Nutrition Science and Everyday Application - beta v 0.1

THE SCIENTIFIC METHOD 83
Figure 2.1. The scientific method is a cyclical process, because it always leads to new
observations and questions.
Through the scientific method, our knowledge of science builds continuously over time.
No one study is enough to fully explain any one phenomenon, particularly in an area as
complex as nutrition. Even experiments that go exactly as expected lead us to new questions
to investigate. Science is also filled with surprises, both big and small. Experiments may not
yield the results that we expect, but that can lead to new and important questions. And
because scientists are human, they can make mistakes along the way or fail to acknowledge
or test an important variable, which is why it’s important that experiments be repeated and
evaluated by other researchers along the way.
The history of nutrition is full of fascinating examples of the scientific method at work,
such as the discovery that iodine is a nutrient. This story of scientific discovery began in
1811, when French chemist Bernard Courtois was isolating a substance called saltpeter, an
ingredient needed to make gunpowder to be used by Napoleon’s army. Part of his isolation
procedure involved burning seaweed. When he did this, he observed the release of an
intense violet vapor, which crystallized when he exposed it to a cold surface. He sent the
violet crystals to an expert on gases, Joseph Gay-Lussac, who identified the crystal as a new
element. It was named iodine, the Greek word for violet. The following scientific record is
some of what took place in order to conclude that iodine is a nutrient. 1,2
Observation: Eating seaweed is a cure for goiter, an enlargement of the thyroid gland in
the neck.