6.2 - What is Life?

Xenology: An Introduction to the Scientific Study of Extraterrestrial Life, Intelligence, and Civilization

First Edition

Robert A. Freitas Jr., Xenology: An Introduction to the Scientific Study of Extraterrestrial Life, Intelligence, and Civilization, First Edition, Xenology Research Institute, Sacramento, CA, 1979; http://www.xenology.info/Xeno.htm

Anthropologists jokingly tell of two cannibals watching an airplane fly overhead. Eyeing the craft wistfully, one says to the other, "It’s very much like lobster. It’s hard to get into, but very good once you get inside."

Kenneth Boulding, Director of the Institute of Behavioral Science at the University of Colorado, insists that the cars, planes and factories which surround us bear an analogous relation to the life inhabiting them as the lobster’s shell does to the lobster. "If a being from outer space were observing this planet," Boulding suggests, "he might well report that the process of evolution had produced a species of large four-wheeled bugs with soft, detachable brains."³⁰

How can we accurately differentiate the living from the nonliving? For years, science fiction writers have been teasing our imaginations, giving us stories about plants that act like animals,^564,2115 animals that act like plants,^607,2168 and other organisms that almost defy classification.^{1561,2163,2210,2221} Countless stories have been written around the theme of "machine life,"^{983,1755,1836,1912} and a well-known Stanford radioastronomer has speculated that there may exist aliens which are simply spherical balls. Instead of handling objects as we do, Dr. Ronald Bracewell suggests that "they might have to ingurgitate them and manipulate them as we can manipulate things with our tongues. Perhaps their tongues would be luminescent and there would be an eye in the roof of their mouth, or a microscope."¹⁰⁴⁰

Science fictioneers have devoted a great deal of time to an attempt to identify some of the problems we may encounter simply in recognizing that an object on another world is alive. False calls in either direction are possible. We may, for instance, mistakenly ascribe life to what is in reality a purely physical process. Conversely, there is the more frightening possibility that we might fail to identify a fascinating but unusual lifeform, which could cause irreparable harm before the error was discovered.

Such hypothetical organisms generally fall into five broad categories (although there are numerous exceptions). First we have the polymorph, a creature having a plural or changeable form. In Olaf Stapledon’s First and Last Men, Earth is invaded by a host of microscopic organisms from Mars. On occasion, these microbes form themselves into a rational entity by solidifying as a kind of "intelligent cloud."⁸¹ Such is not without precedent even on Earth: It has long been debated whether the sponge (Porifera) is a true organism or a colony of unicellular organisms.⁴⁴³

Ralph Milne Farley wrote "Liquid Life" back in 1936, in which a virus in a pond achieves group-collective consciousness.⁵⁸¹ This is similar to the "scum-intelligence" proposed by Bracewell⁸⁰ or the "mold-intelligence" proposed by Academician A. Kolmogorov, a Soviet writer.¹³³⁰ Perhaps easier to view as living but equally difficult to understand are Arthur Clarke’s Palladorians, each of which is described as possessing "no identity of its own, being merely a mobile but still dependent cell in the consciousness of its race."²²⁰⁷ Another class of exotic fictional lifeforms are the lithomorphs, organisms having the form of rock. Such creatures have actually been discussed in sober scientific circles.¹²³⁸ The two extremes of the problem of false calls are nicely illustrated by a pair of science fiction tales involving lithomorphs.

The Star Trek episode entitled "Devil in the Dark" deals with the discovery of a silicon-based organism that lives in the rocky mantle of a small planetoid. The human miners had been collecting and destroying apparently useless spherical silicon nodules -- which turned out to be the Horta’s eggs. In Clarke’s novel Imperial Earth, exactly the opposite difficulty is encountered. Early settlers on Titan, the largest moon of Saturn, discover the "waxworms," entities snaking around on the surface at speeds up to fifty kilometers per hour and often pausing to climb over hills. "To the bitter disappointment of the exobiologists," Clarke writes, "they had turned out to be a purely natural phenomenon. . ."¹⁹⁴⁷

Macromorphs are beings having a large or elongated distribution. Typical of this class is the huge single-cell lifeform encountered in the Star Trek adventure "Immunity Syndrome," or the Gaia concept of the living planet sponsored by scientists Margulis and Lovecock.¹²⁹³

Perhaps the most fascinating suggestion along these lines was made by the Swedish writer Gosta Ehrensvärd, who pointed out that organisms in the sense we understand may not even be a prerequisite for life.²⁵⁷ As an example, he envisions a coordinated network of lakes and streams covering a planet, participating in a complementary carbon cycle together with a sun-activated circum-planetary flow of water. Such a system, Ehrensvärd claims, "would undeniably constitute life, but it would hardly correspond to our idea of organism life. We could hardly recognize at first that we were dealing with something living, for we would not see any mass, body, or anything moving, but only a global activity in chemical serenity."

The fourth class of unusual creatures are the amorphs, those entities which exist without form or shape. Perhaps the best-known amorph is from the 1958 Paramount Studios movie "The Blob," the story line of which will not be gone into here. Suffice it to say that such organisms are not wholly without precedent on Earth. Slime molds are acellular plants which, because their construction is not unlike a sheet of water, find it possible to slowly creep about on the ground.

Blobs could also arise by natural evolution from Euglena ancestors (a photosynthetic microbial animal), or by artificial evolution as a direct consequence of genetic experimentation with "plantimal" cells. Plantimals are created by fusing animal cells with plant cells to form viable interkingdom protoplasts. To date, human tissues have been mated with carrot and with tobacco cells, and rooster cells have been joined with tobacco as well. According to Dr. James X. Hartmann of Florida Atlantic University at Boca Raton, a living, meatlike amorph might eventually be grown as livestock which could build animal protein by converting the sun’s energy directly into chemical energy -- just as plants do.¹⁶¹⁷

There have been many variants on this theme in science fiction,¹³⁸⁹ including petroleum-blobs such as in Brenda Pierce’s "Crazy Oil" on Venus.²⁰⁷¹ In a familiar plot line, the human miners discover too late that the sticky black goo they’ve been extracting is part of a living organism. Still more fascinating is the possibility of superfluid amorphs, such as those described by Larry Niven in his "The Coldest Place":

Finally, we have the electromorphs -- beings having the form of electronic energy, fields or plasmas. These ethereal creatures, first described by the Russian space pioneer K. E. Tsiolkovsky⁴⁴⁵ and later given a more public airing in the Kubrick-Clarke masterpiece 2001: A Space Odyssey,¹⁹¹² are among the most beloved of science fiction writers. Hal Clement notes that "one must admit that very complex electric and magnetic field structures other than those supplied ready-formed by atoms and molecules are conceivable."⁸⁷⁸ One of the first science fiction novels the author ever read, decades ago, was about a form of intelligent ball lightning inhabiting the planet Mercury.*

Arthur Clarke has warned that we might not even be able to detect the presence of an alien species on a planet, save by the use of sophisticated electronic gadgetry. The lifeform could be gaseous, electronic, or could operate on timescales far faster or slower than our own.⁸¹ Hal Clement has fictionally created creatures constructed of densely packed electrons possessing quasi-solid properties and which live inside suns,²¹³⁹ and still others that inhabit neutron stars, existing in a kind of superoptic quantum space and feeding directly on patterns and structures of information.²¹⁸³

The classic electromorph of all time remains, however, astronomer Fred Hoyle’s Black Cloud -- a kind of intelligent comet.⁶² (Being a lifeform of the dimensions of a solar system, it is also a macromorph.) In the novel, a great patch of ionized gas, which enters our solar system and engulfs Sol, is found to be alive when efforts to predict its movements using the simple laws of mechanics fail. Says the astronomer-protagonist in The Black Cloud: "All our mistakes have a certain hallmark about them. They’re just the sort of mistake that it’d be natural to make if instead of the Cloud being inanimate, it were alive."

It turns out that the biochemistry of this amazing organism is plasma physics instead of molecular chemistry. Memory and intelligence are stored on a conductive substrate of various solid materials, and are controlled, operated and manipulated purely by means of electromagnetic forces. Ionized gases carry substances to wherever they are needed, like a bloodstream. The Cloud must therefore be recognized as alive, at least in the sense of possessing intricate structures, a capacity for regeneration and energy utilization, and a complex behavior.

* I have since forgotten the title, which annoys me greatly. (Note added, 2 Jan 2011: Erik van Lhin (aka. Lester del Rey), Battle on Mercury, The John C. Winston Company, Philadelphia PA, 1953.)