Original Link : https://blog.usejournal.com/how-to-imagine-the-4th-dimension-6c3e6684f670

The world we live in is called the **Three Dimensional World **or more commonly known as the **3-D World. **What is meant by this is that our world(the world we can see and observe) is made up 3 things: **Length, Breadth and Height.**

But are length, breadth and height the only possible parameters to construct the universe and the things in it?

Many scientist believe that there are other worlds where there are other constructional parameters than length, breadth and height. These worlds are called as **Higher Dimensional Worlds. **But to visualize the 4th Dimensional world and other higher dimensional worlds is not that easy. So to imagine how the higher dimensions might look like, we must understand how lower dimensions look like from our world and apply the same logic to understand the construction of the 4th dimension.

# 1. One Dimensional World

Let us image a 1-D world, where the only inhabitants are one the dimensional creature. Now a one dimensional creature would be a point.

And the only way ** a point** can move in a one dimensional world(

*that has just one parameter)*is either forward or backward along a single line. This means that the inhabitants of a one dimensional world have only one path to move in and live their lives within a single parameters only(sad creatures!!).

# 2. Two Dimensional World

Now increasing one more parameter in a 1-D world gives us a 2-D world. That being said, it is clear that a 2-D world has length and breadth(but no height).

Since this world has two parameters, the creatures are free to move in two different pathways, rather than just moving forward and backward along a single line. They can move either length-wise or breath-wise.

*Some of the creatures of the 2-D world are; A square, triangle, circle, pentagon, hexagon, parallelogram…..etc…!!!*

But again, a 2-D creature can only move in four directions; Forward, Backward, Leftwards and Rightwards. They cannot move upwards or downwards, since that parameter is absent from their universe!

But as we see these two world, we can see a distinctive pattern as we go on increasing a dimension by one. We can see that the 2-D world has a parameter that is perpendicular to the parameter present in the 1-D world(breadth is perpendicular to length and vice-verse). Applying the same logic in the 3-D world we see that the 3-D world has exactly one parameter more than the 2-D world and that parameter is in fact perpendicular to the parameters present in the 2-D world(the parameter of height is perpendicular to both length and breath).

**3. Three Dimensional World**

These are some basic 3-D shapes that you must have seen or felt in your life. I don’t thin that there is any need to discuss about the creatures of the 3-D world.

The creatures of the 3-D world have the privilege of a third parameter called height. And till now the amount of universe we can observe and study is a part of the 3-D world.

It must be noted here that a 3-D space is in fact a infinite stack of 2-D space stacked against each other in every direction. Similarly a 2-D space is a stack of infinite 1-D space spread out in lengthwise and breadth-wise. If we apply the same logic we can assume that a 4-D space would be an infinite stack of 3-D space in all directions!

But before we jump into the multidimensional universe, there are certain things that must be noted and kept in mind to help visualize the higher dimensions.

- First is the effect of light when visualizing an object. For instance, if you view a sphere in a dimly lit room, all you will see is a circular object with faded sides/circumference. But if you increase the intensity of light you will start the sphere. I.e light plays a crucial part in revealing the dimension of a structure.
- Second one is the perception of size. How do you tell that an object is far from you or near you? Your brain can make this calculation in mere seconds by telling you that a farther object looks smaller than when the object is kept nearer. But what if as the object moves away from you it starts increasing in size proportionally(
*for example a rubber band)*…..Your brain will start failing you, your senses will no longer give you correct results, for your basic knowledge of size is now not proving to be correct!

# 4. Four Dimensional World

This is a mathematical model of a 4th Dimensional world.** It is called a Tesseract .**

This is a still image and this is why it is relatively hard to figure out. You may also be a bit confused, but that is 100% okay as the figure you see is actually an attempt to depict a 4th dimensional world in a 3rd dimensional universe on a 2-D screen.

**Now to help you visualize a 4th dimensional world, here’s a video that shows how the parameters move in a 4-D world!**

This is the video-graphic representation of a 4-D world. But now the question that still remains in mind is that what is the 4th Parameter of a 4th dimensional world?

Here comes the effect of **size and light **while visualizing a 4th dimension!

Einstein’s Theory Of General Relativity has proved (and we have seen and conducted experiments that tell us that General Relativity is true) that space and Time are not two separate things but rather related to each other. Any effect on any one of these parameters will show change in the other. This is called** The Space-Time Continuum.**

The Theory Of General Relativity says that the time is relative and varies from one point to another. It also says that sufficiently bending/altering space can cause a deviation in flow of time from one point to another.

In simple terms it means that Time is also a parameter in the construction of the universe!

When we assume that Time is a dimensional parameter the way the universe works completely changes. This means that in a 4th dimensional world time is actually a physical quantity that can be touched and felt. This means that a person living in the 4th dimension will never have distinctive past, present and future. This is because time is a physical quantity in that world. So if you move forward by 5 years in the dimension of time and again move backward by 5 years, you would have seen the future and still be in the present. And again if you move backward by 10 years in the time dimension, you will be in your past and again if you move 20 years in the opposite direction you will land in the future that would be 10 years farther from your original present. To put this into a simple simple statement, it means that **The concept of past, present and future is meaningless in the 4th dimension.**

# *Points That Must Be Understood*

- You must understand that it is impossible for a 1-D creature to see a 2-D object. Similarly it is impossible for a 2-D creature to see a 3-D world, and the same rule applies for the 3-D and 4-D worlds.
- It is also impossible for 3-D world to have a 2-D object and similarly it is impossible for a 2-D world to have a 1-D object. This is because no matter how thin an object you have with you to demonstrate a 2-D shape or object, it will always have some thickness. And this is the reason why we assume only cross-sections of an object to be 2 dimensional in nature as cross-sections are imaginative surfaces that we use to help us with calculations.
- The idea of time being a 4th dimensional entity is still a debatable topic among scientists. But the knowledge and technology we have right now with us, it is wise and smart to assume that time as a 4th dimensional quantity.
- It is impossible for the human mind to ever see a 4th dimensional world because in that case time will start to flow in a mysterious and confusing way for both of the worlds with respect to each other.
- Scientists assume that there are portals in different parts of the universe that act as doors to higher and lower dimensional worlds.
**This is called the idea of a Multiverse**. These have not yet been discovered, but who knows what the future might hold.

Finally I would like to say that the possibility of a multiverse sounds rather imaginative but so did the concept of black holes and quasars until 200 — 300 years ago. So we cannot restrict our imagination, because it is the greatest tool we have at our disposal that we can use to understand nature and unlock the mysteries of the universe…!!!