# String theory: does the Universe have 10 dimensions?

Imagine you live in a lake. You are a fish that has eyes on both sides of your head, and all you know in your life is the underwater world with its vegetation and other fish swimming around you. Sunlight penetrates, scatters and refracts into the water. You are convinced that this is the whole world, because everything you see and feel is around you.

However, outside there is a radically different environment, far from your visibility, your sensory capabilities – where animals do not need water to breathe, and flowers bloom in a much drier world.

This is also the physical situation in which we all find ourselves. We are something like these fish, and all the other dimensions, higher and more complex than our three-dimensional world, we simply cannot perceive.

In fact, there is a theory that tries to find the connections of our world with quantum mechanics (the laws of the big world with those of the microworld). But this theory could be valid only if we assume that the universe consists of the more familiar to humans 4 dimensions to which we are accustomed. Many physicists believe in this theory and try to prove that there are 10 or even 11 dimensions in the Multiverse (multiple universes, like merging and dividing bubbles).

String theory aims to unite all physical interactions (weak, strong, gravitational and electromagnetic) into one. But this is a rather complex task, a world far more complex than ours. And yet – here is a brief attempt at a simple explanation of the many dimensions of which everything probably consists.

**Our ordinary world**

The reality around us is much easier to understand. To orient ourselves, we need only 3 dimensions, starting from zero. In geometry it is represented by a point. This is an object that each of us knows and is just a simple concept. It has no parameters such as length and width. It has no dimensions.

When we connect two points in space, a one-dimensional system is obtained. It’s called a line. We can move on it and set a position, but the objects in it can only have a width. We call it the “X” axis.

If we build a standard coordinate system, we will get the second dimension – the two-dimensional world of the first animated films. Here we already have width and height (add Y axis). We encounter such objects constantly – the images on the monitor, the drawings, even the games, although they seem deep to us.

If we add the depth measure, the third axis to the coordinate system (Z axis), we will get our already known world. Everything we see around us is three-dimensional (with a few exceptions). You can imagine this dimension as space, but without time.

**The fourth dimension**

Although we do not see it, it is still part of our real world, but it has no spatial significance. It consists of… time. Time helps us to find the location of an object in the universe, as well as to add a way to change the third dimension. Remember we called the third dimension space without time? Well, now we officially have space time.

The one who makes a great discovery, proving that space and time are connected, is called Albert Einstein. But even without it, it is not so difficult to imagine the 4th dimension. Think about your life so far. No matter how long it is, it still consists of individual moments, moments, something like footage from a film tape glued together. If you combine all these events, you will get a dimension. That is why the 4th dimension for you are the shots of your whole life.

**The fifth dimension**

All the dimensions after the 4th are not yet fully proven, and they are also increasingly complex for our ideas. They are all invisible to us, so many scientists believe that they exist on a subatomic level.

According to the Theory of Multiverses, at any given moment we create a new reality in another dimension. You leave your home and turn left, but in another manifestation of your being you turn right. This is the fifth dimension. But here’s an even clearer explanation…

Many of you have read articles and novels about time travel and know what an important role the distortion of the space-time continuum plays in most of them. This is exactly the 5th dimension itself – it is in it that our four-dimensional space-time “folds” to bring two points closer, connecting them in lines. Without this folding, the journey between the two points would be too long or impossible.

If we make a rough analogy – the fifth dimension is analogous to the second. But in it we must consider space-time as a one-dimensional line, part of a two-dimensional plane with all its possible directions, at all angles. Do you get it? If you look at our world as a ruler, it can be oriented in countless many directions, which is why each of our actions creates a new reality in the Multiverse.

Perhaps some more familiar readers have already thought about the possibilities of free will in conditions where the future already exists, but is not yet known. Science calls the answer to this question probabilities. The future is not just a stalk, but a huge wreath of possible scenarios. And we will find out which of them will take place when we get there.

**The sixth dimension**

Each of these probabilities exists as a one-dimensional segment on the plane of the fifth dimension. But how do we quickly jump from one segment to another? Of course – we will fold the piece like a sheet of paper. But where to fold it? That’s right – in the sixth dimension, which gives these complex structures “volume”. This action now allows you to fall not only into the future or past of the present world, but also into every possible reality of another, parallel world. There you can see all possible future, present and past events from the very beginning of our universe. Theoretically, if you can master the fifth and sixth dimensions, you will be able to travel through time and choose a completely different, alternative future. Or the past.

**The seventh dimension**

Here things get even more complicated. From the seventh to the ninth dimension, the possibility of new universes with new physical forces of nature and different laws of gravity and light already appear. The seventh dimension is the beginning in which we encounter new universes that have a different beginning from ours. That is, they did not appear as a result of the Big Bang. In the dimensions up to and including 6, we still had a starting point – namely the Big Bang. In the seventh, however, these starting points are infinitely many. There is an opportunity for any beginning of any event. Infinite number of big bangs.

You can think of the seventh dimension as a new direction, a segment that consists of an infinite number of six-dimensional… points. So each point of this right has an infinite set of options for the development of events in another universe, formed not as a result of our Big Bang, but in other conditions and laws. That is, the seventh dimension is something like highways of parallel worlds!

**The eighth dimension**

It gathers all the lines from the 7th dimension into one “plane”. This is the plane of all possible past and future times for each universe, extending to infinity. The eighth dimension provides even greater possibilities – an infinite number of beginnings and developments of all events. In fact, there you can find out everything about all the universes – from beginning to end.

**The ninth dimension**

It can be compared to a book that contains all the “sheets” of the eighth dimension. It is the totality of all the histories of all the universes with all the possible laws of their physics and all the initial conditions and “big bangs.” Closing this book, we will come to the last, tenth dimension, which in itself is a new “point”. There we are already at the limit.

**The tenth dimension**

It can again be seen as a ‘point’, which, however, already encompasses everything possible and imaginable. Beyond this last dimension, we cannot imagine anything. This is the limit of what we can achieve in the other previous dimensions.

According to the Theory of Strings, it is in the tenth dimension that the strings perform their oscillations – the basic particles that make up everything. If the tenth dimension contains everything and all universes, plus all possibilities, then strings exist everywhere and at all possible times. That is, every string exists in our universe, and in every other at every moment of time.

Interesting, isn’t it?