"To understand what it is to even try and wrap the human brain around the appearance or even existence of a 4th dimensional being is impossible. To give humans a vague idea, picture a race of beings existing in 2 dimensions for a moment. Thats right, youre a stick figure on a sheet of paper, with stick buildings and other stick people who inhabit this sheet of paper. You have a society, religion, and economy. Now, imagine a human entering your world. How does a 3-D being enter a 2-D world, you ask? Easy, stick his finger thru the sheet of paper. The effect could be 2 fold. One, you destroy their world creating a rift in the fabric of their existence. Or two (and this is the accepted idea), you pass thru only revealing to those 2-D stick-people the portion of your physical body that sits on their plane of existence (ie the sheet of paper). You would only be perceived as a floating, shape-changing blob of very odd coloration and texture (the cross section of a human finger).