Backyard Project

[End User]

I want to build one of these, but much bigger (5ft wide), and place it in our backyard against the back fence. It would look awesome, and would be a great conversation piece. The only problem is I dont understand scientifically how it works. If anyone can offer any advice or suggestions, it would be much appreciated.

Click here for a mini version + Scientific explanation

[Leander]

I'm not sure if this will help, but I will give it a go. For an outdoor pond, do yourself a favor and forgo the copper. It would be too damn expensive. Most home improvement stores carry basic pond basins that you would build around. Once you have a foundation for your waterfall, outdoors, I would probably go with a wood, stone, or if you are handy with metal rig to form the waterfall.
Oh, how high do you want to build this? You said about 5' wide. If it won't be that high for a "gossamer" waterfall effect, you should not need any scientifically researched lines to help form the waterfall. Just have a good pond filter/pump that you can adjust.
As for lighting I would think that any low voltage outdoor lighting with a spot type light would work to light it up from behind.
In my mind it really shouldn't cost more than $200.
Good Luck

[End User]

Leander, firstly, thanks for the advice!
I am pretty certain I have the skills and knowledge to build a regular waterfall and pond, however what I was really after was after the 'Gossamer' effect, which is different to normal waterfalls in that it appears like a clean 'slate' of water, rather than a distorted movement like a water fall you would find in nature. So the info that I was really after was how this 'slate' effect is achieved. The website offers some information, but is still vague in how the effect is done.

From the 4physics website: The thin sheet-like configuration of water flowing over the Gossamer Falls® waterfall is maintained by adhesive forces acting between the water and the two guide filaments. In the absence of these guide filaments, surface tension would cause the water to converge into an approximate cylinder, or even globules, after falling from the spillway. The adhesive forces at the filaments prevent this so the water remains stretched into a sheet throughout its descent. The adhesive forces are assisted in their action by the design of the spillway which gives the departing water a sideward flow component.

The attachment of the water sheet to the filaments occurs over only a small part of the filament's circumference. That is, the filaments are not completely embedded within the sheet. This can be easily shown by running your finger lightly along the outer edge of a filament and observing that your finger remains dry. The thin layer of water, in this attachment region, that contacts the filament is called the boundary layer. The water is slowed in the boundary layers and flow disturbances within the boundary layers can cause detachment of the sheet from the filament, just as boundary separation can occur in the flow of air over an airplane wing.

The waves on the sheet of water consist of both large waves and small waves. The large waves originate in the action of the spillway on the departing water. The spillway forces excess water toward the edges and the acceleration of this excess water back toward the center results in the large waves that have an "X" like formation. The tiny wavelets emanate from the boundary layers along the filaments.

[noblejr]

you should ba able to use two strings or wires as the 'guide filaments'. When the water flows between the two, they break the surface tension of the water which makes it want to bead up as it falls.