far horizontally as possible.

2. You need the water to move slowly. Although the force is proportional to velocity, for a fixed distance, the time it acts is inversely proportional to velocity, but the amount of deflection is proportional to force times time squared. So you're better off with less force and more time.

For my penny's worth I think the Coriolis force is to small to measure/have any effect on a draining sink or similar size container. How about a very long tube with a stream of light oil run onto one point of its rim at the top - any Coriolis force would cause the downward trail of oil to spiral.Or am I confused here with Foucault's pendulum.A global experiment would need a simple ,cheap,replicable device.

Hi fellow CR4 people,

I have read through the threads "Aeroplanes and Water Down the Drain" and "Does One's Hemisphere Effect the Direction of a Bullet's Spin?". This is a compilation of all the ideas, theory and concepts that I could see but if I have overlooked anything pleas post it in this thread.

First up here is an overview of the coriolis effect and how it causes the rotation of air as we see it in the Northern Hemisphere.

In the Figure 1 the black dashed arrows shows the path the wind would take if it were flowing towards a low pressure cell labeled L, in the center, without any coriolis effect. Now since the earth is rotating, the air that is closer to the equator, will be moving eastwards slightly faster, than the air at the center of the system. As a result, the actual flow will be deflected slightly eastward, as shown by the orange arrows.

On the other hand the air, that is closer to the north pole, will be traveling eastward slightly slower, than the center of the system. As this air moves towards the center its path will deflect slightly to the west as shown by the red arrows.

Add all these deflections up and you end up with a vortex forming that is rotating in an anticlockwise direction as shown by the green arrow.

In the southern hemisphere the deflection asymmetries between the north and south are reversed and therefore the direction of rotation reverses giving a clockwise rotation.

Before we design any test apparatus I believe we need to look at the sort of deflection we can expect to see due the coriolis effect. The coriolis effect is maximized at the poles so Figure 2 is a detailed look at a system draining through the point centered at the north geographic pole.

The blue arrows show the deflected path that the fluid draining towards the center would take. This path can be broken into two components, the one caused by the motion of the fluid d shown in red and the coriolis component c shown in green. Since this is centered over the pole the deflection c is controlled by two factors, the distance the fluid travels d and the time that it takes to travel. The earth rotates at a rate once every 24 hours therefore the angle D in Figure 2 can be expressed as a function of time as

We can now calculate the deflection as follows

For small deflections we can assume that the tangential part of this function is linear, so by solving the Tan(Time x 72.72μRadSec^-1) component, we can now express the deflection caused by the coriolis effect as a function of time and distance as follows;

So, at the north pole, we can say, over relatively short periods and distances, the deflection of a linear flow is approximately 72 microns per meter the fluid flows, per second it takes to flow. (72 μm s^-1m^-1)

Figure 3 shows the effect of moving away from the North Pole to a position that has a latitude Ø.

If we still have the same initial component of motion, d shown in orange, the component that is effected by the coriolis effect now becomes w and is shown in purple. We can now modify our original equation for the deflection due to the coriolis effect, to include the latitude as follows;

Design Parameters

From the final equation, we can see, the two primary factors, that we have control of and that effect the deflection, are the distance that the fluid flows and the time the fluid takes to flow. Clearly the design needs to maximize these wile minimizing any friction. Using the above equation, the sort of deflection we can expect to see in continental USA is about 50 μm per metre per second. Any device, designed to test for the coriolis effect, would need to be constructed accordingly

Obviously, the shallower and broader the container the better but friction is important so the slipperier the material the better. Teflon would be ideal but this is expensive. Clearly, the container needs to be circular and that means the only realistic method of manufacture is on a lather. However, unless care is taken the process of turning the container may cause defects that impart a rotation to the fluid as it flows over the surface. I believe we can overcome this problem by finishing the inside of the container manually and by reversing the direction of rotation several times during the finishing process.

Something I think we need to avoid is any abrupt change in the profile of the container. This could create turbulence and negate any sort of deflection the coriolis effect is causing. Obviously the base needs to slope as it nears the drain. Therefore, I would suggest, the best shape would be the same profile that you get as water streams from a tap and accelerates under gravity. This would minimize any friction and turbulence and maximize the chance of the coriolis effect causing any rotation..

It also needs some sort of leveling mechanism and way to check that it is level plus a compass so that the alignment can be checked.

For verification purposes it would be good if we could stretch to including a digital camera that was mounted directly over the drain hole. The camera would need to be mounted so that it clearly showed the compass and level indicating devices as well as the water container. I would also suggest that a light coloured plastic and the use of either a dye or potassium permanganate to highlight any rotation.

Any design also needs to take into account that it is going to be shipped around the world so the more compact and lighter, the better.

I think that covers just about everything I can think of. I will hold off drawing anything up until this has been bounced around for a while. If anybody can think of anything I have overlooked pleas post it along with any calculations that you think may help.

MASU- I noticed in your last comment you might hold off on your final measurements concerning any thing machined from plastic. dkwarner in California is about to purchase a block of acrylc for our project. You gave measurements earlier to follow-do you want us to wait or are you confident in the 500mm size you gave earlier? James

Hi James

I came up with those measurements before I realized that the sort of deflections we are talking about are 50 microns per meter per second. If we had a 500 mm diameter container that took 10 seconds to drain we would be talking about a deflection of 125 μm or an eighth of a milli meter. Anything we constructed would need to be constructed with a tolerance considerably greater than ±0.025%. The larger we make it and the slower it drains the better.

What do you think about trying to get the profile to resemble the water leaving a tap? This would minimize any friction and turbulence as the acceleration would be constant throughout the entire container. The less the turbulence, the more chance the coriolis effect is going to have getting it to rotate.

Something else I just thought about was preferred package sizes for postage. I know in Australia they have preferred dimensions and if you go over a certain size the price of shipping increases dramatically. I will have a look on the net and see what I can find and post the results on this thread.

I got to thinking about that shipping problem myself. By the time we got the acrylic to have a bowl deep enough, its going to be somewhat fragile and yet still pretty heavy. This would require a fairly substantial shipping container that would be costly to obtain and expensive to ship.

What about the possibility of using a membrane, say 1 or 2 mm thick vinyl, supported by a ring of segments that could be disassembled for shipping. the vinyl could be rolled up in a shipping tube, and the other parts in a separate container.

The weight of the water would shape the vinyl. The drain would have to extend slightly above the vinyl at the center, but I don't think that would be a problem - it would be like the 'glory hole' of some dams. This way we could have an apparatus perhaps a meter in diamter. I'm still thinking of threaded inserts for the center hole so we could try different sizes and shapes of orifice.

What do you think?

Dick

Hi dick,

I cant see any form of membrane being anywhere near accurate enough to not completely overwhelm the deflection, caused by the coriolis effect. Remember we are only talking 50 microns per meter per second. The shape of the glory holes is however the short of shape I was referring to in my post and is designed to minimize the friction and turbulence. If there was a smooth transition from the floor of the container to the lip of the glory hole type drain I think we would maximize our chances of getting a vortex to from. They don't' use glory hole type drains in reservoirs in Australia so I have never seen one in use. Do they form vortices or do they always drain cleanly?

I need to do some experiments with the rate water drains through various diameter holes but I think we can still go with 500 mm diameter. I believe trick is keeping the surface as symmetric and smooth as possible while maximizing the time it takes to drain. Once I have some flow rates I can calculate the profile that I believe give us the minimum turbulence and therefore maximum chance of a vortex forming.

It will take me a day or so to do the experiments but I am pretty sure that the picture I have in my head will work. Once I have some hard data about flow rates I will draw it up and post it on this thread.

I happened to live within bicycle distance of the Monticello Dam (Google Glory Hole - I tried inserting a link here, but the editor deleted it), and watched it being constructed while I was in high school. I've only seen the lake full once, and that was years ago, but I don't remember any vorticity at all. The water is currently about 7 feet below the glory hole, and we are in a dry spell, so I don't think I'll be able to go see it this year (it is about 50 mi. from my home).

I'm not sure whether it was on CR4 or elsewhere, but in the last few months there was something on the internet that showed pictures of several glory holes around the world, and again I didn't see any vorticity in any of the pictures.

If not a membrane, perhaps spun aluminum (using permanganate crystals, it would not need to be transparent), or molded fiberglass (I haven't done fiberglass since I coated my wooden skis) ? I'm really afraid of the weight and fragility of the solid acrylic.

Dick

Careful how you google this - At Glensanda (Scotland ) there's a "glory hole " - it's used by a Quarry to drop rock about 1/2 Km vertically . I'm gonna take a guess and say they don't notice the Coriolis effect !

Hi Dick,

Are you still seeing the old CR4 editor or have you managed to disable the caching and proxy server, on your web browser, and loaded the current editor?

I Use Microsoft Word to construct all my posts then I just cut the text and past it into the CR4 editor. It does strip off some of the formatting but the hyperlinks and everything still work.

Getting back to the task at hand, the family business was the manufacture and repair of specialized surgical instruments. We used to get big blocks of teflon that would be machined into shape for use in instruments that needed to be autoclaved. Unfortunately the business was sold about six months ago so I havn't got access to it any more but something made from a solid block would be nearly indestructible. It would be reasonably heavy but with some constructive trimming the weight could be kept to a minimum.

I just did a Google search on "glory hole drains" and found some images of several in use. There seems to be no sign of a vortex forming, but, one of the larger ones has several vertical barriers around its perimeter. The only purpose I can see for these would be to stop any sort of rotation occurring, so, maybe there is a problem with vortices. A vortex on this sort of scale could produce some pretty horrendous forces and reduce the flow rate considerably. If they have another purpose then maybe somebody else can tell us what they are for. What do you think?

The spun aluminium is a good idea, it would need some sort of frame around it so that it could be leveled but it would certainly be easily machined into shape and be light. It may be a little fragile for shipping around though as aluminium is notoriously easy to bend or dint.

With a little luck I will be able to do the experiments I have planned tomorrow and that will allow me to draw up the best profile. Once we have that we will have a much better idea of what will be involved in the manufacture or it.

MASU-about how big are you talking about? (spun aluminium-glory hole) 400-500mm?

No, I haven't been able to do that yet. I got and responded to an email from Mark at Globalspec regarding the issue, but haven't received a return yet.

I'm following your suggestion to compose in Word:

This is my thought for a mini-Coriolis tester (one of three leg holes shown, not shown: vertical tube to valve):

There should be a graphic above, but it does not appear in my editor window, and I have to enter bracket-p-bracket to create paragraph breaks.

Dick

MASU-maybe we need to start looking for a suitable replacement for water. Something with less surface tension. (alcohol)? I would think with less surface tension, the better the deflection ratio. Surface tension is typically measured in dynes/cm. Water at 20 degreesC has a surface tension of 72.8 dynes/cm compared to 22.3 for ethyl alcohol. James

Morning James

That's an interesting thought. The answer depends on whether we want to test water down the drain or the Coriolis effect! I have at least a half liter of methanol/ethanol mix on hand, so when I get the test apparatus made, I'll try both that and water.

I figured out how to make the motorized ball valve. If my work doesn't get in the way, I hope to make the motor assembly today.

I just switched from Safari to Firefox, which enables me to do images on my posts.

Dick

Hi folks.

I am still playing with the flow rates through various diameter holes, it's taking considerably longer than I initially intended. It has been giving me some rally weird results like the flow rate being independent of the column height of the water and only being controlled by the diameter of the whole.

Another thing that has shown up is that the results are inconsistent. I did a stack of tests fro a 3.0 mm diameter hole the started again with 3.5 mm hole only to find that the flow rates were slightly reduced.

This little curve ball has me somewhat confused, how the hell a larger hole can cause a reduced flow rate?

Anyway once I have all the data compiled I will send a copy of the spread sheet to those interested then we can all look at the results and see if we can draw a conclusion.

The surface tension is something that has been bouncing around in my head for a while now and I have a feeling that it has something to do with the results I am seeing with the flow rate inconsistencies. When I have finished the flow rate tests with plain water I will have a further play with a few additives like alcohol, NaOH, detergent etc and see what the results.

Reducing the surface tension may actually increase the friction due to a surface as it allows the water to make better contact with the surface. If we just wish to reduce the surface tension then a very dilute NaOH solution is one of the best additives as it doesn't foam or froth up. Dish washing machine detergent is mostly NaOH so a tiny bit added to water may help.

Bear with me folks, I think it's important to get on top of the flow rate discrepancies before we dive into the design of the final apparatus. So far the real world seem to giving results which contradict the text books so we are in completely untested water here. Sorry about the pun, just couldn't resist.

Anyway I should have the results by about this time tomorrow so till then I bid you adieu.

MASU-Now thats a good one, make the hole BIGGER and get LESS flow! We are in uncharted territory for sure! Sounds like you and dkwarner are on top of things! I would think a lower surface tension liquid would be the way to go because of less resistance to the coriolis force. I have read also, if you warm up the solution that you are using, it reduces the surface tension also. James

Hi Masu.

I can understand how important the surface tension is to this experiment but I think viscosity will all so play an important part. It has a very noticable affect when the transition occurs from lamina flow to turbulent flow in pipework.

Looking forward to seeing what your formula looks like.

MASU-dish washing machine detergent just might work! We use it in the asphalt design lab where I work at to break down the bond that dust has to aggregate. James

Hi Dick,

Do you have a preferred diameter ball valve for use in your system? If you can give me a diameter I can then use the formula from the flow experiment to back track and design the profile of the base of the container, that will gives us the best chance of success.

Yes, the smallest ball valve that is readily available here is what is known as a 1/4" NPT (National Pipe Thread) valve. The hole through the ball is actually 9/32 (0.281", or 7.14mm) in diameter. The ball itself is around 9 or 10 mm in diameter (guesstimate). The valve is 40.5mm long, with female threads on both ends. If I make the orifice(s) out of brass, we can attach the valve directly to the orifice, which would place the ball about 30-40mm below the orifice. I originally planned to make the orifice(s) out of teflon, but I don't think the teflon threads would hold up to multiple assembly and disassembly as it gets shipped around the world (disassembled to minimize the size of the shipping container).

The whole assembly is inverted from my original drawing, with the valve now on top and the motor linkage below. With the current design, we can either let the water flow into a channel open to air to reduce siphon action, or add an exit tube to induce siphoning, if that turns out to help create the vortex.

I did get the motorized valve provisionally assembled and tested yesterday. The linkage works as expected, but the little gearmotor I had on hand turned out to be a bit too low on torque to be reliable. I think I know where to get a better one with a higher gear ratio, yet not too heavy, but I have to go to San Diego for about a week, and won't have much time to work on the project 'till I return. I do still have email there.

Dick

Hi Dick,

I will work on the principle that the valve will have a 7.14 mm hole and work backwards from that to give a shape for the base of the container and orifice. I will also try ad do some more experiments on the flow rates with different additives to change the surface tension of the water.

The 2^-½ factor for the flow seems a little to tidy to just be a coincidence but I can't see any other explanation other than it being just that. Hydrodynamics was not a subject that I studied so I have no real idea of the physics behind what is going on here. Have you had any thoughts on it yet?

Have a pleasant trip to San Diego and when you get back I will have some more data to confound even further.

Wow--great analysis! Enjoyed seeing your math and drawings.

Would a teflon-coated pot or bowl with a hole in the bottom work for us po' folk?

You could use a hand level and compass to orient the bowl.

What do you think?

No Need -We're going to build a unit and ship it around the world, I think you may be the highest northern latitude we've seen so far, so keep in touch. Dick

habib-You need to join us in our grand experiment! dkwarner in California is going to build a device we hope will settle the question on the effects of the corolis force. Our plan is to ship it all around the world and everyone get a chance to use it. MASU in Australia made the suggestion of a build, and I, dkwarner, and a host of other fine fellows will start the whole process. You live about as far north as anyone we talked with-so you need to join us! James

Count me in!

You people are hardcore experimenters. I can't contribute anything useful at present but will watch with interest. It's a great project .Kris (51^o North )

Hi fellow CR4 researchers,

I have just finished doing the flow rate tests and have got some interesting results. I will write it all up properly and mail it to those that are interested, but, I will need your email addresses as it has a spreadsheet that goes with it. Don't post your email address here, send me a CR4 email with your address and I will be happy to copy you on all the results.

I am absolutely buggered after doing this so I need to think over the results prior to writing them up properly but here is a quick review of what I did and the results.

I used a 300 ml PET soft drink bottle and cut the bottom out of it. This formed the container for the testing. I then took several tops and drilled holes in them varying in size from 1.5 mm to 5.5 mm diameter in steps of 0.5 mm. Using a medical syringe and stop watch, I then timed how long it took various volumes of water to drain from the bottle. The volumes of water that I tested were 10 ml to 100 ml in steps of 10 ml. Each volume and hole diameter was tested five times and the results collated using a spread sheet. That's a total of 450 separate results plus the initial inconsistencies made it well over 500 tests in all.

Initially I was getting inconsistent results. For example a hole with a diameter of 3.5 mm was taking longer to drain the water than a hole with a diameter of 3.0 mm. Another inconsistency was that if a particular volume/hole diameter was re tested the second set of results would not agree with the original set.

After considerable mucking about I found that to get consistent results the water being used needed to stand in a bowl open to the air for at least 30 minutes prior to carrying out any tests. A second problem was the number of times the water was recycled through with it requiring replacement every couple of hours.

I believe temperature is the most important factor here but I need to think on this a bit longer. If anybody else has any ideas of what could be causing the inconsistencies I am open to suggestions.

The results showed that the flow rate through the holes was fairly linear. The only trouble is that the linear relationship did not pass through the origin. With all the tests regardless of the diameter of the hole the plotted results all showed a linear increase in time with volume. But, as I said, there was an offset that needed to be added to this linear function to get the final time.

For example with a 5.5 mm hole the time it takes to drain a given quantity of water can be expressed by the following equation

Time = Volume x 0.0638 + 1.0333

Where Time is in seconds and Volume is in ml.

All of the holes showed a similar result with a liner increase in time with volume plus a constant.

Anyway it's 03:50 here, so, I am going to get some shut eye and let the results percolate through a few dreams to see if I can come up with a eureka moment. If anybody has any ideas that you think would be helpful pleas, pleas, please, I am all ears, or should I say eyes. I'm waffling again aren't I, it must be time to call it quits, I will write the results up today and post the text here. If you would like a full copy of the results drop me a line as I indicated earlier and I will mail you the full results.

Some possibilities:

1. If you did 500 tests in only a couple days, you can't have waited very long for the water to become still before starting each test. There was bound to be some swirling...

2. Since I believe you said you don't currently have a lathe, some holes were undoubtedly centered better than others.

3. You didn't say whether you countersunk or rounded the upper entrance of the drain holes.

4. Especially since you said you found it necessary to keep the water in a bowl for some time, you may have considerable dissolved air in your water. If so the sudden drop in pressure as the water enters the drain may be causing cavitation .

5. The velocity of the water as it leaves the drain may be causing a Venturi effect, sucking air into the stream and making it more turbulent, in different ways for different hole sizes.

6. Depending on how far the water falls before it hits the ground or receiving container, the stream may be breaking up into individual droplets, thus not grounding the contained water. Since PET is a very good insulator, there may be a buildup of static charge. This would slow the flow, especially for very small hole sizes.

BTW Yes, I do use Excel, although I really prefer the spreadsheet function of Appleworks (less demanding, more intuitive to me)

Dick

"The only trouble is that the linear relationship did not pass through the origin"

Is this due to the narrowing of the bottle toward the neck ? The water within the curved part is at a greater height for a given volume (compared to the straight part of the bottle). I may be talking out of my own orifice so I shall wait until American friends are up and running (9:21 am here). Watching with interest , Kris.

Hi Fellow CR4 research scientists/engineers,

I am still writing up the results of the flow rate experiment but thought you would appreciate a quick summary of the final result.

After considerable analysis the flow rate through a hole confirms to the following chart regardless of the depth of the water above it.

To sum it up the flow rate can be calculated using the equation

Flow_Hole = 0.7076 x Size_Hole + 0.0967

Where Flow_Hole is in mls^-1 and Size_Hole is in mm².

I am sure that this is just a coincidence but that's pretty close to

Flow_Hole = Size_Hole ÷ √2

I will leave you to contemplate that little snippet while I finish writing up the experiment.

Intriguing eh what?

Very interesting. Unfortunately, the background picture, which appears to be of Monticello's glory hole, makes all but the 4mm hole size unreadable.

I find it interesting to note that in the photo the water separates from the concrete on the way down. Presumably at some higher lake water level, there would be more vertical motion and the water would no longer separate from the tube. This seems to imply that there is a 'correct' shape for the mouth, but that shape would be different for different flow rates.

Dick

Here is a rehash of the graph in post #46. I have replaced the background picture with a simple grey background to make it easier to understand.

The original in the spread sheets looks great but unfortunately the process of converting them to an image and posting them in the CR4 editor looses a lot of the detail and renders them difficult to read.

MASU-did you use any water softener to reduce the surface tension ? James

Hi James,

In your response to your question about the water softener, no, I just used plain tap water that was allowed to stand for 30 minutes prior to testing. The results are fairly interesting however and I plan to do some further testing using some water softening agents next.

To everybody else,

I have just e-Mailed the full write up but here is a quick summary of what I found.

The rate that water flows through a hole remains fairly constant regardless of the head pressure and can be calculated using the following equation.

Where the area is in mm² and the flow rate is in ml.

Happy reading and I look forward to your responses.

Hello I have just read through the various ideas, how about using water with a tiny amount of detergent to reduce surface tension and either 1/8" polystyrene balls to indicate direction and flow, or food colour/ink to highlight the waters movement?

The head of water and size of hole and the shape of vessel will effect the result. Circular of course is best so as not to bias the result.

I just ran a quick observation with a regular hand basin and noted that the effect only became visible when the water had almost run out it lasted for about five seconds running from a 6" head to 1 1/4" of water. Through a 1 1/4" outlet. The center screw started the process. The center of the vortex being located at the center of the screws head. It was too fast to see the direction of rotation. It works better in a bath. Perhaps we could persuade swimming pools to drain down for the sake of furthering our knowledge? Just a few things to mull over.

Hi Fellow CR4 researchers,

I have been doing some careful thinking (something that can be painful at my age) about ways to give the Coriolis effect the greatest chance of forming a vortex. I believe the most important thing we need to minimize turbulence in the flow of the water as it leave the container and passes through the valve.

As water leaves a tap it accelerates under gravity and the result is a tapering diameter that is a function of the flow rate from the tap and the acceleration due to gravity. If we shape the base of our container so that it mimics this shape then we will remove any sudden changes in velocity due to the shape of the container. Theoretically this will minimize any turbulence and give the Coriolis effect the greatest chance of forming a vortex.

Since we can calculate the flow rate through a valve from the equation I generated in the water flow experiment, we can therefore calculate the velocity of the water at any moment prior to it passing through the valve. Given that we have a known volume of water and velocity we can now calculate the profile that the water would form if it were in free fall.

I have created a spreadsheet that takes a given valve diameter and calculates the profile of the container as follows:

1. First up it calculates the predicted flow rate through the given diameter of the valve using the equation I generated from the flow rate experiment.
2. It then calculates the velocity the water would be traveling at as it passed through the valve.
3. The next step is to take the velocity of the water and back steps in 1 ms increments to calculate how fast the water would have been traveling if in free fall in prior to the time it passed through the valve. An important factor here is the time at which the water would have had a velocity of zero. This time is important as it will ultimately define the maximum diameter of the container. We now have a series that gives us the velocity of the water at a given time prior to it passing through the valve.
4. The next step takes the sequence of velocities and times, and uses them to calculate the distance above the valve the water would have been, when it was traveling at that velocity.
5. The final steps use the volume of water and the velocity at each given time interval to calculate the cross sectional area, diameter and radius that the container needs to have at that specific point.. The diameter is limited to a maximum that corresponds the to point that the water has a velocity of zero.
6. The resultant radius, diameter and cross sectional area are plotted against the distance above the valve. The distance above the valve is the vertical axis while the horizontal axes represent the radius, diameter and cross sectional area. For clarity reasons the chart of cross sectional area also has a logarithmic scale on the horizontal axis.

• The result is the shape a column of water would form if it ware free falling in such a way that. when it reached the valve it would have a velocity and diameter the same as the calculated flow through the valve.
• The maximum diameter is limited to the diameter at the point the water would have started accelerating from or in other words when the water had a velocity of zero.
• An interesting point that I hadn't previously thought of was, the vertical distance remains constant regardless of the diameter of the valve. This is because there is a linear relationship between the cross sectional area and flow rate. As a result the vertical distance and scale remains constant regardless of the diameter. When you think about this it makes sense since. Since the water is under the constant acceleration of gravity and the flow rate is regulated according to the area, then we should see a constant displacement on the vertical axis.

In theory the water will be in a state of free fall throughout the time it is flowing. This should minimize any friction and turbulence that could affect the results and give the Coriolis effect the greatest chance of forming a vortex.

It also means that the height of the inlet remains constant regardless of the diameter of the valve, the only thing that changes is the diameter.

I have inserted the diameter of the Valve that dkwarner gave in post #52 and here is the resultant ideal profile for the container from the valve to the maximum diameter.

.

If you look at the chart you can see that once you get more than about 15 mm from the axis of the valve, the base of the container is almost horizontal. I think we can get away with a container that is cylindrical and then have an insert in the base that is machined to the appropriate shape. You may also note that the maximum diameter is 214 mm. This makes the device somewhat more compact than I had originally thought.

I have sent everybody on the mailing list a copy of the spreadsheet to have a play with. As sent the sheet is protected and you will only be able to alter the diameter of the valve. If you wish to change anything else you will need to go to the Tools drop down menu and select Protection then select Unprotect Sheet. You will then be able to alter any of the cell contents.

Have a play with the spread sheet and see what you think.

What do you think, dose this all make sense? How you think we can go about constructing the testing mechanism? It the original concept the best way to go about testing or is there a better way to go about it?

The only way to be certain that the affect of the container remains constant is that everybody must use the same container. Identical containers will not do as the effect we are looking for is incredibly small and the slightest deformation or inconsistency could have an adverse affect on the results. If everybody uses the same test rig we at least know that the irregularities and inconsistencies in the container and valve will remain constant throughout.

• PS I apologize for the poor resolution of the graph in this post. You can see the original in the spreadsheet that I have mailed to you directly. If you are not already on the direct mailing list or do not receive your copy following this link and give me your direct email address and I will forward you a copy directly.

Hi Masu

I can't see that you have put any numbers to the rotational rates. When you do, I think you will come to agree with my post number 63 that the flow rate will need to be so small if you are to be able to see that the water is not flowing radially that viscosity will have time to damp the whole thing out. (Tomartoes, tomaitoes, let's call the whole thing off?) The smallest dimensions I estimate that you stand any chance of seeing any effect is about 10-metres diameter "bowl" and 5-cm hole (smaller holes get worse again).

Fyz

I looked at it from the view of deflection we could expect to see in the path of an object as it moves towards the drain. The three factors that have an effect are the distance from the equator, the time taken for the fluid to flow and the distance it flows. I came out with a deflection of around 80 μm s^-1 m^-1 at either pole and less as you move towards the equator. This is bugger all.

However, the whole idea is to show one way or other what affect the coriolis effect actually produces in a fluid as it drains. We more than likely will end up showing that the coriolis effect has no real affect on the formation of a vortex in a drain and that's ok. The whole concept is to have a series of physical experiments that can be used to demonstrate what really happens one way or the other.

I agree that the coriolis effect is way to subtle but no amount of mathematics seems to have convinced everybody that this is the case. Since my avatar has already turned blue from talking till I am blue in the face I suggested that the way to settle the argument once and for all, was to set up an experiment to show it one way or the other.

Besides is a bit of fun and nothing like this has been done before at CR4 so we are really setting a precedent.

Hi Masu

I realised in the shower this morning that I had calculated for the wrong (i.e. grossly sub-optimal) regime. The ideal would be if the water was all viscously coupled together, but there was no coupling to the bowl. In that case, any hole that was less than about 1/4 of the diameter of the bowl would leave most of the angular momentum in the residual water. That means there will be an ideal drainage speed that would maximise the ratio between the couplings (outflow_to_volume vs volume_to_bowl). I expect you could adjust for this using measurements where the initial rotation was known. More significantly, you would then know what the maximum 'gain' was, so that you could estimate the measurement accuracy you would need.

I still think that, even for this case, large is beautiful.

Fyz

I'm an experimentator , and inclined to make measurements [in special in electromagnetism ] .Your Idea with some measurements of Coriolis effect in diverse places on EARTH is very interessant. I hope that I can participate.

with respect,Nic

Hi guys count me in i would like to be a part of the experiment. I have also had another thought on it and that is attached to every drain is a elbow or a pee trap,and the drain hole has heaps of holes in it to stop things going down the drain, may be this has something to do with it .In any case it appeared that in the lower part of Victoria,Australia the effect is greater than where i am living now which is far northern West Australia.

Greetings! -Contact MASU and he will set you up with our special email group. This was his idea of the coriolis experiment. DKWARNER in California (USA) will be making the model that will be used around the world. Thanks for your interest! James

James , do you know if any attention has been given to setting up a place to register interest in conducting tests ? A place where people can simply post there user-name and location , might help control flow of information and facilitate planning how the project will be implemented . This might be a bit early , but I suspect that interest could accelerate rapidly. Regards , Kris.

Sounds like a good idea. Contact MASU , maybe he can set up something along that line. (he is good at those things). James

Just done it James. K

Hi folks,

For all those that have indicated they are interested in becoming involved, I need your direct mailing address. There is a considerable amount of background information that can only be sent as attachments and unfortunately the CR4 system dose not allow attachments, so they need to be sent directly.

DON'T POST YOUR EMAIL ADDRESS HERE!

At this stage I only need your direct mailing address and you can send this to my by following this send MASU an email link. Once I have your direct mailing address I will send you copies of the documentation that has already been distributed and details of the remaining information that is needed from you.

Regards,

MASU

Ok but if you go to Quito you will find a museum directly on the line. Circular basin, hole in centre. On the line, no vertex. A metre either side and there's a vertex. Seen with my own eyes. Any explanation?

Jon Watson (jon.watson@charteris.com)

Assuming that you mean vortex - there are so many ways that it's almost pointless to speculate which they might use, as it only takes the tiniest asymmetry to allow a vortex to be created. For example (these are not intended to be speculations about how it is actually done), here are two possibilities:

If you impart a visually imperceptible tilt to an existing bowl with a suitable asymmetry, you can easily reverse the direction of the vortex the bowl creates.
If the stream filling the bowl has even a tiny offset, that too will create a vortex if you don't allow the water to settle completely before you start to empty the bowl.

How much is the entry charge?

Whatever it is it isn't the coriolis effect causing the rotation. The coriolis effect is proportional to the Sin(Latitude) x distance traveled x time of travel. Put all that together and a few meters either side of the equator gives you bugger all an affect.

I'm not totally clear what you describe , but a museum needs to attract visitors. Being able to advertise "come and see the Coriolis effect in action" is a whole lot more profitable than "come and see that nothing happens". I don't like to suggest dishonesty but it must be tempting to have bowls set up either side of the equator showing opposite spin (with a 'no-spin' bowl in the centre). The set-up could look extremely convincing.

Some of the well thought-out explanations here could enable the museum to continue with the fun illustration of the meaning , together with informative facts about the exact detail. Masu is leading a project that will quite likely be a much sought after reference. Have a look through the detail on CR4 and you will see that some highly skilled people are doing something pretty ground-breaking. I , for one, am convinced that following the progress here will be rewarding just to see how a group of individuals across the globe get together and make something happen. Folk have debated this for years , think how cool it would be for a bunch of individuals to resolve this instead of a major corporation. Join CR4 Jon and follow this - If you have links with Quito it could be very useful. I only speak as an enthusiastic follower of this project , but I'm sure your participation would be welcome. Kris

Thanks Kris.

Good comments and, I hope, accurate. As I've said several times, my work keeps getting in the way, but progress is being made! Be Patient!

Dick Warner (dkwarner)

Kris-You are right, an equator experiment looks convincing on the surface, but I cant believe even for an instant that stepping 1 meter on either side of the line is going to make that big of a difference! The earth wobbles and spins unevenly. There is NO way 1 meter makes or breaks this project! The ONLY way this is going to be proved is to do what we plan. I dont care if it takes dkwarner til Christmas to make this prototype, I know he will do it right! James

Glad you agree James and Dick . I will follow this one as long as it takes , time is not a problem. Whatever the outcome it's going to be one of CR4's finest achievements. I've no doubt that everybody else following here is just as enthusiastic as we are. Kris

Perhaps I should have been more specific and said that there was absolutely no way that these vortices could have been due to the Earth's rotation.

One metre from the equator would make the contribution of the Earth's rotation equivalent to one turn in every ten years. Depending what diameter you are looking at, you'd need a rotation rate of once in a few seconds to be aware of a vortex. If you continuously fill a flat 0.5-metre radius bowl vertically at the edge, the rate of rotation at 0.5-mm would be about once every six minutes. You could get larger rates if you filled and emptied the bowl (water that departs early contributes some of its angular momentum to what remains behind), but even here the required gain of 60x would be hard to achieve.

It is also worth being aware that the Earth's axis of rotation is not fixed. There is a regular 428-day cycle* with an amplitude of +/-5- metres. There are also shorter term as well as local variations of of over a metre. The museum would need to make arrangements to track this accurately - even if they were able to arrange an experiment that could illustrate the effect.

* http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1915MNRAS..75..518L

Fyz

We are in agreement Fyz. I was trying to tactfully suggest that the museum display may not be quite what it seems. Your more detailed post does the same , but in a more factual manner. I have no doubts about what is being seen at the museum (even though , as you say, the mechanism is anybodies guess ), which is why I suggested that they could find this projects findings useful rather than something which may seem to threaten an exhibit (They are in a wonderful situation to educate). Results from this project could be an addition to a display that shows how Coriolis is hard to replicate/easy to influence.

The museum probably influences many people , so enabling the museum to feel comfortable with more evidence is quite important if we want to help people understand.

Yes - both my #89 and Masu's #90 postings had previously made the same point - mine possibly somewhat obliquely, Masu's quite explicitly, yours somewhere in between. I felt it appropriate to add this comment as supporting data for your #91 posting because it seems that at least yours has been read.

Fyz

The more I read this thread, the less I can shake off that it reminds me of the Homeopathy notion, that water has this "chemical memory", which will increase it's medical potency, the more diluted the water. Does this mean that pure H2O is the most potent?

There will an optimum viscosity for any given experiment. The smaller the drainage hole, the better the potential for the departing water contribute its angular momentum to what remains behind. But that requires a lower viscosity to avoid the momentum being lost due to drag. That might mean that 'hot water' is best - even if it does mean 'trouble'.

N.B. I'm not certain whether salty water is better or worse, as I couldn't find data on viscosity. But sugar solutions are definitely not a good idea

Fyz

Hi Fyz, Kris, Dick, James & Guest,

Sorry for being somewhat lax at answering posts but I have been playing at astronomer and trying to figure out how to drive the telescope that I got just before Christmas. Telescope manuals are written is some strange language that is a mixture of Ancient Greek, mathematics and a language that appears to be English except with no concept of continuity or sequential order. They also appear to have never heard of a thing called an index or table of contents either, so finding thins is a hit an miss affair. I have found to ON switch, now if I can just figure out which end to look into I might be able to see something. Considering it has taken me 4 months to get this far and this is a computerized mount that is designed to connect directly to the internet and be controlled remotely it could take me a wile.

I have been thinking about what was going on in the museum experiment as described by the guest in #88 and what could be causing the rotation in a manner that made it look like the coriolis effect at work.

I was thinking that if the tree devices were actually on a perfectly flat surface that was level at its center then the curvature of the earth would mean that the ends of this surface would be slightly higher than the center. If the three devices were on such a surface then the outer two apparatus would not be exactly level and this might affect the fluid.

Unfortunately when I did the arithmetic the difference in height over a meter is something like 78 nm and somehow I doubt that you could ever level something to within this tolerance let alone see the effect it would have.

That crosses of any natural effect that I and think of and only leaves asymmetry due to manufacture and installation. Can anybody think of a natural phenomenon that could appear to cause the results that the museum is confusing with the coriolis effect?