A new article over at LiveScience.com talks about two hot topics in soccer these days. We all have screamed at our TVs over a bad offsides call. Now it turns out the referee may really BE blind when it comes to judging offsides.
Francisco Belda Maruenda, a physician and researcher in Spain, would tell you not to be so hard of the referees, since they’re being asked to perform a physiologically impossible task.
The ability of the eye to change focus on a far object to one located less than 6 yards away is called eye accommodation. For most people, it takes around 600 milliseconds. Since the players and ball are spread all over the field, a referee almost always performs eye accommodation when making an offside call.
But according to Maruenda, the average running player can move roughly 5 feet in the time it takes for the ref’s eyes to refocus, so 600 milliseconds is just too slow.
To make an accurate call, "it is necessary to stop time and to locate all the players who take part in that game in zero milliseconds," Maruenda told LiveScience. To watch the player making the pass, the player receiving the pass, the defender, and the ball at the same time is just too much for our visual systems to handle, especially from the close-up view of the referee.
That makes sense. You have to judge the position of the player taking off right after the ball has been kicked, usually by a player that is farther away. I’m not sure it’s impossible to do, but it isn’t easy. That said, I’m not sure the answer is the fourth official sitting at a video monitor with a button to buzz the center ref’s ear.
They also touch on bending the ball, giving some details on how air pressure affects ball flight:
A forward-moving ball spinning in the clockwise direction creates greater air friction on its left side. This is because the left surface of the ball is moving against air flow.
This creates a slightly higher pressure on the left, causing the ball to move toward the right as the pressure tries to reach a balance. The opposite occurs for a ball spinning counterclockwise.
The faster the ball spins, the greater the friction and pressure difference, which leads to a bigger and more deceptive break.
Scientists call this effect the Magnus force, whereby an object’s rotation or spin affects its path through air or a liquid. The Magnus force plays a role in other sports, too, particularly in baseball. Magnus force named after Heinrich Gustav Magnus, the German physicist who first described it (although some people claim Isaac Newton did it first).
So there you go. Now you know why Beckham can, well, Bend It Like Beckham. I’ve been impressed with a few of the longer shots this week that have bent backwards (right footed kicker hitting the upper right corner with a right bend). Unfortunately one of those was against the US!