From here to infinity... logarithmically

From here to infinity... logarithmically

The entire universe in blog form
Jan. 11 2010 12:00 PM

From here to infinity... logarithmically

Logarithms are cool. Sure, some of you may have flashbacks to middle school and may collapse on the floor twitching upon their mere mention, but seriously, logs are the language of the Universe. Our senses (eyesight and hearing) are sensitive logarithmically, and a lot of ways the world behaves make a lot more sense when you plot them using logs.

For those of you scratching your heads, a simple way to think of logs is to think factors of ten. Instead of counting like we normally do -- 1, 2, 3, 4 and so on -- in log space you count by factors of 10: 1, 10, 100, 1000, and so on. There are lots of advantages to this, one being that you can make graphs that show things that are very small and very big on the same plot. Using regular numbers, it would be hard to make a graph showing the size of a human (2 meters tall) and a skyscraper (200 meters tall) on the same plot, but using logarithms, they are only two ticks apart in size. Easy peasy.

Phil Plait

Phil Plait writes Slate’s Bad Astronomy blog and is an astronomer, public speaker, science evangelizer, and author of Death From the Skies!