Understanding the Impossible
The 4th Dimension
The 4th Dimension
The 4th dimension is very difficult to fully understand because we, as 3-dimensional humans, are not supposed to understand it. It’s something that is fundamentally outside of the world that we can access and manipulate.
Imagine being a 2-dimensional circle on a piece of paper. Your vision is only 1-dimentional lines, and anything other than that would shatter your worldview. Now imagine a 3-dimensional being lifting you from the paper and magically giving you the sight to see the 2-dimensional world.
This is the equivalent of a 4-dimensional being picking you up and giving you the ability to see the entire Earth all at once, around and inside out. This is similar to a 4-dimensional surgeon being able to perform procedures inside without needing to cut through the skin, as they can simply see inside.
To a 4-dimensional being, 3-dimensional borders do not exist. They can see everything all at once. This concept is so mind-boggling that it confuses even the best scientific minds.
The widely accepted 4th dimension is called space-time. It’s two seemingly separate ideas combined to create a confusing science concept. Space-time has many different explanations.
One explanation is that space-time is like a sheet of elastic rubber that gravity can warp. This means that the more gravitational strength something has, the more it alters space-time. An example of this would be the Earth and the Moon. If we think of Earth’s gravity as lying in the “rubber” of space-time, the space-time would sink with the Earth. Then, if the Moon were a marble, thrown into the vicinity of the Earth, it would follow the curvature of the funnel-like distortion of space-time and orbit the Earth.
This is a very complex explanation and still not the full picture. Another explanation of space-time is using a cage. Once more, imagine being a 2-D circle, but this time a square cage has been put around you. From your point of view, there is no way out, no gap in the cage where you can escape. This seems silly to a 3-D being, however, because a 3-D being could just walk over the 2-D line that is trapping the circle.
The same is true for 3-D beings like ourselves. If you are trapped in a cage with 4 walls, a roof, and a floor made out of indestructible metal, how would you get out? Well, a 4-D being would find this trivial because all they would do is use their 4th dimension of space-time to escape. They would simply travel to a point in time where they are not in the cage. Just like how we would use the 3rd dimension to escape a 2-D cage, a 4-D being would use the 4th dimension to escape the 3-D cage.
Time is something that 4-D creatures can travel through, as confusing as that may be. Past the 4 dimensions, the theories have no real proof or explanation. Some say that higher dimensions incorporate spirituality, love, or something that we, as humans, do not yet understand. No matter the answer, explaining these dimensions is key to fully understanding the inner workings of our universe.
Importance
Studying higher dimensions and concepts is important because it unlocks fundamental things about everything, ranging from how light works to figuring out if the movie Interstellar is accurate.
We need to understand these concepts to fully understand all the forces of the universe, such as gravity, electromagnetic, the strong force, and the weak force. If we fully understand these things, it could be possible to harness so much more of the universe. Black holes could be used to travel through space-time in bizarre ways. We could use concepts learned to terraform other planets or give a better quality of life to more people.
Overall, our understanding of the universe is only at the beginning and understanding higher dimensions is a good start.
Sources
A very good video from StarTalk with Neal deGrasse Tyson
https://science.howstuffworks.com/science-vs-myth/everyday-myths/see-the-fourth-dimension.htm