Issue #349 Replace the (wrong) quote from Peter Drucker with one from…

… Lord Kelvin

Software_Carbon_Intensity/Software_Carbon_Intensity_Specification.md

@@ -2,7 +2,7 @@
 
 ## Introduction
 
-> "If you can't measure it, you can't improve it." - Peter Drucker
+> *"When you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind."* -- Lord Kelvin ([Popular Lectures and Addresses vol. 1 (1889) ‘Electrical Units of Measurement’, delivered 3 May 1883](https://www.oxfordreference.com/display/10.1093/acref/9780191826719.001.0001/q-oro-ed4-00006236))
 
 Software systems cause emissions through the hardware that they operate on, both through the energy that the physical hardware consumes and the emissions associated with manufacturing the hardware. This specification defines a methodology for calculating the rate of carbon emissions for a software system. The purpose is to help users and developers make informed choices about which tools, approaches, architectures, and services they use in the future. It is a score rather than a total; lower numbers are better than higher numbers, and reaching 0 is impossible. This specification is focused on helping users and developers understand how to improve software to reduce or avoid the creation of emissions.