Not Fountains of Wayne, but fountains of chain: Check out the beautiful kinetic sculpture that comes from ordinary household materials:
The NYT breaks down what’s going on:
And if that floats your boat (yanks your chain?), check out When Water Flows Uphill:
Colossal explains,
The folks over at Science Friday made this fascinating video about the Leidenfrost Effect, where water dropped on an extremely hot surface is capable of floating instead of immediately evaporating. While studying the bizarre effect, physicists at the University of Bath realized that not only does the water float, but under the right conditions and temperatures it can actually climb upward. The playful experiments lead to the creation of an incredible superheated maze.
Here’s the thing… the empirical evidence suggests a time-based element to this phenomenon. And the fact that you can see variations in height based on assembly (rope vs beads vs chain) suggests that there is a relationship of height to time. There is a maximum speed attained due to the drop distance; the length of chain is set by the distance of the drop, and thus a maximum acceleration due to gravity.
Simple kinetic energy considerations further suggest that the coupling effect of the aggregated rods affects other mechanical properties, such as ability to bend. Bending takes time, as it is nothing more than a transfer of energy. If you consider the effect of being moved ‘downward’ in context of wave propagation, it becomes clear that a major element of the physics is tied to mechanical properties.
So – the chain can only bend at a certain rate. The initial fall causes the chain to ‘stiffen’ a bit and find an optimal bend radius given the rate of energy transfer. This causes the first effect of the chain separating from the container and apparently standing out from the edge. Once that is established, the chain begins to move to a quasi-steady state – it does not change acceleration much, and that includes any additional twists and curls that are ‘baked’ into the procession.
If you watch closely, in all videos where there are multiple curves or twists, the radius settles on a minimum that is strikingly similar to the apex of the fountain. That is a strong indicator that rate of bend is at least one limiting factor, and potentially explain in simple mechanics a relaxation coefficient is at play.
‘Kicking off’ from the pile of chain suggests a much faster energy transfer that would eventually feed back into the bulk and cause effects back into the chain or container that are not observed… the end of the chain would eventually wiggle before the lifting end is moved, and we just don’t see that.
Of course, I’m not currently active in these fields, so could be completely wrong. It just seems to me that looking for a much simpler materials-based solution answers many more questions right off the bat and avoids phantom transfer effects. It’s also simpler to model and easier to test – change the materials in the chain and compare height of the fountain with bend radius under load, corrected by drop distance and acceleration due to gravity.
I was gonna comment that no physics is truly an everyday thing – what would Sir Isaac think, as the apples fall on his headstone …? Except that they buried him in Westminster Abbey!
But he would have been fascinated by the beautiful slow-motion videography here though.
Personally I think that the theory holds up – there is, of course, a major dependence on the material properties involved. Firstly that the smooth beads of that chain and the glass don’t introduce much frictional resistance when the moving links touch the edge of that standard-issue British school chemistry beaker there. Then the chain itself needs to have a density (high) so that the first foot or so of it can setup the wave propagation when it hits the ground (to form the “loop” above the beaker). That’s why rope, or even a chain of plastic beads (not dense enough) won’t work. And, if you made the links less supple, then that would fail too – too much wave damping (as likely with the noodles).
It’s all sort of ironic in a way – Newtonian physics demonstrated with multiple wave actions. But not more so than physicists at the University of Bath playing with water … perhaps it’s what a state-paid university education can support!