**A layman’s explaination of Space-time Continuum, Parallel universes, Principle of Causality & teleportation.**

Imagine a point. It has no dimensions and indicates a position in a system. Now imagine a second point somewhere else in this system. The first dimension is the line joining these two points. Length. The second dimension adds breadth, so imagine a square scribbled on a sheet of paper. A 3 dimensional object is every object you see around you. It has length, breadth and height. Things are easy to visualise till here.

Let’s try and imagine the 3rd dimension in another way. Let’s say there is a tiny ant walking along a huge sheet of paper. Let’s assume the huge sheet of paper is folded to form a massive cylinder. For the ant, as it is very tiny, it will appear no different walking on flat sheet or along the huge cylinder. Think of this as that the ant is not able to visualise the higher dimension (3rd) — or is a ‘flatlander’. It thinks it is just walking in a straight line, but actually it is walking in a circle. Say we have 3 points in a sheet of paper — A in a corner of an edge, B in the middle of that edge and C at the other corner of that edge. When the sheet is in 2 dimensions the ant moves from A to B to C. Now let’s create a cylinder and join A & C. Now the ant can move from B to A and then magically transport to C. We can visualise this, but the ant (flatlander) cannot.

It is convenient to think of higher dimension in this way, as it will help us comprehend dimensions above 3. In other words, **the third dimension is what you have to fold through to jump from one point to another in the dimension below (2nd).**

**Space-Time Continuum**

**It is commonly known that the 4th dimension is time**. If we think of a non-moving object 1 minute ago and then think of this object now, the line that joins these two points is the forth dimension. This four-dimensional ‘continuum’, that joins the three spacial dimensions and one time dimension into a single idea is known as Minkowski space.

A good way to visualise this 4 dimensional space is think of a meeting. Let’s say I tell you to meet me at a place (221B Baker Street, London), which means I gave you the 3 spatial dimensional address of our meeting point. You arrive there but I am not there. Why? Because we didn’t decide on the time when to meet!

As we live in a 3D world, we can only move ‘forward’ in time and are unaware of any motion along this dimension, just like the flatlander can only feel moving forward even on a cylindrical sheet of paper even though they are moving in the 3rd dimension. Hence to us, the forth dimension — time- seems like is only moving in a straight line from the past to the future.

**If we could move in the 4th dimension, we could choose to go to our younger or older self at will**, any time. Think of it as a line (Like Facebook’s timeline) on which you can move along.

**Parallel Universes**

As discussed, the 4th Dimension is Time, Connecting Two 3 Dimensional Events. We can only feel as if we can go forward in the 4th dimension (time) — that is travel in a straight line. If we could move in the 4th dimension, we could choose to go to our younger or older self at will any time.

However, in reality, we are actually twisting and turning along a multitude of paths or branches (as if taking a ’turn’). For example, let’s say you went to a party 5 days ago and met someone there. If you could go back in time 5 days, and decide to not go to the party, this will create a new possibility, or a branch. Or as you may have heard — a **parallel universe**. Hence to imagine our life in the 5th dimension, think of it as a vast 2-D plane of all and every possibility consisting of all parallel universes possible. The life that we live, or our timeline, consists of branches and possibilities that are governed by our choices and chances.

So, **the 5th dimension is like a 2-D plane with all possibilities of events from the day we were born, also called the ‘probability plane’.**

# Travelling in the 5th Dimension

**There are some limitations to moment in the 5th dimension as per the principle of Causality**.

The principle states that an event in a timeline in the probability space (Remember a probability plane is is like a 2-D plane in the 5th dimension with all possibilities of events from the day we were born) can only occur if the effect that caused that event also occurs in the same timeline. In simpler terms, if event A causes event B, and you went back in time to stop event A, event B will not happen. If you now want to go to a parallel universe in your timeline where you become a very successful and famous person (Event B), you will have to go back in the probability space and try every possible option of chance and choice (Events A1, A2 etc that cause B) to get to such a universe.

But there is shorter path — if you could fold this 2D probability plane in the 6th dimension, you could jump from one point on the plane to another in the 5th dimension. Remember the definition of a higher dimension — A dimension is what you have to fold through to jump from one point to another in the dimension below.

One of the possible parallel universe is the one where the asteroids did not fall on earth, and the dinosaurs are still alive. But we can not reach that universe in the 5th dimension. This is because we are limited by causality. We cannot get to other versions of the universe which are not causally connected to the one we’re in right now. In simpler terms, you cannot go back in time & branch out in the probability plane from a point before you were born. This is because in that universe, the events leading to your birth may not happen. Hence, the 5th dimensional probability plane contains all possible universes that had the same initial conditions as ours (at the time of birth).

# Teleportation & 6th Dimension

A way to look at the 6th dimension is from Everett’s Many Worlds Interpretation of quantum mechanics. It presents the **6th dimension as the ‘phase space’ of the set of parallel universes resulting from our universe’s unique initial conditions (the big bang).** So there is probably a parallel universe where the dinosaurs are still alive, or where Donald Trump is not the president of the United States. In simpler terms, everything that could possibly have happened in our past after the big bang, but did not, has occurred in the past of some other universe or universes.

The Many-Worlds Interpretation (MWI) also holds that these worlds exist in parallel simultaneously at the same space and time as our own. This means that these parallel universes do not exist in some other regions of space. Instead, they are right here, superimposed on our universe.

So **the 6th dimension is a 3D space of every possible ‘worlds’ or state of our universe that exist after the big bang.**

In the 6th dimension, 3-dimensional events are not interdependent, and your movement is no longer limited by causality. You can leap across different world lines, and get to other versions of the universe without having to worry about fifth-dimensional causality. In other words, you can teleport — from your universe to any point in time on any universe that was possible after the big bang. So you can travel or teleport yourself to a universe where Dinosaurs are still alive!

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by Aditya Khanduri