Solar, I'm still going through your post. You always have such a amazing way of compiling and rewording information, that I sometimes feel a little jealousSolar wrote:It is interesting that prior to 1923 the universe was considered to consist solely of the Milky Way galaxy. Then, in 1922-23 or so Edwin Hubble suggested that some of the objects vied through the telescope were actually outside of the Milky Way. It took nearly two years before this became accepted as fact making it just over 80 years since this has been recognized.
With that realization one’s perception of the universe exponentially expanded (no pun intended) as ‘space’ functioned to ‘physically’ integrate the newly perceived potential distance relations and automatically subsumes physical continuity.
So before I finish reflecting on that, let me post a few sections from Boscovich concerning gravity, it's not all of course but again gives an indication of train of thought.
Please do note what is said in the last two sections concerning stars and other such particles
Am I wrong in reading in that last bit a tentative approach to a galaxy and galaxy-clusters?398. The primary elements of matter are considered by most people to be immutable, & of such a kind that it is quite impossible for them to be subject to attrition or fracture,unless indeed the order of phenomena & the whole face of Nature were changed. Now, my elements are really such that neither themselves, nor the law of forces can be changed ; & the mode of action when they are grouped together cannot be changed in any way ; for they are simple, indivisible & non-extended. From these, by what I have said in Art. 239, when collected together at very small distances apart, in sufficiently strong limit-points on the curve of forces, there can be produced primary particles, less tenacious of form than the simple elements, but yet, on account of the extreme closeness of its parts, very tenacious in consequence of the fact that any other particle of the same order will act simultaneously on all the points forming it with almost the same strength, & because the mutual forces are greater than the difference between the forces with which the different points forming it are affected by the other particle. From such particles of the first order there can be formed particles of a second order, still less tenacious of form ; & so on. For the greater the composition, & the larger the distances, the more readily can it come about that the inequality of forces, which alone will disturb the mutual position, begins to be greater than the mutual forces which endeavour to maintain that mutual position, i.e. the form of the particles. Then indeed we shall have changes & transformations, such as we see in these bodies of ours, & which are also obtained in most of the particles of the last orders, which compose these new bodies. But the primary elements of matter will bequite immutable, & particles of the first orders will preserve their forms in opposition to even very strong forces from without.
399. Gravity also is counted as a general property, especially by followers of Newton ; & I am of the same opinion, so long as it is not supposed to be in the inverse ratio of the squares of the distances for all distances, but merely for distances such as those that lie between the distance of our bodies from the far greatest part of the mass of the Earth, & the distances from the Sun of the aphelia of the most remote comets ; & so long as in this region it is not assumed to follow the law of the inverse squares exactly, but only very approximately to any desired degree of closeness, as I said in Art. 121. Now gravity of this kind is represented by the last arc of my curve in Fig. I ; & this, if gravity goes on indefinitely according to this same or any similar law, will be an asymptotic branch. Indeed, it may be, as I remarked in Art. 119, assumed that gravity is even accurately as the inverse square, & that it extends to all distances according to the same law, but that in addition there is some other force represented by another curve ; then the law of forces of Fig. I is to be resolved into this force & into gravity reckoned as being exactly as the inverse square of the distance. This force, then, at those distances, for which gravity follows very approximately such a law, will be an insensible force ; but at most other distances it would be very great. Where Fig. i gives repulsions, the force that is assumed to follow this other law would also have to be repulsive, & greater than the force, given by the law of the primitive curve of Fig. i, by an amount equal to the supposed value of gravity at that place ; & this must be cancelled by the addition of this repulsive force. However, this would depend upon our manner of assumption ; & in this my own primitive & actual law, I consider that gravity is indeed universal & follows the law of the inverse squares of the distances, although not exactly, but very closely ; I consider that it does not extend to all distances, but only to those I have set forth.
400. For the rest, that gravity exists universally throughout the whole planetary system, I think is thoroughly demonstrated by those arguments derived from Astronomy which are used by the disciples of Newton ; these I do not repeat here, since they are set forth everywhere ; I too have discussed them in several places, besides including them in Adnotationes ad poema P. Noceti De Aurora Boreali. But I consider that it is most evident that the approach to the Sun of the comets & primary planets, & that of the secondaries to the primaries, such as we see in the descent from the rectilinear tangent to the arc of the curve, & to a far greater degree other motions depending on mutual gravitation cannot possibly be due to fluid pressure. For, to omit other reasons truly numerous, the fluid that can avail so much in its action on spheres of this kind merely by its pressure, would certainly have a much greater effect upon their tangential velocities, by its opposition ; these would in every case be bound to be diminished by such resistance, with a huge perturbation of areas,- & the perversion of the whole of astronomical mechanics. Thus the fluid would either be bound to set up a huge resistance to 'the progress of a planet or a comet, or else it does not even by its pressure impress any sensible motion upon it.
401. Now, the principal laws of gravitation are that it varies directly as the mass & inversely as the square of the distances from each of the points of that mass ; & in my Theory it is quite clear that this must be the case. For, as soon as we reach the arc of my curve that represents gravitation, all the forces are attractive, & to all intents obey the same law ; & so some of them do not cancel others in opposite directions, but their sum approximately corresponds to the number of points. Except in so far as, on account of the inequality between the distances of the points, & their relative positions, there will be need, in order to obtain the sum of the forces accurately when the volumes are somewhat large, to make use of the reduction usually employed by mechanicians ; by the aid of which are found the laws according to which a point situated at a given distance & in a given position from a mass of given shape is attracted by that mass. Here, as I indicated in Art. 347, one sphere gravitates towards another sphere in the manner that it would if the whole of their masses were for each condensed at their respective centres ; whilst for other figures we meet with altogether different laws.
402. But the greatest support for my Theory lies in a statement in Art. 212, which I said ought to be noticed ; namely, in the fact that we see so much uniformity in all masses with regard to the force of gravity ; in spite of the fact that these same masses, for the purpose of other phenomena depending on the smaller distances apart, have differences so great as those possessed by different bodies as regards hardness, colour, taste, smell &sound. For, a different combination of the points of matter induces totally different sumsfor those distances up to which the curve of forces still twists about the axis ; where a very slight change in the distances changes attractive forces into repulsive, & substitutes, vice versa, differences for sums. Whereas, at those distances for which gravity obeys the laws we have stated very approximately, the curve has its ordinates all in the same direction &, even if the distance is slightly altered, practically unaltered in length. This of necessity produces a huge difference in the former case, & a very great uniformity in the latter.
403. The distinction between gravitation (which is proportional to the mass on which it acts, directly, & as the square of the distance, inversely) & weight (which is, in addition,proportional to the mass causing the gravitation) is just the same in my Theory as in that of Newton & all mechanicians. The former gives the accelerating force, the latter the motive force ; since the former gives the force of any gravitating point, upon which depends the velocity of the mass, & the latter the sum of all the forces pertaining to all such points. Similarly, the agreement is the same in my Theory with regard to anything relating to the motions of heavy bodies stated by Galileo & Huygens ; except that, in descent along inclined planes, or bodies supported by two inclined planes or inclined strings, I substitute for their resolution of gravity the principle of composition, as in Art. 284, 286 ; & I deduce the centre of oscillation, as well as the centre of equilibrium, the lever, the balance & the principles of machines from a consideration of three masses acting mutually upon one another ; & this more especially by means of a simple theorem depending on that consideration, which I investigated fully in Art. 307. The agreement is just as close in my Theory with regard to anything occurring in the celestial mechanics of Newton, now universally accepted, with regard to the motions of planets & comets, particularly the perturbations of the motions of Jupiter & Saturn when at less than the average distances from one another, the aberrations of the Moon, the flow of the tides, the figure of the Earth, the precession of the equinoxes, & the nutation of the axis. Finally, for the correct solution of these latter problems, a much safer & more expeditious path is opened to me, such as will lead me to it after an investigation of the system of four masses, not even lying in the same common plane, connected together by mutual forces ; just as the consideration of a system of three masses led me with such ease to the centre of oscillation even to one side in the same plane, & to the centre of percussion in the same straight line.
404. In addition to these, there is one thing in which I do not agree, namely, in that which relates to the immobility of the fixed stars ; it is usually objected to the universal gravitation of Newton, that in accordance with it the fixed stars should by their mutual attraction approach one another, & in time all cohere into one mass. Others reply to this, that the universe is indefinitely extended, & therefore that any one fixed star is equally drawn in all directions. But in things that actually exist, I consider that it is totally impossible that there can be any absolute infinity. Others fall back on the immense distance, which they say will not permit the motion arising in the fixed stars from the force of gravity to be perceived by the senses, even after an immense number of ages. In this they assert nothing but the truth ; for if we consider the fixed stars equal & similar to our sun, or at any rate the amounts of light that they emit, as not being far different from the ratio of their masses ; then since also the force is proportional to the masses, & in addition both force & light decrease in the inverse ratio of the squares of the distances, it must be that the force of gravity of our solar system on all the stars is to the force of our gravity on the Sun, which latter is many times less than the force of gravity of our heavy bodies on the Earth, as the total light which comes from all the stars is to the light which comes from the Sun ; & this ratio is the same as the ratio of night to day in respect of light. How slight is the motion that can arise from this in the time (the comparatively short time available for observation) nobody can fail to see. Even if all the fixed stars were situated in the same direction, the motion could be considered as absolutely nothing.
405. However, since our period of life & memory, in comparison with the immense number of ages perchance to follow, is almost as nothing, if universal gravitation extends indefinitely with the same law, & the same asymptotic branch, not only this solar system of ours indeed, but the universe of corporeal nature, would, little by little in truth, but still continuously, recede from the state in which it was established, & the universe would necessarily fall to destruction ; all matter would in time be conglomerated into one shapeless mass, since the gravity of the fixed stars on one another will not be cancelled by any oblique or curvilinear motion. That this is not the case cannot be absolutely proved ; & yet a Theory which opens up a possible way to avoid this universal ruin, in the way that my Theory does, would seem to be more in agreement with the idea of Divine Providence. For it may be that, as I remarked in Art. 170, the last arc of my curve, which represents gravity, after it has reached distances greater than the greatest distances from the Sun of all the comets that belong to our solar system, will depart very considerably from the hyperbola having its ordinates the reciprocals of the squares of the distances, & once more will cut the axis & be twined about it. In this way, it may be that the whole aggregate of the fixed stars, together with the Sun, is a single particle of an order higher than those of which the system is composed ; & that it belongs to a system immensely greater still. It may even be the case that there are very many such orders of particles, of such a kind that particles of the same class are completely separated from one another without any possible means of getting from one to the other, owing to several asymptotic arcs to my curve, as I explained in Art. 171.