reality #2

I assume most people have a 'concept of reality' similar to mine: I live in a large universe, which contains galaxies, the solar system and our planet Earth. My body contains a human brain, which creates my conscious experiences based on sensory input from my eyes, ears etc.
Of course, the universe evolves and physics describes the movements of the various parts of the universe, from atoms to the galaxies.

This 'concept of reality' is very useful and therefore we acquire most of it already during childhood, but it is not difficult to see that it is deeply flawed.

An important part of the concept is the idea of evolution and change, which means that we (have to) divide reality into the past, which no longer exists, the future, which does not exist yet and the present, an infinitesimal sliver of existence.
I think Aristoteles was one of the first to articulate the paradox of time and the fact that only an infinitesimal part of reality actually exists.
Augustinus wrote: "What then is time? If no one asks me, I know what it is. If I wish to explain it to him who asks, I do not know."
His statement is of course equivalent to saying that 'time' and our 'concept of reality' is very useful, but actually flawed.

However, we need to go a step further and consider an important insight from the theory of relativity, which provides us with this causal diagram:



The theory tells us that the infinitesimal sliver of the present shrinks to a single point, the 'here and now' (somewhere at the center of the red ring), surrounded by past, future and space-like events. It is quite obvious that 'my brain' and not even a single atom would fit into this point.

There is a big problem with our 'concept of reality' if none of it actually exists ...

However, sometimes the assumption is made that all of space-time somehow exists and the diagram just displays the causal relationship of events, which are all real; I think that e.g. Hermann Minkowski believed that.
Unfortunately, this point of view would be in conflict with quantum theory (more about that in a another blog post), but worse, it does not really solve the problem.
In fact it is just a play with words: Of course I can imagine that future events already exist somehow, but this does not change the obvious fact that I have no direct experience of them. The same is true of events from the past and I cannot have direct experience of space-like events.
So the 'here and now' is the only part of reality I can directly experience - but it is a single point only.
And it is the point at which I realize that my 'concept of reality' is just as flawed as the 'concept of a refrigerator' my dog used.