I have found scientists wrong with there 4d and 3d idea....
Space = vacume...... objects can go any direction and will never stop unless another force is acted upon them... (newtons law)..... Meanin 3d!
4D = GRAVITY
All planets have gravity.. Here horizontal components well only stop unless another force is acting on them... but verticle remains 9.81N ''down''... This sense of direction up, down, left, right, due to gravity, I believe is the 4th dimension!
Crazy

I randomly thought of this the other day.
It goes against many rules of science and logic... But thinking about it it makes sense?