Why are clouds pink and other questions

Article 3 Module 1

Here are 9 questions that made me think through the answers. Try giving yourself a few minutes to come up with an answer that makes sense. I welcome comments and answers that help expand on mine. 

Clouds with dark underbellles

Why are the underbellies of clouds dark?


There are more liquid droplets than packets of air in the bottom most part of the cloud. Those masses of liquid water droplets absorb light, leaving very little to reflect back to us.

clouds with flat bottoms and cauliflower tops

Clouds with flat bottoms

Why are the tops of clouds the whitest part of the cloud?


As warm and moist air makes its way higher in the Troposphere, it meets lower pressures. With lower pressures, there is expansion of the mass of air and cooling. Water vapor and liquid water droplets cool into ice. This captures air molecules in place, allowing for white light reflection. 

pink sunset

Why are clouds pink at sunset?


For the same reason that clouds are white. During the daytime, the air molecules are reflecting white light. At sunset the lightwaves coming from the sun are only the longer wavelength ones. These are red. 

Clear ice cubes

Clear ice cubes: no air bubbles

How can one produce clear ice cubes?


To produce clear ice cubes, the water has to freeze from the bottom to the cube to the top. If this is done slowly, it allows the air bubbles in the liquid water to be pushed out as the ice freezes upwards. The ice cubes shown were produced using this method.

Polar bear white fur

Why do polar bears fur look brown or discolored?


It could be one of several factors. Aging of the hair shafts (with discoloration of the keratin molecules), an oily covering from hunting seals, or wear and tear on the hairs.

Giant soap bubble

How does one make huge soap bubbles?


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.

Fog in Autumn

Why can't we see in fog?


In fog, as in clouds, there are disorganized masses of air molecules that are held in place by a water vapor netting. 

The layers and layers of air molecules bounce light all over the place, preventing it from going through. It would be like placing several shrouds in your field of vision. The light cannot penetrate through.

Blue color underneath the footprints

Why does snow sometimes look blue?


In the arctic, even after snowstorms, deep snow can reflect blue light back to us. The blue is a stunning bright sky-blue color. Such snow will have to have to be more than 1 meter deep, starting out as wet snow, and with larger ice crystals to create that blueness. 

As a result, this blueness is used as a measure of safety by explorers: This is because older, thicker. and denser ice has no crevices harboring air. Fresh ice is white; it is thinner and has air bubbles mixed in between the frozen crystals.

Huge soap bubble

Why does a single soap bubble look clear and transparent as opposed to white?


Air molecules in the environment around us are spread far apart. Thus, even though the molecules are randomly distributed, there is more than enough space between them for light waves to go between.

Contrast that with air molecules in clouds or a polar bear's hair shaft. Those molecules are packaged in packets through a translucent netting. This crowding and bunching up of the air molecules creates different interfaces for light to reflect off. Moreover, lightwaves have no clear pathway to go through and come back without hitting a grouped packet of air molecules

Picture Credits: 

elPadawan. Giant Soap Bubble: Giant soap bubble outside the New Yorker shop, Můstek subway station, Prague. Flickr photo-sharing. July 12, 2012.

  1. Kaarina Dillabough.  Sky beauty. Flickr photo-sharing, taken on June 9, 2007.
  2. J. Hijab. Mounds of clouds. Summer, 2019.
  3. Valentina Powers. sunset. Flickr photo-sharing, taken on July 21, 2007.
  4. J. Hijab. Clear ice cubes made at home, summer 2019.
  5. Björn Söderqvist. Looking cute. Flickr photo sharing, taken on April 28, 2007.
  6. elPadawan. Giant Soap Bubble: Giant soap bubble outside the New Yorker shop, Můstek subway station, Prague. Flickr photo-sharing. July 12, 2012.
  7. J. Hijab. Fog on a fall day, Fall 2018.
  8. 3. By Yiyi Huli. Shutterstock, ID: 1465523039. In the cold winter, the outdoor road is covered with heavy snow. People walk on the snow to leave footprints. When there are more people walking, they become deep footprints.
  9. kismihok. Bubble: Giant soap bubble and the sky before storm. Flickr photo-sharing. Taken July 17, 2012.