Cloud in a Bottle Experiment (Keep-it-Simple Science)

We haven't been using any specific Science program or textbook this year.  Reason 1: the textbooks I previewed looked dull.  Reason 2: we live in a wonderful fantastic world and my husband and I try to be very intentional about training ourselves and our children to see it, to observe and study it, to appreciate it, and to recognize the glory and wisdom of God in it all.  I'm sure as the years pass we'll need a more official science text or program, but for now we take hikes, collect nature, grow plants, use our magnifying glasses, and conduct simple experiments around the home (often impromptu).

Because science is one of the subjects that we keep kind of loosey-goosey, and it's largely based on our interests and the availability of resources, I think I might start keeping a record of it here - to share with you some of what we do, and for my own reference since I don't have a book with an index!  And so I start Keep-it-Simple Science.

To help pass the winter days, the boys have been going to a weekly program for homeschoolers at our local science museum.  Last week, they came home with the instructions for this experiment: A Cloud in a Bottle.

   

STEP 1: Gather supplies - 2 liter bottle with cap, matches.  Have your kids blow into
the bottle to get all the dents out... this is really just a time-waster so you can
grab the matches and the camera.

STEPS 2 and 3: take the label off the bottle and fill the bottle 1/3 full of warmish hottish water

STEP 4: put the cap on the bottle and squeeze it.  Nothing happens.

Temporarily suspend experiment for a funny picture.

STEP 5: while holding the camera and taking pictures with one hand,
light a match, hold it over the opening of the bottle for a few seconds,
then drop it in.  Replace the bottle cap immediately.

STEP 6: squeeze the bottle again and see a "cloud"
form as you release and change the air pressure in the bottle.
I could not capture the "cloud" in a photo, but it did work!

Explanation: The warm water evaporating provides water vapor inside the bottle.  The smoke particles from the match enhance the process of water condensation, and squeezing the bottle causes the air pressure to drop - the three ingredients needed for a cloud to form.

Experiment was from weatherwizkids.com - more info there on what forms a cloud and why the experiment works!  (I think we're going to try the make-your-own fog experiment tomorrow!)