Social Construction and Physics: Reality as 4-D Space-time – Phil of Sci # 5-2

This is the second part of the fifth instalment in the Philosophy of science series. In the links below, you can find the previous entries.

Abstract

Of what are things made, and what is their nature? It is one of the oldest and most awe-inspiring questions there is. Although you might say it is the least practical, all people operate with an implicit understanding, and assumption of what is fundamentally real, what is composite, what is essential to something and what is not, and so on and so forth. For this reason, the conceptual scheme operating in the background makes a very practical difference in the lives of every person. It is framework setting, from which everything else flows.

Contemporary trends indicate the dominance of a view that takes key elements of all systems of classification and understanding of the world around us as socially constructed, whether they be natural entities, or social concepts alike. Taxonomies and systems of classification bear the mark of the social – the norms, habits and customs of those who think them up. Whatever may be that is real, is hidden behind a veil of constructs – intellectual, physical, and social that blind us from what may truly be.

How relativistic thinking about the nature of things is manifested in different domains

In the preceding section, we saw how major currents of thinking have influenced the dominant elements of the mainstream of thought and practical life in our contemporary world. It is common today to hear the idea that conceptions of beauty, goodness, and truth are strongly ‘socially constructed’, that knowledge is relative and cannot be arrived at, or that claims to these types of truth are mere expressions of subjectivity. Ironically, by jettisoning a grounding in the rigorous use of reason, logic, and tests of coherence at the philosophical level, the dominant interpretive frameworks in major scientific disciplines bear the features of their social milieu in a strong sense, and do not hold water.

In the next three instalments, we’ll examine how these collections of ideas have woven their way into specific subject-matter, and how our understanding of the world has changed dramatically as a result, starting with physics.

Physics: reality as 4-D Spacetime Events

The 20th century saw the influence of relativistic thinking in multiple domains, and physics would not be spared.
Einstein’s development of the Special and General theories bear features of the relativistic frame of thinking that would revolutionize the world.

Albert Einstein was no narrow specialist, ignorant and dismissive of philosophy[1], like so many of our contemporary eminent and popular scientists. He spent some of his formative years as an adolescent reading Kant, as perhaps any good intellectual German of his day would have done.[2]

“I fully agree with you about the significance and educational value of methodology as well as history and philosophy of science. So many people today—and even professional scientists—seem to me like someone who has seen thousands of trees but has never seen a forest. A knowledge of the historic and philosophical background gives that kind of independence from prejudices of his generation from which most scientists are suffering. This independence created by philosophical insight is—in my opinion—the mark of distinction between a mere artisan or specialist and a real seeker after truth.”

Albert Einstein

Like other modern thinkers in their respective fields of study, Einstein brought the Kantian ‘Copernican revolution’ in philosophical worldview to the domain of physics.

In a summary of his Special and General Theories of Relativity[3], he starts with the dominant big picture frameworks for understanding physical reality that preceded him – the Euclidean system of Geometry and the system of Cartesian points.

Cartesian system of coordinates

Euclidean Geometry

The Euclidean system of geometry developed under the influence of Descartes into the system of Cartesian points. This forms the framework for understanding the world that is perhaps most intuitive from the practical standpoint. It is this: the world is comprised of matter, extended in three-dimensional reality, and mappable through a system of points along three axes – height, length, and depth, the ‘3 dimensions’.

The Special Theory of Relativity

The Special Theory of Relativity describes the relationship between space and time. Einstein recognized that the Galilean system of coordinates and Newtonian system of Classical Mechanics assumed this view of reality through conceptions of space, time, and position that we can all readily recognize.

He would come to argue that space is not extension along the Cartesian points of a static rigid body, but ‘motion relative to a practically rigid body of reference.’ It follows that – from the perspective of an empirical observer – there is no such thing as an independent existing trajectory, only a trajectory relative to a particular body of reference. In order to completely describe motion, we must make reference to time-values at each point and treat them like magnitudes.

Every reference-body (coordinate system) has its own time; unless we are told the reference body to which the statement refers, there is no meaning to ‘the time of an event.’

In other words, time had hitherto been referred to as a transcendental or absolute, but now we see that it has a relative definition from the perspective of someone trying to describe it according to physics. On this view, time is another empirical feature of reality with ‘parts’, if you like.

However, it should be noted that the interpretation is often overblown here. Only the absolute nature of time as a static reference point had become relativized, not time itself. It had been assumed that time passes at the same speed, and in the same way everywhere in the known universe. Einstein showed that the constitution of matter and the gravitational forces acting upon it make a difference. That is not to say that time is itself relative, as it remains a constitutive element of reality, applying anywhere and everywhere. In this sense, time retains its transcendental, and absolute qualities.

Next, Einstein modifies two assumptions from Classical mechanics:

  1. The time-interval between two events is independent of the condition of the motion of the body of reference;
  2. Space-interval (distance) between two points of a rigid body is independent of the condition of motion of the body;

He replaces these with the relativity (dependence) of both to a reference body.

With this seemingly free-floating relativism of reference, there seems to be little ground for the objectivity of any claim about the regularity and consistency we observe everywhere in nature. In order to provide a unifying explanation of the regularities in nature, the problem becomes one of specifying the body of reference. This, Einstein finds in the four-dimensional ‘event.’

The General Theory of Relativity

The General Theory of Relativity generalizes the findings of special relativity by refining what Newton had discovered about gravity. The result is a unified description of gravity as a property of space and time, or 4-D spacetime.

The event in 4-D – height, length, depth, and time signatures – becomes the ‘rigid body of reference’ in classical physics, and metaphysically to some, the most basic frame of reference through which we can understand the natures of things. The four-dimensional event is held together by the constant that allows us to pin down a rigid reference body – the speed of light in vacuo.

Minkowski’s four-dimensionalism

Gaussian coordinates

Building on Minkoswki and Gauss’ understandings of space and mathematical continua, this most basic ‘event’ framework is described as follows.

Minkowki’s four-dimensionalism:

  • An infinitely dense system of u-curves covers the whole surface
  • The points on the u-curves do not intersect;
  • Thus, a definite value of u belongs to every point on a surface
  • The same is true for the v. curves
  • Thus, a (u,v) value belongs to every point on the surface.
  • We can add coordinates to this continuum to give it additional dimensions.

Gauss invented a method for the mathematical treatment of continua in general, in which:

  • Size-relations (distances between neighboring points) are defined;
  • Every point of a continuum is assigned as many numbers as the continuum has dimensions.
  • Every potential description resolves itself into a number of statements, each of which refers to the space-time coincidence of two events, A&B.
  • Every such statement is expressed by the agreement of their 4 coordinates x,y,z,t
  • Thus, description of the space-time continuum by means of Gaussian coordinates doesn’t require a body of reference.

From his observations, Einstein concludes that the geometrical properties of space are not independent – as the structure of the universe – but are determined, or filled-in by matter.

“We might imagine that, as regards geometry, our universe behaves analogously to a surface which is irregularly curved in its individual parts, but which nowhere departs appreciably from a plane: something like the rippled surface of a lake.”[4]

He concludes by speculating about the nature of space according to the theories of relativity. He reasons that if space were infinite, then the density of matter would be 0. Thus, it couldn’t be inhabited by matter everywhere. On the other hand, if matter were distributed uniformly, the universe would be spherical or elliptical. Since matter is not uniformly distributed, the universe will deviate in parts from the spherical, but it will be necessarily finite. Thus, arriving at what is still the contemporary view in physics, that the universe began with a ‘big bang’ and is expanding, after which reaching a certain point, it will collapse back to the initial point in which it began. A universe with a beginning and an end is one that is intriguingly consistent with that posited by the Abrahamic religions.

Thus, arriving at what is still the contemporary view in physics, that the universe began with a ‘big bang’ and is expanding, after which reaching a certain point, it will collapse back to the initial point in which it began. A universe with a beginning and an end is one that is intriguingly consistent with that posited by the Abrahamic religions.

3-D doesn’t exhaust ‘reality’, and neither does the 4-D spacetime event – it is form and matter, act and potency

For our purposes, it is often claimed by naturalistically inclined philosophers and scientists that the 4-D spacetime ‘event’ is that which is most ontologically basic in the universe. There are no cats, dogs, atoms, quarks, etc., but 4-D time slices that are the constitutive elements of reality with an intrinsic nature, causal force, and ontological status. The small, medium, and large-sized objects we recognize in our day to day lives – of practical and theoretical types alike – are simply arrangements of 4-D time slices on this view. The causal constitutive forces lie in the laws of nature- and the most basic type of ‘stuff’ – spacetime slices of matter-energy.

However, we can see that this reductionist explanation is unwarranted, for there is still a body of reference to which that 4-D event refers. When posing the question – ‘What is the 4-D event comprised of?’ – one would naturally posit that it is a certain kind of substance. Therefore, it is misleading to think that that which is most basic can be anything other than a kind of substance, a thing.

When it is said, for example, that space and time are relative to the observer and that they cannot be defined apart from one another – that is the case only in light of the explanation being sought: that of explaining certain kinds of motion.

Spacetime could be thought of as the substratum, insofar as particular nodes in the spacetime continuum – that are physical in nature – can be defined only with reference to the larger totality to which they belong. However, it is in fact a way of describing the properties of things over the course of their spatio-temporal existence. It tends to refer to things therefore as events, even though every event is still made up of things, and not the other way around. Therefore, spacetime is not some nebulous entity – a kind of thing – but a way of describing the properties of things over time.

To summarize, the four-dimensional space-time continuum ‘event’ cannot be a more basic way of understanding reality, for it must presuppose material and formal nature to which it refers. It appears this way to those who are inclined to imbibe the currents of the time – reductionist and relativistic thinking that leave little room for the deeper use of reason.

Physics tells us about the different types of particles, their spatiotemporal relations, their causal roles, and the like. But it does not tell us the intrinsic nature of the entities that bear these relations to one another and play these roles.[5]

Substance, to which all descriptions of things and concepts refer, must always be defined according to its nature. That is the collection of its intrinsic principle of being and substantial form, that exist both in act (as those present properties of the entity), and in potency (as those existing in latent potentiality).


[1] “I fully agree with you about the significance and educational value of methodology as well as history and philosophy of science. So many people today—and even professional scientists—seem to me like someone who has seen thousands of trees but has never seen a forest. A knowledge of the historic and philosophical background gives that kind of independence from prejudices of his generation from which most scientists are suffering. This independence created by philosophical insight is—in my opinion—the mark of distinction between a mere artisan or specialist and a real seeker after truth.” Don A. Howard, “Albert Einstein as a Philosopher of Science,” Physics Today 58, no. 12 (December 2005): 34–40, https://doi.org/10.1063/1.2169442 Quoted from: A. Einstein to R. A. Thornton, unpublished letter dated 7 December 1944 (EA 6-574), Einstein Archive, Hebrew University, Jerusalem.

[2] Indeed, by age 16 he had already read all three of Kant’s “Critiques”: of Theoretical Reason, Practical Reason, and Judgment. Howard.

[3] Albert Einstein and Nigel Calder, Relativity: The Special and the General Theory, Penguin Classics (New York: Penguin Books, 2006).

[4] Einstein and Calder, 103.

[5] For more on physics and its philosophical interpretation, see Edward Feser, Aristotle’s Revenge: The Metaphysical Foundations of Physical and Biological Science, Editiones Scholasticae (Neunkirchen-Seelscheid, Germany: Editiones Scholasticae, 2019), 307.


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