A pulsar clock is a

clock A clock or a timepiece is a device used to measure and indicate time. The clock is one of the oldest human inventions, meeting the need to measure intervals of time shorter than the natural units such as the day, the lunar month and t ...

which depends on counting radio pulses emitted by

pulsar A pulsar (from ''pulsating radio source'') is a highly magnetized rotating neutron star that emits beams of electromagnetic radiation out of its magnetic poles. This radiation can be observed only when a beam of emission is pointing toward E ...

Pulsar clock in Gdańsk

The first pulsar clock in the world was installed in St Catherine's Church,

Gdańsk Gdańsk ( , also ; ; csb, Gduńsk;Stefan Ramułt, ''Słownik języka pomorskiego, czyli kaszubskiego'', Kraków 1893, Gdańsk 2003, ISBN 83-87408-64-6. , Johann Georg Theodor Grässe, ''Orbis latinus oder Verzeichniss der lateinischen Benen ...

Poland Poland, officially the Republic of Poland, , is a country in Central Europe. Poland is divided into Voivodeships of Poland, sixteen voivodeships and is the fifth most populous member state of the European Union (EU), with over 38 mill ...

, in 2011. It was the first clock to count the time using a signal source outside the Earth, other than

sun dial A sundial is a horological device that tells the time of day (referred to as civil time in modern usage) when direct sunlight shines by the apparent position of the Sun in the sky. In the narrowest sense of the word, it consists of a flat p ...

s. The pulsar clock consists of a

radiotelescope A radio telescope is a specialized antenna and radio receiver used to detect radio waves from astronomical radio sources in the sky. Radio telescopes are the main observing instrument used in radio astronomy, which studies the radio frequency ...

with 16 antennas, which receive signals from six designated pulsars.

Digital processing Digital data, in information theory and information systems, is information represented as a string of discrete symbols each of which can take on one of only a finite number of values from some alphabet, such as letters or digits. An example is ...

of the pulsar signals is done by an

FPGA A field-programmable gate array (FPGA) is an integrated circuit designed to be configured by a customer or a designer after manufacturinghence the term ''Field-programmability, field-programmable''. The FPGA configuration is generally specifi ...

device.

Pulsar clock in Brussels

On October 5, 2011, a display showing the exact time of the pulsar clock, as a repeater of Gdańsk's pulsar clock, was installed in the

European Parliament The European Parliament (EP) is one of the legislative bodies of the European Union and one of its seven institutions. Together with the Council of the European Union (known as the Council and informally as the Council of Ministers), it adop ...

Brussels Brussels (french: Bruxelles or ; nl, Brussel ), officially the Brussels-Capital Region (All text and all but one graphic show the English name as Brussels-Capital Region.) (french: link=no, Région de Bruxelles-Capitale; nl, link=no, Bruss ...

Belgium Belgium, ; french: Belgique ; german: Belgien officially the Kingdom of Belgium, is a country in Northwestern Europe. The country is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeast, France to ...

References

Clocks in Poland Clocks in Belgium Pulsars Culture in Gdańsk Culture in Brussels {{Astronomy-stub