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Curling works at atomic level

Curling wasn't invented in Canada despite the commercials on TSN proclaiming it as a "Canadian game." But it is a sport we are very good at.
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Curling wasn't invented in Canada despite the commercials on TSN proclaiming it as a "Canadian game."

But it is a sport we are very good at. Some of the best curlers in the world come from Canada and the best Canadian women's skip of all time, Jennifer Jones, was in Prince George this week giving a talk at UNBC.

One could make a very strong argument she is one of the top ten all-time Canadian skips, period.

The game, however, originated in Scotland. The granite used for the stones is still supplied from a single quarry on a Scottish isle. There is a well-documented history of the game in Scotland dating back to the 16th century.

Canadians, though, spend much of the year experiencing the joys and hazards of trying to negotiate their way around our winter wonderland. Sometimes even driving feels like a game of curling with cars doing a slow turn before knocking one another out of the house. We have ice in our blood - although not literally.

Curling is a mixture of sport, science and everyday life. The behaviour of curling rocks has inspired researchers to think about the interactions on an icy surface.

For example, materials scientist Jane Blackford and her team at Edinburgh University were interested in helping the British Olympic curling team.

In 2000, they developed the sweep ergometer, a high tech broom designed to measure how the brush is moving and how hard it is pushing against the ice.

In essence, scientists believe sweeping helps to melt the ice in front of the rock providing a very thin surface of liquid water for the rock to travel across. As anyone who has ever walked on wet ice will attest, it is a very slippery surface.

Indeed, just standing still on wet ice can be a challenge - let alone moving!

Optimizing the power of the brush to generate a sliding surface provides better results in theory. By using their sweep ergometer, the scientists have been able to help curlers perfect their sweeping.

Over the past decade, much more progress has been made in ensuring that the ice created for games is much better.

Researchers interested in cryotribology or the study of ice friction have been able to improve the curl.

To learn more about how ice melts under pressure and with friction, Blackford's team designed and built an instrument to study the process in detail. It is fairly simple, consisting of a stylus dragged across a rotating disk of ice.

Different substances can be used for the stylus - such as metal or granite (like a curling rock), and even rubber - while conditions such as temperature and velocity can be altered.

The path on the disk is then examined using a scanning electron microscope.

Doing this gives a very detailed picture of how the different forces or pressures can affect the microscopic properties of ice along with the effects generated by different materials and temperatures. Amazingly, despite the fact we have been dealing with ice for hundreds of thousands of years, there is still a lot that isn't known about what exactly is happening at the surface.

Refining the experiment and upping the magnification using an atomic force microscopic - which is capable of "seeing" the surface at the atomic level - has ultimately answered some of these questions science has about ice.

Is the surface of ice really a liquid? (Yes, for a couple of molecules deep.)

Is it the mobility of the surface layer allows an object to slide? (Sort of.)

Is pressure really necessary to create a liquid layer? (No. But it helps.)

There are all sorts of arguments and opinions in the research literature about ice and what is occurring at the surface.

The best understanding is it is a solid with a very mobile monolayer of water molecules adhering to the surface acting as a liquid. It is on these mobile molecules curling rocks slide.

But broom design has benefited from this research and sweepers are now almost able to steer a rock down a sheet of ice.

Modern brushes can "scratch" this surface effectively creating micro-ruts which help to push the rock in one direction or the other. This is why you often see only one sweeper sweeping.

Still it is the ice which matters. For example, de-ionized and de-aerated water generates ice which is more reliable and uniform.

Gone are small pockets of air and mineralization which could potentially affect a stone. And temperature control across the surface allows icemakers to fine tune the running line. Making good curling ice is much more than simply pouring water over a cold surface.

Ultimately, a better scientific understanding of the science of ice allows all curlers to play a better game. And world champions, like Jennifer Jones, to shine.