fi = the number of planets which are populated by intelligences with their own ability to act during the lifetime of their sun.
fc = the number of planets inhabited by intelligences that already have a developed technical civilisation.
L = the life-span of a civilisation, for only civilisations that were very long lasting could encounter each other given the vast distances in the universe.
If we take the lowest possible figures for all terms in this formula, we get:
N = 40.
But if we take the admissible maximum value, we get:
N = 50,000,000.
In other words, in the most unfavourable case the fantastic Green Bank Formula calculates that there are forty groups of intelligences in our Milky Way who are seeking contact with other intelligences.
The most audacious possibility gives 50 million unknown intelligences who are waiting for a sign from the cosmos.
All the Green Bank calculations are based not on present astronomical figures, but on the number of stars in our Milky Way since it existed.
If we accept the formula of this scientific brains trust, civilisations with more advanced technologies than ours may have existed hundreds of thousands of years ago—a fact that supports the theory put forward here of visits by 'gods' from the cosmos in the dawn of time. The American astrobiologist Dr Sagan assures us that according to statistical calculations alone the possibility exists that our earth may have been visited by representatives of an extra-terrestrial civilisation at least once in the course of its history. Fantasy and wishful thinking may be concealed in all the deliberations and suppositions, but the Green Bank Formula is a mathematical formula and enables us to determine the number of stars on which life is possible.
A new branch of science is in the process of formation— what is known as exobiology. New branches of science always find it difficult to achieve recognition. Exobiology would certainly find it harder to find acceptance if recognised personalities were not already devoting their work to this new field of research which tackles extraterrestrial life with complete impartiality. What better proof of the seriousness of this new science than a group of the names which subscribe to it:
Dr Freeman Quimby (Chief of the NASA exobiological programme), Dr La Blei (NASA), Dr Joshua Lederberg (NASA), Dr L. P. Smith (NASA), Dr R. E. Kaj (NASA), Dr Richard Young (NASA), Dr H. S. Brown (California Institute of Technology), Dr Edward Purcell (Professor of Physics at Harvard University), Dr R. N. Bracewells (Radio Astronomy Institute, Standford), Dr Townes (Nobel Prizewinner for Physics, 1964), Dr I. S. Shklovsky (Sternberg Institute, Moscow), Dr N. S. Kardashev (Sternberg Institute, Moscow, Sir Bernard Lovell (Jodrell Bank), Dr Wernher von Braun (Head of the USA Saturn Rocket Programme), Professor Dr Oberth, von Braun's teacher, Professor Dr Stuhlinger, Professor Dr E. Sanger and many others.
These names arc representative of many thousands of exobiologists all over the world. The desire of all these men is to break through the taboos, to tear down the walls of lethargy which until now have always surrounded the desert areas of research which are specifically singled out in this book. In the face of all the opposition exobiology exists and one day it may become the most interesting and important field of research.
But how can a proof of life in the universe be produced until someone has been there? There are statistics and calculations that definitely favour the idea of extraterrestrial life. There is the evidence of bacteria and spores in space. The search for unknown intelligences has begun, but has not yet produced results that are measurable, demonstrable and convincing. What we need are verifications of theories —are proofs of suppositions still disqualified as Utopian today. The NASA has a research programme ready that is intended to produce evidence of unknown life in the cosmos. Eight different probes, each one as unique as it is complicated, are to show evidence of life on planets in our solar system.
The following are the probes planned:
Optical Rotary Dispersion Profiles
The Multivator
The Vidicon Microscope
The J-Band Life Detector
The Radio isotope Biochemical Probe
The Mass Spectrometer
The Wolf Trap
The Ultraviolet Spectrophotometer.
A few hints as to what is hidden behind these technical tides that are double-dutch to the layman:
'Optical Rotary Dispersion Profiles' is the name of a laboratory probe with a rotary search light. Once landed on a planet, this light begins to emit beams and search for molecules. Molecules are well-known prerequisites for every kind of life. Once of these molecules is the large spiral-shaped DNS molecule, which consists of three chemical combinations arranged next to each other: a nitrogenous organic alkali, sugar and phosphoric acid. When polarised light strikes a sugar molecule, the search beam is interrupted, because the nitrogenous alkali adenin in chemical association with sugar has an 'optically active' effect. Since the sugar combination in the DNS molecule is 'optically active', the search beam of the probe has only to encounter a sugar-adenin combination to produce an immediate signal that, automatically sent to earth, would provide proof of life on an unknown planet.
The 'Multivator' consists of a probe weighing barely 1 lb which is carried by a rocket as light baggage and ejected when near the planet. This miniature laboratory is then in a position to conduct as many as fifteen different experiments and transmit their results to earth.
The 'Radio Isotope Biochemical Probe' is the official name of a probe developed under the nickname 'Gulliver'. It is intended to carry out a soft landing on the surface of another planet and immediately afterwards to shoot out three 45-ft-long sticky ropes in various directions. In a few minutes these ropes will be automatically withdrawn into the probe; whatever stays clinging to the ropes—dust, microbes or any kind of biochemical substances—will be immersed in a liquid culture medium. A part of this culture solution is enriched with the radioactive carbon isotope C 14; the micro-organisms introduced would logically have to produce carbon dioxide, C02, through their metabolism. The gas carbon dioxide can easily be separated from the liquid culture and led to a measuring apparatus which measures the radioactivity of the gas containing C 14 nuclei and radios the results to earth.
I should like to describe one more apparatus which the NASA has developed for the search for extraterrestrial