[Kelly Aiello]

Kelly Aiello  asked the Naked Scientists:
   
Hello how are you?

I am doing an experiment on clouds and I decided to make a cloud in a bottle.

There is one problem this experiment is for my school. We can't have matches.

What do I do? Do I use a lightbulb and dust? Or what? Please give me ideas!

From,

Kelly Aiello, 11

What do you think?

[CliffordK]

What kind of a cloud?

Rain clouds (most of what we see) are made of water droplets. 

Any kind of a teapot, or anything that boils water will make steam, and usually in sufficient quantities that it appears to be a cloud.  Unfortunately many electric teapots have an auto-shutoff.

A humidifier might also give you a nice cloud.

[Bass]

We used to make cloud chambers to observer cosmic rays- fairly easy to do.

What you need:

Wide mouth jar
small piece of felt
rubbing alcohol
dry ice (be careful to handle only with gloves).

Cut the felt to size of the inside of the lid.
Place (or glue) the felt in the lid
Saturate the felt with alcohol
screw the lid on tightly
place the jar upside-down (lid side down) on dry ice (best to put dry ice in some sort of metal container)

The dry ice will cause the alcohol to condense and a small cloud will form just above the lid.  As a bonus, watch for cosmic ray trails.  Cosmic rays are charged ions and will cause condensation as they travel through the jar.

[imatfaal]

Didn't Dave and Ben make a do-it-yourself cloud chamber a few months ago on kitchen-science?

How often would you pick up a Cosmic Ray, Bass?

[daveshorts]

To do that you need to have a much larger pressure change if you want to do it without smoke. If you can put a car or bicycle valve into the lid of your bottle, and pump it up - I think steve spangler does this. But be very careful about the pressure you pump it to, as I know someone who caused a lemonade bottle to blow up in his face which was very scary. Keep the pressure below about 2 atmospheres and you should be ok if the bottle is undamaged.

[Bass]

Didn't Dave and Ben make a do-it-yourself cloud chamber a few months ago on kitchen-science?

How often would you pick up a Cosmic Ray, Bass?

Depending on elevation and latitude, you can see several per minute (The higher your elevation and latitude, the more tracks you will see).  Sometimes they would come in groups, 15 to 20 at a time.

[imatfaal]

Gotta be tried - Thanks Bass

[C-Wolf]

To add to daveshorts.
You have to relieve the pressure suddenly.

I used to build “rockets” as a kid by pressurising 2l soda bottles with about 30% water inside.
When it exceeds a certain pressure, the valve would be blown out forcing the water out and launching the bottle into the sky.  The water was just enhanced the effect of Newton’s law on action/re-action.
What you would end up with is a “cloud” on the inside.

You do not need to add the water however, as normal atmospheric air should have enough moisture to make you the cloud.
Just figure out a way to safely relieve the pressure in a few seconds and you will have your cloud.