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Dewey B. Larson
755 N.E. Royal Court Portland, Oregon 97232 |
Aug. 30, 1961
Dr. Martin Harwit
Center for Radiophysics and Space Research
Phillips Hall
Cornell University
Ithaca, N. Y.
Dear Dr. Harwit:
In reply to your letter of Aug. 23, I am, of course, aware that those of your colleagues who have attempted to calculate the rate of inflow of matter into the existing galaxies as a guide to estimating the amount of material available for formation of new galaxies have been unable to find anywhere near enough to “support adequate rates of galaxy formation.” As I see it, however, they have arrived at this conclusion only because they are carefully counting the minnows but overlooking the whales: the globular clusters.
If we direct our attention solely to the facts as revealed by observation and measurement, and for the moment lay aside theories, speculations and inferences, it is practically obvious that the globular clusters are being drawn in from the surrounding space by the galactic gravitational forces and are simply falling into the galaxies. In our own galaxy we can see them coming in; that is, we can measure their velocity of approach. As Otto Struve puts it, they “move much as freely falling bodies attracted by the galactic center.” The other observed characteristics, their nearly spherical distribution around the galactic center and their lack of participation in the galactic rotation, corroborate the conclusion that this is just exactly what they are.
Furthermore, the existence of numerous galactic clusters in spite of the evidence which shows that these aggregations can have only a relatively short life indicates that a regular process of replenishment is operative, and the existence of intermediate structures such as M 67 with many of the globular cluster characteristics just where the remnants of newly arrived globular clusters ought to be found, high above the galactic plane, supports the natural and logical conclusion that the break-up of globular clusters which fall into the galaxy is the source of supply.
We cannot observe the situation in as much detail in other galaxies, but it is clear that the number of associated globular clusters is a function of the size of the galaxy, just as it should be if the foregoing explanation is correct, since the larger galaxies exert greater gravitational forces over a greater volume of space. This relation between size of galaxy and number of clusters is maintained all the way from the two or three clusters which can be seen in a small galaxy such as the one in Fornax to the thousand or so that surround M 87. Observational verification of the presence of the clusters in inter-galactic space that are required in order to maintain the circumgalactic concentrations is obviously a difficult matter, but even so a substantial number of such clusters have been located, some of which are as much as a half million light years away.
If we calculate the rate at which the clusters are currently adding mass to the Galaxy this should give us the rate at which the clusters are being produced within the region under the gravitational control of the Galaxy, and we can then compare this figure with the volume expansion to determine whether or not the new mass is being produced at an “adequate rate.” Since many of the quantities which enter into such a calculation are uncertain by a factor of two or three, we cannot expect any high degree of accuracy, but we can at least show that the rate of formation of clusters is somewhere within the required range.
There are approximately 200 globular clusters surrounding the Galaxy, after making some allowances for those which cannot be seen for one reason or another (estimate by H. S. Hogg). According to Hugh Johnson a lower limit for the mass is 400,000 solar masses. The work of Lohmann also indicates that there is a substantial loss in mass as the cluster approaches the Galaxy (he finds a 30 percent differences between 25,000 and 10,000 parsecs) and since the entire original mass will be captured, an estimate of 500,000 solar masses per original cluster is reasonable. The total mass of the 200 clusters is then 100 million solar masses.
Struve estimates the “period” of M 13 on a rectilinear basis as 70 million years. If we extend this to 200 million years for the average cluster, the equivalent time to fall into the Galaxy is one-quarter of this figure, or 50 million years. We thus have a capture of 100 million solar masses in 50 million years, a rate of 2 x 109 solar masses per 1000 million years.
The amount of capture of diffuse material is probably not significant, but in addition to the observed clusters there are undoubtedly many captures of re-clusters, dust and gas clouds which have not had time to condense into stars (the amount of dust and gas now existing in the Galaxy supports this conclusion) and the equivalent of a very large number of clusters is added whenever a small galaxy is swallowed. The Magellanic Clouds, for instance, will bring in something on the order of 2 x 10 solar masses in the relatively near future, the equivalent of the normal captures for 1000 million years. A reasonable estimate of the effect of these two types of additions is that they increase the normal rate by fifty percent, which brings the total inflow of mass up to 3 x 109 solar masses per 1000 million years.
There is considerable question as to the size of the region from which the Galaxy draws its clusters, but it is logical to assume that over the period of time during which the existing clusters have been drawn in (a period in which the average mass of the Galaxy was considerably less than it is now) the radius of this region has been somewhere in the neighborhood of half of the distance to M 31. (I have some theoretical confirmation of this estimate, but for the moment I would like to look at the situation purely from the standpoint of the information available from observation.) Let us then take the radius of the region under the gravitational control of the Galaxy as 375,000 parsecs.
I t has been estimated that the average distance between “bright” galaxies is 750,000 parsecs. An average galaxy of this kind will have about 1010 solar masses. The currently accepted values of Hubble’s constant indicate that from 4000 million to 8000 million years are required to duplicate the existing volume of space, and if we take .an intermediate figure this means that the volume will expand one-sixth in 1000 million years. Since all matter that is produced will ultimately be gathered into one of the major galaxies a rate of production sufficient to provide 1/6 of an average large galaxy per 1000 million years in each spherical region of 375,000 parsecs radius will maintain the existing density, and we can ignore any fluctuations in the dispersed matter and the smaller galaxies. It will be necessary, therefore, to produce 1.7 x 109 solar masses per 1000 million years in each region of this size.
We have just calculated that the current inflow of matter into the Galaxy from a spherical region of approximately the same 375,000 parsecs radius (which is equivalent to the rate at which matter is being produced in this region) is somewhere in the neighborhood of 3 x 109 solar masses per 1000 million years. Within the range of accuracy of the calculations, these results are in agreement.
All of the foregoing has been based entirely on available astronomical information, without regard to my own theoretical findings, and it is therefore equally consistent with any other theory of the steady-state type. It is irreconcilable with the various evolutionary types of cosmological theory, of course, but I have deliberately avoided any reference to any theoretical support for these conclusions in order to emphasize the point that the conflict with evolutionary theories is not a conflict between theories; it is a conflict between the evolutionary ideas and what I consider the only reasonable and logical interpretation of the observed facts.
I realize that this is not the accepted interpretation of these facts, but when we have a group of objects surrounding the Galaxy which “move as freely falling bodies attracted by the galactic center,” and which are distributed spherically about that center as such objects would be if they were drawn in from a substantially uniform concentration in the surrounding space, and which are obviously foreigners, since they do not participate in the rotational motion of the Galaxy, I believe that any reasonably realistic appraisal of the situation must lead to the same conclusion which I have reached. Furthermore, it is generally conceded that the stars must have been formed by the condensation of cool and diffuse clouds of dust and gas. It therefore follows that a very young star will be relatively cool and very diffuse; from which the natural and logical conclusion is that the stars which exhibit these characteristics, the red giants and their infrared precursors, are young and the stars farthest removed from these conditions, the hot massive stars, white dwarfs, etc., are old. On this basis the stars of the globular clusters are young just as they must be if the clusters are the raw material from which the galaxies are formed.
This simple and natural view of the situation is rejected in present-day astronomical thinking simply because the currently popular assumption as to the source of stellar energy requires the hot massive stars to be relatively young. To an outsider such as myself it seems almost incredible that the astronomical profession would disregard the findings of its own work and base the whole structure of astronomical and cosmological theory on a pure assumption imported from another branch of science, particularly when it is so widely recognized that this leads to serious contradictions. “It is no small matter,” says Bok, “to regard as proved the conclusion that some of our most conspicuous supergiants, like Rigel, were formed so very recently.” Struve refers to certain observational results as “apparent defiance of modern evolutionary theory.” Practically everyone admits that the presence of white dwarfs in some of the supposedly young galactic clusters is inexplicable. And so on. The chaotic state of thinking with respect to stellar ages since Sandage and others have come up with twenty billion year estimates is a vivid illustration of what this curiously unquestioning faith in a pure hypothesis can lead to.
There is no shred. of factual evidence that the popular hydrogen to helium conversion process is actually operative in the stars or that the condensation of the stable H1 isotope to form helium is a naturally occurring process anywhere. It can be made to take place on a single atom basis under certain conditions, to be sure, but the initial steps in this reaction involve combination of stable isotopes to form unstable isotopes and combination of smaller units to form larger units, both of which are directly opposite to the normal probabilities at extremely high temperatures. The rejection of observed facts in order to conform to this purely hypothetical energy generation process certainly cannot be justified from a scientific standpoint. It is an extreme example of the results of the characteristic human reluctance to admit ignorance, which causes us to advance our best guess in the guise of an established fact and to say “we know” when we should say “we think.”
If my work does nothing else in the lon run, it will at least accomplish a worth-while purpose in calling attention to such weaknesses in present-day theory. This is probably what Dr. Fracostoro of the Catania Astrophysical Observatory had in mind when he concluded a review of my book in the journal “Scientia” with the statement: “The work furnishes a useful exercise for those who wish to review objectively their scientific ideas and beliefs.”
Sincerely yours,
D. B. Larson