astronomers-from-the-netherlands

"Entirely different is the organization of common production by means of workers' councils. Social production is not divided up into a number of separate enterprises each the restricted life-task of one person or group; now it forms one connected entirety, object of care for the entirety of workers, occupying their minds as the common task of all. The general regulation is not an accessory matter, left to a small group of specialists; it is the principal matter, demanding the attention of all in conjunction. There is no separation between politics and economy as life activities of a body of specialists and of the bulk of producers. For the one community of producers politics and economy have now coalesced into the unity of general regulation and practical productive labor. Their entirety is the essential object for all."

"Economic and spiritual power are made an active power through organization. It binds all the different wills to unity of purpose and combines the single forces into a mighty unity of action. Its outer forms may differ and change as to circumstances, its essence is its new moral character, the solidarity, the strong community-feeling, the devotion and spirit of sacrifice, the self-imposed discipline. Organization is the life principle of the working class, the condition of liberation. A minority ruling by its strong organization can be vanquished only, and certainly will be vanquished, by organization of the majority."

"Collaboration of equal companions replaces the command of masters and the obedience of servants. The sense of duty, the devotion to the community, the praise or blame of the comrades according to efforts and achievements, as incentives take the place of fear for hunger and perpetual risk of losing the job. Instead of the passive utensils and victims of capital, the workers are now the self-reliant masters and organizers of production, exalted by the proud feeling of being active co-operators in the rise of a new humanity."

"The consolidation of State capitalism in Russia itself was the determining basis for the character of the Communist Party. Whilst in its foreign propaganda it continued to speak of communism and world revolution, decried capitalism, called upon the workers to join in the fight for freedom, the workers in Russia were a subjected and exploited class, living mostly in miserable working conditions, under a strong and oppressive dictatorial rule, without freedom of speech, of press, of association, more strongly enslaved than their brethren under Western capitalism. Thus an inherent falsehood must pervade politics and teachings of that party. ... The doctrine it taught under the name of Marxism was not the theory of the overthrow of highly developed capitalism by a highly developed working class, but its caricature. ... The Communist Party did not intend to make the workers independent fighters capable by their force of insight themselves to build their new world, but to make them obedient followers ready to put the party into power."

"In the present time production is dominated by capital. The capitalist, possessor of money, founded the factory, bought the machines and the raw materials, hires the workers and makes them produce goods that can be sold."

"As an instrument of fight for the working class against capital the trade unions are losing their importance. But the fight itself cannot cease. The depressing tendencies grow stronger under big capitalism and so the resistance of the workers must grow stronger, too. Economic crises grow more and more destructive and undermine apparently secured progress. The exploitation is intensified to retard the lowering of the profit rate for the rapidly increasing capital. So again and again the workers are provoked to resistance. But against the strongly increased power of capital the old methods of fight no longer can serve. New methods are needed, and before long their beginnings present themselves. They spring up spontaneously in the wild [outlaw] strike, in the direct action."

"Labor is a social process. Each enterprise is part of the productive body of society. The total social production is formed by their connection and collaboration. Like the cells that constitute a living organism, they cannot exist isolated and cut off from the body. So the organization of the work inside the shop is only one-half of the task of the workers. Over it, a still more important task, stands the joining of the separate enterprises, their combination into a social organization."

"Public ownership is a middle-class program of a modernized and disguised form of capitalism. Common ownership by the producers can be the only goal of the working class."

"Under the new circumstances discontent is universal; all the workers feel depressed under capitalist superiority; fuel for explosions has accumulated everywhere. It is not for others, it is for themselves if they join the fight. As long as they feel isolated, afraid to lose their job, uncertain what the comrades will do, without firm unity, they shrink from action. Once, however, they take up the fight, they are changed into new personalities; selfish fear recedes to the background and forth spring the forces of community, solidarity and devotion, rousing courage and perseverance. These are contagious; the example of fighting activity rouses in others, who feel in themselves the same forces awakening, the spirit of mutual and of self-confidence. Thus the wild strike as a prairie fire may spring over to other enterprises and involve ever greater masses."

"So the light darkened that had illuminated the world; the masses that had hailed it were left in blacker night, either in discouragement turning away from the fight, or struggling along to find new and better ways. The Russian revolution first had given a mighty impulse to the fight of the working class, by its mass direct actions and by its new council forms of organization—this was expressed in the widespread rise of the communist movement all over the world. But when then the revolution settled into a new order, a new class rule, a new form of government, State capitalism under dictatorship of a new exploiting class, the Communist Party needs must assume an ambiguous character. Thus in the course of ensuing events it became most ruinous to the working class fight, that can only live and grow in the purity of clear thought, plain deeds and fair dealings. By its idle talk of world revolution it hampered the badly needed new orientation of means and aims. By fostering and teaching under the name of discipline the vice of submissiveness, the chief vice the workers must shake off, by suppressing each trace of independent critical thought, it prevented the growth of any real power of the working class. By usurping the name communism for its system of workers' exploitation and its policy of often cruel persecution of adversaries, it made this name, till then expression of lofty ideals, a byword, an object of aversion and hatred even among workers. In Germany, where the political and economic crises had brought the class antagonisms to the highest pitch, it reduced the hard class fight to a puerile skirmish of armed youths against similar nationalist bands. And when then the tide of nationalism ran high and proved strongest, large parts of them, only educated to beat down their leaders' adversaries, simply changed colours. Thus the Communist Party by its theory and practice largely contributed to prepare the victory of fascism."

"In the production under common ownership the bookkeeping is a public matter; it lies open to all. The workers have always a complete view of the course of the whole process. Only in this way they are able to discuss matters in the sectional assemblies and in the shop-committees, and to decide on what has to be done. The numerical results are made visible, moreover, by statistical tables, by graphs and pictures that display the situation at a glance. This information is not restricted to the personnel of the shop; it is a public matter, open to all outsiders. Every shop is only a member in the social production, and also the connection of its doings with the work outside is expressed in the book-keeping. Thus insight in the production going on in every enterprise is a piece of common knowledge for all the producers."

"Owners are the shareholders, living outside the process of production, idling in distant countryhouse and maybe gambling at the exchange. A shareholder has no direct connection with the work. His property does not consist in tools of him to work; with his property consists simply in pieces of paper, in shares of enterprises of which he does not even know the hereabouts. His function in society is that of a parasite. His ownership does not mean that he commands and directs the machines; this is the sole right of the director. It means only that he may claim a certain amount of money without having to work for it. The property in hand, his shares, are certificates showing his right - guaranteed by law and government, by courts and police - to participate in the profits; titles of companionship in that large Society for Exploitation of the World, that is capitalism."

"Private ownership, originally a means to give everybody the possibility of productive work, now has turned into the means to prevent the workers from the free use of the instruments of production. Originally a means to ascertain to the workers the fruits of their labor, it now turned into a means to deprive the workers of the fruits of their labor for the benefit of a class of useless parasites."

"The Russian economic system is state capitalism, there called state-socialism or even communism, with production directed by a state bureaucracy under the leadership of the Communist Party. The state officials, forming the new ruling class, have the disposal over the product, hence over the surplus-value, whereas the workers receive wages only, thus forming an exploited class."

"The system of production developed in Russia is State socialism. It is organized production, with the State as universal employer, master of the entire production apparatus. The workers are master of the means of production no more than under Western capitalism. They receive their wages and are exploited by the State as the only mammoth capitalist. So the name State capitalism can be applied with precisely the same meaning. The entirety of the ruling and leading bureaucracy of officials is the actual owner of the factories, the possessing class."

"In the present and coming times, now the Europe is devastated and mankind is impoverished by world war, it impends upon the workers of the world to organize industry, in order to free themselves from want and exploitation."

"The capitalist is not driven by the desire to provide his fellow-men with the necessities of life; he is driven by the necessity of making money."

"The sense of right and wrong, the consciousness of justice in men, is not accidental . It grows up, irresistibly, by nature, out of what they experience as the fundamental conditions of their life. Society must live; so the relations of men must be regulated in such a way - it is this that law provides for - that the production of life-necessities may go on unimpeded. Right is what is essentially good and necessary for life. Not only useful for the moment, but needed generally good and necessary for life. Not only useful for the moment, but needed generally; not for the life. Not only useful for the moment, but needed generally; not for the life of single individuals, but for people at large, for the community; not for personal or temporal interests, but for the common and lasting weal. If the life-conditions change, if the system of production develops into new forms, the relations between men change, their feeling of what is right or new forms, the relations between men change, their feelings of what is right or wrong changes with them, and the law has to be altered."

"The Workers' Councils are the form of self-government which in the times to come will replace the forms of government of the old world. Of course not for all future; none such form is for eternity. When life and work in community are natural habit, when mankind entirely controls its own life, necessity gives way to freedom and the strict rules of justice established before dissolve into spontaneous behavior. Workers' councils are the form of organization during the transition period in which the working class is fighting for dominance, is destroying capitalism and is organizing social production. In order to know their true character it will be expedient to compare them with the existing forms of organization and government as fixed by custom as self-evident in the minds of the people."

"All who stand together in the shop, in the very same position, as direct associates, subject to the same exploitation, against the same master, stand together in common action. Their real community is the shop; personnel of the same enterprise, they form a natural union of common work, common lot and common interests. Like specters from the past the old distinctions of different membership fall back, almost forgotten in the new living reality of fellowship in common fight. The vivid consciousness of new unity enhances the enthusiasm and the feeling of power."

"Wars always were contests of similar competing powers, and the deepest structure of society remained the same, whether one won or the other. Contests of classes are fights for new principles, and the victory of the rising class transfers the society to a higher stage of development. Hence, compared with real war, the moral forces are of a superior kind: voluntary devoted collaboration instead of blind obedience, faith to ideals instead of fidelity to commanders, love for the class companions, for humanity, instead of patriotism. Their essential practice is not armed violence, not killing, but standing steadfast, enduring, persevering, persuading, organizing; their aim is not to smash the skulls but to open the brains. Sure, armed action will also play a role in the fight of the classes; the armed violence of the masters cannot be overcome in Tolstoian fashion like by patient suffering. It must be beaten down by force; but, by force animated by deep moral conviction."

"There exists also another type of galaxy agglomeration. These have diameters between roughly one and ten times those of large clusters, but have much smaller densitities; they are usually irregular, with patchy density variations and no central concentration. The larger and most conspicuous of these agglomerations may contain several clusters, which explains why they have been given the name "superclusters." In their longer dimensions, crossing times exceed the age of the Universe. They are thus unrelaxed. Unrelaxed appearance, together with large size, might be taken as a definition of superclusters."

"The distribution of galaxies is clumpy on all scales, ranging from binaries, triples, and multiples, through groups containing a few and a hundred galaxies, to rich clusters with thousands of members, masses up to 1015±1M☉, and diameters of the order of 10 Mpc. The latter have been discussed by Neta A. Bahcall in a preceding volume of this series. The clusters are at the end of the scale of the more or less regular structures in the Universe."

"Soon after he joined the Leiden faculty in 1926, Dr. Oort obtained the first direct observational evidence of the Milky Way's rotation. Through complex complex calculations, he measured the relative velocities of stars moving with the rotating galaxy and deduced their distances from the galactic center. In this way, he determined that the Sun and its planets were not even close to the galaxy's center but 30,000 light years away, in the galactic hinterland, traveling an orbit of that center that takes 300 million years to complete."

"From a score of well-observed original orbits it is shown that the "new" long-period comets generally come from regions between about 50000 and 150000 A.U. distance. The sun must be surrounded by a general cloud of comets with a radius of this order, containing about 1011 comets of observable size; the total mass of the cloud is estimated to be of the order of 1/10 to 1/100 of that of the earth. Through the actlllllllllthis cloud into the vicinity of the sun."

"The combined effects of the stars and of Jupiter appear to determine the main statistical features of the orbits of comets."

"The article indicates how three facts concerning the long-period comets, which hitherto were not well understood, namely the random distribution of orbital planes and of perihelions, and the preponderance of nearly-parabolic orbits, may be considered as necessary consequences of the perturbations acting on the comets."

"In electromagnetism... the law of the inverse square had been supreme, but, as a consequence of the work of Faraday and Maxwell, it was superseded by the field. And the same change took place in the theory of gravitation. By and by the material particles, electrically charged bodies, and magnets which are the things that we actually observe come to be looked upon only as "singularities" in the field. So far this transformation from the force to the potential, from the action at a distance to the field, is only a purely mathematical operation."

"Gradually... during the second half of the nineteenth century, the uncomfortable feeling of dislike of the action at a distance, which had been so strong in Huygens and other contemporaries of Newton, but had subsided during the eighteenth century, began to emerge again, and gained strength rapidly. This was favoured by the purely mathematical transformation (which can be compared in a sense with that from the Ptolemaic to the Copernican system), replacing Newton's finite equations by the differential equations, the potential becoming the primary concept, instead of the force, which is only the gradient of the potential. These ideas, of course, arose first in the theory of electricity and magnetism or perhaps one should say in the brain of Faraday.<!--"

"If de Sitter's solution were valid everywhere, then it would be thereby shown that the purpose which I pursued with the introduction of the &lambda;-term has not been reached. In my opinion the general theory of relativity only forms a satisfactory system if according to it the physical qualities of space are completely determined by matter alone. Hence no g&mu;v-field must be possible, i.e., no space-time-continuum, without matter that generates it."

"Our own galaxy system is only one of a great many, and observations made from any of the others would show exactly the same thing: all systems are receding, not from any particular centre, but from each other: the whole system of galaxies is expanding."

"[Einstein's cosmological constant] is a name without any meaning. ...We have, in fact, not the slightest inkling of what it's real significance is. It is put in the equations in order to give the greatest possible degree of mathematical generality."

"Hubble, who knew nothing of the work of Friedmann and Lamaître, had read de Sitter, whose sometimes comic absentmindedness masked a supple and inventive mind. Stimulated by one of Einstein's papers on general relativity penned in 1916, de Sitter entered into a fruitful correspondence with its author and soon produced three lengthy papers of his own on the subject. In the third article, published in 1917, he simplified his calculations by assuming that the universe is devoid of matter, a mathematical fiction that he defended on the basis that the real universe is composed mostly of space anyway. He then conjectured that if two stationary objects were introduced into this void, light passing between them with respect to one another would be redshifted. Curiously, the redshift is not due to either the expansion of intergalactic space or the Doppler effect. Instead, it is the effect of the mysterious slowing down of time at great distances. ...the amount of reshift in de Sitter's model was directly proportional to the distance between the emitting and receiving objects, a relationship that had only to be tested by someone with a telescope powerful enough..."

"From 1916 Einstein and de Sitter corresponded extensively on exactly what kind of universe best fit the relativity equations. De Sitter initially developed a model of a spherical universe, in contrast to the cylindrical one Einstein had envisioned. De Sitter also tried to map out the shape of the spherical universe in absence of all matter. Einstein's reaction to de Sitter's model was strong and negative...de Sitter's sphere described a universe that changed in size instead of remaining nicely constant. ... Einstein saw matter—and its corresponding gravitational field—as what inherently created the shape of the universe. He cited what he dubbed "Mach's principle,"...the movements of any object ...were determined by all other bodies in the universe. ...how a body moves through space is tantamount to what shape space is, the concept of "shape" without matter, Einstein insisted, was meaningless."

"It was early 1932, when Einstein and I both were at the California Institute of Technology in Pasedena, and we just decided to look for a simple relativistic model that agreed reasonably well with the known observational data, namely, the Hubble recession rate and the mean density of matter in the universe. So we took the space curvature to be zero and also the cosmological constant and the pressure term to be zero, and then it follows straightforwardly that the density is proportional to the square of the Hubble constant. It gives a value for the density that is high, but not impossibly high. That's about all there was to it. It was not an important paper, although Einstein apparently thought that it was. He was pleased to have a simple model with no cosmological constant. That's it."

"There is no direct observational evidence for the curvature [of space], the only directly observed data being the mean density and the expansion, which latter proves that the actual universe corresponds to the non-statical case. It is therefore clear that from the direct data of observation we can derive neither the sign nor that value of the curvature, and the question arises whether it is possible to represent the observed facts without introducing the curvature at all. Historically the term containing the 'cosmological constant &lambda;' was introduced into the field equations in order to enable us to account theoretically for the existence of a finite mean density in a static universe. It now appears that in the dynamical case this end can be reached without the introduction of &lambda;."

"De Sitter's redshift phenomenon is not caused by the Doppler effect of stars moving away. It is a property of space-time, which appears when these are forced into the bitter conditions of the empty universe with the lambda-term. ...de Sitter was the first to suggest, in 1917 when galaxies were not yet known, that one should try to find a redshift-distance relation for very remote celestial bodies. ...Even Friedmann, who five years later demonstrated the possibility of an expanding universe, failed to point out the redshift phenomenon as a property of his own model."

"Both the law of inertia and the law of gravitation contain a numerical factor or a constant belonging to matter, which is called mass. We have thus two definitions of mass; one by the law of inertia: mass is the ratio between force and acceleration. We may call the mass thus defined the inertial or passive mass, as it is a measure of the resistance offered by matter to a force acting on it. The second is defined by the law of gravitation, and might be called the gravitational or active mass, being a measure of the force exerted by one material body on another. The fact that these two constants or coefficients are the same is, in Newton's system, to be considered as a most remarkable accidental coincidence and was decidedly felt as such by Newton himself. He made experiments to determine the equality of the two masses by swinging a pendulum, of which the bob was hollow and could be filled up with different materials. The force acting on the pendulum is proportional to its active mass, its inertia is proportional to its passive mass, so that the period will depend on the ratio of the passive and the active mass. Consequently the fact that the period of all these different pendulums was the same, proves that this ratio is a constant, and can be made equal to unity by a suitable choice of units, i.e., the inertial and the gravitational mass are the same. These experiments have been repeated in the nineteenth century by Bessel, and in our own times by Eötvös and Zeeman, and the identity of the inertial and the gravitational mass is one of the best ascertained empirical facts in physics-perhaps the best. It follows that the so-called fictitious forces introduced by a motion of the body of reference, such as a rotation, are indistinguishable from real forces. ...In Einstein's general theory of relativity there is also no formal theoretical difference, as there was in Newton's system. ...the equality of inertial and gravitational mass is no longer an accidental coincidence, but a necessity."

"In astronomy two characteristics are common to all data on which the solution of the great problems depends. The first is the extreme minuteness of the quantities to be measured. ...New epochs were inaugurated in the beginning of the seventeenth century by the invention of the telescope, and in the last third of the nineteenth by the discovery of photography and spectroscopy....The other characteristic is that astronomy always requires a very large number of data. ...These two characteristics of the data that the astronomer requires to build his science on make two things more necessary in astronomy than in any other science: patience and organised coöperation. ...The astronomer—each working at his own task...—is always conscious of belonging to a community, whose members, separated in space and time, nevertheless feel joined by a very real tie, almost of kinship. ...whatever his special work may be it is always a link in a chain, which derives its value from the fact that there is another link to the left and one to the right of it. It is the chain that is important, not the separate links."

"We know by actual observation only a comparatively small part of the whole universe. I will call this "our neighborhood." Even within the confines of this province our knowledge decreases very rapidly as we get away from our own particular position in space and time. It is only within the solar system that our empirical knowledge extends to the second order of small quantities (and that only for g44 and not for the other g&alpha;&beta;), the first order corresponding to about 10-8. How the g&alpha;&beta; outside our neighborhood are, we do not know, and how they are at infinity of space or time we shall never know. Infinity is not a physical but a mathematical concept, introduced to make our equations more symmetrical and elegant. From the physical point of view everything that is outside our neighborhood is pure extrapolation, and we are entirely free to make this extrapolation as we please to suit our philosophical or aesthetical predilections—or prejudices. It is true that some of these prejudices are so deeply rooted that we can hardly avoid believing them to be above any possible suspicion of doubt, but this belief is not founded on any physical basis. One of these convictions, on which extrapolation is naturally based, is that the particular part of the universe where we happen to be, is in no way exceptional or privileged; in other words, that the universe, when considered on a large enough scale, is isotropic and homogeneous."

"In 1916 and 1917 de Sitter presented to the Royal Astronomical Society a series of three papers on "Einstein's Theory of Gravitation and its Astronomical Consequences." Because there was no communication between Germany and England during World War I, these papers were instrumental in introducing general relativity to the English scientific community, and they played an important part in the decision of Arthur Eddington and others to send expeditions to observe the solar eclipse of 1919..."

"In 1913, Willem de Sitter suggested that fast-moving binary stars... could be used to measure the effect of a moving source on the speed of light. Various experiments of this sort over the past eight decades have verified that the speed of light received from a moving star is the same as that from a stationary star... a wealth of other detailed experiments have been carried out during the past century..."

"In the beginning of 1917, two solutions of the field equations for a homogeneous isotropic universe had been found, which I... call the solutions "A" and "B." ...at that time only static solutions were looked for. It was thought that the universe must be a stable structure...In one of these solutions (B) the average density was zero, it was empty; the other one (A) had a finite density. ...In B, to get the real universe, we should have to put in a few galactic systems, in A we should have to condense the evenly distributed matter into galactic systems. The universe A... has an average density, but no expansion. It is therefore called the static universe. B, on the other hand... expands, and it could only parade in the garb of a static universe because there is nothing in it to show the expansion. B is therefore called the empty universe. Thus we had two approximations : the static universe with matter and without expansion, and the empty one without matter and with expansion.The actual universe... has both matter and expansion... In 1917... the actual value of the density was still entirely unknown, and the expansion had not yet been discovered."

"Matter is actually distributed very unevenly... conglomerated into stars and galactic systems. The average density is the density that we should get if all... could be evaporated into atoms of hydrogen, or protons, and... distributed evenly over the whole of space. ...three or four protons in every cubic foot. ...a million million times less than that of the most perfect vacuum that we can produce... The universe thus consists mostly of emptiness... consider a universe without any matter at all, an empty universe, as a good approximation. But we may also take as our first approximation a universe containing... three or four protons per cubic foot. The local deviations from the average, caused by the conglomeration of matter into stars and stellar systems, are then disregarded in the grand scale model, and are only taken into account when we come to study details."

"If we put in the details, the singularities of the field, viz. the galactic systems and the stars, we find that there is... a tendency, called gravitation, to decrease the mutual distances of these "singularities." At short distances, within the confines of a galactic system, this second tendency is by far the strongest, and the galactic systems retain their size independent of the expansion or contraction of the universe..."

"The triangles that we can measure are not large enough... to detect the curvature. Fortunately, however, we are, in a way, able to communicate with the fourth dimension. The theory of relativity has given us an insight into the structure of the real universe: ...a four-dimensional structure. The study of the way in which the three space-dimensions are interwoven with the time-dimension affords a kind of outside point of view of the three-dimensional space... from this outside point of view we might be able to perceive the curvature of the three-dimensional world."

"In both the solutions A and B the curvature is positive, in both three-dimensional space is finite: the universe has a definite size, we can speak of its radius, and, in the case A, of its total mass. In the case A... the density is proportional to the curvature... Thus, if we wish to have a finite density in a static universe, we must have a finite positive curvature."

"The field equations, in their most general form, contain a term multiplied by a constant, which is denoted by the Greek letter &lambda;... sometimes called the "cosmical constant." This is a name without any meaning... We have, in fact, not the slightest inkling of what its real significance is. It is put in the equations in order to give them the greatest possible degree of mathematical generality, but, so far as its mathematical function is concerned, it is entirely undetermined: it may be positive or negative, it might also be zero."

"Purely mathematical symbols have no meaning by themselves; it is the privilege of pure mathematicians, to quote Bertrand Russell, not to know what they are talking about. ...It is the physicist, and not the mathematician, who must know what he is talking about."

"To help us to understand three-dimensional spaces, two-dimensional analogies may be very useful... A two-dimensional space of zero curvature is a plane, say a sheet of paper. The two-dimensional space of positive curvature is a convex surface, such as the shell of an egg. It is bent away from the plane towards the same side in all directions. The curvature of the egg, however, is not constant: it is strongest at the small end. The surface of constant positive curvature is the sphere... The two-dimensional space of negative curvature is a surface that is convex in some directions and concave in others, such as the surface of a saddle or the middle part of an hour glass. Of these two-dimensional surfaces we can form a mental picture because we can view them from outside... But... a being... unable to leave the surface... could only decide of which kind his surface was by studying the properties of geometrical figures drawn on it. ...On the sheet of paper the sum of the three angles of a triangle is equal to two right angles, on the egg, or the sphere, it is larger, on the saddle it is smaller. ...The spaces of zero and negative curvature are infinite, that of positive curvature is finite. ...the inhabitant of the two-dimensional surface could determine its curvature if he were able to study very large triangles or very long straight lines. If the curvature were so minute that the sum of the angles of the largest triangle that he could measure would... differ... by an amount too small to be appreciable... then he would be unable to determine the curvature, unless he had some means of communicating with somebody living in the third dimension....our case with reference to three-dimensional space is exactly similar. ...we must study very large triangles and rays of light coming from very great distances. Thus the decision must necessarily depend on astronomical observations."