As you may have figured out already, I tend to enjoy writing these blogs about sports and fairly dangerous activities...so I will continue this trend with curling. Although not the most exciting sport to watch, playing it is a whole different story due to two main physics principals: friction and collisions. Curling is played on a ice surface to allow the stone to glide easily and smoothly to the target because the friction between the ice and the stone is very little. If you've ever seen even one throw of a curling game then you have seen the people so stand there with brooms and brush the ice and you probably thought "well that just looks silly" (myself included). Well there actually is a purpose to this; the act of brushing the ice causes the top layer of the ice to met and turn in to water. The friction between the stone and water is much greater than the friction between the stone and ice. So, what these people are doing is slowing down the stone in order to make it stop right in the middle of the target circle.
Similar to billiards, curling is filled with collisions; and that is the biggest part of the game. The ability for the thrower and the 'brushers" to judge the speed and direction necessary to accomplish a task is key to the sport. For example, is the thrower throws the stone way to fast, the brusher wont be able to stop it and then is will smack into every other stone and they will all be scattered in every which way. This obviously isn't what is wanted because the task of stopping in the middle was not achieved. Rather, the thrower wants to throw it at just the right speed in order for the stone to collide with one or more stones and stop right in the middle while sending the other stone out of the target area. So, next time you watch or play curling, you will actually know what the goofy people with the brushes are for!