Thank you for your post, this is what I am looking for! I agree with most of
The valve placed at the top would act like scissors and cut the water
column. It would then immediately fall on both sides to around 33 feet.
There is no point trying this unless you doubt the 33 ft limit exists in a
single upstanding capped tube.
In one experiment I had a T junction which was air tight. The idea was that
I could inject saline solution via a valve into the loop. It failed because
the water boiled, it was like air was being sucked into the water from the
walls of the tube at the top of the loop. I guess the interruption
The tube I used was 6.5mil strong nylon, the type used in the brewery trade.
I have observed the column breaking during the experiments and noted that
the level in both tubes falls rapidly to the 33 ft mark.
Ray Girvan <ray.girvan at zetnet.co.uk> wrote in message
news:2000031411151571207 at zetnet.co.uk...
> David Allsopp <dallsopp at signal.dera.gov.uk> writes:
>> > Andrew Kenneth Fletcher wrote:
> >> 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.
>> > Whoa! I can picture chemists across the land falling off
> > their chairs! ... You have some _major_ convincing to do here...
>> >> 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.
>> > What do you mean, 'causing the water to behave like an
> > elastic band' ?
>> Actually, I think this is the key to the Brixham Cliff observations.
> I vaguely remembered something from university, and tried a web
> search for "tensile strength of water".
> A constrained column of water does, in fact, possess tensile
> strength; to stretch or 'break' it is doing work against the hydrogen
> bonds between molecules. One of the references mentioned a
> centrifuge experiment showing a water column could take -26 MPa
> pressure without cavitating (1 atmosphere = 0.1 Mpa). This is a
> known phenomenon, and I think Andrew has hit upon an intuitive
> description of this, and an experimental setup that demonstrates it.
> The likely explanation, then, is that the 78 foot column is
> partly supported from below by atmospheric pressure, and partly by
> the tensile strength of the water column itself.
If atmospheric pressure is responsible, why does the water level go up the
tubes when the tube ends are pulled from the vessels? Surely the level would
fall resulting in water flowing from the tubes. This is simply not the case
in the Brixham experiment.
>> However, it's nothing to do with the loop setup: I'd predict that a
> single closed column of water would do just as well. Andrew could
> test this by putting a valve or clip at the top of the loop, and
> seeing what (if anything) happens if it's closed after the tube is filled.
It would inevitably fail Ray.
If you would like to come to Paignton and see the video and bench
experiments, and hear what I have to say about how this theory fits with
everything, just give me a call on 01803 524117.
Kettle is always on and my wife Judy is an excellent cook. I will give you
some tube so that you can repeat my experiment and test your own idea.
I would like to share your post with the other groups to see if it will
stimulate some more responses, if this is OK with you?
>ray.girvan at zetnet.co.uk +++ Technical Author +++ Topsham, Devon, UK
>http://www.users.zetnet.co.uk/rgirvan/ +++ The Apothecary's Drawer
> Message Board Title: "INCLINED TO SLEEP INCLINED"