Q: In tennis coverage on TV, there is often a computerized view of the ball and where it landed on the court. Is this an official tool used by the judges? How does it work?
—John Vaughn, Newnan
A: The computerized line-calling system is called Hawk-Eye, which also is the name of the British company that developed the technology. Hawk-Eye uses 10 cameras per court to record the flight of the ball at tennis tournaments. The system uses that input to map the ball's trajectory and reconstruct its path, projecting where the ball most likely would have landed. Players receive three challenges each set, and if used, Hawk-Eye determines whether the ball was in or out, sometimes overruling umpires and line judges. The system, which is approved by the International Tennis Federation, is used at the Australian Open (hard court), Wimbledon (grass court) and the U.S. Open (hard court), among other tournaments, but not at the French Open, which has a clay surface that shows ball marks. Creator Paul Hawkins said in 2008 that the system was 99.9 percent accurate.
Q: Can you tell me about the mission of the Rainbow PUSH Coalition? Did Jesse Jackson start it, and how long has it been in existence?
—Sherrill Lang, Tyrone
A: The coalition was formed by Jackson in 1996 as a "multi-racial, multi-issue, progressive, international membership organization fighting for social change," according to its website (rainbowpush.org). Jackson merged People United to Serve Humanity (PUSH, founded in 1971) and the Rainbow Coalition (1984) to form the Rainbow PUSH Coalition.
Andy Johnston wrote this column. Do you have a question about the news? We’ll try to get the answer. Call 404-222-2002 or email q&a@ajc.com (include name, phone and city).