Welcome to the DC Digital Lab!

Our team has put together a collection of videos, experiments and activities that you can do at home. We are here to help you overcome boredom and learn a few things in the process! Simply click the image or video to start your at home discoveries.

 

Clouds

Have you ever looked into the sky for cloud animals or figures? Did you wonder how the clouds form? A cloud is a large collection of very small droplets of water or ice crystals. The droplets are so small they are capable of floating in the air. All air contains water, but near the ground it is typically in the form of an invisible gas called water vapor. When warm air rises it expands and cools. Cool air cannot hold as much water vapor as warm air. This causes some of the vapor to condenses into tiny pieces of dust that float in the air and form as tiny droplets around each dust particle. When billions of these droplets come together, they form a visible cloud.

Why do clouds change color?
Since light travels as waves of different lengths, each color has its own unique wavelength. Clouds are made up of a combination of water and ice crystals. The water and ice scatter all light, making clouds appear white. If the clouds get thick enough or high enough all the light above does not make it through, which gives it a gray or dark look. Also, if there are lots of other clouds around, their shadow can add to the gray or multicolored gray appearance.

What type of clouds are there?

Cirrus – Cirrus clouds are high level clouds that are thin and wispy. They appear during good weather.

Stratus – Stratus clouds are low level clouds that are flat and tend to cover much of the sky. They are gray in color and may produce light rain or drizzle.

Cumulus – Cumulus clouds are low to mid-level clouds. They are big, white, puffy, and beautiful clouds. They usually mean good weather unless they grow really tall and turn into cumulonimbus clouds.

Cumulonimbus – Cumulonimbus clouds are very tall clouds that span all the way from low level to high level. They can cause violent thunderstorms with heavy rain, hail, and even tornadoes.

Why do clouds form at different heights in the atmosphere?
The characteristics of clouds are dictated by the elements available, including the amount of water vapor, the temperatures at that height, the wind, and other air masses.

Why do clouds float?
A cloud is made up of liquid water droplets. A cloud forms when air is heated by the sun. As it rises, it slowly cools it reaches the saturation point and water condenses, forming a cloud. As long as the cloud and the air that it’s made of is warmer than the outside air around it, it floats!

How do clouds move? Clouds move with the wind. High cirrus clouds are pushed along by the jet stream, sometimes traveling at more than 100 miles-per-hour. When clouds are part of a thunderstorm, they usually travel at 30 to 40 mph.

How is fog formed?
There are many different types of fog, but fog is mostly formed when southerly winds bring warm, moist air into a region, possibly ending a cold outbreak. As the warm, moist air flows over much colder soil or snow, dense fog often forms. Warm, moist air is cooled from below as it flows over a colder surface. If the air is near saturation, moisture will condense out of the cooled air and form fog. With light winds, the fog near the ground can become thick and reduce visibilities to zero.

Now that you know a little bit about clouds, check out the fun activities and videos below!

 

 

Cloud in a Jar

Materials

  • A jar with lid
  • About 1/3 cup hot water
  • Ice
  • Hairspray (which I forgot to include in the picture below)

Procedure

  • Start by pouring the hot water into the jar. Swirl it around a bit to warm up the sides of the jar.
  • Turn the lid upside down and place it on the top of the jar. Place several ice cubes onto the lid, and allow it to rest on the top of the jar for about 20 seconds.
  • Remove the lid, quickly spray a bit of hairspray into the jar, and then replace the lid with the ice still on top. Watch the cloud form
  • When you see a good amount of condensation form, remove the lid and watch the “cloud” escape into the air.

Explanation

When you add the warm water to the jar, some of it turns to water vapor. The water vapor rises to the top of the jar where it comes into contact with cold air, thanks to the ice cubes on top. Water vapor condenses when it cools down. However, a cloud can only form if the water vapor has something to condense on to. In nature, water vapor may condense onto dust particles, air pollution, pollen, volcanic ash, etc. In the case of this activity, the water vapor condensed onto the hairspray.

Cloud Type Art

Materials

  • Piece of paper
  • Cotton balls
  • Marker
  • (vinegar/ food coloring optional)

Procedure

  • Choose between 4 different cloud types (cirrus, stratus, cumulus, cumulonimbus)
  • Use cotton balls to mimic the cloud shapes
  • (if you choose to use food coloring on cotton balls, soak them in a bowl with ¼ cup of water, a tsp of vinegar and approximately 10-15 drops of food coloring)
  • Review what the clouds look like and create your cloud similar to description

Explanation

A cirrus cloud should look wispy and feathered, it is typically found high in the sky. This cloud appears in good weather. Cumulus clouds are middle height, the look fluffy. These clouds typically change shape and occur during nice weather. Stratus clouds look like blankets of grey and sit low in the sky. Cumulonimbus clouds are big tall and wide. These clouds typically bring in bad weather and storms. 

Video Experiments and Activities

DIY Science PDF experiments

Virtual Critter Corner