Labrats Update by Shawn Carlson: Lesson Eight

In Lesson Seven we learned about feedback, that very important principle that governs all things whose rates of growth depend on their size. Things are said to have positive feedback if their rate of growth gets larger as the things themselves get larger. Things that experience positive feedback grow faster and faster. An avalanche is one of many examples. Things are said to have negative feedback if their rate of growth gets smaller as their size gets bigger. Things that experience negative feedback do not undergo explosive growth. Rather, they tend to remain "well behaved," meaning they tend not to run away out of control. A child on a swing is one very important example.

Did you keep your eyes open this last week for other things that experience either positive or negative feedback? I hope you'll share your observations with me at DrShawn@sas.org.

Meanwhile, let's learn about clouds and weather. Find out more by reading Lesson Eight at http://www.scifair.org/Labrats/LessonEight/LessonEight010.html.

See you there.

Dr. Shawn