How do Trees Really lift Water to their Leaves?

@Chris,
Why does this thread have to be moved? We have agreed that it crosses the boundaries of Biology, Physics and even Chemistry.
It also crosses the medical and physiology boundaries, geology and palaeontology and even evolutionary boundaries.
If this is not general science then what is?

Dave:
If you connect a large tube and a small tube together in teh way you suggest it will work, however water is not being gained or lost from the tubes, so the flow in litres/second will be the same in the big tube as the small tube, the velocity in the big tube will just be slower.

The down bottle fills up by the same amount as the up bottle empties doesn't it?

If the up pipe is 12mm and the down pipe is 6mm, to test this colour the saline red and the water in the up bottle blue you will see that when the red drops all the way down the pipe the blue will lift up about 1/4 as far as the saline drops. so you have lifted 4times as much water 1/4 of the distance as the saline dropped - so overall water has just moved from one bottle to another.

A tree lifts water to it's leaves ans 98% of it evaporates, your model lifts water to the top then all of it comes back down. The two are not equivalent at all!!!
I am the people at my homepage so that won't really help - and at no point have I argued with the results of your experiments just your interpretations of them, so doing the experiments wouldn't necessarily help, although I would be happy to come and see yours at some point when I am in Devon and not too busy.

NO David, if the tree is killed and the flow continues for another three weeks, it definately is not the tree that is lifting the water!

But you are missing my point with regards to this flow in a tree. The very nature of the trees construction enables transpiration to take place. I would not even know where to start trying to make an artificial tree. But killing the tree and the water / sap inside it is still flowing for 3 weeks is a vertual artificial tree.

If saline solution were to be some how introduced at the top of the tree once it has stopped flowing after the three weeks, we should observe fresh circulation due to the initiation of said flow and return system. Obiously, we would have to refil the tree to its previous levels of water to replace the losses from the falling levels of water inside the tree.

Give me a date, and I will drive to Cambridge and give a demonstration for all to see.

Andrew

Moth:
Reply #96 on: 11/05/2005 10:07:08 »
Andrew, I too met you in Brixham with CHaOS (yes we are ganging up on you , so have had some time to think about your idea.

I believe your experiment works, but i mostly disagree with the conclusions you draw from it and the arguments you use to explain it. I also disagree with your dismissal of the other princples involved.

I imagine that there could exist a tree which transpired very little, but instead used your salt-siphon principle to create a vertical conveyor-belt of water to transfer chemicals between its roots and leaves. Dilute solution would rise up one set of tubes while an equal flow of denser, more concentrated solution would fall down another set of tubes, and at either end living cells could maintain the concentration difference by extracting solutes at the bottom and injecting them at the top. I'm sure this does some violence to a biologist's understanding of trees (and i know it doesn't match mine), but as a physicist i am happy with it in principle.

I consider it an interesting and clever idea, but don't believe it has much to do with how real trees actually work. The key flaw is that the salt-siphon cannot explain transpiration. Your idea requires almost equal up and down flows, while transpiration means that (vastly) more water flows up than down.

You rubbish root pressure, saying that if it worked then jets of water would squirt from the roots of felled trees. I don't think that follows. Water is almost incompressable at the pressures we are discussing, so it is entirely possible for the roots to contain water at a significant pressure without causing them to squirt when cut as the water would need to expand only a tiny amount to completely relieve the pressure. What i would expect as evidence for the existence of root pressure is for roots to gently ooze liquid for some time after they are cut. Indeed this is what i have observed: when I have cut limbs from trees during the spring and summer i have often seen liquid flow from around the edges of the wounds (where the current year's phloem and xylem are). To be clear, i'm not prepared to swear root pressure is all there is, but i don't find you dismissal of it convincing.

Osmosis is a complex, subtle and powerful phenomenon. It is quite possible that the widespread explanations of it are faulty, and yet osmosis really happens. I found this paper which discusses the many ways of analysing osmosis: arxiv.org/abs/physics/0305011

Your recent answers to Dave's questions about the energy budget refer to differing sizes for up and down tubes. This is strikingly similar to a perpetual motion machine I invented when i was 14. It works like this: construct a siphon from a short fat tube and a long thin tube connected at the top. Place the bottom ends in buckets and fill the system with water. As there is a greater weight of water in the fat tube it will pull water up the thin tube, so transfering water from the lower bucket to the higher one. I hope you can see why this doesn't work, and why your replies don't answer Dave's question.

I don't buy your dismissal of the 'conected water column powered by evaporation at the top' idea, but i want to do some calculations before i post on that subject.

You seem to attack most things simply by saying they are implausible. This is not an argument that holds any weight with me. If you want any acceptance of your idea you will have to start making sense in terms of accepted scientific priciples. Our discussion in the E=mc^2 thread suggests that you are not prepared to do this, but i still hope you will. It is as if we are speaking different languages. I have not managed to learn yours from your postings here, so if we are to be able to communicate you must learn mine.

I would be interested in seeing your experiment, but even if it works exactly as you say it does it wont change my opinions of your explanation of it. Mostly i am just curious about the details of your method, and would rather see it for my self than through your discription.

I suggest this thread remain in General Science - the subject is a mix of biology and physics with a hint of chemistry. The discussion has lacked biologists so far and could certainly benefit from their input, but while Dave and I continue to examine the physical basis of Andrew's theory it would be out of place in the Biology section.

One other point I would like to add is that if the Brixham experiment was inside the trunk /sleeve of a tree, it would be able to support the column to much greater heights, furthermore it would add another interesting force to the equation. It would generate an increase in the head of the dilute solution, picture an inverted U tube with clean water on one side and a small amount of concentrated solution in the other, the water levels will change, pushing the dilute solution up and out of the opposing tube, and the resting place of each side of the fluids level will be much higher in the dilute side than the side with the salt added.

This is the mechanism for water to exude from a cut stem and this is why it has been erroneously attributed to root pressure!

I look forward very much to showing you the experiments.

Andrew

Dave:
I believe that if you cut a stem right off (at the right time of the year) it will exude sap - I know a dandelion does, wouldn't this preclude your explanation as you have just cut off your inverted U tube?

I don't think that root pressure allways explains the whole pressures involved (apart from anything else if it is being powered by osmosis it is an energy intensive process and would waste a lot of sugar if it were used it for transpiration), but it certainly exists.

RE: Tubular differences, try to see that the increase in tension of the fluids pulling the sap through ever smaller tubes, forcing the excess out through the leaves as transpired pure water. The forces generated by the falling solutes in other areas of the tree are more than enough to cause water to be drawn up and evaporated.

Remember also. When I first came up with this theory all those years ago, I did not have the Brixham Experiment to show the principles. In fact the experiment was built to show the forces and flow rates generated by this liquid pulley system \ Not siphon effect.

At the time, I also believed in the thirty three feet limit, but gave the experiment a go anyway, believing that the cohesive force in the experiment would easily exceed the adhesive forces in the capped tube experiment previously used to determine the height that water can be drawn up with a pump, as in Galileo's problem at The Grand Duke of Tuskany's Palace.

As I carefully drew the water beyond the 33 feet limit, I knew in my heart that this was and is a very important part of fluid mechanics and fitted beautifully with my hypothesis. When I added the salt to the one side to see if it would draw water from one bottle to the other, over the thirty three feet limit, I was ecstatic to say the least.

My colleague, Adrian VanZweden, who was top in Physics at his University In Holland and had worked for many years as an water engineer at South West Water, sat on a step with his hands on his head shaking it, saying this is not possible, This cannot be happening, after previously stating that the experiments could not work according to current Physics literature. Adrian and I have conducted the experiments many times, and he was there also at the Brixham experiment, along with John Russell, pictured in the news article with my wife Jude.

Moth, thank you also for seeing the logic in leaving the thread in the General Science section.

Sincere regards

Andrew

The Doc:
Maybe we should derive a new forum... MAD SCIENCE

Anthony:

The majority of scientific publications in this area appear to be in "Plant Physiology", "Journal of Experimental Botany" and "Tree physiology" I suggest you try either the British Library or a local university library to read these journals.

I don't have much time available to me but have found an interesting abstract on the topic, that represents something close to the "state-of-the-art" currently in the field. I think you'll be surprised at how advanced the field is.

Thermodynamic analysis of the interaction of the xylem water and phloem sugar solution and its significance for the cohesion theory. Lampinen, Markku J.; Noponen, Tuula. Laboratory of Applied Thermodynamics, Helsinki University of Technology, Finland. Journal of Theoretical Biology (2003), 224(3), 285-298.

Abstract

The cohesion theory explains water transport in trees by the evapn. of water in the leaves (transpiration), which in turn generates the tension required for sap ascent, i.e., the flow of pure water from the soil through the root system and the non-living cells of the tree (xylem tracheids) up to the leaves. Only a small part of this water flow entering the leaves is used in photosynthesis to produce sugar soln., which is transported from the leaves through the living cells (phloem) to everywhere in the tree where it is needed and used. The phloem sieves are connected to the xylem tracheids by water transparent membranes, which means that the upflow of pure water and downflow of sugar soln. interact with each other, causing the osmotic pressure in the sugar soln. (Munch model). Here, the authors analyze this interaction with a thermodn. approach and we show that some open questions in the cohesion theory can then perhaps be better understood. For example, why under a quite high tension the water can flow in the xylem mostly without any notable cavitation, and how the suction force itself depends on the cavitation. Minimizing Gibbs energy of the system of xylem and phloem, we derive extended vapor pressure and osmotic pressure equations, which include gas bubbles in the xylem conduits as well as the cellulose-air-water interface term. With the aid of the vapor pressure equation derived here, we est. the suction force that the cavitation controlled by the phloem sugar soln. can generate at high moisture contents. The authors also est. the suction force that the transpiration can generate by moisture gradient at low moisture contents. From the general osmotic pressure equation we derive an equation for calcg. the degree of cavitation with different sugar soln. concns. and we show the conditions under which the cavitation in the xylem is totally avoided. Using recent field measurement results for a Scotch pine, the theory is demonstrated by showing its predictions for possible amts. of cavitation or embolism from morning hours to late afternoon.

Your argument on this website has been interesting and some excellent scientific points have been made about your theories and experiments by very talented scientists. However, they are not experts in the field and I think you might benefit from that input. The first two journals I mentioned are, most probably, peer-reviewing journals, which means that, subject to the editors decision, the editor may also be an expert scientist, submissions will be reviewed by two experts. If you are serious about your ideas I suggest you submit your experiment and theories as a what is known as a "letter" or "communication", this may need be no longer than one side A4. You should first read the journal for style and think about reading the literature to reference your work relative to that of others. I think a day or two reading these journals may be very fulfilling for you. It is not necessary to have a university address to get published, but your submission must be professional and new.

If you were prepared to write a manuscript, and place the text online here, I would be prepared to comment on style, and I suggest others might too.

@Anthony I have read very much all that has been written on this subject, including the cohesion theory, which, as shown in the abstract, does begin to attribute some force from the solutes to the picture:

The phloem sieves are connected to the xylem tracheids by water transparent membranes, which means that the up-flow of pure water and down--flow of sugar solution. interact with each other, causing the osmotic pressure in the sugar solution.

Now I wonder where the idea of sugars causing what is believed to be osmotic pressure, originated?

I have approached many journals to get my work published, only to find a very tightly closed shop.

1. New Scientist. Dr David Concur was the Editor when I first approached them to publish my findings. He said if I can get one academic involved in either physics or biology to back me on this discovery, He would break with traditions and primary publish my work. I got quite a few people to back me and he went back on his word!
2. I approached New Phytologist, only to find the same “Not invented here syndrome”. Got some encouraging letters and no logical reason for refusing to publish.
3. Nature, Well, They would not give me a reason for not publishing. Nor would they offer any help for a new author as one would expect from such a well read journal. They did say that it was not fit for their journal in either format or content?
4. The Lancet, relating to the massive amount of work I have done with neurology, helping people to regain a huge amount of function and sensitivity in people suffering from a whole range of neurological disorders, ranging from multiple sclerosis to spinal cord injuries. The Editor was genuinely interested and we exchanged a fair bit of information, including some amazing case histories, yet, they refused to publish also.
5. And there are many more attempts to obtain publication like this. In fact, I have one investigation into Plagiarism ongoing at the moment on another subject.

I wish to say thank you for your offer to help me achieve the correct pitch for publication and will do everything I can to get this important discovery into the public domain.

I wrote to The Association of Science and Education to get the basic theory into their School Science Review Journal. They claim to have lost my paper, even though it was submitted electronically to several people in the same organisation. They blamed it on the Editor leaving and deleting my work? I have since been asked to resubmit it. They have been looking at this article since the year 2000.

Someone on here called me paranoid. I would say realistic in the face of everything that has been done to stop me from publishing.

But I will pick myself up;--no matter how many times I am kicked in the teeth while I am down and have another go.

As I see it there are two ways of protecting ones work. One is to tell no one and the other is to shout it from the rooftops, so that in the event that some thief tries to claim it as their own, they will inevitably come un-stuck, thanks to the Internet's amazing capacity to record and date stamp almost everything discussed on the Internet.

There are many more open Journals available now online, which are putting a tremendous amount of pressure on the closed shop journals. In fact they are squealing like stuck pigs about the amount of published papers that are going to these journals, and the beauty of these journals is they are open for everyone to read the publications and free of any charge for the privilege of doing so.

I accept your offer to help me to publish and cannot thank you enough for your offer to help.

I believe the basic theory, which was written for School Science Review, is a good place for us to start.

Professor H.T.Hammel has said that he would help with the paper, maybe I could invite him to join the forum. Also Professor Michel Cabanac from University Laval, Quebec Canada has expressed an interest in this discovery.