Como hacer una nube en una botella.

The best and easiest cloud in a bottle ever! All you need is an empty water bottle, cap, and rubbing alcohol. Pour in some rubbing alcohol. Swish it around. Cap it. Grab the bottom half of the bottle. Start twising it to create pressure. Keep twisting until you cant twist anymore. Uncap it quickly.. Let it pop!
  http://youtu.be/VNwZjkqd92Y

Materials 

1-liter clear plastic bottle with cap 

Foot pump with rubber stopper attached 

Water Rubbing alcohol 

Safety glasses

http://www.stevespanglerscience.com/experiment/cloud-in-a-bottle-experiment