What do We Understand to be the Fourth Dimension?
The first step in understanding the fourth dimension is learning that it is the dimension of duration, or time. While this may seem very complicated and abstract at first, and while it is theoretical, understanding the fourth dimension is not actually that complicated, though the implications and conjectures based upon the premise of the fourth dimension may be a bit more challenging. However, if you are willing to imagine a few thought experiments and accept descriptions for what they are, an understanding of any dimension may be reached.
The second step to being able to understand the fourth dimension is to merely accept it’s explanation. A thought experiment will be shown afterward which will make the description make more sense, but first we must merely understand the fourth dimension for what it is. For example, if we were to visualize ourselves in the fourth dimension, it would be a long, stretched out version of ourselves, from the moment of conception to the very microsecond before we die. If you will, imagine your fourth dimensional self as something like a snake, a long string of infinitely divisible moments within a finite frame. Remember that this is merely an example of how we would appear in the fourth dimension and not meant to represent the entirety of the fourth dimension, just as we can visualize a cube and agree it exists in the third dimension, but imagining a cube to represent the entire third dimension would be erroneous.
Understanding the Fourth Dimension With a Thought Experiment
It may be easy to understand the description of the fourth dimension, or at least to understand what the appearance of an object or person may be in the fourth dimension. However, in order to understand what this really means, we should examine a famous thought experiment involving the second dimension.
There is no height in the second dimension. There is left and right, but no up or down. Therefore, everyone and everything is totally flat. Imagine, if you will, a reality like this, where everything is two dimensional. Now, if a three dimensional entity decided to land in this two dimensional space, could the second dimensional creatures living there see it? If we understand that height cannot be seen in the second dimension and everything is totally flat, then we can understand why second dimensional creatures could only see a sliver of an three dimensional object, were it to land in their second dimensional space. For example, if you stepped into the second dimension, second dimensional creatures would only be able to see the very bottom sliver of your foot, or the portion of your foot directly on the ground.
In order to use this thought experiment to understand the fourth dimension, compare your three dimensional body visiting a two dimensional world to the stretched out snake version of your fourth dimensional self visiting a three dimensional world. Just as we understand the second dimensional creatures could only see a sliver of a three dimensional object, creatures in the third dimension can only see a silver of objects in the fourth dimension. Therefore, we can only see ourselves in this very instant, though our entire self may exist in the fourth dimension. If you want to imagine, it is almost like the fourth dimension passes through the third dimension, giving the appearance of someone aging.
WORKS CITED
Rucker, Rudy V. B. The Fourth Dimension: toward a Geometry of Higher Reality. Boston: Houghton Mifflin, 1984. Print.
Sagan, Carl. “Flat-land Thought Experiment.” 2011. Lecture
