The Fourth Dimension by Rudy Rucker

If you have read Flatland and were left wondering about its implications regarding higher dimensions this book is a absolute must read. The book then goes much further than simply explaining the 4th spatial dimension and explores the possibilities of higher universes.

Does it talk about time ?

Extensively, in fact the third part, chapters 9, 10 and 11 all talk about time.
Rucker seems to favour the eternalist model and spends quite a lot of time describing, quite convincingly, a “block universe” in which past, present and future are all equally “real”.

St. Augustine wrote that God is outside of time and that Time exists only within the created universe. On this view, God would perceive something like a block universe, while we would be limited to seeing it frame by frame in the present.

He also writes of time cones, circular time and in chapter 10 analyses the implications of time travel.

In the final chapter "what is reality?" he imagines getting rid of all preconception and building from scratch. At the core he sees only 2 realities that he calls certain: “I exist and I perceive things. I could be a robot, a spirit, an eye of God, a software or who knows what, but I am sure I exist. I am sure I am the entity that is typing these words. You the reader could doubt of my existence, but you know for sure that you exist”

On the perception of things it’s a little trickier, Rucker talks about the philosopher George Berkeley, and his concept of reality, His concept of “spirit” is close to the concept of “conscious subject” or of “mind”, and the concept of “idea” is close to the concept of “sensation” or “state of mind” or “conscious experience”. Berkeley denied the existence of matter as a metaphysical substance, but did not deny the existence of objects such as apples or mountains. Berkeley’s claims on immaterialism has many followers today under the more common term of subjective idealism.

He also mentions quantum mechanics and the implication that might have on our perception of "reality".

All great food for thought.

Flatland - an introduction to higher dimensions

This book is probably the one that got me started on this quest for the 4th dimension and subsequently, the better understanding of time. I devoured this book and I recommend it to anyone interested in higher spacial dimensions.

It was written in 1884 as a satirical novel, a “hidden” critique of Victorian society but what fascinated mathematicians, physicists and myself is the thought provoking effect Abbott brings about in his analysis of a higher dimension.

By describing a 2 dimensional universe he automatically puts us in the position of possessing a higher vantage point from which we can analyse that world. By the time you reach the end of the book it is only natural to imagine someone living in 4 dimensions looking down on our simple 3 dimensional world.

Though flatlanders live in a 2 dimensional universe there are hints to the fact that that plain actually exists within a 3 dimensional universe, such as the thickness of the shapes that allows them to recognise each other and finally the crossing of the plain by a sphere who apparently possesses god like powers. I have therefore started looking for hints, in the nature around us, of hyper-dimensional activity and certainly found it in tales of Religion; most of the miracles performed by the Prophets seem to go against our laws of physics but would be child play for anyone moving in 4 physical dimensions. Rudy Rucker in his The Fourth Dimension certainly leads us to a great voyage through higher dimensional universes.

But I have also in recent years observed certain events in nature in which certain living organism move in hyper-shapes. To do this they must have a clear image in their mind of a 4 dimensional space. The only reason for them to visualise space in 4D is that we in fact live in a 4D universe but we are for now stuck on our 3D plain.

The organisms that move in 4D are of various species and are found around the world and I will describe them, and their movements,  in a separate article.