I have been reading about dimensions, and I understand that: A dot has no dimensions A line has 1 dimension A square has 2 dimensions A cube has 3 dimensions A tesseract has 4 dimensions And time is another dimension just like those In theory we can think of lines and squares, but we can't build them in the real world. If any of all the dimensions of an object is zero, then the object does not exist. For example: If a square has 0 depth, it can't exist in the real world, or can't be built because even a atom has 3 dimensions. The same applies to time, because if a tridimensional object exists for 0 seconds, than it never existed. (all above is what I understood, correct me if I'm wrong) But what I really want to ask is: If nothing can exist or be built in less than 3+1 dimensions, does that mean every object in the universe must occupy some space on all the other dimensions that exist? For example, if our universe is described by 4+1 dimensions, and tesseracts can be real objects and be built somehow, then our bodies, cars, houses and anything we can build, must occupy some space on that fourth dimension, or they couldn't ever exist on our perceptible 3+1 dimensions. Because if the length of a body on the forth dimension was 0, it couldn't exist at all. If that is true, than everything we see and touch must occupy some space on all other dimensions the universe has, even our own bodies. Does that mean there's a portion of our ourselves we can't see or perceive?