How is wind speed measured?
Wind speed is most often measured using an anemometer. The simplest ones are made
with cup-shaped devices that spin and catch the winds. The number of spins translates
into an approximate value for the wind speed. The more accurate electronic
anemometer has a free-moving turbine suspended in the middle of the instrument
that, when held correctly, measures the wind speed. The speed of the turbine sensed
by an infrared light relays the signal to an electrical circuit. From there, the wind
speed is digitally displayed.
What do plant hardiness zone numbersmean?
Plant hardiness zones are another way numbers are used. In this case, they indicate
the average annual minimum temperatures for landmasses around the world. For
example, one common Plant Hardiness Zone Map is broken down into 20 different
zones based on the average annual minimum temperatures. In zone 5a, for example,
the average annual minimum temperature ranges from 20 to 15 degrees Fahren-
heit (26.2 to 28.8 degrees Centigrade; for example, Des Moines, Iowa). In zone 11,
such temperatures are above 40 degrees Fahrenheit (4.5 degrees Centigrade; for
example, Honolulu, Hawaii). And in zone 1, such temperatures are below 50 degrees
Fahrenheit (45.6 degrees Centigrade; for example, Fairbanks, Alaska). There are
other maps, too, that break down the zones into even more detail.
MATH, NUMBERS, AND THE BODY
Is a human’s normal body temperaturereally 98.6 degrees Fahrenheit?
Although everyone seems to be taught that the normal human body temperature is
98.6 degrees Fahrenheit, in reality, “normal” has a range. In fact, a person’s actual
measured temperature is rarely exactly 98.6 degrees Fahrenheit. One reason for this
has to do with how the old standard was calculated: using an oral mercury thermome-
ter and basing the results on a small human sampling.
Gone are the days of putting a thermometer under one’s tongue for five to ten
minutes. Today’s thermometers are more sophisticated, accurate, and faster. Thus
researchers believe that, based on better data—and more people tested—normal body
temperatures measured orally range from 97.5 to 98.8, with about 1 in 20 people hav-
ing a bit higher or lower normal temperatures. These numbers change throughout
the day, too, varying from 1 to 2 degrees (on the average, reaching a low at about 2
a.m. to 4 a.m., and a high twelve hours later). An even more accurate representation
of a body’s temperature is to measure the core temperature, or the actual temperature
inside the body, usually by using a rectal or inner-ear (tympanic) thermometer. 405