Beacon

A beacon is an intentionally conspicuous device designed to attract attention to a specific location.

Beacons can also be combined with semaphoric or other indicators to provide important information, such as the status of an airport, by the colour and rotational pattern of its airport beacon, or of pending weather as indicated on a weather beacon mounted at the top of a tall building or similar site. When used in such fashion, beacons can be considered a form of optical telegraphy.

For navigation

Beacons help guide navigators to their destinations. Types of navigational beacons include radar reflectors, radio beacons, sonic and visual signals. Visual beacons range from small, single-pile structures to large lighthouses or light stations and can be located on land or on water. Lighted beacons are called lights; unlighted beacons are called daybeacons.

For defensive communications

Classically, beacons were fires lit at well-known locations on hills or high places, used either as lighthouses for navigation at sea, or for signalling over land that enemy troops were approaching, in order to alert defenses. As signals, beacons are an ancient form of optical telegraphy, and were part of a relay league.

Beacon (Metro-North station)

Beacon is a Metro-North Railroad station that serves the residents of Beacon, New York, via the Hudson Line. Trains leave for New York City every hour during off peak hours, and about every 15–25 minutes during rush hour. It is 59 miles (95 km) from Grand Central Terminal and travel time to Grand Central Terminal vary depending on run, ranging from 1 hour and 10 minutes (super-express runs) to 1 hour and 15–18 minutes (trains making all local stops north of Croton-Harmon and 1 hour and 25–30 minutes (trains making all local stops north of Croton-Harmon and some lower Hudson stops, such as Ossining, Tarrytown, Yonkers, Marble Hill).

It is a wheelchair accessible station, featuring wheelchair ramps, an elevator to the train platform, and a high-level island platform which is level with the doors on the train (for many years, most Upper Hudson Line stations had platforms that were lower than the train doors). It also boasts a small newsstand on the platform itself, open daily. It is not fully ADA accessible.

Facebook Beacon

Beacon formed part of Facebook's advertisement system that sent data from external websites to Facebook, for the purpose of allowing targeted advertisements and allowing users to share their activities with their friends. Beacon would report to Facebook on its members' activities on third-party sites that also participate with Beacon. These activities would be published to users' news feed. This would occur even when users were not connected to Facebook and would happen without the knowledge of the Facebook user. One of the main concerns was that Beacon did not give the user the option to block the information from being sent to Facebook. Beacon was launched on November 6, 2007 with 44 partner websites. The controversial service, which became the target of a class-action lawsuit, was shut down in September 2009. Mark Zuckerberg, CEO of Facebook, characterized Beacon on the Facebook Blog in November 2011 as a "mistake". Although Beacon was unsuccessful, it did pave the way for Facebook Connect, which has become widely popular.