# Logarithms and their use in the real world

1. Jan 26, 2014

### Niaboc67

Hello, I have been studying Logarithms in University. I understand it's how many of ONE number to get another number, and I see how it is rearranged to find these "missing" links. But maybe I am overlooking something, but I don't quite see the bigger picture here with how to use Logarithms. How can they be applied to something in real life? If someone could present a problem and then a solution to how logarithms could be used in real life that would be fantastic.

Thank You

2. Jan 26, 2014

### Simon Bridge

There are lots of situations where the rate of something depends on the quantity ... i.e. of form: $\dot y(t) = ky(t)$

Biological processes like hearing and eyesight are based on logarithmic relations.
There are also thermodynamic processes that bear logarithmic relations.

It can also be a good tool - lots of situations where plotting the the log of some quantity against another gets a line - lines are usually easier to regress to, so it saves work.

If you google for "logarithms in nature" you get a lot of stuff:
http://www.nature.com/news/2008/080529/full/news.2008.866.html
http://enjoyingmath.pbworks.com/w/page/31757192/NATURE and LOGARITHM
http://goldenratiomyth.weebly.com/the-logarithmic-spiral.html