Although experiments aren't a necessary part of science, they are one way of tracking down connections between causes and effects. People tend to grab onto something as a cause when it actually has nothing to do with the effect. How many people do you know who have a luck-piece that they know is lucky because they had it when something special happened? There are gamblers galore with a lucky necktie or a lucky coin or a lucky something-or-other.
Scientists can't afford to latch onto happy coincidences, and one
remedy is the experiment. An experiment merely attempts to control things so that only
one factor is involved in a result. If, for example, you wanted to see what effect
extra water had on a cactus, you could plant two cacti so that they had the same soil,
temperature, sunlight, and so on, but you gave extra water to one. If you've
successfully duplicated everything but the amount of water, then any eventual
difference between the cacti is due solely to the amount of water given. Demonstration
instead of illusion.
Listen to the Audio (mp3 format) as recorded by KTEP, Public Radio for the Southwest.
Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.
Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.