tag:blogger.com,1999:blog-3338557.post116917303676045329..comments2021-06-21T18:08:29.354-04:00Comments on Byzantium's Shores: chronicling the misadventures of an overalls-clad hippie: Fun with numbers!Kelly Sedingerhttp://www.blogger.com/profile/10704114189919711467noreply@blogger.comBlogger1125tag:blogger.com,1999:blog-3338557.post-1169358615212642302007-01-21T00:50:00.000-05:002007-01-21T00:50:00.000-05:00More importantly, it demonstrates an abject lack o...More importantly, it demonstrates an abject lack of understanding the means by which uncertainties propagate in calculations. Generally speaking, the method for calculating this propagation involves summing over the product of each uncertainty with the deriivative of the calculated function wrt to variable in question.<BR/><BR/>The upshot of this is that when you have some calculated quantity that depends on 100 variables, you're taking 100 partial derivatives (one for each variable), and multiplying each one by it's uncertainty, and then adding them in quadrature (think pythagorean theorem). In the end, you find that your uncertainty is driven primarily by a few variables that have either large uncertainty, or large partial derivatives (meaning that the function depends very strongly on the variable in question)or large both.<BR/><BR/>So, the initial supposition, and the retort were equally silly, although it's obvious that the retort was meant to be silly...Anonymousnoreply@blogger.com