The concept of "Could it be so easy?" refers to the idea that the fundamental laws of physics governing the universe may have a simple and elegant explanation, despite the complexity of the universe itself.
Space being three-dimensional means that it has three spatial dimensions: length, width, and height. This is the most commonly accepted understanding of space in the field of physics.
We perceive space as three-dimensional because that is how our brains interpret the information from our senses. Our visual system, for example, uses depth perception to determine the distance and position of objects in space, giving us a three-dimensional perception of our surroundings.
There is a significant amount of evidence from various fields of study, including physics, mathematics, and neuroscience, that supports the idea that space is three-dimensional. For instance, the laws of motion, such as Newton's laws, are based on the assumption that space is three-dimensional.
Yes, there are alternative theories, such as string theory, that propose more than three dimensions of space. However, these theories are still speculative and have not been fully supported by empirical evidence.