8 things that are unusually white in nature

Disorganized and different-sized air bubbles reflect white light back to us.   

Pockets of air are not only encompassed with water. Other natural materials hold air bubbles hostage. For example, molecules such as proteins from a translucent egg white that is beaten by a mixer can form pure white meringue.

Most of the time, the gas molecules are air molecules (oxygen  (O2) and nitrogen (N2) gas).

But other times, the entrapped gas is something else. For example, the gas that forms the beer head and the foam on a soda drink is carbon dioxide (CO2)

Fermentation proteins of beer forming the “head” of a pint of beer.  The gas that produces the "head" in a pint of beer is carbon dioxide, though nitrogen is sometimes added to produce a longer lasting, less acidic taste. 

Fats are also very good at holding air bubbles captive. There needs to be  at least 30% fat in cream to allow the fat globules to encompass enough air bubbles for a whipped texture.  

Whipped cream that lasts for days

Of note, if you add protein (which act as cohesive molecules) to the cream, this will help make the whipped cream keep its shape longer. This is because the proteins attach to the water layer of the milk and create molecular nets that also hold the air bubbles in place.  Examples include adding gelatin or non-fat powdered milk to the whipped cream mixture. 

Both techniques will result in whipped cream that has stiffer peaks that keep their shape for longer than 1 day.

What is the biggest soap bubble one can make?

On another note, one can make single large bubbles that maintain their shape for a longer time. One way of doing this is through adding corn syrup to the soapy mixture.

Keep in mind that the netting that holds air bubbles in place - in soap, cream, or egg whites - contains a layer of water. When one incorporates a sugary molecular substance into that water layer, everything becomes many times more cohesive. 

The increased stickiness of the water layer allows the soap bubble to expand to considerable dimensions. 

Moreover, since the glucose molecules attract the water molecules, the soap bubble takes longer to dry out. It lasts longer without popping.  

Even glass can trap air bubbles. When there is enough of them to cause a disorganized refraction of light, they will appear white.

Polar bear skin is not white. The hairs that make up the bear's fur are transparent and hollow; this fur covers a black skin! However, when sunlight hits a polar bear's fur, the light scatters from the air mass within the straw-like strands of hair. The result is a white coat.

Polar bears and Mynah birds have something in common. Their protective covering encases air pockets in translucent materials. Mynah bird feathers are not white: the feathers of the Bali Mynah bird tend to be hollow entrapping pockets of air. 

In both the fur and feather examples, the casing is made of protein molecules that are a form of keratin. This is the same protein that makes up our hair and nails.

The same concept - adding cohesive molecules to foamy liquids makes the foaming bubbles last longer - is the reason sea foam gets created.

Proteins from broken down biodegradable material, like algae, mixes with the water. Thin layers of protein and water hold innumerable bubbles in place. The result is a long lasting foam.

Keep in mind, that not all white things in nature are due to reflection off a bunch of gas bubbles. The microscopic structure and arrangement of the fibers can reflect light back to us, creating a structural white color.

Examples include:

• wings of butterflies 
• bright-white beetles
• the white bark of birch trees.

In some of those cases, the actual material is colorless and transparent. However, because it scatters white light, it will appear white. In those 3 cases, air bubbles are not the reason for the white color.

Finally, some flowers create a pigment that echoes all light; , creating white flowers. 

In effect, disorganized interfaces that entrap gas molecules (like nitrogen N2 and Oxygen O2) reflect light. Keep in mind that air - like most gasses - is colorless. It doesn't absorb any wavelengths of light. Without a visible container encompassing gas molecules, the gas would be transparent.

Even if the substance holding the bubbles in place is transparent (like water), light can be bounced at the level of the interface. Some of the light echoes back to our eyes. This creates the whiteness, as if the bubbles were painted.

 "Whiteness" is produced depending on the level of chaos around bubbles. The more refraction (bouncing around) of light, the whiter the surface of the object will appear.