Humans use logarithms in many ways in everyday life, from the music one hears on the radio to keeping the water in a swimming pool clean. They are important in measuring the magnitude of earthquakes, radioactive decay and population growth. In the financial world they help in the calculation of interest rates, according to Reference.com Even the melting rate of glaciers depends on the use of logarithms.
If the music at a party is above the number of decibels set by noise regulation of the local authority, the police have the authority to issue a citation to the responsible party. Decibels, derived from "bels," are units useful in measuring many types of wave functions of from acoustics, electronics and telecommunications. The bel is a base 10 logarithmic function. If the pH of the swimming pool is too high, algae is more likely to grow in the water. Pool owners adjust the pH in their pools to keep the water clear and ensure the comfort of swimmers. This logarithmic function measures the concentration of hydrogen ions in solution. Scientists use the Richter scale to compare the seriousness of earthquakes. The increase from a 4.0 earthquake to a 5.0 quake is tenfold. Bankers use natural logarithms to calculate the time required for a sum of money deposited at an interest rate to reach the desired balance.