Ever since I was in high school, I have found your “Handbook of chemistry and physics” to be a useful reference tool for finding a variety of important physical and chemical constants quickly. Even in this internet age, having a dog-eared copy of the “Rubber Bible” in lab is useful when someone wants to know how to get unusual elements into solution, or remember which metals catch fire when put into water.
So it was with mixed feelings that I noticed your 2008 edition contained a one-page geologic timescale.
On the one hand, the inclusion of a geologic time scale is great. On the other hand, a book that is updated every year should endeavor to be current. And the time scale you included was from 1983.
The inclusion of radiometric numbers on a geologic time scale requires and accurate and precise method of determining geologic ages. And most of the methods used today were still in their infancy in 1983. The earthtime website shows just how much the timescale has been revised over the last century as methodology has improved. If you are going to include a timescale, please ensure that it is up-to-date: The International Commission of Stratigraphy updates the timescale regularly, and the Geological Society of America also has a recent timescale available.
Saturday, January 23, 2010