In 1950 radiation at radio frequencies originating in M 31, the big spiral galaxy in Andromeda, was detected at the Jodrell Bank Observatory by Hanbury Brown and Hazard. This, the first observation of radio emission from a definitely identified extragalactic source, was an interesting and important event in itself, but it had a far greater significance that was not realized at the time, for it was the first step in a series of developments that have completely revolutionized the astronomy of the extra-galactic regions. Probably no sub-division of human knowledge has ever before had the experience of making so many surprising and dramatic discoveries in so short a time.
The radio emission from the Andromeda galaxy is very similar to that which originates within our own galaxy, and it raised no new issues of a major character, but in 1951 a very much stronger radio source, Cygnus A, was identified with a faint galaxy which, as nearly as can be determined, is about 700 million light-years distant, more than 300 times as far away as the Andromeda spiral. In order to transmit so much energy over such a stupendous distance the source must be enormously powerful, and the astronomical community thus came face to face with the first of the bafHing new problems: How could such an enormous amount of energy be generated?
The situation as it stood in 1960 was summed up by Steinberg and Lequeux in these words: The problem posed by the existence of these radio galaxies is one of the most mysterious in the universe. . . . At the present time, according to all appearances, we Iack even the most elementary foundations for constructing a theory of extragalactic radio sources.1
The next ten years after the identification of the first radio galaxy saw a gradual improvement of radio astronomy equipment and techniques, and this, in turn, resulted in a relatively rapid increase in the supply of information from observation. Thousands of discrete radio sources were detected and located with a constantly increasing precision. Optical identification of these sources is a difficult undertaking and proceeded more slowly, but both the number and the accuracy of these identifications grew steadily. A particularly significant finding during this period was that a very substantial number of the radio galaxies have two centers of radio emission located on opposite sides of the galaxy. This suggested the possibility of explosive ejection, and in 1962 A. R. Sandage of Palomar and C. R. Lynds at Lick Observatory were able to secure optical evidence of an explosion that had apparently taken place some two million years ago in the galaxy M 82.
Here was a most
spectacular discovery: an event millions, perhaps billions, of times more
energetic than anything ever before detected anywhere in the universe.
But this did not solve the problem of the radio galaxies; it merely deepened
the mystery. Even at this early stage of inquiry we find that radical
new ideas are needed to account for the enormous energies involved in
these events, reported Sandage, and he ivent on to say, It
is obvious that conventional energy sources are not adequate to explain
the phenomenon we are observing, and some totally new energy principle
may have to be devised.2
Again a big step forward has been taken in the observational field and a significant addition to astronomical knowledge has been made, but once more the mystery has only deepened. The existence of these QSS, quasi-stellar sources, or quasars, has not explained the galactic explosions or the radio galaxies. On the contrary, it has merely added another dimension to the mystery; it has supplied a new set of unexplained and seemingly inexplicable facts. This 1963 statement by Jesse Greenstein may still be regarded as the current assessment of the situation:
In any event, we have encountered a most baffling group of astronomical objects. Whether fundamental new processes lie behind their brilliant but ephemeral appearance, or whether our imaginations are still too limited, remains for the future to determine.3
But there was actually no need to leave this determination to the future. During all of the time that these spectacular advances in observational knowledge were being made by the astronomers without any semblance of a theoretical understanding of the phenomena they were observing, a logical and consistent theory of these phenomena was available, having been developed in total isolation from the men in the observatories, entirely independent, and generally far in advance, of the observational discoveries. As early as 1959, long before the first observations of an exploding galaxy were made at Palomar, the first book in this present series advanced a new explanation of the structure of matter, and showed that on this basis the atoms of matter were subject to certain limits, the attainment of which would cause the atomic mass to revert to kinetic energy. One of these limits, it was demonstrated, is reached in the interiors of the oldest and largest galaxies, hence at a certain stage of its existence a substantial portion of the mass of such a galaxy is transformed into energy, giving rise to exactly the kind of a phenomenon observed by the astronomers.
A further development of the theory revealed that the explosions of this nature would necessarily be accompanied by radiation of substantial amounts of energy at radio wavelengths, and the 1959 publication predicted that radio astranomy would be the most probable avenue through which these exploding galaxies would be located. The general characteristics of the explosion products were also predicted, with special emphasis on the point that these products would be of two distinct kinds, one quite normal in the material environment and the other highly abnormal.
At that time it did not seem advisable to extend the study of these unknown phenomena into any great detail, inasmuch as this was only one relatively small portion of the total field that was being covered by the investigation. Thus the preliminary results did not by any means exhaust the potentialities of the new theoretical approach to this explosion phenomenon, and now that the predictions have become observed realities, the same theory that foresaw the existence of these phenomena is available to explain the observations and to clear up the details and relations that are the occasion for the frequent use of the term mystery. On the basis of this new system of theory, the quasars are not freaks or incidental phenomena; they are directly in the main line of the cyclical process that constitutes the fundamental action of the universe, and both their existence and their properties can be derived theoretically from nothing more than the postulated properties of space and time.
There is, of course, a general reluctance to accept any such farreaching revision of scientific thought as that required by this theory. As the quotations in the earlier paragraphs indicate, the astronomers have recognized that some drastic modifications of existing ideas will probably be necessary, some radical new ideas or fundamental new processes, and the physicists, who have as their field of endeavor the basic principles of those phenomena that the astronomers observe on the grand scale, are no less candid concerning the status of those basic principles. There will have to be some new development, says P. A. M. Dirac, that is quite unexpected, that we cannot even make a guess about.4 But the individual who is quite willing to accept the necessity of radical new ideas as an abstract proposition, and even to proclaim their inevitability, usually takes a very different attitude toward any concrete new ideas. The abstract concept of a change in fundamental thinking is quite innocuous. The individual scientist can cheerfully accept the prospect of such a change, secure in his confidence that his own cherished ideas are so firmly grounded that they will not be affected. But any concrete proposal for a change in fundamentals necessarily comes in conflict with some of these strongly held beliefs, and it consequently meets immediate hostility.
The attitude of the astronomers toward the new structure of theory that is here being discussed is no exception to this rule. This theory is the equivalent, from the astronomical standpoint, of a new instrument of exceptional power and versatility; that is, it produces a detailed picture of the astronomical universe from purely theoretical sources, completely independent of any information derived from observations, and it should be particularly welcome because it is not subject to the inherent limitations of physical instruments. But the more powerful the instrument the more errors it finds in currently accepted beliefs, and astronomers, like other members of the human race, dislike changes in long-standing patterns of thought. While they talk bravely of radical new ideas they do not actually want anything of the kind. What they want is some sort of a magic formula that will solve their problems and explain the galactic explosions, the radio galaxies, the quasars, etc., without having any radical effect on anything else, without affecting current astronomical thought in other areas. They are not favorably disposed toward any solution of those problems which, like the one that will be described herein, involves major changes in the theoretical outlook elsewhere in astronomy: in the processes of energy generation in the stars, the course of stellar evolution, the process af formation of galaxies, etc. So the gap has remained; on the one side a series of problems without answers; on the other side the answers to the problems, but no means of getting them into service.
After more than a decade, a break, or at least a crack, in the wall separating these problems from their answers has finally occurred. It is difficult to find a qualitative test that will decide between existing theory and a challenger, or between any two theories, because it is nearly always possible to make further assumptions that will sidestep any qualitative difficulties that a theory may encounter. For this reason, a final decision is not ordinarily possible until some conclusive quantitative information becomes available. The event that has stimulated the preparation of this present volume is the appearance of some new information of the necessary character. Studies by Halton Arp of the Mount Wilson and Palomar Observatories have disclosed that some of the quasars are apparently associated with peculiar galaxies that show evidence of having been subject to violent processes of some kind, explosions such as those previously mentioned, or other events involving the release of huge amounts of energy. Arp finds that in many cases a pair of radio sources, generally radio galaxies or quasars, are lacated on opposite sides of one of these peculiar galaxies and approximately in line. His conclusion is that the two radio sources have been ejected from the exploding galaxy at some earlier time and have moved out to their present locations in the interim.
Here we have an opportunity to apply the new theoretical system to an aspect of the quasar situation that is complex enough to require a full scale theoretical treatment. There is wide latitude for the constructon of ad hoc theories of the quasars alone, or the radio galaxies by themselves, or the galactic explosions as isolated phenomena, and a fantastic assortment of super-stars, quarks, and the like, has emerged from the theorists speculations. But the more we find out about a subject the less room there is for speculation. As Harlow Shapley remarked about theories of the origin of the universe,
Facts have been the No. 1 enemy of cosmogonic theories. If we did not know sa much, we would have less to explain.5
Specific mathematical relations are particularly effective in restraining the theorists flights of fantasy, and if Arps conclusions are correct some mathematical consequences necessarily follow that are incompatible with all existing ideas as to the nature of the quasars, while they are in full agreement with the values calculated on the basis of the new system of theory. Inasmuch as this theory also produces a complete qualitative explanation of the quasars and associated phenomena-the galactic explosions, the supernovae, the white dwarfs, the pulsars, etc: it would seem that the time has come to brush away the theoretical cobwebs and take a fresh view of the universe in which we live.
Although the primary objective of the presentation in this volume is to demonstrate that the new structure of theory herein outlined produces a full qualitative explanation of the existence and properties of the quasars, and is in complete agreement with the quantitative results obtained from an analysis of Dr. Arps findings, results that are inexplicable on the basis of current quasar theories, the theoretical development will, as just mentioned, have a significant bearing on a number of additional phenomena that are to some degree associated with the quasars. Inasmuch as one of these associates is equally as mysterious, to the astronomers, as the quasars, and even more recently arrived on the scene, it will be appropriate to consider the information that can be derived from the theory with respect to this new arrival, the pulsar, and to compare the theoretical conclusions with the rather meager amount of observational data thus far accumulated.
The first of the objects naw known as pulsars was discovered in 1967 by a group of astronomers at Cambridge who were undertaking a special survey of the quasars. The pulsars emit radiation at radio wavelengths, which explains why they were found unexpectedly in a quasar survey, and their special characteristic is that most of the radiation is received in the form of regular pulses. Each pulsar has its own pulse interval, which is subject to some occasional short term variations and a gradual lengthening with time, but otherwise is surprisingly constant. The longest interval thus far measured is 3.5 seconds and the shortest .033 second, the latter being the measurement abtained for the pulsar NP 0532, which is located in the center of the Crab Nebula, a point that has an important theoretical significance, as we will see when we undertake a theoretical examination of the pulsars later in the work. A pulse of approximately the same period has been found in both the optical and the x-ray radiation from a star that has been identified with NP 0532.
Like the quasars, the pulsars simply do not fit into the existing structure of astronomical theory, and the workers in the field find it hard even to speculate about these objects without invoking fantastic concepts such as neutron stars or gravitational collapse , purely ad hoc constructions that are essentially equivalent, in all but the language in which they are expressed, to the spirits and demons of the pre-scientific age. The status of the attempts to account for the observed properties of the pulsars on the basis of current astronomical thought was summed up by H. Chiu of the Goddard Space Flight Center at a symposium on the Crab Nebula in June 1969 in these words:
The nature of the pulsars is perhaps one of the most perplexing astrophysical problems of this centurya.6