[raaaid]

do you want to be able to percieve the fourth dimension:

you know now how to see double:

take two identical pencils aiming away from you on a table and look double at them overimposing them

depending on weather the pencils shape a v a ^ or a II your having the perception of the fourth dimension within the third in different directions

so in the third dimension you know the pencils aim away but in the fourth dimesion you see them aiming towards you

think about it from stereoscopic flat surface you perceive 3d from stereoscopy volume you percieve 4d

thats why its so relevant us not having depth perception, if we did we would have accs to the fourth dimension + time