Why a Balloon Floats in the Air and Bubbles Rise in Water - Mystery & Facts

• There is no mystery whatever is involved in the floating of balloons in the air.  A balloon filled with helium will certainly float in the air just like the bubbles rising in water.  
• The scientific explanation here is that the balloon is lighter than the air and the bubbles are lighter than water.
• While gravity pulls down the air, it also pulls down the balloon and since the air is dense, gravity has the ability to act on it but not with the balloon.  
• Same is true with the bubbles which rise in the water, gravity has the ability to act on the water because it is dense but not with the bubbles.
• In other words, gravity can only pull objects with corresponding weight and not objects without weight.  This has something to do with relative densities.  
• Objects which are heavier are pulled more intensely than lighter objects.  Space is also an important factor in analyzing this case.
• The 2 major factors that contribute to the ability of gravity to pull down the air and water are weight and volume.  Weight is known as mass in Physics and volume or space is termed as density.  
• These 2 major factors are the determinants on what objects rise and sink in the water and on air.
• This theory known as displacement states that whatever volume has on objects tend to displace or move something out of its path to occupy a space.  
• In simpler terms, this means that when objects with different densities are in fluid form such as air and water, the objects with more density sink lower than the objects with lesser density.
• Therefore, the force of gravity against the object is stronger to force the object with lighter weight out of the heavier object’s way.  Since the water is denser than air, water sinks below the air.  
• A stone is denser than water so it sinks below water and air.  Helium which is inside the balloon is less dense than air and water so it rises above the air and water.
• Even with the small weight of the balloon, Helium is still less dense than the air which enables it to rise.  Gravity pulls down everything but there are some objects which have greater forces than other objects.  
• Whatever floats in the air is the same as in water.  An object which is less dense than water will float in the same way as an object which is denser than water will sink.  
• An object less dense than water which is suddenly released from the bottom of water will definitely rise.
• In the same way that Helium which is less dense than the air if suddenly released from the ground, Helium will rise.  
• However, in the outer space, helium will not rise; it will be pulled down by the force of gravity in the atmosphere, while a human being which is dense than the air will float in the outer space.  
• If you weigh a balloon full of air and a balloon full of helium, the latter will be less dense.