Imagine this. You have some object (let say barrel) and fill it with water. The water remains rather calm so it doesnt' spills out. Then we take a balloon filled with air and push it in that tank. What will happen when i release the balloon? Which side it will go? (if its in the middle) Will it direct to the open area of the barrel or to the bottom?
Same goes if somehow we form a perfect sphere of water and put the balloon inside of it. Where it will be pushed?