The default assumption is that our knowledge of the measurement result can be described by a Bayesian posterior which is a Gaussian with the stated mean and standard deviation. -- Gene
________________________________ From: Dan Asimov <dasimov@earthlink.net> To: math-fun <math-fun@mailman.xmission.com> Sent: Saturday, November 23, 2013 8:34 PM Subject: Re: [math-fun] how many decimal places exist in the mass of an electron (& other such things)?
This is my chance to ask: When a physicist writes a measurement like
548.57990943 ± 0.00000023,
does the number after the ± represent the standard deviation (root-mean-squared error), or something else?
Thanks,
Dan
On 2013-11-23, at 7:57 PM, Rowan Hamilton wrote:
Physicists spend a great deal of time and effort on understanding the errors in any physical measurement. A particle physics PhD involves about 2 years of classes, 2 years of slave labor, 1 year of measurement and then 3 years of error analysis. This is no joke. Since particle physics is an inherently statistical field, particle physicists are experts at error analysis.