
The most exciting part of any Winter Olympics, for me at least, is the ice hockey tournament. Professional leagues around the world (National Hockey League, Kontinental Hockey League, Swedish Elite League) suspend operations for nearly three weeks to allow the world's stars the chance to play for international glory. Unfortunately, early indications are this is the last tournament which will feature professional players of such caliber. The NHL wants to create a World Cup of Hockey and then monopolize the sport much the way FIFA does with association football.
My point: get your hockey fix now, because this will likely be the last of the best Olympic team sport ever played.
So if you're new to skates, but have a critical eye for the many intersections between science and sport, then this is the technical guide for enjoying this year's hockey tournament.
Hockey players are valued for their ability to leverage basic physics and arithmetic principles into a comprehensive strategy. The old Slapshot joke is that hockey players are dumb, and while they aren't aware of their observance, hockey players are indeed physicists and mathematicians. And magicians.
Like everything else, the sport abides by Newton's three laws of motion. The physical strength of a player determines his or her ability to apply and resist inertia; their mass and velocity dictates the force with which they play; and withstanding the impulses on their bodies to stay in the game after blocking a slapshot, throwing a check, or taking a punch.
Playing the Game
The game starts with a faceoff. A cylindrical puck, that is 1 inch thick, 3 inches in diameter and is made of vulcanized rubber (go see my man Doug Sharpe!), is dropped into the center of the faceoff circle and two players use their sticks to win control. Players are arranged around this symmetrical feature to ensure parity on the drop. Sometimes they fight instead.
Once a team retains control of the puck, players disperse across the ice to move the puck towards the other team's net. A system of kinematics takes place, where teammates strategize movements based on where defenders are positioned. The passer notes his teammate's velocity and determines where he expects the teammate to be in position to accept the pass. Likely, the passer is already skating with the puck. To make an accurate pass he or she must account for the vector of the puck and the vector of the pass. The resultant is the route of the pass.
The receiver accepts the pass and accelerates toward the opponent's net and past defenders. He enters the offensive zone of the rink and looks for another teammate. With defenders closing in on his position, he banks a pass off the boards--knowing that the angle of incidence and reflection are equivalent--and completes a pass to a player near the blue line, a position known as the point.
The point player takes a stride to his right, swings his stick backwards to build potential energy, and swings the stick forward. He scrapes the ice about 10 inches behind the puck to flex the stick and build potential energy. This blend of potential and kinetic energy shoots the puck at speeds up to and more than 100 mph.
The goalie sees the shot easily. Though he has less than .45 seconds to respond, the goalie has "played to the angles" and restricted the prospective shot parabolas. His shoulders stayed square and he glided a few feet closer to the shooter to present the widest surface area. He has been anticipating the shot and has extensive training for this moment. To make the save, he doesn't even think about it. Receptors at the end of the sensory neurons trigger signals at the sensory afferent pathway. The spinal cord receives this signal, and provides localized command and a quicker reaction. The goaltender bats the puck into the corner with his stick. This shot was easy to block; others are more challenging.
A player on the offensive team, about six-feet tall and 210 pounds, recovers the puck and skates along the boards-until a defenseman, about six-foot-five and 250 pounds, throws a check. He accelerates into the offensive player, and his impulse connects with the smaller player. The collision is inelastic; both players fall. The puck continues on its vector uncontained, until another offensive player-the one with slaphot just seconds ago-regains possession. He skates closer to the goalie to increase his angles of attack and to take advantage of the downed defensemen.
He opts for a wrist shot this time--a shot based more on accuracy and finesse than power. A smaller impulse is imparted on the puck, and its angular motion is determined by the stick's follow through on the shot. Gyroscopic motion retains the puck's orientation during flight. It flies past the goalie and strikes the net. Lights illuminate. Horns blare. Fans scream.
And, minus the goal scoring, this situation happens hundreds of times per game. I promise the real thing is more exciting, and if you watch the games you won't even consider the above-just like the players.
Russia is the favorite to win the 2014 men's tournament, but Canada won in 2010. The Americans are favored just behind these two teams, with Sweden one step back.
As far as the women's game, the Olympics Committee changed the rules this year because the United States and Canada are so dominant, so take that for what it's worth.
No matter who wins gold, it's actually me, because I love hockey.
Resource
National Science Foundation-Science 360: Science of [Ice} Hockey
|