The Doppler effect (or Doppler shift), named after the Austrian physicist Christian Doppler, who proposed it in 1842 in Prague, is the change in frequency of a wave (or other periodic event) for an observer moving relative to its source. It is commonly heard when a vehicle sounding a siren or horn approaches, passes, and recedes from an observer. The received frequency is higher (compared to the emitted frequency) during the approach, it is identical at the instant of passing by, and it is lower during the recession.

The Agricultural Commissioner/Weights & Measures Department routinely conducts price verification inspections at retail locations to confirm that prices charged to consumers are the same as those posted or advertised. On a typical visit to a store, the inspector will select up to 15 items and then take them to the check stand for payment. When the items’ bar codes are scanned at the register, the price showing at the register must match what is posted on the shelf or advertised. If the prices do not match, the store will receive a notice of violation and the case may be turned over to the District Attorney’s Office or local city attorney for prosecution.

The title Grandmaster is awarded to chess players by the world chess organization FIDE. Apart from World Champion, Grandmaster is the highest title a chess player can attain. Once achieved, the title is held for life.

The Scientific Services Bureau operates one of the largest full-service crime laboratories in the United States. A staff of 198 members provides forensic science support to all Los Angeles County law enforcement agencies, except the Los Angeles Police Department. Approximately one half of the nearly 70,000 cases submitted annually to the Crime Lab is from Sheriff's Department investigators , while the remainder is from local, state, and federal agencies. Since 1989 the Scientific Services Bureau has been an accredited laboratory through the American Society of Crime Laboratory Directors/Laboratory Accreditation Board (ASCLD/LAB).

Speed skating is a competitive form of ice skating in which the competitors race each other in traveling a certain distance on skates. Types of speed skating are long track speed skating, short track speed skating, and marathon speed skating. Short track speed skating takes place on a smaller rink, normally the size of an ice hockey rink. Distances are shorter than in long track racing, with the longest Olympic race being 3000 meters. Races are usually held as knockouts, with the best two in heats of four or five qualifying for the final race, where medals are awarded. Disqualifications and falls are not uncommon. The sport originates from pack-style events held in North America and was officially sanctioned in the 1970s, becoming an Olympic sport in 1992. Although this form of speed skating is newer, it is growing faster than long track speed skating, largely because short track can be done on an ice hockey rink rather than a long-track oval.