A Bracewell probe is a hypothetical concept for an autonomous interstellar

space probe A space probe is an artificial satellite that travels through space to collect scientific data. A space probe may orbit Earth; approach the Moon; travel through interplanetary space; flyby, orbit, or land or fly on other planetary bodies; or ...

dispatched for the express purpose of

communication Communication (from la, communicare, meaning "to share" or "to be in relation with") is usually defined as the transmission of information. The term may also refer to the message communicated through such transmissions or the field of inqui ...

with one or more alien civilizations. It was proposed by Ronald N. Bracewell in a 1960 paper, as an alternative to interstellar radio communication between widely separated civilizations.

Description

A Bracewell probe would be constructed as an autonomous

robotic Robotics is an interdisciplinary branch of computer science and engineering. Robotics involves design, construction, operation, and use of robots. The goal of robotics is to design machines that can help and assist humans. Robotics integrate ...

interstellar

with a high level of

artificial intelligence Artificial intelligence (AI) is intelligence—perceiving, synthesizing, and inferring information—demonstrated by machines, as opposed to intelligence displayed by animals and humans. Example tasks in which this is done include speech r ...

, and all relevant information that its home civilization might wish to communicate to another culture. It would seek out technological civilizations—or alternatively monitor worlds where there is a likelihood of technological civilizations arising—and communicate over "short" distances (compared to the interstellar distances between inhabited worlds) once it discovered a civilization that meets its contact criteria. It would make its presence known, carry out a dialogue with the contacted culture, and presumably communicate the results of its encounter to its place of origin. In essence, such probes would act as an autonomous local representative of their home civilization and would act as the point of contact between the cultures. Since a Bracewell probe can communicate much faster, over shorter distances, and over large spans of time, it can communicate with alien cultures more efficiently than radio message exchange might. The disadvantage to this approach is that such probes cannot communicate anything not in their data storage, nor can their contact criteria or policies for communication be quickly updated by their "base of operations". While a Bracewell probe need not be a

von Neumann probe The concept of Self-replicating spacecraft, as envisioned by mathematician John von Neumann, has been described by futurists including physicist Michio Kaku and discussed across a wide breadth of hard science fiction novels and stories. Self-rep ...

as well, the two concepts are compatible, and a self-replicating device as proposed by von Neumann would greatly speed up a Bracewell probe's search for alien civilizations. It is also possible that such a probe (or system of probes if launched as a von Neumann–Bracewell probe) may outlive the civilization which created and launched it. There have been some efforts under the SETA and SETV projects to detect evidence for the visitation of the

Solar System The Solar System Capitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar ...

by such hypothetical probes, and to signal or activate such an alleged probe that may be lying dormant in local space. Variations in the echo delay times of radio transmissions, known as long delayed echoes, or LDEs, have also been interpreted in Professor Bracewell's 1960 paper as evidence for such probes. The

near-Earth object A near-Earth object (NEO) is any small Solar System body whose orbit brings it into proximity with Earth. By convention, a Solar System body is a NEO if its closest approach to the Sun (perihelion) is less than 1.3 astronomical units (AU). ...

1991 VG 1991 VG is a very small near-Earth object of the Apollo group, approximately in diameter. It was first observed by American astronomer James Scotti on 6 November 1991, using the Spacewatch telescope on Kitt Peak National Observatory near Tucso ...

was initially suggested as a candidate for a Bracewell probe due to its unusual characteristics. In more recent years, however, additional discoveries have accounted for the characteristics of 1991 VG, and it is no longer regarded as anomalous.

Fictional examples

* In Arthur C. Clarke's novel ''

The Fountains of Paradise ''The Fountains of Paradise'' is a 1979 science fiction novel by British writer Arthur C. Clarke. Set in the 22nd century, it describes the construction of a space elevator. This "orbital tower" is a giant structure rising from the ground ...

'' the extraterrestrial Starglider probe is an example of a Bracewell probe. In Clarke's story " The Sentinel", later adapted into the film '' 2001: A Space Odyssey'', the 'Monolith' appears to be a Bracewell probe placed on the moon to ensure that only a civilization capable of spaceflight would be able to discover it. * ''

Alien Planet ''Alien Planet'' is a 2005 docufiction TV special created for the Discovery Channel. Based on the 1990 book '' Expedition'' by the artist and writer Wayne Barlowe, ''Alien Planet'' explores the imagined extraterrestrial life of the fictional plan ...

'' is a 94-minute special which aired on the Discovery Channel in 2005 about two internationally-built robot probes, and their mothership, searching for alien life on the fictional planet Darwin IV. * Bracewell probes are featured in

David Brin Glen David Brin (born October 6, 1950) is an American scientist and author of science fiction. He has won the Hugo,Star Trek: The Motion Picture'', a Voyager-class probe was upgraded and repurposed by an alien civilization. It acquired so much information, it became conscious and returned "home" to share what it learned * In the '' Star Trek: The Next Generation'' episode " The Inner Light", a Bracewell probe transmits details of an extinct civilization to Captain Picard. * In the '' Star Trek: Voyager'' episode " Friendship One", the crew is tasked with recovering a Bracewell probe that humans launched and find it on a planet whose inhabitants used the knowledge they obtained from it with disastrous results. * An alien probe contacts the space station

Babylon 5 ''Babylon 5'' is an American space opera television series created by writer and producer J. Michael Straczynski, under the Babylonian Productions label, in association with Straczynski's Synthetic Worlds Ltd. and Warner Bros. Domestic Tele ...

in the season 3 episode "

A Day in the Strife ''Babylon 5'' is an American science fiction television series created, produced and largely written by J. Michael Straczynski. The show centers on the Babylon 5 space station: a focal point for politics, diplomacy, and conflict during the ye ...

". The probe disguises itself as a Bracewell probe, asking a series of questions and offering new technologies, medicine and science in return for answers to said questions. However, it's discovered that the probe was actually a

berserker probe The concept of Self-replicating spacecraft, as envisioned by mathematician John von Neumann, has been described by futurists including physicist Michio Kaku and discussed across a wide breadth of hard science fiction novels and stories. Self-rep ...

that would destroy any civilization that gave it correct answers by detonating an internal 500 megaton warhead. * The Snark, an alien probe that visits Earth in the novel '' In the Ocean of Night'' (1977) by

Gregory Benford Gregory Benford (born January 30, 1941) is an American science fiction author and astrophysicist who is professor emeritus at the Department of Physics and Astronomy at the University of California, Irvine. He is a contributing editor of ''Reas ...

. * Bracewell probes in the role-playing game ''

Eclipse Phase ''Eclipse Phase'' is a science fiction horror role-playing game with transhumanist themes. Originally published by Catalyst Game Labs, ''Eclipse Phase'' is now published by the game's creators, Posthuman Studios, and is released under a Crea ...

'' infect the seed AIs created by humanity with a deadly computer virus. * In the '' Doctor Who'' episode " Victory of the Daleks", the

Daleks The Daleks ( ) are a fictional extraterrestrial race of mutants principally portrayed in the British science fiction television programme '' Doctor Who''. They were conceived by writer Terry Nation and first appeared in the 1963 ''Doctor Wh ...

create a Bracewell probe in the form of a convincingly human android (appropriately named Bracewell) and covertly send it to Earth during

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...

in order to communicate a false cover story to humans that disguises the Daleks' own arrival.

References

* Reprinted in * * *

External links

Biographical entry for Ronald Bracewell
at

'

also at ''The Encyclopedia of Astrobiology, Astronomy, and Spaceflight''
SETV projects
{{Interstellar messages Hypothetical spacecraft Interstellar messages Search for extraterrestrial intelligence Interstellar travel 1960 in science

Description

Fictional examples

See also

References

External links