|MadSci Network: Other|
Mike, Very observant of you to notice both the condensation and the 'trails.' These trails are caused by drops of water. As you know, the condensation is just water collecting on the side of the bottle. As more and more water molecules join the condensation, they start piling up and forming droplets. Eventually, some of the droplets get big enough and start dripping down the bottle, leaving the little trails. If you would like to see this process in action, you can try this little experiment. Take an empty water bottle and fill it half full of hot tap water and put the lid back on. You will see the condensation for immediately, and within 5 or 10 minutes you will watch the drops dripping down on the inside leaving little trails behind. There are lots of previous answers on our site dealing with condensation, dew, humidity, etc. Use our search engine to find them: http://www.madsci.org/MS_search.html
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