In the 21st century, films and television have evolved to show 3D images. However, most people only have a crude understanding of what dimensions actually mean. This is a guide that will explore the incredible journey from a zero-dimensional point to a tenth-dimensional point and all the wonderful lines and folds that lie in between.

A point in space has no area – this is the zeroth dimension.
When two points are connected, it forms a line – the first dimension. This line allows one to travel from one 0D point to another, introducing the concept of length.
Another line is drawn branching off this line in a different direction – we have entered the second dimension. Now we have the concept of width.
By adding another concept – depth – we ascend to the third dimension. Now it is possible to go from one point on a 2D surface to another as we have “folded” a branch in the second dimension to meet the other branch. A simple explanation would be lifting your finger off one point and placing it on another point.

To simplify our journey to the third dimension we have:

Assumed a “point” in space as a dot (.)(0D)

“Joined” two dots to form a line (|)(1D)

“Branched” the line to create two ends (Y)(2D)

“Folded” the branches together to make the two ends meet (P)(3D)

These four concepts of point, joining, branching and folding are crucial in understanding how the different dimensions interact.

An interesting thought regarding the concept of dimensions is perception. How would inhabitants of each dimension view different dimensions? This is easy for lower dimensions (2D and below) because we can see them as a dot, line, square and cube (our dimension). Ergo, we can easily understand all the concepts of the lower dimensions (e.g. width). However, the opposite would not be possible (e.g. a 2D being trying to understand depth) as the concept does not exist in their dimension.

To further explore this thought, we must explore the world of Flatland.

As we live in a three-dimensional world, it is difficult to imagine that there are higher dimensions. To illustrate this, the thought experiment of the hypothetical “Flatland” can be considered. Let us assume that there is a two-dimensional world called Flatland. Here, the concept of depth does not exist. Only forwards, backwards, left and right exist; there is no up and down. Everything that happens here would look like it was drawn on paper.

Now let us interact with Flatworld. If we were to touch Flatworld with our finger, it would be like poking your finger through a newspaper. The inhabitants of Flatworld would see a circle suddenly appear out of nowhere that grows larger and larger. A person would appear as if they were being seen through a CT scanner – in sections. The concept that things can be above or below would sound crazy to a Flatlander, even though to us it appears as a simple concept.

Let us take an ant walking along a piece of paper as an example of a “2D object”. If the ant wishes to go from one edge of the paper to the opposite edge, it must walk along the 2D plane. However, with our 3D powers, we can fold the paper into a cylinder; now the ant can walk to the other point in an instant (across the fold). To another ant on the other side, the ant would look as if it teleported and suddenly appeared out of nowhere.

In another experiment, we make a Mobius strip (a ribbon is twisted once then its two sides are joined) and make an ant walk along it. Although the ant would think that it was walking in a straight line along a two-dimensional surface, it would have walked on both sides of the strip – a three-dimensional concept. If the Mobius strip concept is confusing, think of a garden hose instead: an ant walking along a straight garden hose is walking in: 1D (straight line), 2D (hose is actually a flat surface) and 3D (the ant can walk in a corkscrew pattern along the hose).

If we were to tell that ant that it had just travelled in a higher dimension, that ant would either scoff at us or be genuinely terrified of the experience. To it, we (or the giant pink circle that it sees our finger as) would look like some omnipotent being that can see everything going on in its world and teleport from one place to another. And although the concept of depth would initially intimidate the ant, it would bring the level of the ant’s understanding of the world up one dimension. For if we see what we only know, then how can anyone see anything new? The only way to truly learn and understand new things would be to jump out of the box and see everything from the outside – just like an ant seeing the piece of paper it was on from a higher ground.

Although we may laugh at the foolishness of the Flatlanders (and the ant), to a being of the 4th dimension, we would appear just as stupid and naive. By applying what we learned from the world of Flatland to our three-dimensional world, we can expand our horizon of knowledge and understand what the fourth-dimension is.

The first three dimensions covered the three variables that determine space: length, width and depth. Then what could the fourth dimension possibly add? The answer is duration. The third dimension effectively becomes a point and the 4th dimension connects different 3D points to form a line that we refer to as time. For example, the “you” at this exact time is different to the “you” in five years time. These two “you”s are different (3D) points that lie on a 4D line (more specifically, your life). This is exactly the same principle as the 0th dimension being points in a 1D line, except three dimensions higher.

As a “moment” in 3D space is just a point on a 4D line, travelling from one point in time to another (i.e. time-travelling) would be as easy as walking along a straight line for a four-dimensional being. This concept is mind-blowing for us as we cannot fathom the concept of manipulating time. We are unable to see time as a dimension as we exist in a lower dimension. Every single moment in our lives is a brick that paves the road called time, meaning that we can only see each individual brick and not the overall picture. This is exactly the same as how a Flatlander could not understand the concept of depth and how we can be above them.

Although we see time as linear and straight, we are under the same illusion as the ant walking down the Mobius strip. Time is actually twisting and turning in the fifth dimension, creating multiple timelines that branch out like a tree of possibilities. These branches are influenced by our own choice, chance and the actions of others.
In other words, if a man proposes to girl A then he will go down the branch where he marries girl A. However, if he chose not to propose, he would end up marrying a different girl (or not at all). Therefore, he has entered a different branch than the girl A branch.
Now, if the man wanted to go from a timeline where he married girl A to another timeline where he married girl B, what could he do?

One method would be if he bent the 4th dimension (time) on itself through the 5th dimension to travel back in time to when he met the girl and not ask her number. This is exactly like folding a 1D line into a 2D circle to make the end point meet the starting point. However, to marry girl B he would have to make the right sequence of choices that lead to him marrying girl B (much like a role-playing game). This is the long-way round that would be too time-consuming and complex.

A simpler approach would be if he folded the 5th dimension through the sixth dimension and jump from the ending of timeline A to timeline B. This would be like the finger-lifting analogy we have been using time after time. If we pretend that the 5th dimension was a piece of paper, then we could fold it into a 6D cylinder so that the two edges meet. Now we are able to jump from one ending to another effortlessly, just as we did in the 2nd dimension.

It is easy to confuse the 5th and 6th dimension as they both deal with “alternate realitites”. Here is one way to differentiate the two: 5D space is like a 2D space for time – a flat plane where different timelines cross each other. Therefore, it can contain all of the possible outcomes from an initial condition – that depends on an action, choice or chance – such as your conception (visualise a dot on a piece of paper with many lines radiating out from it).
If we were to put a dot on a piece of paper above the first piece of paper (in the 3D space for time), we have entered a universe where there is a completely different starting point (before your conception), such as dinosaurs not existing. This means that the line called “you” may not even exist, and the two pieces of paper would never meet. The only way to jump from one piece of paper (5D) to the other would be through the 6th dimension.
Therefore, by jumping up a dimension, we gain a degree of freedom where we can move in yet another direction. This is seen between every dimension, such as 2D versus 3D. The 6th dimension merely lets us travel between different sheets of 5D paper.

So somehow we have reached the 6th dimension where one can not only time-travel, but jump from one alternate reality to another. Shall we venture further into the seventh dimension – infinity – and beyond?

So far we have covered 6 dimensions: point, length, width, depth, time, alternate universe and travelling between possible futures being the key feature of each. Hopefully, you as the reader have caught on to the pattern of dimensions so far: point (0D) -> line (1D) -> branch (2D) -> fold/point (3D) -> line (4D) -> branch (5D) -> fold (6D)… This pattern of point/line/branch/fold continues past the 6th dimension. Therefore, the 6th dimension acts quite similarly to our 3D world in that we can assume it to be a point.
The 3rd dimension was a point in time. So what could the 6th dimension be a point of? The answer is infinity.

It was mentioned that the 5th dimension carries all of the possible alternate timelines that are created from a certain point. In the 6th dimension, these branches fold up to meet so that we can travel freely between every point. Therefore, the 6th dimension is a point that contains every possible timeline – where anything that can happen in the universe exists. This is infinity.

But by definition, infinity encompasses everything as there is no “end”. Then has our journey ended? In a fascinating turn of events, it turns out that we can not only ascend to the 7th dimension, but there are still 3 more dimensions to travel through.
By now we know that as the 6th dimension was a “fold/point” dimension, the 7th dimension must be a line connecting different 6D points (infinity). How can there be more than one infinity? Actually, infinity is only as great as the initial conditions from whence it was born – the Big Bang. In terms of universes, these initial conditions are the laws of physics such as gravity, the speed of light and hundreds of other constants. For example, gravity is 9.81ms-² in our universe. But if this value was off by even 0.0001, our entire universe would be completely different. Ergo, our universe and all the timelines that have and will form depend on the Big Bang. This also means that there can be many other “infinities” with different laws of physics. The line that these infinities lie on is the 7th dimension.

A good analogy for this is genetics. People’s lives have different outcomes depending on their choice, actions and random chance, but they cannot escape their pre-programmed genes. For example, it is not expected that a boy will (naturally) grow into a woman or sprout wings and fly. But if they were born with two X chromosomes or born with the DNA of a bird, this life would be possible.

Now let us follow the basic pattern to move to the 8th dimension. Here, the 7D line branches to meet yet another point of infinity (6D). And yet again, we can bend these branches through the 9th dimension to jump from one universe to another.

Lastly, we can take all of these branches and folds that encompass all possible timelines and all possible universes and draw it as a single point in the 10th dimension. This one point is the relative and absolute “everything”.

But what now? It is impossible to reach past the point of “everything possible”. This means that we cannot jump up another dimension as no other 10D point exists to be connected to. Ergo, the highest possible dimension is 10D and this is the basis of string theory. The 10th dimension is where the so-called superstring vibrates to form the subatomic particles that are building blocks of every matter in our universe.

As mind-boggling a journey it was, if you were able to follow through from the start, we have travelled from a single point that occupies no space to another point that encompasses all things possible in our universe in all possible timelines. We have zoomed out to the point that there is no longer a box to “think outside of”.

Can one ever reach that point where one knows everything that was, is and will be? To know every piece of knowledge that is the absolute yet relative truth? Although we cannot physically jump through dimensions, our minds can keep rising up to raise our level of understanding and enlightenment higher and higher. As we only live in the 3rd dimension, we have no less than 7 more dimensions to explore and understand. Only when we have reached the 10th dimension can we say that everything possible has been discovered.