How do Trees Really lift Water to their Leaves?

@Sophie
If you were a thinker instead of a sheep you would engage your brain before opening your mouth. Again you attack me. It is I that has trashed the bullshit that you have been teaching not you that has trashed my experiments. Worth remembering that don't you think?
Any moron can keep churning out the same written literature without questioning it.

Albert Einstein
Humiliation and mental oppression by ignorant and selfish teachers wreak havoc in the youthful mind that can never be undone and often exert a baleful influence in later life.

Albert Einstein
Education is what remains after one has forgotten everything he learned in school.

Lyner aka Sophie:

I have just read your last outburst, which I will ignore.
I was about to post the following reply when I read it.You will notice that I am trying to be constructive.:

I see no point in stating the obvious
It may appear obvious to you but nothing is 'just obvious' in Science. If you have an incomplete model in your mind of what is going on then you can't explain this.
The reason that you don't explain it must be because you can't.
You are doing to me exactly what you claim that Science teaching is doing to children.
What you are saying. effectively, is "You just have to accept this obvious fact". If it isn't obvious to me then are you going to shout at me as if I were a naughty / thick child or are you going to try to help me with my obvious misconception?
Which should I do if I were trying to get an idea across to a child who didn't get what I was saying?

Some comments:

Cohesion evident in the flow from one vessel to another is clearly not relying on adhesion

Do you have a cohesion meter and an adhesion meter to tell you this? What justification for this statement? (we are not dealing with a chain or wire made up of a solid substance)

I was relating to your capped end tube all along.

But I was, 'all along', asking you to draw a distinction between the two situations - yours and mine.

One could go on to argue that the cord used to raise the rope exerts a constricting pressure

Precisely. The weight of the rope will pull down on the pulley. The rope is a solid and, despite being able to distort a little (become a bit narrower and longer), the 'constricting pressure' is balanced by the molecular forces which are there - the properties of a solid. If you were to hang a length of chewing gum (a very plastic substance) over the pulley the gum would stretch and get thinner because it would flow. Water flows, too, but more easily, so you would expect the same if you didn't provide the tube outside it which could provide some extra forces.

I melted the end of a 130 CM length of the same tubing used in the Brixham experiment

Well, you did try. It worked as expected. During your whirling phase, it is not surprising that water flowed out - the tube could flex and bubbles would have been admitted into the bottom, allowing air in. Also, the opening at the bottom would not have been horizontal so there would have been a pressure differential (Hydrostatic - not atmospheric) across the inverted surface of water - that would start a water flow - you can see this happen with an inverted bottle of water, too where the water flows (gloops) out quicker if the bottle is not exactly vertical. If you had suspended the tube motionless and tapped the sides I would expect the same sort of thing to happen. It was worthwhile trying but you were not in a position to see what was actually going on inside the tube. If you were to try the same thing with your U tube, I think the water would fly out even quicker with such rough handling (see the last comment on this post for the reason).

Again I must state that there is little to no point repeating the same experiment with a longer length of tubing as the force exerted by the column of suspended water will easily cause the water to be pulled from the tube.

That presupposes your original ideas are correct and that the inside of the top of the tube was as smooth as the top of the looped U tube.
There are many problems associated with implementing the closed tube experiment and I can see how the continuous loop provides both a much smoother surface and a better chance of eliminating bubbles. That is a practical and not a fundamental difference between the two experiments. Very easy to draw the wrong conclusions about the actual mechanisms at work.

It may interest you to know that when the U tube is performed lower than 10 metres and the ends of the tubes are removed from the water, the water flows out and will not remain in the tubes

That is precisely what I should have expected to happen. It's an unstable situation. Unless the two arms of the tube are precisely the same length then there will be a hydrostatic pressure differential across them causing water to flow. Once it has started, the difference increases further and the flow will increase. If the tubes are kept in small reservoirs, such as in your original videos, the levels will self-adjust. This, of course, explains why, when you added a more dense liquid to one side, the levels started to change; the hydrostatic pressures are not equal. If you were to raise the side with the salt in, you would find a new position in which the flow would be zero. (Until diffusion of the salt solution into the freshwater side started to change things).

To sum up, I can see nothing in your last post which proves or justifies further you explanations. Half way through you, yet again, beg the whole question by making the assumption all over again.
All you have described fits in perfectly with conventional theory.
I think I have identified the crux of our differences enough times. Are you really not capable of answering my one small point about the way the molecules must be working 'at the top' IN BOTH CASES?

It was Einstein not me that wrote those quotes attacking his own experience in the education system.

To sum up:

1 the experiments at Brixham were roughly handled over a relatively prolonged period of time, due to the person at the top of the cliff lowering the tube rather than holding it steady, yet the bead of water remained intact as shown in the unedited actual time footage. More experiments have been done many times and recorded showing this bead of water to be a lot more robust than you are imagining it to be. I knew you would argue that gently rotating the smaller capped tube would not represent the longer tube. But surely you can comprehend how much tension there is in a u tube suspended to 78 feet = two columns of water pulling on each other. The tension BTW should be the same throughout the water column, because as you state each molecule must act on it's neighbouring molecules. A further experiment was conducted at a greater height than 24 metres. The water inside the tube was observed to boil without heat.

NeilP:
Glad to see everyone is being so cordial, courteous and gracious

Lyner:
Thank you Neil!
Andrew:
You need to refomat your post. The quote includes some of your own words at the bottom, I think.

Your original post did not discuss how the space at the top had formed. Are you suggesting that the gap at the top of the tube was a vacuum? In which case , when you removed your 'extra force', the water would have gone back up to the top (as Galileo et al have found). If the gap remained, then it was full of air. This air can only have got there as bubbles from the bottom, out of solution or via a leak in your 'sealed end. It must have come from somewhere.
Quote

The tension BTW should be the same throughout the water column,

Just not true. If you take a chain (of finite mass) and hang it up. The tension between the bottom two links is equal to the weight of the bottom link. The tension between the top two links is equal to the weight of the whole chain - less the top link weight. How can the bottom link 'know' how many links there are above it? If there were more tension acting on the bottom link than its weight then it would move upwards. (Newton's First Law of Motion applies, as always)

How can you pontificate about this topic if you make a simple error like that? Some serious rethinking is needed, I fear.

I wouldn't mind betting that Einstein made a point of learning, thoroughly, all about Newtonian Physics before he started leading off that it was inadequate or wrong. He never treated anything as 'obvious'.
I can sympathise with him regarding his view that his education was lacking. HE, as it proved later, was actually very clever and was probably frustrated at his teachers not even approaching him in ability and he never did suffer from an understated ego. Andrew - you are no Einstein.
I am just a humble proponent of a system which seems to work very well and is very consistent (except at its esoteric edges) - because the people who have constructed it are are lot more clever than you or I. But I do my best to avoid skating around difficult points - unlike you, who still refuse to address one pivotal question which I need not repeat, surely.

Paul Fr:
Well im only reading this topic for the insults. Although i do find in upsetting when two grown men (ok, one may or may not be a woman..oh and i discount BC because he is a chemist) yadda yadda yadda...

Lokk, just get on with slagging eachother off, i have popcorn ready you know!

You know Sophie, you must be correct. I must be a complete idiot for showing you that water can be placed under tension when you refuted it. But where does that leave you?

Tension is brewing
Of course every molecule in the columns is under tension. Each and every single one of them. The downward pull from gravity on the water must also have an effect on the walls of the stiff nylon tubing, but not sufficient to account for the water springing up the tube when the ends are removed from the water container at ground level.

Add a pinch of salt to one side and water is drawn up under tension. Not because of pressure changes either. 1 grain of salt will trigger this flow! How can you account for this in pressure changes? Surely this flow is responsible for generating the pressures and not the other way around. What drives the circulation before a heart forms? Gravity is a good starting place! This is not the same as a siphon. I keep trying to explain that there is a huge difference between a siphon flow and a density flow. Thought experiment. Coloured salt solution added to upward flow side of a siphon in sufficient quantity to generate a density flow in the upward flowing side. Here we have a downward density flow in the same side as an upward flowing siphon flow. Seen it done it!

Do I have a laboratory and unlimited funds to go with my cohesion and adhesion measuring device? Perhaps an entire university behind me even as you do?

You avoid most of my questions and ignore most of my answers and concentrate on what is happening to the molecules inside the tube? I do not understand what you want from me other than for me to become a verbal punch bag that is?

Lyner:
I did try to deal with all the issues in your last post. Did I avoid any of them?
I am surprised that you don't think the behaviour of molecules is relevant to the way substances behave. To my mind that is a crucial issue upon which all other things in this topic must hinge. Any explanation just has to include the molecular consideration or we are back in the middle ages.

Have you given some thought to my chewing gum idea? Is that not relevant to the situation with water?

One grain of salt will cause a flow? Of course it will. The solution around it is more dense and will drop through the fresh water, albeit quite slowly. It would be a real surprise if it stayed there or went up.

What is 'surely' about the flow generating the pressure? You can measure a pressure difference with out needing any flow. As I suggested, try raising the salty side and you will get a balance point (equalise the pressure difference) with no flow. Why do you muddle up cause and effect so often? What do you suppose started the flow in the first place? Everything needs energy from somewhere to make it happen. Where does the energy come from for your flow if not from the salt having been lifted, by some means or another and gaining Gravitational Potential.

How about my question regarding the space that you saw above the column of water? Did it stay there? Was it air? How did it get there? There is an interesting practical question here.

The fact that an open-bottomed U tube doesn't stay full is very well explained in terms of small pressure difference. You have not replied to my general comments about your latest trials. I think they were mostly good-willed comments??

What is a "density flow"? It is not a term in common use.

I fully believe you saw what you saw but the girl saw the tooth fairy's money too. Was she right to believe in the tooth fairy? She could have found the real cause by the appropriate experiment - staying awake all night- or asking someone who knows.

Ok let me ask you to state what you know about the Brixham experiment.