Plato, in a spurious sense, is often regarded as a ‘realist’ since he assigned ‘real’ status to his ‘forms’. However, he is a proponent of an idealist’s perspective because ideas (forms), though projected as belonging to an independent realm, but actually existed within mind. For Plato, forms constituted objective reality and the ‘observed reality’ was nothing but shadow imagery of those ‘forms’. If we regard Plato as a realist then we would be treating idealism as realism because a treatment of mind contents as an independent realm is a sign of extreme idealism and not a mark of realism.
In the Platonic theory, external things are shadow images and real things are basically just ideas of mind but anyhow Plato regards them absolute forms that exist in a supposed objective and real ‘world of ideas’ and not within mind. Perhaps it is his insistence that forms belong to an objective ‘world of ideas’ and not to the mind that he is often acknowledged as a realist which he is not actually because basically he just assigned status of an independent realm to forms which are nothing but ideas that belong to mind and do not possibly exist anywhere else.
Due to the rise of Sophistry, Philosophy had lost meaning and reputation. Socrates was the first to realize that argumentative method was in a dire need of refinement and regularization. Socrates himself introduced the concept of definition. Imagine how meaningless those arguments would be that did not employ definitions with specific scope.
Regularization of arguments then reached to its peak through the special efforts of Aristotle. Without Socrates, by now, philosophy would have become total meaningless jumble of words.
In a letter to Isaac Newton, David Gregory declared in 1694: “A continual miracle is needed to prevent the Sun and the fixed stars from rushing together through gravity.” Newton pondered the issue over the years starting around 1685 and concluded:
“The fixed stars being… at such vast distances from one another, can neither attract each other perceptibly, nor be attracted by our Sun.”
I. Newton, Principia (1728)
Newton reasoned that:
“if the matter of our sun and planets and all the matter in the universe were evenly scattered throughout all the heavens, and every particle had an innate gravity toward all the rest, and the whole space throughout which this matter was scattered was but finite; the matter on the outside of the space would, by its gravity, tend toward all the matter on the inside, and by consequence, fall down into the middle of the whole space and there compose one great spherical mass. But if the matter was evenly disposed throughout an infinite space, it could never convene into one mass; but some of it would convene into one mass and some into another, so as to make an infinite number of great masses, scattered at great distances from one to another throughout all that infinite space.
I. Newton, letter to theologian Richard Bentley (1692)
Therefore, if we assume that both Einstein and Newton were logically correct and differed only in the underlying assumption, then we see that concept of galaxies is a logical outcome of the assumption of an infinite universe. If we say that Einstein’s cosmological constant prevented the collapse of whole universe but did not prevent the collapse at smaller scale of individual galaxies (or clusters) … then still the point remains that up to the year 1924 i.e. when existence of galaxies was confirmed through observations, there were at least three solutions (i.e. Einstein (1917), de-Sitter (1917) and Friedmann (1922)) to the GR equations (as applied to whole universe) available and none of them was able to describe such collapses at smaller than whole universe scale. Therefore, if their logic was correct and they did not derive such localized collapses in their works then our conclusion is that cosmological constant also won’t help in the derivation of localized galactic structures within a finite universe. In other words, mere existence of galaxies is the proof that either this is an infinite universe or at least the universe is much larger in size than what standard model has to tell.
Based on the (Happiest) idea that free falling is an inertial frame, coupled with already known fact that different masses fall at same pace as reinforced by the Eötvös Experiments — Einstein intuitively concluded that massless objects (i.e. light) should also fall at same pace.
Step-2: So light also falls but it cannot get increasing speed because according to Einstein’s own principles light could not get increasing speed.
Step-3: Light can fall towards gravity but cannot accelerate by way of increasing speed. So what were other commonsense or intuitive options? There were two commonsense based philosophical answers. (1) Light could accelerate by way of change in direction (bending of light) and; (2) by way of blueshifting.
Step-3: Commonsense conclusion: Falling light is getting blue shifted. Its commonsense meaning is that frequency of light is increasing. Frequency of light itself is time clock. So time is getting speed up near the massive object.
Oh… What? Time speeds up near mass? But official physics says that time slows down due to mass. Well, following is the actual official position, fortunately well explained by Mr. Allen Everhart:
They (gravitational redshifting and time dilation) are the same thing. The time dilation near a massive body makes oscillations take longer when viewed from higher altitudes. If the oscillator is an electron then the frequency of light received at higher altitudes will be less than that which an observer at low altitude observes is emitted.
So leave aside whether time is slow or fast near mass … Official position is that time appears to slow down near mass when viewed from higher altitude. This position is confirmed by other experts also. For example, George Dishman writes:
The same effect applies to clocks, a clock on the surface of the Earth would seem to run slower as seen from orbit, and GPS clocks in orbit run faster than those on the ground.
However, his mention of “GPS clocks in orbit run faster” makes it confusing. This is not clear position and situation is still fishy. What is more appropriate is that official concept of gravitational time dilation is a relative concept i.e. not an absolute concept. Time near mass only seems to be slowed down as seen from orbit in higher altitude. But still the confusing aspect is about GPS clocks for which explanation by experts in invited in the comments section.
Father of Physics is Aristotle. He made physics a separate discipline. Modern Physics developed only out of critical inquiry of the Aristotelian ideas.
It is pointless to say that Aristotle was wrong and Galileo was right. Galileo received all his raw materials for the critical inquiry from Aristotle. Aristotle’s ideas were wrong. But in case there were no ideas on Physics at all then there would have been no Galileo or Newton as well.