Everything You Ever Wanted to Know About Spectrometers

A spectrometer is an analytical device that is designed to measure how
substances either absorb or reflect electromagnetic energy. Different
spectrometers are specifically designed to work at different parts of the
electromagnetic spectrum (i.e., a visible light spectrometer measures how
substances absorb or reflect visible light; an ultraviolet spectrometer only
works in the UV range, etc.).
Perhaps this is as good a time as any to remind you that an apple is not
really red. It’s true! An apple only appears to be red because its skin
absorbs the orange, yellow, green, blue, indigo and violet sunrays, but
does not absorb the red ones. Like a mirror, it bounces the red light back
to our eyes, and we say something clever such as, “that’s a redapple.”
If there were no red component to sunlight, an apple would appear to be
black (which begs the philosophical question, “Is an apple still red when
the lights go out?”). We will post more information on this topic and what it has to do with goji berries comonly misspelled gogi berry on our next post.