As many long-time followers of Metaphysics of Physics will know, we take issue with certain aspects of modern physics (for instance we talk about that here). That includes many of the central assertions of General Relativity(GR).
Key among these is the assertion that space and time are mathematical dimensions which are also somehow an aspect of physical reality. That they are somehow unified into some mathematical abstraction known as “spacetime”.
But space and time or spacetime are not things. Which is how GR and this article treats them. If it did not the whole premise and conclusion of this “thing” called spacetime swirling around a dead star falls apart. And this is exactly what happens when we define space and time as valid concepts.
Space and time are abstractions. And abstractions do not swirl or twist or dance around anything!
And spacetime is an invalid abstraction in as far as it is treated as anything other than a mathematical technique.
What is Space?
Space is a concept which indicates relationships between positions. Meaning?
Suppose that we consider one of the rooms in our house, say the living room. The living room is that part of the house between the four walls of the living room and between those four walls is some “space”.
The “space” within that room simply indicates relationships between the positions of those four walls. One wall is over here, another wall is over there and the other two are other there and there. In between is all this space. The space essentially refers to the separation between objects. This “space” then forms some area or volume in which you can find things.
So, for instance, you can walk into the living room and say “Well, we have these walls. They are in different positions. There are other positions in between them.” And the sum of those other positions is the “space” inside the room.
(You can find more in episode twenty-one of the podcast, where this section was derived from).
What is Time?
Time measures motion or change. For instance, it takes two motions or changes and identifies a relationship between them.
For instance, suppose we are talking about how old I am. What fact of reality does my age refer to?
Well, we take two events, my birth and the writing of this article. And identify the fact that there is a certain relationship between these two. My birth happened during a particular revolution of the Earth around the Sun. This moment is occurring within a different revolution of the Earth around the Sun.
While I write this, 37 such revolutions have happened. And so I have thus identified a relationship between my birth and the writing of this article.
I could do something similar with myself starting a race and ending it. Except, presumably I would use a second to measure the relationship between the start and end of this event; a second as measured by the motion of a second hand around a clock or by a digital equivalent.
Or suppose I wish to measure how long it takes me for me to grow larger muscles and be able to work my way from bench pressing 100 to 125 pounds. And suppose I track the time using the date on my phone.
What am I measuring here? Relationships between my strength levels, a change in such over time.
(You can find out more about time in this subscription article).
We will go into what space and time are only far enough to see that they are abstractions. They are measurements of relationships.
What are Dimensions?
A dimension is a mathematical concept that indicates mathematical relationships. It is a technical concept that indicates how many independent parameters there are. In geometry, it indicates a set of coordinate axes required to specify any point.
The details are not important for this discussion. What is important is that dimensions are a mathematical concept that establishes mathematical relationships.
But physics treats dimensions as physical aspects of the universe. They treat the universe as if it was a thing that was somehow built up out of the dimensions. But space and time are not physical things, they are not aspects of the universe. They are relational concepts, they deal with abstractions.
But relativity supposedly proves that space is a set of dimensions!
Does it? Show me the proof that shows this. Space is an abstraction, nothing in physics justifies treating it as though it is a physical thing that is somehow subject to bending or distortions as a physical object might be. The same is true about time.
The reason modern physicists do this is that they are reifying mathematical abstractions. They do not understand that mathematics is a science of method for measuring reality. They do not understand that the equations of Relativity do not describe physical objects.
What the equations describe are relationships. The equations need to be given a reasonable physical interpretation. Which is where rational metaphysics comes in. However they refuse to engage in rational philosophy, instead choosing to interpret it in any way which is mathematically consistent. Without regard to logic, reason, that is, rational metaphysics.
What then to make of things getting shorter or longer based on relative speed? That objects get longer or shorter for other reasons. It does not justify the reification of space.