The Ancient Description
Ancient Toltec Indians (source: Carlos Castaneda) described existance in essence as being energy, luminous energy (2D) strings that transcends all matter and awareness in the whole universe. Furthermore, we human beings are luminous eggs of light. The luminosity in the eggs are made of these strings, and the luminosity is equivalent to awareness itself. The size of these eggs are about the size of an egg that would cover our body wherever it could be stretched. If we imagine that old da vinci picture (http://www.da-vinci-code.nl/vitruvius.jpg), we can approximately find the size of our luminous eggs.
The Assemblage Point
The assemblage point is a stronger light in the luminosity of the egg of our being. It is located a couple of feet behind our shoulder blades. This stronger 'light' in our 'light' body is what makes us perceive. This is where the higher dimensions come into play. When we experience the normal physical world, the realmspace, our assemblage point assembles strings of light, and 'activates' them. It clusters together the strings, making them appear as clusters (as we experience 3D). Why I say activates is because our assemblage point doesn't only assemble the strings, but it lights them up, and makes us perceive them.
Why is it 4D?
Well now, let's say we move our assemblage point. Obviously we cannot move it in any direction in 3D, because when we move in realmspace it doesn't dissolve into another dimension. However, if we could dissolve normal physical realmspace and perceive a completely different third dimension, it would mean by definition that we must have moved in at least one higher direction.
How to perceive our luminosity
It is possible to perceive this, and all beings can sense it intuitively. To perceive it however, we cannot use our normal realmspace sensory organs, such as eyes, ears, etc. We have to go beyond that, perhaps with (what Tibetan Buddhism call) the sixth sense, which would be the mind where all senses lie. The mind is quite directly related to dreams, which in my theory could be expressed as the experience of the higher dimension. However, it is not limited to dreams, as these ancient indians used dreams to move in higher dimensions; they could move in them also awake.
How to experience the higher space in real life?
In order to perceive that at least one higher space dimension exists can be done with a lot less concentration or meditation (or drugs) that you need in order to perceive our luminous (higher dimensional) body. We can in fact do it with a little twist of the premises of science.
The premise of science
Take the premise of science that we can use experiments to prove the existance of phenomena. Usually this suggests that what we perceive is true, however if we hallucinate it is not true, because it is believed to be only imagined. The twist needed here is that we actually can observe the universe objectively, and that machines are not more objective than we are (ok, in fact they are objects and we aren't right
), but they are tuned in to function precisely in three dimensions. If we can observe 3D-phenomena generated by machines, then why wouldn't our perception be able to perceive higher dimensions? And where would the machines ever find them, when anything beyond 3D can't be pointed at? Only we can perceive it, with parts of ourselves that extend the physical, using those parts, those parts only being able to exist in what is usually called hallucinations 
So, how do we find it already?
I have found two ways to find this in normal life, if we exclude lucid dreaming.
The first way, is to objectively look at objects around us. Take anything on your table, anything that you can focus on. Focus on it thouroughly, really trying to grasp how it appears. I look at a plate. I recognize the plate of course, know that it is the place I left there earlier, and that it functions normally in 3D-space. In other words, it has the same length, width and depth as always; the same colour, the same texture, etc.
However, if the object is 4D, how could we perceive it? We cannot perceive it by interacting with it normally, as everything we are used to is already defined as three-dimensional. If we take however that our minds actually can perceive the higher dimension, we can check in our minds to see if any property we can think of relates to a higher dimension. Since we are not really using higher senses we have to use some kind of 'feeling'. Is there anything about the plate that feels different? I mean if we look absolutely as precisely as possible. Is there some way that the object we perceive in fact isn't exactly the same? Again, I don't mean if the 3d shape is different, we know it isn't. I mean if the 3d shape feels different, because a circular object might not feel to appear exactly the same every time we look at it.
I know this method is a bit farfetched, and many of us might not notice any different in perception. A questioned arised here is of course when is it different from? That is where the experimentation actually can take place. If you find an object, and look at it like described above several times, especially when you feel different. When you feel bored, when you feel inspired, when you feel happy, when you feel sleepy(!). The best way to notice this is to use the old trick of being sleepy. You can even hold your keys in your hands and fall asleep in your chair. Instantly when you wake up look at the object. Do you see what I mean?
Since it actually requires a lot of concentration to do this in real life, I would ask those of you who don't experience the difference to at least try to understand how I mean it is actually a way to show a fourth dimension. It doesn't matter if anyone believes in this or not, but it is a 4-dimensional exercise that can help you expand your mind and try to visualize the higher dimension.
That's it for now! I'd be very happy if anyone would try out my theories, and not bother too much with small factual errors. Of course if I have made mistakes I'm glad that you tell me, but the point here is to try to find the higher dimensions, not to try to explain it away, right?
Thank you for your time,
Ribot.
