The Quest for Intelligent Life Beyond Earth

Advances in astrophysics and particularly cosmology have aided greatly for the study in possible intelligent life manifestations in the multiverse.  However, as pointed out by I.S. Shklovskii, the multiverse studies are still in the embryonic stages without concrete success in the search (Kardashev, 2017). An assessment by Barnes on various scientific literature regarding fine-tuning of the multiverse for the support of the intelligent life brings forth conflicting conclusions by various researchers (Barnes, 2012). The idea of intelligent civilization beyond earth continues to baffle physicist and astronomers alike who strive to look for answers. This paper examines the views of various physicists and astronomers on the issue of the existence of the intelligent life.

Marcelo Gleiser divides the cosmological history into four ages from the big bang to the intelligent life. These include; physical age describing the origin of the universe, matter, cosmic nucleosynthesis including the formation of the first stars and galaxies, the chemical age that describes the role of heavy stars in providing the ingredients for life through stellar nucleosynthesis. The chemical age also covers the heavier chemical elements collected in nascent planets and moons to give rise to prebiotic biomolecules. The third is the biological age that examines the origin of early life, evolution through Darwinian natural selection and eventually the emergence of complex multicellular life forms. Cognitive age is the final age that that describes the emergence of complex and intelligent life forms that are capable of self-awareness. The cognitive age also describes the ability of the complex and intelligent life to manipulate materials and energy for technological development and advancement (Gleiser, 2012).  

In his analysis, Gleiser, (2012) argues that the existence of intelligent life beyond earth is unquestionable. The scientific evidence, however, stands as the major impediment to this quest of providing the existence of intelligent life. Further, the presence of abundant organic chemicals in the interstellar and circumstellar media, as well as the “remarkable resilience of terrestrial extremophiles, it is hard to support the idea that life has only found its way on our planet” Gleiser (2012, p.5).  An example of the organic chemicals in the interstellar and circumstellar medium include the recently-found polycyclic aromatic hydrocarbons (Salama, 2008).

Peter Ward and Donald Brownlee (Rare Earth: Why Complex Life Is Uncommon in the Universe), on the other hand, suggested that if the life exists beyond our universe, then it must be on its simplex forms i.e. alien microorganisms (Ward and Brownlee, 2005). The argument is based on the various planetary factors that support complex multicellular life. Such factors include a large moon to stabilize the planetary axis tilt and hence the seasons, a magnetic field to shield off radiation, plate tectonics to remix surface and ocean chemistry that helps regulate carbon dioxide levels among others (Gleiser, 2012).

In the quest to find the existence of intelligent life beyond our universe, several programs and research centres have been put up to support the quest. For instance, the SETI institutes centre for SETI research that has conducted various projects in search of intelligent life such as planetary-scale engineering projects and other possible signs of purposeful redesigning at astronomical scales as well as the RadioAstron and Millimetron Space Observatories (Davies, 2011; Kardashev, 2017). Barnes (2012) analyzes the findings of various researchers in their quest to prove or disapprove the existence of life in other universes:

Changing the laws of nature:

Supposing that the existence of intelligent life solely depends on the same laws and parameters existing on our universe, would fine-tuning these parameters still determine life exists elsewhere? ). The probability of supporting life in the other universes depends on the laws and parameters that exist there. Barnes (2012, p.7) discusses the claims below that suggest absence of intelligent life if the life-permitting probability is robustly small:

A universe governed by Maxwell’s Laws i.e. with no quantum regime at small scales, would not have stable atoms — electrons radiate their kinetic energy and spiral rapidly into the nucleus— and hence no chemistry. We don’t need to know what the parameters are to know that life in such a universe is plausibly impossible. 

If electrons were bosons, rather than fermions, then they would not obey the Pauli Exclusion Principle. There would be no chemistry. 

If gravity were repulsive rather than attractive, then the matter wouldn’t clump into complex structures. Note: your density, thank gravity, is 1030 times greater than the average density of the universe.

If the strong force were a long rather than short-range force, then there would be no atoms. Any structures that formed would be uniform, spherical, undifferentiated lumps, of arbitrary size and incapable of complexity. 

If in electromagnetism, like charges attracted and opposites repelled, then there would be no atoms. As above, we would just have undifferentiated lumps of matter.

The electromagnetic force allows the matter to cool into galaxies, stars, and planets. Without such interactions, all matter would be like dark matter, which can only form into large, diffuse, roughly spherical haloes of matter whose only internal structure consists of smaller, diffuse, roughly spherical subhaloes.

Coolness and the Measure Problem

According to Barnes (2012), the universe consists of inflating and non-inflating regions. Our universe, for instance, its inflation ended 13.7 billion years ago followed by matter-dominated, decelerating expansion. In the other universes that are still inflating, the matter is absent and therefore, life. Conversely, other universes that have stopped inflation, intelligent life may be present. Barnes (2012) adds that other universes that continued to inflate have become exponentially larger thus nucleate exponentially more matter-dominated regions that are slightly younger and warmer than in our universe. These younger and warmer universes would take less time to make an intelligent life. For the universes that stopped inflation same time as ours, on the other hand, are as cold and life permitting as ours. This is the concept of coolness problem, also known as the youngness paradox as discussed by Max Tegmark (2005) in ”What does inflation really predict?”. Inflationary mutiverse proposal of intelligent life can be depended upon to make predictions based on the calculations and measurements made.

Stars  

According to Barnes (2012), stars provide two crucial elements regarding the origin and evolution of intelligent life. The first role is the synthesis of the elements that are needed by life through big bang nucleosynthesis that provides lithium, hydrogen and helium that when combined, they for two chemical compounds (H2 and LiH). Secondly, Stars provide a long-lived, low-entropy energy source that is necessary for planetary life including the gravity that holds planets in stable orbits. Further, ”the low entropy of the energy supplied by stars is crucial if life is to evade the decay to equilibrium” (Barnes, 2012, p. 19).

Distance between stars

The challenge, however, has been to provide more comprehensive studies of the stars. For instance, it will take 90,000 years for New Horizons (the fasted human device ever launched) to reach the nearest star, four light years. Therefore, the possibility of human beings leaving the solar system is almost zero.  Despite the many allegations of the ”unidentified flying objects” (UFOs), these claims have been disapproved for lack of evidence (Seeds & Backman, 2012).

Radio Communication

Radio communication would be the most efficient way for humans to communicate with distant civilizations. The major disadvantage of using radio communication is the time it would take for the message to reach the destination or even get a reply. An attempt to send an anti-coded greeting message was initiated toward the globular cluster M13, 26,000 light years away, using the Arecibo radio telescope (Seeds & Backman, 2012). The message will be received 26,000 years in the future by the ‘astronomers’ in the intelligent life.

Another restriction of using radio communication has been described as the reduced speed of the radio waves due to the enormous distances between stars. Therefore, the ability of the humanity to carry out conversations with intelligent life is greatly affected and would take decades for questions to receive answers and vice versa (Seeds & Backman, 2012).

Another limitation of getting radio communication that would aid in detecting intelligent life is the increasing babble of radio noise that has been collected from human civilization.  Communications on earth are taking up wider and wider electromagnetic spectrum as well as the stray electromagnetic radiation emitted by electronic devices such as computers has had it increasing difficult to hear the alien radio signals. Seeds & Backman (2012) have suggested that astronauts can alternatively look for extraterrestrial signals such as rapid flashes of laser light at optical or near-infrared wavelengths if they exist because they can be distinguished from natural light sources.

Number of Inhabited Worlds

Search for extraterrestrial life will ultimately depend on the number of inhabited universes. Astronomer and astrophysicist Frank Drake formulated a probabilistic argument to estimate the number of technological civilizations in the Milky Way Galaxy with which we might communicate. This probabilistic argument is based on an equation, the Drake equation demonstrated as follows (Seeds & Backman, 2012);

 Nc=N*.fp. nHZ. fl . fI . f s

N* is the number of stars in our galaxy

Fp represents the fraction of stars that have planets. If all single stars have planets

Fp is about 0.5.

The factor nHZ is the average number of planets

The factor fl is the fraction of suitable planets on which life begins

The factor fi is the fraction of those planets where life evolves to intelligence

Factor fs is the fraction of a star’s life during which an intelligent species is communicative.

These factors on the right-hand side of the equation are roughly estimated with decreasing certainty from right to left. For instance, the factor fs is extremely uncertain. Therefore, if the intelligence life available in a given society is small, say 100 years, the chances of communicating with such a society are slim. Seeds and Backman (2012) argue that civilizations lasting for a short time make it impossible for radio transmission in the course the cosmically short interval when Earthlings are capable of building radio telescopes to listen for them. Conversely, civilizations that are capable of being technologically stable and available for a long time are much more likely to be detected.  In their illustration, Seeds and Backman (2012) give the example of a star with a lifespan of 10 billion years, fs might conceivably range from 10-8 for extremely short-lived societies to 10 -4 for societies that survive for a million years. The table below provides many scientists consider a reasonable range of values for fs as well as other factors:

The Number of Technological Civilizations per Galaxy

Source: Seeds and Backman (2012, p. 469)

Seeds and Backman (2012) further argue that there could be a communicative civilization within a few tens of light-years from Earth if the optimistic estimates on the table above are true. On the contrary, Earth may be the only planet that is capable of communication within thousands of the nearest galaxies supposing pessimistic estimates are true.

Gleiser (2012) ponders whether intelligence is a reproducible feature of the existence of life, capable of art and technology that matches that our universe. The question of whether this intelligent life is widespread in the cosmos is answered only with continued technological advancement and research. Through assumptions, however, Gleiser (2012) describes the complex evolution and technological advancement of the intelligent life considering the technological advancement that has already been achieved by humans in the last four hundred years of modern science. There would be sufficient time to explore their galaxies and satisfy their inquisitive nature if it’s comparable with that of humanity.

The question of intelligent life in the multiverse has been lingering for a long time with astronauts, physicists and other enthusiasts finding ways of finding this evidence. While there have been agreements on the existence of intelligent life in the multiverse by various groups, lack of concrete evidence on the matter has created sceptics and lack of support in the research. Various programs such as the SETI (Search for Extraterrestrial Intelligence) program have however continued with the research in findings ways to communicate with other technological civilizations. Although receiving radio waves from the intelligent life may take a very long time, this will be the greatest breakthrough in confirm that humanity is not alone.

Further research and understanding in the multiverse will enable humanity to apply the Drake equation with much certainty and give a more concrete answer regarding an estimate of the number of universes with intelligent life. A suggested by Barnes (2012), the youngness paradox that explains the inflationary multiverse explains the existence of a more complex and evolved intelligent life that developed in other warmer and younger universes. While the existence of intelligent life in the multiverse remains controversial, much has been achieved through advancement in technology and research. It may take more time to provide this evidence, but eventually, the existence of intelligent life is set to be demystified and prove to the sceptics that, as is said, ‘absence of evidence is not evidence of absence’.  

References

Barnes, L. (2012). The Fine-Tuning of the Universe for Intelligent Life. Publications Of The Astronomical Society Of Australia, 29(04), 529-564. doi: 10.1071/as12015

Davies, P. (2011). The eerie silence: Renewing Our Search for Alien Intelligence. Boston, MA: Mariner Books.

F. Salama, in Organic Matter in Space Proceedings IAU Symposium No. 251, eds. S. Kwok and S. Sandford (2008).

Gleiser, M. (2012). From cosmos to intelligent life: the four ages of astrobiology. International Journal Of Astrobiology, 11(04), 345-350. doi: 10.1017/s1473550412000237

Kardashev, N. (2017). RadioAstron and millimetron space observatories: Multiverse models and the search for life. Astronomy Reports, 61(4), 310-316. doi: 10.1134/s1063772917040096

Seeds, M., & Backman, D. (2012). Horizons. Australia: Brooks/Cole, Cengage Learning.

Tegmark, M. (2005). What does inflation really predict?. Journal of Cosmology and Astroparticle Physics, 2005(04), 001.

Ward, P., & Brownlee, D. (2005). Rare earth: Why Complex Life Is Uncommon in the Universe. New York: Copernicus.