Un viaje por las estrellas: Viajemos a Alfa y Próxima Centauri. Los prometedores hallazgos de vida inteligente según SETI.

En los próximos años, asistiremos a interesantes búsquedas en vecindarios estelares cercanos. Tal es el caso del sistema Centauri, a 4.5 años luz de nuestro sol, compuesto por tres estrellas, dos de ellas semejantes a nuestro sol y la tercera una enana roja, que orbita las otras dos.

Son interesantes las distancias entre las tres estrellas que conforman un ecosistema ternario, en el que se han encontrado planetas en la zona que los científicos denominan “Ricitos de oro” o zona habitable global. No olvidemos que el sistema centauri es nuestro más próximo vecino estelar, de ahí la nomenclatura de “próxima centauri”, la enana roja que orbita a las otras dos estrellas del sistema (alfa y beta centauri).

Hoy vamos a viajar a ellas con esta interesante conderencia de la mano del SETI, y del inestimable Dr. Christian Marois.

StarViewerTeam 2017.

¿Realmente crees que estamos solos en el Universo?

Recientemente asistí a una interesante ponencia del profesor Dr. Andrew Fraknoi (Ganador del premio de investigación en astronomía), quién habló de las cuestiones mas interesantes sobre la investigación de las cuestiones que la ciencia encuentra más intrigante hoy, la búsqueda de exoplanetas en otros sistemas solares.

Lo que realmente transluce en la búsqueda de exoplanetas, es el hecho que desde ellos podemos llegar a estar próximos a determinar la respuesta a la cuestión fundamental de si estamos solos en el Universo.

Ciertamente me sentí emocionado al escuchar su hipótesis ya que pocos días antes, me encontré con un par de científicos del Observatorio Mauna Kea Keck en Hawai, que habían creado algo así como un nuevo proyecto científico basado en Big Data, llamado Project PANOPTES– cuyo objetivo era la búsqueda y el estudio de exoplanetas.

El objetivo principal del proyecto consiste en establecer una red global de voluntarios que puedan interactuar con una red de telescopios automatizados para monitorizar una gran fracción del espacio con la idea de encontrar exoplanetas. Los datos recolectados por los voluntarios serán analizados por lotes y analizados y compartidos por astrónomos profesionales que tienen acceso a telescopios más potentes para verificar los hallazgos.

Dado que los exoplanetas son difíciles de observar comparados con las estrellas (de más fácil observación), la búsqueda de éstos es relativamente nueva en el campo de la astronomía, tal y como afirmó MacArthur F. Olivier Guyon, co-fundador del proyecto PANOPTES, que además es uno de los físicos ópticos de la Universidad de Arizona y astrónomo en el Telescopio Subaru en Hawai.

Tras mi encuentro con Guyon, y el astrónomo Josh Walawender del Proyecto PANOPTES cuando estaban impartiendo una charla en el marco del evento de búsqueda de estrellas en Hawai a principios de este año, ellos me explicaron que desde el primer descubrimiento a principios de 1990, los astrónomos han detectado más de 2.000 exoplanetas, normalmente usando alguno de los dos métodos actualmente disponibles, mediante las observaciones del telescopio Kepler.

El primer método, implica analizar la velocidad radial, es decir, calcular la pequeña cantidad de influjo gravitacional que influye en la estrella que orbitan, causando una fluctuación en la estrella matriz, cada vez que realizan el movimiento de traslación. Usando una tecnología sofisticada, los científicos pueden detectar esas fluctuaciones, midiendo los cambios en el espectro de luz que la estrella emite.

El otro método que los investigadores usan, es el “método de tránsito”, que implica detectar una pequeña variación en el brillo de la estrella cuando el planeta transita o pasa en frente de ella. El método del tránsito, requiere potentes lentes y un esfuerzo tecnológico importante, pero sólo funciona cuando el planeta se mueve directamente entre la estrella y el observador, similar al efecto que podríamos reportar en un eclipse. Adicionalmente, los científicos tan sólo pueden usarlo para escrutar una ínfima región del cielo al mismo tiempo, ya que consume un gran esfuerzo temporal.

Para lograr eso, Guyon diseñó hace unos pocos años, un sistema telescópico robotizado que usa un sistema clusterizado de cámaras, lentes y que permite la observación sin interferencias desde un monte en una posición ecuatorial que permite seguir los movimientos del cielo en la noche.

El equipo del proyecto PANOPTES incentiva a usar la técnica de multiobservación (Muchos ojos mirando el mismo fenómeno), de manera que los ciudadanos puedan participar en el método científico, buscando un método de tránsito determinado y convertir esa observación en una mejor estrategia para la búsqueda de exoplanetas.

Fuente: Plos.org.

StarViewerTeam 2017.

Nuevas claves en la búsqueda de señales extraterrestres inteligentes del proyecto SETI.

Tenemos que pensar que en un universo tan infinito, no tiene sentido creer que estamos solos en el Universo. Existen iniciativas de SETI para buscar inteligencias extraterrestres. Los estudios sobre las inteligencias extraterrestres, deben enfocarse en las nuevas señales como los círculos de las cosechas y otras evidencias empíricas.

La imagen y credibilidad de todos los periodistas que investigan el fenómeno de la inteligencia extraterrestre, está en entredicho cuando cada evidencia se cuestiona entre todas las evidencias disponibles. Si no somos capaces de entender que el fenómeno es real y existente, tendremos que abrir nuestra mente para poder llegar a entender la lógica de sus comunicaciones.

En el escenario de la investigación, ofrecemos también el gran despliegue de recursos que está realizando el proyecto SETI, en el marco de la nueva inestigación presentada por Andrew P. V. Siemion, James Benford, Jin Cheng-Jin, Jayanth Chennamangalam, James Cordes, David R. DeBoer, Heino Falcke, Mike Garrett, Simon Garrington, Leonid Gurvits, Melvin Hoare, Eric J. Korpela, Joseph Lazio, David Messerschmitt, Ian S. Morrison, Tim O’Brien, Zsolt Paragi, Alan Penny, Laura Spitler, Jill Tarter, Dan Werthimer que merece ser tomada en serio.

El artículo se titula: “Searching for Extraterrestrial Intelligence with the Square Kilometre Array” y acaba de ser presentado el 16 de Diciembre de 2014. El artículo científico pretende analizar el despliegue y requerimiento  de las características y capacidades necesarias para hacer posible la detección con la mayor precisión posible de señales de Civilizaciones extraterrestres en nuestra Galaxia en el marco de los nuevos avances de la ciencia y tecnología disponibles.

Pueden descargarlo aquí: http://arxiv.org/pdf/1412.4867v1.pdf

fundadacion_emprendedores_logo

 

La obsesión con el binomio inteligencia= tecnología en la búsqueda de Inteligencia extraterrestre.

En el ejemplar de junio de 2013 de la revista “Astronomy magazine”, va a publicarse un interesante trabajo científico que lleva por título: “How to Find ET with Infrared Light”, es decir: Cómo encontrar ET con luz infrarroja. El estudio analiza la necesidad de localizar civilizaciones extraterrestres en nuestra galaxia utilizando la huella que dejan en emisión de calor y energía en el espectro infrarrojo como consecuencia del desarrollo tecnológico de su civilización.

El estudio ha sido conducido por Jeff R. Kuhn del Instituto de Astrofísica de la Universidad de Hawaii, Svetlana V. Berdyugina de la Universidad de Freiburg ,David Halliday de la empresa Dynamic Structures, Ltd. y  Caisey Harlingten del Searchlight Observatory Network in The Grange, Norwich, Reino Unido.(1)

La cuestión implica una relación entre inteligencia y tecnología, suponiendo siempre nuestro modelo de referencia como base para la búsqueda de inteligencia: Es decir, que una civilización produce energía eléctrica o nuclear, etc…para el suministro de su planeta. El concepto es todo un clásico de la presunción del binomio inteligencia=tecnología.

Para ello, proponen la construcción de un gran telescopio Colossus capaz de barrer el espectro infrarrojo y detectar esas fuentes de calor que son independientes de la irradiación procedente de la estrella. (2)

La construcción de este gran telescopio tendría por objeto explorar esas emisiones como huella de la existencia de otras civilizaciones.

Con independencia de la innovación que supone este tipo de metodologías novedosas para la búsqueda de Inteligencia Extraterrestre, muchos científicos argumentan que la Inteligencia no necesariamente imprime ese tipo de emisiones, a menos que supongamos que toda inteligencia requiera necesariamente la producción de suministros de energía tal y como la conocemos y/o una huella tecnológica.

Lo que si es cierto es que este método nos permitiría detectar Inteligencias tecnológicas en nuestra galaxia, siempre que su tecnología se parezca a la nuestra, es decir que una vez más nos consideramos la medida de todas las cosas.

Sin perjuicio de lo anterior, el estudio supone un nuevo avance metodológico en la búsqueda de señales de inteligencia extraterrestre, aunque una vez más se basa en la presunción de considerar que esas civilizaciones se comportan de forma similar a nuestra civilización.

Ver artículo sobre el nuevo proyecto Colossus Telescope en Astrobiology.com 

Fundación EticoTaku 2013.

——-Notaciones del artículo——-

(1).- Literalmente los autores del estudio argumentan: “The energy footprint of life and civilization appears as infrared heat radiation,” says Kuhn, the project’s lead scientist. “A convenient way to describe the strength of this signal is in terms of total stellar power that is incident on the host planet.” The technique arises from the fact that a civilization produces power that adds to the heat on a planet, beyond the heat received from its host star. A large enough telescope, idealized for infrared detection, could survey planets orbiting stars within 60 light-years of the Sun to see whether or not they host civilizations.”

(2).-Ver literalmente: “The international team thus seeks funding to build a 77-m telescope, which would be constructed from revolutionary thin-mirror slumping and polishing technologies developed by the Innovative Optics team. The telescope would consist of approximately sixty 8-m mirror segments, and would operate at a high-altitude site.”  (Ver Astrobiology.com)

 

Un informe presentado por Stephen Battersby ofrece nuevas metodologías de búsqueda de Inteligencia Extraterrestre.

El nuevo artículo presentado por Stephen Battersby en New Scientist, publicado el 6 de abril de 2013, ofrece un nuevo marco metodologógico de búsqueda de inteligencia extraterrestre, mediante la presunción de que estas civilizaciones han sido capaces de modificar y modelar las leyes de la física. aether

La cuestión de base del artículo que pueden encontrar en la edición de abril de la revista New Scientist, ofrece una nueva perspectiva metodológica de búsqueda que se basa en la lógica de que las civilizaciones más avanzadas de la Galaxia han sido capaces de transformar su entorno para generar energía e incluso de crear las denominadas esferas Dyson.

¿Qué son las esferas Dyson?.  Las esferas Dyson o aetherofactos son auténticas esferas-planeta-nave de tipo artificial capaces de desplazarse utilizando la energía de las estrellas.

Estas capacidades extenderían la búsqueda de Inteligencia Extraterrestre a civilizaciones que podrían encontrarse en el diámetro de la Vía Láctea, es decir unos 100.000 años luz.

En el estudio se abordan las nuevas perspectivas de señales complejas que deben encontrarse, señalando que las búsquedas hasta ahora realizadas, eran precarias, ya que únicamente atendían a respuestas de señales de Radio, en el supuesto de que esas civilizaciones eran como nosotros. Por tanto, el nuevo marco de referencia de búsqueda de señales irá apoyado por telescopios de nueva tecnología, así como métodos basados en detección de señales ultratecnológicas y de patrones de detección de esferas Dyson o patrones de detección aetherofactal.

Recomendamos la lectura de este informe porque supone un giro de 180º en la metodología seguida hasta ahora por SETI en la búsqueda de inteligencia extraterrestre.

Bibliografía complementaria:

1. To boldly look: Another way to find aliens
Battersby, Stephen, New Scientist, 218 (2911), p.42-45, Apr 2013
doi:10.1016/S0262-4079(13)60891-X
…million years, building spheres as they go. “I would argue that…Milky Way, there should bespheres everywhere. “To find one or a few Dyson spheres in our galaxy would be very strange…Berkeley, his team will be searching for unusual patterns of…
Published journal article available from   ScienceDirect
similar results

2.
Who are the SETI sceptics?
Ćirković, Milan M., Acta Astronautica, In Press, Accepted Manuscript,Mar 2013
doi:10.1016/j.actaastro.2013.03.012
…either colonized all planetary systems in the Galaxy or at least leave detectable traces and manifestations, like the [24] spheres. The absence of both extraterrestrials in the Solar System and their traces or manifestations in our astronomical databases…
Published journal article available from   ScienceDirect
similar results

3.
Statistical mechanics of complex neural systems and high dimensional data
Madhu Advani / Subhaneil Lahiri / Surya Ganguli , Journal of Statistical Mechanics: Theory and Experiment, 2013 (03), p.P03014, Mar 2013
doi:10.1088/1742-5468/2013/03/P03014
Recent experimental advances in neuroscience have opened new vistas into the immense complexity of neuronal networks. This proliferation of data challenges us on two parallel fronts. First, how can we form adequate theoretical frameworks for understanding …
Published journal article available from   IOP Publishing
similar results
 Todo sobre Esferas Dyson.

 
1. Dyson Spheres [4K]
Sep 2003
Some Sketches of Dyson Spheres Early Stage in the Construction of a Dyson Sphere Solar collectors are placed in orbit around a…scrap energy farther out). Other Images Drawing of aDyson Sphere in the solar system (Figure 1 of Detectability…
[http://www.aleph.se/Trans/Tech/Megascale/dyson_page.ht…]
similar results

2.
Galileon Hairs of Dyson Spheres, Vainshtein’s Coiffure and Hirsute Bubbles
Kaloper, Nemanja / Padilla, Antonio / Tanahashi, Norihiro, article, Jun 2011
…thin shell sources, a.k.a. Dyson spheres, in a { fully nonlinear covariant…distinct branches. On one, a Dyson sphere surrounds itself with a galileon…of regulated solutions, where theDyson sphere explodes outward, and its…
Full text article available from E-Print ArXiv
similar results

3.
IRAS-BASED WHOLE-SKY UPPER LIMIT ON DYSON SPHERES
Richard A. Carrigan Jr , The Astrophysical Journal, 698 (2), p.2075-2086, Jun 2009
doi:10.1088/0004-637X/698/2/2075
…IRAS-BASED WHOLE-SKY UPPER LIMIT ON DYSON SPHERES Richard A. Carrigan, Jr. Fermi…intelligence at work. A search for Dyson spheres has been carried out using the…fully cloaked) and partial Dyson spheres in the blackbody temperature region…
Published journal article available from   IOP Publishing
similar results

4.
IRAS-based whole-sky upper limit on Dyson Spheres
Carrigan, Richard A., article, Mar 2009
…intelligence at work. A search for Dyson Spheres has been carried out using the…pure (fully cloaked) and partial Dyson Spheres in the blackbody temperature region…to eliminate sources that mimic Dyson Spheres very few candidates remain and…
Full text article available from E-Print ArXiv
similar results

5.
IRAS-based whole-sky upper limit on Dyson Spheres
Carrigan, Richard A., Jr. / /Fermilab, Sep 2008
…IRAS-based Whole-Sky Upper Limit on Dyson Spheres Richard A. Carrigan, Jr…intelligence at work. A search for Dyson Spheres has been carried out using the…fully cloaked) and partial Dyson Spheres in the blackbody temperature region…
Full text available from United States Department of Energy   Department of Energy
similar results

6.
Actualité Le Fermilab à la recherche des extraterrestres et des sphères de Dyson [226K]
Futura-Sciences, Dec 2010
…recherche des extraterrestres et des sphères de Dyson Retrouvez toute l’actu de…particules. Les étoiles sont des sphères gazeuses auto-gravitantes…entrepris de détecter de telles « sphères de Dyson ». Le nom de Dyson est familier…
[http://www.futura-sciences.com/fr/news/t/physique-1/d/…]
similar results

7.
A program to search for dyson spheres with the infrared space observatory
Tilgner, C.N / Heinrichsen, I, Acta Astronautica, 42 (10-12), p.607-612, May 1998
doi:10.1016/S0094-5765(98)00015-0
…in scientific context by Dyson [1] . “Dyson spheres”, the astro-engineering project…rings in a planetary orbit or incomplete Dyson spheres might exist apart from complete Dysonspheres around a star. In order to detect these…
Published journal article available from   ScienceDirect
similar results

8.
A search of the IRAS database for evidence of Dyson Spheres
Timofeev, M.Yu / Kardashev, N.S / Promyslov, V.G, Acta Astronautica, 46 (10-12), p.655-659, Jun 2000
doi:10.1016/S0094-5765(00)00028-X
…in space. Historically such constructions are called Dyson Spheres (DS). We suggest a new name for such kind of…and analyzed the possibility that these sources were Dyson Spheres. His main conclusion is following. It is necessary…
Published journal article available from   ScienceDirect
similar results

9.
Cambridge Journals Online – Abstract [106K]
Harrop, Brooks L. / Schulze-Makuch, Dirk, Apr 2010
…as an alternative to a traditional Dyson Sphere and its implications for remote…99164, USA Abstract The search for Dyson Spheres has been propelled not only by the…ever-increasing need for energy. However, the Dyson Sphere is not a practical design…
[http://journals.cambridge.org/abstract_S14735504100000…]
similar results

10.
RealClimate: Freeman Dyson’s selective vision [122K]
Jul 2012
…Next » 1 KamatariSeta says: 24 May 2008 at 6:01 PM Dyson is a good physicist, but far too often his predictions…speculative and don’t seem to address current problems. DysonSpheresDyson Trees, and genetically engineered plants for Carbon Sequestering…
[http://www.realclimate.org/index.php/archives/2008/05/…]
similar results
 

Fundación EticoTaku 2013
.

Aetherofactos y las Esferas Dyson: Si los aetherofactos no existen, ¿entonces por qué la NASA busca las esferas Dyson?

Si los recientes esfuerzos que la NASA realiza para construir un motor capaz de realizar la propulsión warp, no son más que un mero espejo de la imaginación y la ciencia ficción. ¿Qué sentido tiene que el Departamento de Astrofísica de Penn investigue acerca de la existencia de las Esferas Dyson?.

Según el equipo de la Penn State , algunas inteligencias serían capaces de crear esferas artificiales lo suficientemente grandes como para albergar dentro de ellas un sistema planetario completo. Tal es el caso de las esferas Dyson, que curiosamente coinciden con el tamaño de algunos objetos avistados por satélites tales como SOHO-LASCO y que también se han denominado aetherofactos.  Dichos objetos, han sido denominados Oficialmente  Esferas Dyson, en honor a la teoría del físico Freeman Dyson que en 1960 fue uno de los artífices de la búsqueda de Inteligencia Extraterrestre. Tal y como la teoría de Dyson refiere, dichas esferas serían objetos oscuros de tamaño superior a la órbita de la Tierra y construidos al rededor de la órbita de una estrella. Estos objetos podrían tomar y generar energía de la estrella y albergar vida dentro de forma indefinida, alimentándose de la energía de la estrella de secuencia principal. Igualmente tendrían autonomía para poder traspasar la estrella y migrar hacia otro sistema estelar utilizando esa misma energía.

Aunque el mismo Dyson concluyó hace años que su teoría era ridícula en base a los conocimientos de su época, ya que la construcción de dichas esferas implicaría la generación de enormes cantidades de energía, actualmente el joven profesor  Jason Wright  y su equipo del Departamento Estatal de Astronomía y Astrofísica, están utilizando el (WISE) s Wide-field Infrared Survey Explorer  para poner a prueba la teoría de Dyson en el marco de la búsqueda de Inteligencia Extraterrestre. Lo cierto es que las esferas Dyson constituyen objetos de interés indudable para la astrofísica utilizando la tecnología de detección infrarroja del WISE.

El Equipo del Penn State fue constituido por la aplicación de Fondos con cargo a la Fundación John Templeton con cargo al programa “Nuevas Fronteras ” con el objeto de determinar si existen otras civilizaciones inteligentes en nuestro vecindario estelar. Ciertamente si Wright y su equipo son capaces de encontrar evidencias aetherofactales o Esferas Dyson, cabría concluir que oficialmente estaríamos hablando de evidencias definitivas de la Inteligencia extraterrestre.

Curiosamente, hasta hace poco se cuestionaba en paralelo la existencia de las esferas Dyson, mientras otros científicos fotografiaban en directo estas esferas denominadas aetherofactos en las inmediaciones del sol , gracias a satélites como LASCO-SOHO o STEREO.

La misión del equipo  será determinar de una vez por todas su existencia.

Fuentes:

Dyson Paper 1960 (Reproducimos seguidamente el contenido). 

Shells Around Suns May Have Been Built 
Science News Letter, June 18, 1960, page 389, Astronomy

Intelligent beings in another solar system could have hidden their sun by knocking their planets apart and using the pieces to build a hollow ball around their sun.

Dr. Freeman J. Dyson of the Institute for Advanced Study, Princeton, N. J., says that other civilizations may be millions of years ahead of the earth. They may have rearranged their solar systems to meet the needs of their exploding populations.

A hollow ball built around the sun would solve the space and energy problems. It would also cut off the sun’s light. To detect such an advanced civilization, earthlings would have to detect the invisible heat radiation from the hollow ball.

A search for such infrared radiation should be coordinated with, Project Ozma, a program now underway for detecting artificial radio waves from nearby stars, Dr. Dyson reports in Science, Vol. 131, 1960, page 1667.

Using our own solar system as an example, Dr. Dyson calculates that it would take about 3,000 years for population and technology to expand one trillion times at the rate of one percent a year. Pressures of population and energy needs could be met only by trapping all of the sun’s radiated energy.

To trap the energy, earthlings could knock apart the planet Jupiter and rearrange it as a hollow ball about 10 feet thick with a diameter twice the size of earth’s orbit. This would take all the energy given off by the sun in 800 years. Such a sphere would be “comfortably habitable.”

Dr. Dyson states he is not suggesting that this is what will happen in the solar system, but only proposes what may have happened in other stellar systems.


Search for Artificial Stellar Sources of Infrared Radiation 
Freeman John Dyson, Science, Vol. 131, June 3, 1960, pp. 1667-1668.

ABSTRACT: If extraterrestrial intelligent beings exist and have reached a high level of technical development, one by-product of their energy metabolism is likely to be the large-scale conversion of starlight into far-infrared radiation. It is proposed that a search for sources of infrared radiation should accompany the recently initiated search for interstellar radio communications.

Cocconi and Morrison [1] have called attention to the importance and feasibility of listening for radio signals transmitted by extraterrestrial intelligent beings. They propose that listening aerials be directed toward nearby stars which might be accompanied by planets carrying such beings. Their proposal is now being implemented [2].

The purpose of this report is to point out other possibilities which ought to be considered in planning any serious search for evidence of extraterrestrial beings. We start from the notion that the time scale for industrial and technical development of these beings is likely to be very short in comparison with the time scale of stellar evolution. It is therefore overwhelmingly probable that any such beings observed by us will have been in existence for millions of years, and will have already reached a technological level surpassing ours by many orders of magnitude. It is then a reasonable working hypothesis that their habitat will have been expanded to the limits set by Malthusian principles.

We have no direct knowledge of the material conditions which these beings would encounter in their search for lebensraum. We therefore consider what would be the likely course of events if these beings had originated in a solar system identical with ours. Taking our own solar system as the model, we shall reach at least a possible picture of what may be expected to happen elsewhere. I do not argue that this is what will happen in our system; I only say that this is what may have happened in other systems.

The material factors which ultimately limit the expansion of a technically advanced species are the supply of matter and the supply of energy. At present the material resources being exploited by the human species are roughly limited to the biosphere of the earth, a mass of the order of 5 x 1019 grams. Our present energy supply may be generously estimated at 1020 ergs per second. The quantities of matter and energy which might conceivably become accessible to us within the solar system are 2 x 1030 grams (the mass of Jupiter) and 4 x 1033 ergs per second (the total energy output of the sun).

The reader may well ask in what sense can anyone speak of the mass of Jupiter or the total radiation from the sun as being accessible to exploitation. The following argument is intended to show that an exploitation of this magnitude is not absurd. First of all, the time required for an expansion of population and industry by a factor of 1012 is quite short, say 3000 years if an average growth rate of 1 percent per year is maintained. Second, the energy required to disassemble and rearrange a planet the size of Jupiter is about 1044 ergs, equal to the energy radiated by the sun in 800 years. Third, the mass of Jupiter, if distributed in a spherical shell revolving around the sun at twice the Earth’s distance from it, would have a thickness such that the mass is 200 grams per square centimeter of surface area (2 to 3 meters, depending on the density). A shell of this thickness could be made comfortably habitable, and could contain all the machinery required for exploiting the solar radiation falling onto it from the inside.

It is remarkable that the time scale of industrial expansion, the mass of Jupiter, the energy output of the sun, and the thickness of a habitable biosphere all have consistent orders of magnitude. It seems, then a reasonable expectation that, barring accidents, Malthusian pressures will ultimately drive an intelligent species to adopt some such efficient exploitation of its available resources. One should expect that, within a few thousand years of its entering the stage of industrial development, any intelligent species should be found occupying an artificial biosphere which completely surrounds its parent star.

If the foregoing argument is accepted, then the search for extraterrestrial intelligent beings should not be confined to the neighborhood of visible stars. The most likely habitat for such beings would be a dark object, having a size comparable with the Earth’s orbit, and a surface temperature of 200 deg. to 300 deg. K. Such a dark object would be radiating as copiously as the star which is hidden inside it, but the radiation would be in the far infrared, around 10 microns wavelength.

It happens that the earth’s atmosphere is transparent to radiation within the wavelength in the range from 8 to 12 microns. It is therefore feasible to search for “infrared stars” in this range of wavelengths, using existing telescopes on the earth’s surface. Radiation in this range from Mars and Venus has not only been detected but has been spectroscopically analyzed in some detail [3].

I propose then that a search for point sources of infrared radiation be attempted, either independently or in conjunction with the search for artificial radio emissions. A scan of the entire sky for objects down to the 5th or 6th magnitude would be desirable, but is probably beyond the capability of existing techniques of detection. If an undirected scan is impossible, it would be worthwhile as a preliminary measure to look for anomalously intense radiation in the 10-micron range associated with visible stars. Such radiation might be seen in the neighborhood of a visible star under either of two conditions. A race of intelligent beings might be unable to exploit fully the energy radiated by their star because an insufficiency of accessible matter, or they might live in an artificial biosphere surrounding one star of a multiple system in which one or more component stars are unsuitable for exploitation and would still be visible to us. It is impossible to guess the probability that either of these circumstances would arise for a particular race of extraterrestrial intelligent beings. But it is reasonable to begin the search for infrared radiation of artificial origin by looking in the direction of nearby visible stars, and especially in the direction of stars which are known to be binaries with visible companions.

References

  1. G. Cocconi and P. Morrison, Nature, Vol. 184, 1959, pp. 844-846.
  2.  Science, Vol. 131, April 29, 1960, page 1303.
  3. Astrophysics Journal, Vol. 31, 1960, pp. 459, 470.

Science Vol. 132, July 22, 1960, pp. 250-253.
Letters and Response
Search for Artificial Stellar Sources of Infrared Radiation

It is unfortunate that Dyson’s suggestion [Vol. 131, 1960, page 1667] as to how intelligent beings might survive after reaching “the limits set by Malthusian principles” does not do justice to the intelligence of these beings by explaining how they would overcome some of the obstacles which, at first sight, would seem to militate against their curious way of life.

Dyson’s report describes a uniformly thick shell of fluid with a thickness of a meter or two and a radius twice the earth’s distance from the sun. The shell is said to revolve around the central star, which implies that the material revolves as a whole. Presumably the material of the shell must be enclosed on both surfaces by transparent plastic sheaths of similar constructions, for self-gravitation cannot be expected to make the material cohere. However it is not conceivable that it would be possible to quarry from the material of a planet like Jupiter sufficient structural steel to keep the shell rigid against the shear forces and those that would tend to move material towards the equatorial plane.

Therefore it must be assumed that radiation pressure must play a part in supporting the shell, so that its form will be that of an oblate spheroid rather than a sphere. For example, material at the poles of revolution of the shell would be supported entirely by radiation pressure, so that the polar radius of the shell would necessarily be less than the equatorial radius. However, a cursory calculation will show that this would be possible only at a distance from the central star comparable to but less than the radius of the sun.

Beings of lesser intelligence, not having discovered the appropriate laws of physics, might therefore seek some other distribution of their dismantled Jupiter that would have more intrinsic stability – for example, a torus lying in a plane perpendicular to the axis of its own rotation. The mass of Jupiter distributed in this way would yield a torus whose cross-sectional area was comparable with that of the moon, but unfortunately the flux of stellar radiation would be reduced by a factor of 109.

With conventional laws of physics, however, as Laplace was the first to show, even this arrangement would not be stable, and it is to be expected that the material of the torus would coalesce into one or more planetary objects. This suggests that the present state of intelligence, the dispersal of Jupiter into a thin shell about the sun would not be an effective means of escaping the consequences of continued population growth but that it might be an experiment with important bearing on various theories of origin of the solar system. It would, for example, be interesting to see whether the outcome of the experiment was the recreation of Jupiter or the creation of a number of asteroids.

Another point is that a search for infrared stars would be valuable even in conventional science for the light it might throw on the evolution of stars which are very young or very small as compared with the sun.

John Maddox
Washington Post
Washington, D.C.


Freeman Dyson’s report suggesting that intelligent life elsewhere in the universe may be detected by looking for sources of infrared radiation was delightful. However, as an old science-fiction hand, I feel obliged to sound a cautionary note to the scientists. Or am I merely to dense to recognize a satire?

The basis of Dyson’s argument is that an industrial culture may eventually occupy an artificial biosphere completely surrounding its sun, thus maximizing the territory and energy available for population expansion “to the limits set by Malthusian principles. The mass of Jupiter could be converted into a “spherical shell revolving around the sun at twice the Earth’s distance from it,” utilizing incident solar radiation which would be reradiated into space in the 10-micron band.

Offhand, I should think rotational and gravitational stresses alone would rule out such a structure of such dimensions. But since it is admittedly dangerous to assert that anything is impossible, I shall confine myself to the questions of economics. Even Dyson intimates that the project would take several thousand years to complete; he calculates the energy required as equal to the sun’s total output for eight centuries, and one does have to eat meanwhile. And meanwhile, too, the population growth necessitating this project will presumably continue. As Hauser remarks in the same issue [Science, Vol. 131, 1960, page 1642], at our present-day rate of increase we would reach “a population of one person per square foot of the land surface of the earth in less than 800 years. Thus, the economic surplus needed for the biosphere project would be consumed long before the latter got well started.

If we assume a ratio of population increase to industrial expansion low enough so that this contretemps does not occur, we must ask ourselves how any intelligent species could be induced to patiently to continue this enormous task, millennium after millennium. True, our human history contains epochs of grandiose and useless construction, such as the pyramid building of Egypt, but they never lasted very long. Any revolutionist who promised relief from the crushing burden of the biosphere project would be well received! He could doubtless get support for some or other population-control program; those who demurred would be martyred by exasperated taxpayers, or the equivalent thereof.

Of course, the entire species might by advanced psychological techniques, be conditioned into such an antlike state that its government could never be overthrown, or break down from internal stresses, or evolve into something new. But given subjects as meek as this, and nor reason to breed vast armies (for only a well-established world government could seriously entertain these ideas in the first place), the masters could regulate birth and death by fiat. Thus, the population would have stabilized at some rational figure and projects such as Dyson’s would never be indicated.

In short, uncontrolled population growth will make the construction of artificial biospheres impossible, and control will make them unnecessary. So astronomical discovery of infrared sources won’t prove anything about the inhabitants of other planets.

Paul Anderson
3 Las Palomas Road
Orinda, California


The suggestion by Freeman J. Dyson for investigating solar far-infrared radiation as one way to detect extraterrestrial intelligence sounds quite practical and sensible.

This leads me to suspect that if Dyson’s assumption is correct – that intelligent beings exist of a far higher order technological achievement than our own – it would be well – nigh impossible for such beings not to have detected us.

Eugene A. Sloane
Air Engineering
Detroit, Michigan


RESPONSE: In reply to Maddox, Anderson and Sloane, I would only like to add the following points, which were omitted from my earlier communication.

  1. A solid shell or ring surrounding a star is mechanically impossible. The form of “biosphere” which I envisaged consists of a loose collection or swarm of objects traveling on independent orbits around the star. The size and shape of the individual objects would be chosen to suit the inhabitants. I did not indulge in speculations concerning the constructional details of the biosphere, since the expected emission of infrared radiation is independent of such details.
  2. It is a question of taste whether one believes that a stabilization of population and industry is more likely to occur close to the Malthusian limit or far below that limit. My personal belief is that only a rigid “police state” would likely to stabilize itself far below the Malthusian limit. I consider that an open society would be likely to expand by proliferation of the “city-states” each pursuing an independent orbit in space. Such an expansion need not be planned or dictatorially imposed; unless it were forcibly stopped it would result in the gradual emergence of an artificial biosphere of the kind I have suggested. This argument is admittedly anthropomorphic, and I resent it in full knowledge that the concepts of “police state” and “open society” are probably meaningless outside our own species.
  3. The discovery of an intense point source of infrared radiation would not by itself imply that extraterrestrial intelligence has been found. On the contrary, one of the strongest reasons for conducting a search for such sources is that many new types of natural astronomical objects might be discovered.

Freeman J. Dyson
Institute for Advanced Study
Princeton, New Jersey

 


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