Coroner
You often see logarithms in action on television crime shows, according to Michael Breen of the American Mathematical Society. On such shows, coroners often attempt to determine how long a body has been dead. These television coroners, as well as their real-life counterparts, use logarithms to make such determinations. Once a body dies, it begins to cool. To calculate how long the body has been dead, the coroner must know how long the body temperature has not been at 98.6 degrees. Because the rate of the body cooling is proportionate to temperature differences between the body and its surroundings, the answer is found by calculating exponential decay using logarithms.
Actuarial Science
An actuary's job is to calculate costs and risks. Many of these calculations involve complicated statistics. For example, an actuary may work as a consultant designing pension plans for a company's employees.To do so, the actuary may have to figure out the chances of a particular 50-year-old employee living to be 89 years old. The actuary then designs that person's pension using statistics that are exponential in nature, and that's where the logarithms enter in.
Medicine
Logarithms are used in both nuclear and internal medicine. For example, they are used for investigating pH concentrations, determining amounts of radioactive decay, as well as amounts of bacterial growth. Logarithms also are used in obstetrics. When a woman becomes pregnant, she produces a hormone known as human chorionic gonadotropin. Since the levels of this hormone increase exponentially, and at different rates with each woman, logarithms can be used to determine when pregnancy occurred and to predict fetus growth.
Archaeology
Archaeologists use logarithms to determine the age of artifacts, such as bones and other fibers, up to 50,000 years old. When a plant or animal dies, the isotope of carbon, Carbon-14, decays into the atmosphere. Using logs, archaeologists can compare the decaying Carbon-14 to the Carbon-12, which remains constant in an organism even after death, to determine the age of the artifact. For example, this type of carbon dating was used to determine the age of the Dead Sea Scrolls.
