[lyner]

It's a shame that you don't appreciate my point about Science being reductionist. But, having seen your approach, which tends to be the inverse of this, I should not be surprised. If one is going to have any chance of improving one's understanding of Science then you need as few factors as possible in the treatment of any situation.

I do not propose to have any strong opinions about the way trees work and I think that there are too many facets for the amateur to understand the process in detail.

What I do feel qualified to have an opinion on is the basic way in which your experiment with elevated tubes experiment may work.

Adhesion is not going to happen with a liquid metal because of the delocalised electrons. You won't get any bonding forces like the water molecules exhibit. That's why you get an inverted meniuscus with mercury. It wouldn't stick to the top a a tube any more than it sticks to the sides. It's not a candidate for a scale model. 
I notice that, yet again, you avoid the issue of what molecules actually 'do'. Toricelli, brilliant as he was, knew nothing of molecular bonds so he can't be expected to get it all right. In 2008, I should expect anyone to include the idea in explaining virtually anything.

Do you 'suck'in the air or is it pushed in by the external pressure? Interestingly, in my suggested experiment, there is no air pressure and no water goes up the tube and, in your suggested experiment, there is air pressure and the water moves.

Quoting endless instances of very high trees doesn't make your case better - just one tree would be enough and we all accept that the phenomenon does happen. What we are after, I thought, was some sort of explanation which is consistent with other explanations of other phenomena. That's what Science is all about isn't it?

There are so many differences between your experiments and what goes on in trees that, without some more detailed treatment (involving the molecular level) there is little chance of really improving our understanding of what goes on.

Trees may function after they are dead, for a while,  but the structures and materials were put there whilst it was alive - millions of years of development.
I'm afraid that I find it very hard to give credence to many of your personal Scientific models because you just don't apply the very basic concepts of cause and effect in your explanations. Dense fluids SINK through less dense fluids - explicable in historical and modern terms. Yet, on your video, you claim that they are pulled down. This is right, if you say that it is Gravity which is pulling - but Gravity is pulling everything down. It is the difference in density which makes it happen, the same as in the Oceans.

I leave you with my usual question. "How do the molecules know where they are?" I look forward to an answer. Don't bother with stuff about trees. Let's do one thing at a time.

"Wood for the trees" nice one (LOL), does your theory hold water tho?

[Andrew K Fletcher]

Your question about how molecules know where they are has been ignored because molecules cannot know where they are. If you could re-word your question so it makes more sense, maybe I can understand where you are coming from better.

I have tried to explain that the bead of water behaves how water and other liquids behave under tension. This is cohesion in water. The ability of water to stick to water is stronger than water sticking to the tube. This is why the loop works and the single upright tube close at the top either rounded off or flat, or twice as big at the top than the bottom is only as strong as 1 molecule sticking to the tube. As soon as one molecule pulls away more follow, just like blue tack pulling away from a wall, the water tears away from the top of the tube because of the weight of the water column below. The higher the tube goes the greater the weight of the water column. Obvious really.

The unbroken bead of water has a continued unbroken water cohesive bond, at no point is this bond relying solely on adhesion as is the case with your rounded closed end tube thought experiment.

Having a glass tube made to test your experiment is impractical, will inevitably fail,  And I see no point in considering testing it given the failings of Galileo on the same subject and many more that have followed.

It’s difficult to ask trees whether this flow and return system is holding water. On the other hand it is easy to ask people if it holds water in human physiology and circulation. More to the point it is even more fruitful to ask people with varicose veins to photograph them as they shrink using an inclined bed, when doctors and nurses predict the opposite will happen.

I would love a chance to talk to you and show these experiments so you can see them for yourself. They are quite humbling to physicists, one in particular a good friend and water engineer to boot sat on the floor with his hands on his face shaking his head saying this cannot be. Why have I not been shown this before. Why have I accepted without question what I have been taught? This same man also benefited tremendously from tilting his bed when he realised the significance of this discovery.

Andrew   tel: 01803524117

[lyner]

Your question about how molecules know where they are has been ignored because molecules cannot know where they are. If you could re-word your question so it makes more sense, maybe I can understand where you are coming from better.

Here lies the crux of our problem. The molecules in the water are what determine what it is going to do. A molecule at the top of your U tube will be in exactly the same situation as one at the top of a single tube; they will both have water molecules below them and plastic molecules above them. You have kept on insisting that they will behave differently in each case. I ask the question because there is no difference in the situations for each of the molecules so how can they behave differently? i.e How could they know where they are? You have acknowledged that that is a nonsense question.

Try to read the following carefully and, if you want to answer it, please keep strictly to the content. Neither trees nor human bodies  play any part of the argument or the context here.

Let us consider what is happening at the top of your u tube. First of all,  a liquid will flow and cannot 'keep its shape' without some sort of container - that's the  definition of any fluid. Furthermore there is a fundamental principle of pressure / stress  in fluids and that is it acts in all directions, equally. If you don't accept those two then we must part company - don't bother to read on.

At the top wall of the tube there can either be positive, zero or negative pressure.
If there is positive pressure then the force on the walls will be outwards and balanced by the force from the walls of the (rigid) tube.
If the pressure is negative then there will be an inwards force as well as one 'along' the bead. The liquid will flow 'inwards' or away from the walls unless it is acted on by some other, balancing, force . This force must be due to the attraction of the molecules of water to the molecules on the sides of the tube.
The third option is that there is no force at all - in which case you could take the wall of the tube away and the bead of water would stay intact and behave as it did before.

You must believe that the presence of the tube is necessary for the thing to work - that's the only totally "obvious, really"  thing about any of  this, actually. We can agree that option three does not apply, I'm sure.

The pressure can hardly be greater at the top than at the bottom. I think you would agree - so the first option cannot apply either.

So we are left with the fact that there must be  negative pressure at the top - whether it is a U or a single tube- once the 10m height has been reached. The molecules and the way they interact with their neighbours are what determines how the water will behave. Left to itself, with or without tension between the water molecules, the bead of water would become thinner and thinner (the 'tension' acting equally in all directions) unless the molecules at the interface stick to the molecules on the tube surface. Unless you acknowledge that you may as well say that water is like a solid and that you could replace it with a steel wire running through the tube and expect the same behaviour for steel as water when it emerged at the other end.

Your model implies that the tube is not interacting with the water - or you would have taken the tube into consideration - involving the forces on the molecules. That just cannot be correct or, by the same argument, you would be able to scoop up a handful of water and raise a column - like treacle (and even that will flow back down unless contained within a tube).
If water were like a' chain' then it would not need a tube to guide it - you could just pass it over a pulley. The tube must be doing something which you don't seem prepared to discuss in Scientific terms.

[Andrew K Fletcher]

Didn't think anyone was interested in my experiments on the forum enough to go into them in more depth. I agree with the molecules of water interacting with the molecules of the inside of the tube. And indeed called this adhesion. Adhesion in a resin requires the same interaction between the adhesive and the tubular wall.

Trees must make use of this by producing resins in the sap. This must also contribute to the heights achieved by some tree species. One only has to have this resin between the finger and thumb and pull them apart to see how the resin forms fluid strands, much the same as a spiders silk.

Without any tube. The flow and return will take place in or out of a vessel as gravity causes a density flow, which in turn causes other molecules to be dragged behind it, completing a flow and return. Constant evaporation from the surface of a container filled with fluid containing denser solutes will alter the density at the surface.

There are a number of other anomalies going on in the tubular experiment too, for example, when the salt solution flows down and becomes diluted down the flow leg of the U tube, the flow appears to accelerate. I am not sure what is happening here, but having a stab at it, I think that gravity is able to align / polarise the salt molecules and the water to improve the flow. Conjecture I know, but have no idea what else could be introducing a boost because the upward flow of pre boiled / degassed water is maintained, and no further salt is added to the downward flow side. Another possibility is that gravity interacts better with the same amount of salt as it moves down towards the ground (sea level). Any ideas?

The simple boiled sugar solution video shows how the concentrated solution at the bottom of a pan of water on a gas ring operates a flow and return system that prevents water vapour from reaching the surface. Looking closely we can see active boiling below the surface yet the surface is free from bubbles breaking the surface.

Cavitations have been observed in a scaled down flow and return system consisting of a catheter bag, a bladder wash bag, a drip bag, and a network of vessels designed to show how circulation works in the body at the London International Inventions Fair 1997. This circuit worked very well with the drip bag introducing coloured salt solution at the top of the tubular circulation system. The downward flow caused the whole system to circulate and could be operated by, and indeed was, many thousands of visitors. The salts flowed down through a T junction at the bottom was a bladder wash bag to collect the salts, the coloured solution flowed through a catheter bag using a T junction again and the concentrated solution flowed to the bottom of the bag, as clean water flowed out to replace the salt solution lost. A convenient tap on the bladder bag represented the urine being released from the system. Many doctors, nurses, inventors, scientists and government officials for several countries were entertaining the circuit and discussing the implications with me. Yet none of those people were prepared to rock the boat and do something with it. Anyway, that’s history now. The point I was making is that this flow and return model produced it’s own cavitations. Everyone could see that the flow continued around them with out problem. Bubbles forming, even 5 mil long were observed to flow down instead of up using small pulsate amounts of salt solution released from the bag to drive the circuit.

Once you have observed this and look at a diagram of either the human body, and animal, insect, plant, tree, or the ocean current, or indeed the experiment at Brixham, it all comes alive in front of you. You don’t see inanimate drawings any longer, but a coherent flow and return. It is everywhere in nature, one just needs to understand it to see it.

[lyner]

There is no point in my replying to your comments because you have avoided addressing the one serious scientific point which would help to solve what is really going on. Another string of instances have not advanced the topic in any way. Clearly your Science is too fuzzy to discuss the issues I brought up. Did you not read what I wrote?
Pity.

[lyner]

Would anyone else like to contribute some sense?

[Andrew K Fletcher]

You are stating the obvious. Of course the water interacts with the tube, why else would we have performed this experiment had it not?

The analogy of a rope or chain is merely to show the dragging effect of each molecule on it's neighbour. This reaction to movement will make the water flow up or down and even up and down in the same side of the tube if required. Yes a two way flow in the same tube. So how does this fit with your tubular interaction?

[lyner]

If, as you say, the cohesion is stronger than the adhesion, why does the water not stick to itself and pull away from the tube walls to form an ever-narrowing bead?
Why should the water interact differently with the walls of the U tube and the single tube? I don't think that you have actually considered this in detail.
Most of the links I can find imply that the adhesion between water and glass (as an example) is stronger than the cohesion between water molecules. That explains the positive meniscus with water in glassware. The negative meniscus for mercury is because the adhesion is much less.
But you clearly don't want to discuss what is happening between molecules. You'd rather use  generalised 'chat' ideas which don't help with the Science at all.
What is this 'reaction' you quote in your last post? Is it the Third Law 'reaction' or what?
The only reference I have read from elsewhere which actually discusses your 'tension' (several posts earlier) implies that it is 1. Dynamic (it won't last) and 2. Less than the adhesion. Neither of those facts predict your u tube behaving any differently to a smoothly terminated single tube.
BTW, i will repeat another question - how wide can your u tube before the effect will cease? From your arguments, I would infer that there is no limit - even the total height of the U.
And, please, no more trees until this is sorted out.

[Andrew K Fletcher]

As you said earlier, the tension must be acting on all the water, so why do you expect it to be acting closer to the wall? The fact that cavitations take place and can be observed taking place is good enough for me. Even with water vapour bubbles in the column of water the bead does not give up immediately. It is irrelevent whether you believe it or not unless you go ahead and repeat the experiments.
But it is worth considering that a molecule has an affect on it's neighbour. This must also apply when the bead of water fails.

How wide will it go? This is a new one for me. I have no idea having never considered it. We have gone higher than 24 metres though only by a few metres more, though with careful hoisting we could I am sure go higher still. The other video's I have show the experiment more clearly. I must find a way of changing them to digital format for the web.

We have not tested the experiment with a larger bore than 6 mil. But I suspect the diameter increasing more will reduce the stability of the experiment due to the inevitable increase in the weight of each column placing more tension on the water if this is what you mean. So diameter should be on a sliding scale to height achieved. logially that is.

[lyner]

As you said earlier, the tension must be acting on all the water, so why do you expect it to be acting closer to the wall?

It acts everywhere, as I said. The molecules which are in the bulk of the water will only act on the water molecules immediately around them. The tension will be acting in all directions there but not 'on all the water', just on adjacent molecules. I was interested in what happens at the interface - because that will be where there are molecules of water right next to molecules of plastic. If there are no attractive forces between these molecules then the water will part company with the plastic, pulled away by cohesion. You don't seem to think that this is relevant but, once the water and plastic are separate, the bead will collapse due to its cohesion.  If you try this with mercury it won't work at all because the cohesion in mercury is so much higher than the adhesion to the tube.
How can you not see this? If the tension 'within' the water is greater than the adhesive forces (stress) then the column will collapse and fall. Whatever the shape of the water container below the surface we are considering this will apply.  As long as there are no rough edges, the column will be supported in both the U and the single tube (I have said this so many times) because the molecules on the surface are under precisely the same conditions. What is your problem with understanding that - or in seeing the relevance of it?
If you believe that a liquid can behave in any other way then you must also believe that water ( and liquids in general) behave totally differently from the way they actually do. You seem to be so attached to the notion that the U tube is essential, rather than just happening to work better because of its inherently unbroken surface and because it is so much easier to fill with liquid without bubbles etc.

If you were to melt the end of some tube and blow a good, smooth, bulb on the end, it would allow just the same thing to happen as happens at the top of your U.
Just because you have produced an interesting and novel effect it doesn't mean that you have explained it correctly.

[Andrew K Fletcher]

You are totally and utterly wrong about the shape of the tube not making any difference.

Let me put it in simple terms for you.

On either side of the tube we have suspended a column of water, which stretches like elastic under tension! The walls of the tube cannot collapse and account for the changes in water level when the open ends of the tube are pulled out of the container filled with water.

Now let us deal with the two plates of glass sticking together due to what you, et al say is showing the strength of adhesion in water molecules.

You are obviously adhering to what you teach in physics relating to adhesion being the stronger force so let me clear things up a little for you.

Question 1. Are you assuming that when two plates of glass are pressed together with water between them, the glass is close enough to have only the molecules that are stuck to each other and in contact with the glass. Or are we saying that there is water between the glass which has many water molecules that do not make contact with the glass too?

[lyner]

The walls of the tube cannot collapse and account for the changes in water level when the open ends of the tube are pulled out of the container filled with water.

Can we not agree that a force is needed in order for the tube to be having an effect? If there's no force involved then you could take the tube away and there would be no difference - clearly nonsense, so this must be true.
The tube must be doing something. Just 'being there' does not describe what it does.

What does "like elastic" mean?
Elastic ( I think you mean a rubber band) is a solid which needs no container for it to stay in shape. As you stretch a piece of rubber, you distort the bonds throughout the bulk until the forces balance out. The length increases and the width reduces - keeping the volume constant. What is there in a piece of water which will achieve the same thing? All the water I have seen (0-100C) flows, except for small water drops - which we aren't discussing here.

How can your forces only apply 'along' the length of column yet not apply  across the width of it? ("like a piece of elastic")

Re your 'glass plate' question: An ''ideal' pair of glass sheets, which are totally flat (to within the thickness of one molecule) would probably stick together in any case, without water - welding, effectively. In practice, there will be many spaces between. The addition of water molecules would increase the adhesive force because they would provide thousands of times more molecules 'in contact' with each face. That will increasing the 'temporary' bonding between the faces - adhesion at work???

If  you look at any picture of menisci at a glass - water interface, you will notice that the water is pulled upwards at an angle of greater than 45 degrees. How can you explain this if you deny that the water molecules attract each other more than their attraction to the glass molecules? Also, how do you square your idea with the behaviour of mercury in glass? Do you subscribe to the normal ideas of vectorial addition of forces or do we part company here also?

Real Science does not use Metaphor and Simile to describe what is going on. Can you give a reply which doesn't rely on either of these?

[Andrew K Fletcher]

I put it to you that the two not so ideal sheets of glass have many more molecules of water between them, many of which are not in contact with the glass on either side and only have contact with each other. So we are not only looking at adhesion but also at cohesion and each is as strong as each other until the water parts company with the glass. In fact there is little chance of the water being able to share 1 molecule with the other sheet of glass is there? So cohesion conveniently ignored here is very relevant. And when the water does separate from the glass sheets it is because water has been pulled away from the glass, not pulled away from other water molecules.

[lyner]

I do get a little tired of sneering remarks about the teaching of Science. Unlike the mass of fringe and fanciful approaches to Science which ignore selected bits of conventional Science yet use other bits, where they suit, good Science and Science teaching try to be consistent and rigorous. If a new idea comes to a 'true' scientist, it will be examined thoroughly to see where it agrees with and where it clashes with the rest of our experience. THAT is the sort of questioning that advances our understanding. Any serious Science teacher will use the conventions because they have stood against many tests, unlike 'alternative' and unproved ideas which come along and pass as frequently as No. 39 buses.
Alternative proponents tend to have an amazing arrogance about their abilities to understand things. We have to protect young minds from a lot of misinformation which presents itself as a crusade against the establishment.

[lyner]

and each is as strong as each other until the water parts company with the glass

That is merely a statement. How do you 'know' that water will part company with the glass before some water molecules part? On what evidence is it based? A simple piece of evidence which refutes what  you say is the angle of a water meniscus. Does that not weigh in your assessment? Are you going to ignore the most basic ideas in mechanics, now?

[Andrew K Fletcher]

Nice try SophieCentaur. But you fail to address the fact that the water volume between the two plates of glass has a massive number of molecules that do not come into contact with the glass and stretch from the molecules that do. So if the two plates of glass are stuck together it is not just because of adhesion is it? If you agree with this, then you must also accept that cohesion in this experiment is = to the adhesion, because this has been used to state the strength of adhesion.

[lyner]

UH?
You have a chain which breaks. One of the middle links is weaker than the rest. You do an experiment to determine the relative strengths and, low and behold, you choose to say that one of the stronger, end, links broke first.
That just doesn't make sense to me.
Whilst you have some tension then all the links are holding. When the weaker links break, the chain breaks.
Do you contest the evidence of the shape of a meniscus which implies that the adhesion is stronger than the cohesion?
Did you learn any Science (or even some logic) at School, or did you reject it even then?

[Andrew K Fletcher]

http://www.imss.fi.it/vuoto/eberti.html#


Experiment by Gaspare Berti in the Minim Convent at Pincio.
Gaspar Schott, Technica curiosa, sive, Mirabilia artis, Würzburg 1664

Three and a half centuries ago, most scientists didn't believe in the concept of a vacuum, or a place with no air. But there were a few renegade researchers including Gasparo Berti, who set out to make a vacuum. Berti rigged up a huge glass tube, several stories high alongside his house, and filled the tube with water. Then he sealed off the top of the tube and opened the bottom into a pail full of water. He found that the water level in the tube dropped a few feet, but then didn’t move. Berti claimed that he had produced a vacuum in the tube above the water line, and that’s just what he did. He also made a barometer by gosh, but he didn’t realize it, so it was no big deal. But a couple years later, a guy named Torricelli after carefully eyeing Berti’s vacuum thingamajig, set out to make a barometer with mercury instead of water, because Berti’s barometer was just too big. The experiment was a success, and Torricelli became the creator of the barometer. So, a classic mercury barometer is only about 2 1/2 feet high and much easier to deal with than Berti’s water barometer which would be about the size of your average house. So, on a beautiful spring day, if you used Berti’s barometer, the pressure would read about 30 feet, instead of 30 inches.

The Weather Notebook is underwritten by Subaru, the beauty of all wheel drive with major support by the National Science Foundation. http://www.weathernotebook.org/transcripts/1998/01/30.html

[lyner]

Nice picture - was it a holiday snap?
But what about my questions? They actually contain some serious Science.
p.s. Yet again you don't read your own links. It was a LEAD siphon. Adhesion to metals would be very low so even your tube experiment wouldn't work at >10m.
You could always try to repeat it with lead, I suppose. A tenner says it wouldn't have the same result as for your plastic tube.

[Andrew K Fletcher]

Im beginning to Like you SophieCentaur