# 4th Dimension Explained and Visualized (Examples)

Let's understand the weird world of fourth dimension with some exciting examples. Suppose a three -dimensional being enters into the world of two-dimensional beings. Let's call the 2 dimensional beings flatlanders.In a two dimensional world, all the beings and their objects are flat having only length and breadth.

There is nothing like above or below for them. So flatlanders cannot see anything which is above or below their 2D plane. The 3D being would seem like a superhuman to the flatlanders.

Now suppose that person from the 3rd dimension wants to steal an object placed inside the safe of a flatlander.

## Fourth Dimension Video

## Let me remind you that the safe of the flatlander would also be flat may be like a rectangle, square or of circular shape.

The boundaries of the safe are enough for the flatlanders to keep their flat objects secure, as they cannot take out objects from the flat safe simply by moving it from above or below their 2D plane.

But a 3D being can easily take out the object kept in the flat safe through the 3rd dimension simply by picking it up.

Just like we can pick any object placed inside a ring.

But this extremely simple task of 3D being of picking up the object is enough to blow the mind of the 2D being.

He would have no idea, how someone can steal the object from the safe without opening or breaking the walls of the safe!!!

Not only this, if the 3rd dimensional being is present below or above the flatland of the two dimensional being, the flatlander cannot even see the 3D being. Because they can only see things lying in the plane of their flatland.

In the same way a 4 dimensional being can easily take out objects kept inside a 3 dimensional closed box without opening or breaking it.

He can remove the object through the 4th dimension and a 3D being like us would wonder, where the object has gone?

Actually one extra dimension- the 4th dimension, is available to the 4D being to interact with the object. Beings of 3rd dimensions can't see or perceive that fourth dimension. For 3D humans like us, that object would simply seem to disappear from the box.

As we know that 2 dimensional structures like a square, triangle or circle cannot bound 3D beings like us.

We would easily escape from the 3rd dimension that is perpendicular to the plane of these 2D shapes.

You will be surprised to know that the fourth dimensional beings cannot be bounded by 3 dimensional structures like closed box or cage. They would escape through the 4th dimension without opening or breaking the box.

So we 3D humans cannot imprison the 4 dimensional beings.

Now we will visualize the fourth dimension using the method of cross section of objects.

If a 3 dimensional object passes through the 2 dimensional plane, the beings living in the 2nd dimension would only see the cross section of the 3D object cut by that 2D plane.

Because a person living in two dimensional world can only see the objects that are present in its 2D plane. It is not possible for him to see anything which is above or below its two dimensional plane.

Let's try to visualize this with the help of an interesting example.

Suppose an apple which is a 3D object, enters into the world of 2 dimensional beings.

The flatlanders would not be able to see the Apple until it touches their flatland as it is not possible for them to see anything that is not present in their plane.

But when the Apple just touches the 2D plane, it appears as a dot to the flatlanders. As the apple passes through the 2D surface of the flatlanders, the apple will appear as a growing circle. The circle appears to grow until it reaches the diameter of the apple.

When the Apple keeps moving perpendicular to the plane, the circle will appear smaller and smaller, then again a point and finally, when it leaves the flatland, it will disappear from the eyes of the flatlanders.

But let me tell you that two dimensional beings would have one dimensional retina in their eyes, so they

would not see the apple as a growing circle.

Actually one dimensional projection of the circle would be projected on their one dimensional retina.

If you didn't get this concept of retina, let me explain, how we see our 3 dimensional world with our eyes.

We are three dimensional beings and we have two dimensional retina.

On this two dimensional retina, 2D images of 3D objects are formed.

This is actually the two dimensional projection of the 3D objects. But our brain is smart enough to create a 3D model of the object from this 2D projection on our 2 dimensional retina.

The brain gathers 2 dimensional information like lightening, shadow gradient and perspective from our eyes. Then after processing it, the brain creates an image with depth.

Therefore we can not see 3D objects in their entirety as we only get 2D projection of the 3D objects on our 2 dimensional retina.

For example, if there is a opaque closed box, we cannot see what's inside it. It's also not possible for 3D beings like us to see all the surfaces of the box simultaneously.

To see the box in its entirety, we need to see it from different angles separately. But we can see a two dimensional object in its entirety because of our 2D retina.

For example we can see a rectangle in its entirety, it's all sides and also it's complete inner area at the same time.

In the same way, a 4 dimensional being would be able to see a 3 dimensional object in its entirety.

It would be possible for him because of his 3D retina. The entire 3D projection of the 3D object would be formed on their 3D retina.

So a being of 4th dimension would be able to see all the surfaces of the solid objects simultaneously. He would easily see what's present inside a closed box or what's happening on the other side of the wall.

It would be possible for him to see all the internal organs of your body and many other incredible things like this.

But the 4 dimensional beings would not be able to see the four dimensional objects in its entirety as they don't have 4D retina. So only 3D projection of the 4D object would be formed on their 3D retina.

Friends, There is one more way that can be used to visualize the 4 dimensional world. This method is called the bounding volumes.

As we know that 2 dimensional objects are bounded by one-dimensional boundaries.

For example- A two dimensional square is bounded by one dimensional edges.

In the same way three dimensional objects are bounded by two dimensional surfaces. For example- A 3 dimensional cube is bounded by 2 dimensional square faces.

So by applying the dimensional analogy we may infer that a four dimensional object is bounded by three-dimensional volumes.

It has also been proved by mathematics that a 4 dimensional structure known as the Tesseract is bounded by 3 dimensional cubes.

Actually tesseract is the four dimensional analogue of the cube which is also called as the hypercube or the 4D cube.

It is considered as one of the simplest 4D shape.

A tesseract can be drawn by drawing two 3D cubes, one encompassing the other, on a 2 dimensional plane. We now connect the respective 8 vertices of both the cubes.

Actually these 8 lines that connect the vertices of both the cubes represent a "single direction" in the 4th dimension, that we can not see.

Guys, we have already seen many superpowers of a 4 dimensional being related to space but now we will see, how the 4D being can control time.

The 4 dimensional being would be able to move freely in time dimension; in the past or in future.

That being would also be able to go back in time and change his decisions and start a new timeline.

But let me tell you that parallel universes do not exist in the fourth dimension, because of this, he would be able to have only single timeline. Therefore his old timeline will end and new timeline will start based on his changed decision.