Transfer of Liquid
Official reason in physics why you can suck up and transfer liquid from can "A" to can "B", is because of "atmospheric pressure" on utensil "A".. (I will ALSO consider the utensil B, because I know that people like to change story once proven wrong. So I know that they will say: oh, no, it was because of atmospheric pressure on utensil B...).
1. The water flows always from utensil A to utensil B.
a) The air pressure on utensil A can't cause that because it's LESS than atmospheric pressure on utensil B.
b) If they meant the air pressure on utensil B causes it, then it's not possible because then the liquid would go UPWARDS.
(Pic.1)
The transfer occurs because the weight of the water on the side of Can "B" is bigger than the weight of the water on the side of Can "A". Since creating a vacuum in the hose would take more force then the weight of the water on the side of Can "A", the water in the hose on the side of Can "B" pulls the water from the Can "A".
The water in the hose of the utensil on the floor weighs more, than the water inside the hose of the utensil on the table. The atmospheric pressure is absolutely negligible compared to the weight of the water in the hose. It would take more force to separate the water in the hose, than the force that is provided by weight.
It can be verified simply by lifting hose up and noticing that the water stops flowing once both sides of the hose are at the same level.
PAWEL KOLASA