12+
Gallery 8

Meander

Two large glass and aluminum panels hinged on their centre and sitting behind an information display.
Water droplets on glass show a meandering pattern

The way water tends to flow or meander in S-shaped streams influences how streams and rivers meander through landscapes.

How it works

Tilt two very large glass panels back and forth to see how water trickles across the panels when they are tilted at an angle or flat (horizontal).

Things to try or ask around the exhibit

  • If the panel is tilted, do the water droplets change the way they move across the glass?
  • What do you remember about raindrops trickling down a window pane; do they flow in straight lines or in wiggly lines?
  • Why do some large canyons snake around in an S-shaped formation?

Background

On horizontal surfaces, trickles of water tend to meander in S-shaped patterns. Reasons behind this are still being explored by scientists, but meandering is thought to be affected by: surface tension; previously wet surfaces; the way the flow starts and pressure changes within the trickle.

On a steeply tilted panel (that's closer to being vertical than horizontal), the force of gravity overcomes other effects and makes the water trickle flow in a more direct, straight line.

Finding the science in your world

The slope and geology of a landscape influence the shape of meandering rivers and canyons and while the meandering of small trickles of water may seem insignificant, over many thousands and millions of years, the movement of these small trickles can accumulate and help to create straight or S-shaped rivers and canyons.

The next time it rains, watch how raindrops trickle down a dry pane of glass. Check how raindrops flow along wet panes of glass after it has been raining for a while. Also try to tilt the pane of glass (if you can) to check whether the raindrops flow differently.