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Andrew
developed a new theory how trees manage to defy a law of physics
by lifting fluid up to 375 ft high. The best of our pumps
cannot lift a column of water higher than 33 ft. Andrew's theory
led him on to postulate that there may be spin-offs for human
health and better sleep.
There are 3 pages in all here. On the first two Andrew describes
his discovery, and on the third page you can read his
article
The
Importance of Gravity to our Health and Wellbeing, and its
Relation to Rest & Sleep
If you like to discuss these ideas with Andrew himself and
others, you can do so on our Tree Community Message Boards. Andrew
is presently a member of The-Tree Community |
Introduction
All life on earth developed with one thing in
common: Earth! The constant forces are gravity, and the energy from the sun. The
most abundant resources are minerals and water.
Plants and animals alike, all depend on the
properties of water for transporting minerals and nutrients. Because life is
based on water, in that everything alive started from a few drops, life must
have evolved by finding the easiest and most direct pathway, after all liquids
are very good at finding the most direct route possible. Yet, at first glance,
everywhere one looks life appears to have chosen the least likely of paths, if
it is trying to overcome the effects of gravity. Would trees, with species like
the giant Californian redwoods (sequoia sempervirens), towering over a
hundred metres high have chosen a vertical direction? How then have plants and
animals harnessed the constant pull of gravity in order to thrive and grow?
On a summer day a large oak tree may take up a
hundred gallons of water or more, enriched with minerals and nutrients from the
soil. At first glance it is doing so against the pull of gravity, producing flow
rates, which cannot be explained or shown by working models based on osmosis,
capillary action or root pressure. So how are trees doing it?
Explanation
Over 95% of the waters drawn in at the roots of
a tree evaporate into the surrounding air through the leaves by transpiration.
The evaporated moisture contains no minerals. However, the water remaining
inside the tree contains a variety of mineral salts dissolved from the soil,
together with sugars produced by the tree. The transpired water results in a
concentration of salts and sugars within the leaves. Concentrating a liquid,
(sap), which contains substances that are heavier than water, must result in the
production of a heavier solution than the pre-transpired liquid. Because of the
resulting imbalance in density the heavier solution is drawn towards the base of
the tree, due to the effect of gravity (maple syrup, latex and amber are
evidence for this). Downward flowing sap occurs predominantly within the phloem
vessels. When an excess of concentrated liquid is produced during favourable
weather conditions, the downward flowing sap forms new tubes from the cambium,
as it is forced down by gravity, in a continual cycle of growth.
In hard woods, sap flows from cell to cell
through openings or perforations, in the membrane between abutting vessels.
In soft-woods, the sap flow controls movable
valves, or pits - (thin areas), in the walls of conducting tracheids.
Concentrated pulses of sap may eventually be found to be present in some xylem
vessels, as gravity inevitably finds the most direct route, with the least
resistance, to the ground.
But for every action there must always be a
reaction, and the reaction in this case is that the downward flowing liquid
behaves exactly like a plunger in a syringe. As it flows down it causes the
entire contents of connected tubes filled with the less dense liquid to be drawn
up.
Here we have a simple power source, which is
driven purely by evaporation, posture and gravity.
The forces produced by this phenomenon are easy
to demonstrate in simple tubular experiments. The main forces are produced at
the head and tail of the falling solutions. The head produces a positive force,
or pressure, and the tail produces a negative pressure. I believe that the
positive force within the mineral laden sap is responsible for the formation of
the tubular structures found in timber. The positive force prevents tubes from
closing.
As more sap flows through the same pathways,
some of the sap is used to strengthen the tubes which will eventually become
strong enough to resist the negative pressures. The tree transports the dilute
solution of water and minerals to the leaves using these tubes. Thereafter
becoming what we call the xylem vessels.
As the concentrated liquid falls towards the
ground, minerals are locked away as timber, while the mineral laden liquid
arriving at the roots is inevitably re-diluted by the dilute solution drawn from
the soil. The imbalance in the liquid is corrected as it becomes lighter or less
dense than the downward flowing sap and begins its journey back to the leaves,
where the process continues, providing the tree with a constant supply of water
and nutrients.
In the autumn, when the leaves have fallen, the
circulation is altered as a greater positive pressure is exerted towards the
roots, because transpiration has ceased and therefore fluids flowing towards the
top of the tree would be compromised. At this time of the year root growth would
be most productive.
As fluid channels begin to offer resistance,
the sap must find alternative routes. The new directions may be vertical or
horizontal, but always in the path of least resistance. Eventually tubes become
redundant and new tubes are formed. Fluids of different specific gravity have
been observed to flow in both directions, simultaneously while in the same tube.
In fact this ‘transpiring gravitational flow system’ is able to operate
without tubes and has been attributed to causing the oceans to circulate
(Atlantic conveyor system).
Early attempts at
lifting water
The story goes that the reigning Grand Duke of
Tuscany had ordered a well to be dug to supply the ducal palace with water. The
workmen came upon water at a depth of 40 feet, and the next step was to pump it
up. A vacuum lift pump was erected over the well, and a pipe let down to the
water, but the water was found to rise to a height of 33 feet and no more, in
spite of the most careful overhauling of the pump mechanism. It was at this
stage that Galileo was consulted. While the famous philosopher was unable to
offer a solution, he at least indicated the problem. Here above the 33 feet of
water was seven feet of vacuum. The limit for raising water by suction in a tube
appeared to be thirty-three feet.
Why should there be this limit when trees are
observed to ignore it?
By introducing a loop of tubing, instead of a
single tube, to simulate the internal structure of plants and trees, and
suspending it by the centre, the problem of raising water above the 33 feet
limit is solved. The reason a loop of tubing succeeds where a single tube fails
is because the cohesive bond of water molecules is far stronger than the
adhesive qualities of water observed in Galileo’s lift-pump problem. Using a
loop of tubing enables water molecules to bond to each other in an unbroken
chain. It helps to picture the unbroken loop of water as a cord instead of a
liquid, supported by a pulley in the centre with tension applied to both ends.
The columns of water held in both sides of the
tube exert a downward force due to the weight of the water contained in the
tube. This force causes the water molecules in the tube to be stretched, causing
the water to behave like an elastic band. In order to demonstrate this affect on
water molecules I repeated the experiment shown in figure 1 without the added
saline solution, the two open ends of the tube at ground level were removed from
the demijohns, exposing them to the air.
Though the tube contained water, it did not
flow from either side of the tube. In fact the opposite effect was observed; the
water level in both sides of the tube immediately rose to a new level about half
a metre from the ends of the tube. Even more surprising the water columns stayed
there suspended by the cohesion between the water molecules.
In order to try to upset the balance I then
blew up one side of the tube, causing the water level on that side to rise. I
then released the pressure and the water returned to the same equal level. This
observation offers an exciting explanation to the problem of explaining why
water does not pour from the wound when a tree is felled.
However, the present laws of physics state that
water cannot exist in its liquid form below 4.6 torr, yet the water remains in
the tube. Only when the tube is lowered, or if a bubble appears at the top of
the loop of tubing does the water flow out from the open ends.
THE BRIXHAM
CLIFF EXPERIMENT
This experiment successfully demonstrated
fluid transport to a height, which exceeds the current accepted limit of 10
metres and how this applies to the way that trees draw water to their leaves.
Apparatus
48 metre single length of clear nylon tubing,
6.35 mm inside diameter x 9.5 mm outside diameter (type used to draw ales in the
brewery trade), two clear glass demijohns, a large tray, 50 mils of concentrated
salt solution with added red food dye, 50ml syringe minus the needle, sufficient
degassed or previously boiled and cooled water to fill the tubing, the
demijohns, and for adequate top ups. Adequate nylon cord to hoist the tubing and
pulley to the desired height, a small pulley and adhesive cello-tape.
Method
The two demijohns were filled to the brim with
the water and placed in a suitable tray to catch any displaced water. The length
of tubing was half filled with the water by siphoning. This was achieved by
submerging one end of the tube in the water filled demijohn placed on a table.
When the water reached the centre of the loop, the open end of the tube was
capped with a thumb. The end of the tube in the demijohn was removed and the 50
mils of coloured salt water was introduced via the large syringe. The demijohn
was then re-filled to the brim and the tube was re-submerged, making sure that
no bubbles were introduced by adjusting the height of the unfilled side of the
tube. By removing the thumb, the remaining length of tube was filled and again
capped, making sure that no air was trapped inside the tube. At this point the
demijohns were, refilled. The capped end of the tube was then inserted into the
other water filled demijohn and both ends secured at an equal level, with
cello-tape, again making sure that no air was allowed to enter the tube.
A length of the nylon cord equal to that of the
length of tubing used was passed through the pulley, provided a safe ground
level means to hoist the loop of tubing to the desired height. The pulley and
the main nylon cord was hoisted to the desired height and secured at the top of
the cliff on a separate length of cord. Adhesive cello-tape was wrapped heavily
around the two sides of the loop of tubing 15cm from its centre to secure one
knotted end of the main nylon cord, which ran through the pulley for the purpose
of lifting the tube, taking care not to reduce the tubes diameter. The
cello-tape was used to bind the cord to the tube.
Coloured insulation tape was used to secure
both sides of the tube together providing an excellent ascent measurement when
placed at one-metre intervals.
The Brixham Cliff
Experiment
 The
centre of the tube was then gently hoisted, taking care to keep the ascent as
smooth as possible. As the tube was raised the salt solution began to fall, due
to the influence of gravity; this caused one of the demijohns to start
overflowing indicating a positive pressure, while the second demijohn began to
lose water at the same rate indicating a negative pressure. The emptying
demijohn received frequent top ups, until the salt solution arrived at the
overflowing demijohn and the flow stopped.
Conclusion
The fifty mils of salt solution caused the
water in the tubes to circulate. The amount of water displaced and collected in
the tray represents approximately the volume of water held in one side of the
tube. Which meant that the fifty mils of salt solution had lifted water from one
demijohn to the height of 24 metres and caused water many times its own weight
and volume to rise. (I have used as little as 10 mils of coloured salt
solution in the same experiment with a slower rate of decent but with similar
displacements of water). Initially the experiments were tested at lower
levels of elevation. 24 metres vertical lift was achieved when demonstrating the
phenomenon before an audience of journalists and Forestry Commission scientists
at the Overgang cliff, Brixham, July 1995.
Bench
demonstration (pictured above)
For the purpose of demonstrating this
phenomenon use a scaled down two metre high version of Fig 1. Substituting the
demijohns for small narrow necked bottles. The type of tubing used to oxygenate
aquariums is ideal for this purpose. A two-mil syringe minus needle, filled with
coloured salt solution, connected to a T piece via a short length of tube, may
be added close to the centre of the elevated tube to introduce salt solution
intermittently while the tube is elevated, providing multiple demonstrations.
Furthermore, the tube used in the salt free side of the experiment, (return
side), may be of a larger bore size. Soft wall, silicon tubing shows visible
signs of distortion when the saline solution is allowed to flow through it. The
side containing the saline solution expands while the other side contracts,
again indicating the presence of both positive and negative, pressures.
The experiments shown have been repeated using
a variety of substitutes for salt solution, such as strong tea solution, fruit
juices and milk etc. in order to relate directly to plants and animals. The flow
rates achieved using different solutions, produced different rates of flow.
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