Is there a fourth dimension? I am not talking about the 4th space-time dimension because time, even though is one dimension, isn’t the same as space.
Think of it, why should spatial dimensions stop at 3?
If you are a one-dimension being, you can only move forward and backward. In such a world, you will not know of the concept called left and right, because you would think that they don’t exist. The same situation exists for a creature in a two-dimensional world, who knows how to move forward, backward, right and left, but doesn’t know anything about up and down. Ask the creature in the 2D world to go up, and they will ask you to prove to them by showing them how. Well, you may think it is easy to show them, but convert yourself to a 2D creature, ie flatten yourself from head to toe, float into the 2D world, and then try to show them how to go up. You will suddenly find that you can’t go up or down anymore. The reason is because the up-down force or propulsion for moving up or down doesn’t exist in a 2D world (like a car that has no engine to fly). Also, in a 2D world your eyes will only allow you to look forward, so you can’t see anything upwards or downwards, thereby making the third dimension an imaginary one only.
Likewise, in our 3D world, we do not have the propulsion mechanism or force in the 4D direction, and our eyes can only see in 3D and therefore can’t imagine the 4th dimension. However, not all is lost though. It seems that we can use analogies between the 2D and 3D worlds pretty well to help us understand the 4D world.
First, the person in the 2D world, unfortunately, cannot get to the 3D world himself because he doesn’t have the propulsion ‘technology’ to jump! So he needs someone from the 3D world to pick him up. In other words, a 3D up-force is needed to lift the person up. When the person is lifted from the 2D world, he disappears from the 2D world because he is now floating above the 2D world. His friends in the 2D world can’t see him but he is actually just above them. Now when he speaks to them, they will get a shock because the sound is coming out of nowhere to his 2D friends. The amazing thing is hovering above the 2D world, this guy can actually see the top view of his friends which is actually the inside of their bodies! Next surprise is if he lands back into the 2D world after being flipped over, he is still in 2D but a mirror image of himself!
Now, apply the above scenario to someone going from 3D to 4D. First, someone in the 4D world must ‘pick’ him up. Then he literally disappears from the 3D world, much like the behaviour of spirits and ghosts. Then when he speak to his friends in the 3D world, they get a shock as the sound appears to come out of nowhere to them, even though he is just next to them in the invisible dimension. Now, the beauty of the next dimension would be mind-boggling because from the 4D world, he should be able to see everything in 3D at the same time, meaning front, back, top, bottom, left, right and even the inside of a 3D object. He could practically do surgery on the inside of his friends without touching the outside! That’s a little hard to imagine, but I think it would be close to imagine it as a pure 3D solid space that permeates everything inside that space. It is something like picturing the person inside your eye where you can turn him around in your eyes and look at him from all directions and then go inside him to look at him from inside-out. And that’s just imagining 4D vision, not 4D beings. The final surprise is if he lands back into the 3D world after being flipped over, he ends up in a mirror image of himself, changing from right-handed to left-handed, and his heart appearing on the right hand side! Wow, that would be cool, and it will surely mess up all the science/physics of the 3D world!
Does that sound far-fetched? Well, I don’t think so, since the spirit world almost definitely exists and the only way the spirits appear invisible to us must be due to the fourth dimension. And who knows whether there are even more dimensions after the fourth? Somebody that can see the inside of ghosts?