© 1975-1979, 2008 Robert A. Freitas Jr. All Rights Reserved.

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

17.1  Communication vs. Transportation

Many scientists who might admit the possibility of starflight nevertheless question it on grounds of necessity. Why, they ask, should we or any other sentient race go to the trouble of transporting massive material structures from star to star when information about extraterrestrial intelligences can be gained much more cheaply by listening with radio waves? Indeed, notes Purcell, "a 10-word telegram can be transmitted over a 12 light-year path with a dollar’s worth of electrical energy."

And ET communications might not be limited to the speed of light, either. It is well-known that the equations of Special Relativity (and other theories too*) yield solutions for particles that go faster than light. These hypothetical particles, called "tachyons," have rest masses represented by "imaginary" numbers. Since no one could see how objects with "imaginary mass" could possibly exist, the solutions were long ignored.

Then, in 1962, Drs. O.M.P. Bilaniuk, V.K. Deshpande, and E.C.G. Sudarshan of the University of Rochester in New York reexamined the entire question. In their seminal paper "Meta-Relativity" they pointed out that if tachyons were always in motion, and at speeds perpetually faster than light, it wouldn’t matter what kind of number represented the mass. What really mattered was that tachyonic energy and momentum be "real" -- which they are. According to the three physicists:

In classical mechanics the mass is a parameter which cannot be measured directly even for slow particles. Only energy and momentum, by virtue of their conservation in interactions, are measurable, therefore must be real. Thus the imaginary result for the rest mass of the {tachyon} offends only the traditional way of thinking, and not observable physics.¹⁵¹⁵

In recent times scientists have managed partially to resolve many of the apparent causality violations engendered by faster-than-light tachyons. (See especially Antippa and Everett,^1495,1477 Bilaniuk and Sudarshan,^1516,1517 Feinberg,¹⁴⁹² Harwit,¹⁴⁷⁸ Newton,⁶⁴⁵ Parmentola and Yee)¹⁴⁹³ Recami and Mignani,¹⁵¹¹ and Trefil.²⁰²⁶) Several experimentalists are now quietly searching for the controversial and elusive particles in what one describes as "a low key effort."⁶⁴⁶

Confirmation of the existence of tachyons would have dramatic implications in the field of interstellar communications. Normal matter as we know it, when propulsive energy is applied, goes faster. Tachyons, in contrast, are expected to speed up as they lose energy. At zero energy they should have infinite velocity, and be present everywhere (along a Great Circle route) in the physical universe at the same time. (This is called a "transcendental tachyon.") If tachyons exist, information could be transmitted between stars and even galaxies arbitrarily fast. Any location in the cosmos could remain in direct communicative contact with any other. With such a perfect means of communication, extraterrestrial races need never leave home and venture out into space.

Conversely, let us imagine a civilization with perfect, instantaneous transportation. Any location in the physical universe can be reached in the blink of an eye. In such a society there may be no need for communications at all -- it’s quicker just to travel. We see that there is a kind of complementary relationship between travel and communications: The better either is, the less is the need for the other.⁸¹

There is, however, one very critical difference. A single party may engage in travel, but it takes two parties to communicate. If alien societies are to talk, both communicants and recipients must exist. Yet either can launch an interstellar exploratory mission without any knowledge of the other. Furthermore, if extraterrestrial cultures are to communicate, each must make a series of correct assumptions about the motivations, psychologies, and technologies of the others in order to be successful. Interstellar exploration by starship, on the other hand, requires no such ad hoc assumptions to succeed.

There are many other reasons why xenologists have concluded that interstellar travel is the preferred mode for first contact and galactic unification. Communication by radio does not permit contact between an advanced society and one that is intelligent but is not in possession of electronic technology. Such a culture need not necessarily be "unlikely to be of interest to us" as asserted by some radioastronomers. Aliens without radio may have other forms of technology -- biological, chemical, social, economic -- that would be fascinating to observe and yet do not involve electromagnetic radiation. As Arthur C. Clarke says, only starflight makes it possible "to gain knowledge of star systems which lack garrulous, radio-equipped inhabitants."²⁷³¹

Interstellar travel also would allow the exchange of artifacts and biological specimens, direct observation of a multitude of independent biologies and societies, and the making of symbolic gestures of sociopolitical and cultural community. The sciences of astronomy and astrophysics would prosper. Direct astronomical samplings of stars in various stages of evolution, distant planetary systems, ancient globular clusters, and interstellar gas clouds could be made. Cooperative scientific ventures could be undertaken with other races, such as performing trigonometric parallax experiments on extremely distant objects. And direct contact is probably the most effective way to achieve a meeting of minds between beings with utterly different histories and ways of thought.¹³¹⁷

* In one mathematical model of particle motion in a special five-dimensional space-time, velocities as high as 10²¹ times the speed of light appear possible.²⁸⁹³

Last updated on 6 December 2008