Do extra dimensions exist in the universe? Why do scientists want to prove multidimensional space?

Einstein's theory of relativity proposed that the universe is a four-dimensional space-time consisting of three-dimensional space and one-dimensional time.

However, with the development of physical theories, more and more scientists believe that additional dimensions may exist in the universe. The proposal of extra dimensions has given a whole new direction to physical theories, and many advanced physical theories have started to use extra dimensions to complete the relevant theoretical foundation.

If the existence of multiple dimensions can be proved, many theories can be developed more widely. In three-dimensional space, the structure of matter is confined to three dimensions. If there is a four-dimensional or even higher dimensional space, the structure of matter can be more abundant.

Multidimensional space can provide more possibilities:

If we live in two-dimensional space, then the whole world is only long and wide, and the structure of matter will be very simple. We can draw the possible structures in two-dimensional space on a blank sheet of paper.

But when two-dimensional space is extended to three-dimensional space, the structure of space will be instantly much more complex. Considering Plato's three dimensions, in three dimensions we can see tetrahedra, octahedra, cubes, dodecahedra, and icosahedra. Each face of these three-dimensional blocks consists of a polygon.

Three-dimensional space is just one more dimension than two-dimensional space, but the spatial structure will be much more complex and the movement of objects can get additional directions.

Using the extra dimension, physicists can discover many advanced theories. These advanced theories, although difficult to prove, can form a relatively unified physical theory that unifies the four fundamental forces of the universe.

A representative of advanced theories is string theory, which requires a high degree of extra dimensionality because string theory is based on the assumption that all particles are composed of vibrating strings.

However, scientists have now discovered a large number of particles, and it is difficult for strings to produce enough particles just by vibrating in three dimensions. So string theory suggests that there are at least ten spatial dimensions in the universe and that strings can vibrate in ten dimensions to produce enough microscopic particles to give rise to the universe we are familiar with.

Do extra dimensions exist in the universe?

Because human cognition is limited to three-dimensional space, we know a lot about one-dimensional, two-dimensional, and three-dimensional space, but nothing about four-dimensional space.

It is unrealistic to imagine a four-dimensional space based on space. Scientists mainly speculate about four-dimensional space through scientific phenomena in one-dimensional, two-dimensional, and three-dimensional space.

The hypercube, the model of four-dimensional space that we often see, is a model of four-dimensional space inferred from the connection between two-dimensional space and three-dimensional space. The cube in the middle of the hypercube is not small, but a cube of the same size as the periphery. Due to the emergence of the fourth dimension, the cube has the perspective effect of near large and far small, so the cube inside the model is smaller.

Two-dimensional planes can be copied and connected to form three-dimensional bodies. Copying and connecting three-dimensional blocks, perhaps four-dimensional blocks, is also the main idea of the hypercube.

But the line formed by the connection of cubes is not the dimension of three-dimensional space, but the fourth dimension. So we can't observe the four-dimensional blocks, we can only see the projection of the four-dimensional blocks, and this projection is the hypercube.

The hypercube is not two cubes, but eight cubes.

Imagine two-dimensional space squares stitched together into a cube, and the squares need to be stitched upwards. The place where the two-dimensional planes are stitched together is the third dimension.

If you replace the two-dimensional plane with a three-dimensional block, use a similar method to crimp the patchwork. The cube will be squeezed to form a four-dimensional volume.

Because our spatial perception and observation ability are limited to three-dimensional space, we cannot observe the three-dimensional volume being squeezed to form a four-dimensional volume, we can only observe the projection of the four-dimensional volume through the hypercube.

Does the inability to observe four-dimensional space mean that there are no additional dimensions :

For four-dimensional space, scientists have built many models related to it, but objects in four-dimensional space never appear in our life. Is it possible for a dimension of space that cannot be observed and appears to exist?

If the space we live in belongs to a three-dimensional universe without a fourth dimension, then all physical theories with extra dimensions would be empty talk, so extra dimensions beyond three-dimensional space must be all around us.

To find extra dimensions, scientists have conducted a special experiment - to find evidence of interactions between different dimensions. Simply put, it is proof that talking in two dimensions can also be heard in three dimensions.

Scientists experiment with gravity, but the experimental results show that the gravitational force of three-dimensional space objects all act in three-dimensional space, consistent with the conservation of kinetic energy, with no additional force loss.

It shows that these dimensions cannot influence each other, or the influence is very limited, and cannot be found with the current precision of human equipment.

It can also be concluded that even if we find the four dimensions, we can't disturb it too much or even disturb it, and these extra dimensions may only have a great influence on the microscopic world.

Summarize:

With the introduction of extra dimensions, many scientists have discovered new directions in physical theory, but there is no evidence for the existence of extra dimensions.

Although extra dimensions have not yet been proven, for physicists, extra dimensions can provide more possibilities for advanced development of physical theories, rapid formation of more advanced theories, and even the discovery of theoretical "unified theories" using extra dimensions. Therefore, many scientists want to prove extra dimensions to give fundamental support to advanced physical theories.