New Scientist

How to suspend a raindrop in mid-air
16:55 29 February 2012

Rebecca Hill, contributor

A single water droplet hovering in mid-air, a rainbow still shining long after sundown - they aren’t things you’d expect to come across every day.

But down a darkened north-London street, tucked away in a small industrial-looking art gallery, there they were - thanks to Alistair McClymont, artist in residence at the Art House Foundation gallery.

Raindrop and Rainbow are the latest of what McClymont describes as ‘phenomena’ artworks, in which he tries to capture natural, often overlooked occurrences and evoke a sense of wonder. “It’s a real shame if people lose their thrills,” McClymont says. “That’s the impetus for all of this - seeing a little thing that makes you full of a childish glee.”

After seeing a documentary that featured a machine that could keep a single raindrop in free fall, McClymont was eager to figure out how it worked. He contacted physicist Clive Saunders, a member of the team that built the machine at the University of Manchester, to ask if he could come and have a look. “What it was doing - the idea of being able to see just a single raindrop - was really beautiful,” he says.

After meeting with Saunders, McClymont set about building his own machine. Now, just over two years later, the results are on display, along with various tools, diagrams and Saunders’ 1974 paper that inspired it all.

The machine keeps a water droplet in perpetual free fall using a wind tunnel. McClymont created his tunnel based on the one Saunders developed in the 1970s, using layers of steel gauze and honeycombed aluminium to smooth the air, and a narrow top to make the air flow quickly. The water droplet is simply squeezed out of a syringe into this airstream, which is travelling at a few metres per second - the same as a falling raindrop.

The free-falling droplet is not the familiar teardrop shape, however. Saunders explains why: “Surface tension keeps the drop nearly spherical, but the air stream flattens it at the base. This is how real raindrops fall.”

For me the most interesting - if slightly unnerving - part of watching something in free fall is that doesn’t actually look like it’s falling. McClymont suggests you imagine that, if the raindrop is at its terminal velocity, and you’re keeping up, you must be falling through the sky with it. “It’s a leap, but if you can put yourself in that position there’s something magical about it.”

The magical side of nature has captured McClymont’s imagination in more ways than one. In the other work, Rainbow, he has recreated elements of the fabled arc by shining an incredibly powerful light at a steady, fine stream of water from a tropical plant sprinkler, hoisted high on a steel girder outside the gallery. I’m assured that standing right underneath the sprinkler would show you the rainbow’s full arc, but choosing to keep a safe (and dry) distance away gives a beautiful view of the shimmering, incandescent colours as they float to the ground.

And that really did bring a childish smile to my face.

Alistair McClymont’s Raindrop and Rainbow were on show at the Art House Foundation from 8- 26 Feb 2012.

February 29, 2012