A researcher studying the science of curling for Canada's Olympic team has found that sweeping doesn't melt the pebbly ice as many believe, but softens it and subtly changes its physical characteristics.
"What we discovered is that it never melts. It only slightly warms up due to the friction of the sweeping," said Tom Jenkyn of the University of Western Ontario.
Sweeping can warm the ice by about 1.5 degrees, Jenkyn said, and reduces friction for the curling rock.
Jenkyn is studying the physics of curling using an infrared camera as part of the Canada's $22-million Own the Podium research program into sports of the Winter Olympics.
Jenkyn's full results are being kept secret until June 2010, revealed only to Canada's Olympic athletes, coaches and officials.
"We're sworn to secrecy," he said.