Quotes About Critical-mass

Models often overlap. The measles epidemic is usually a critical-mass process.4 A succession of epidemics, with intervening periods in which the pool of susceptibles renews itself, corresponds to a cyclical model.

But whether the measure is the number of people engaged, or the number times the frequency or the length of time they engage in it, or the ratio of the number who do to the number who do not, or the amount of such activity per square foot or per day or per telephone extension, we can call it a "critical-mass" activity and a lot of people will know what we mean.

The tipping model is a special case—a broad class of special cases—of critical-mass phenomena. Its characteristics are usually that people have very different cross-over points; that the behavior involves place of residence or work or recreation or, in general, being someplace rather than doing something; that the critical numbers relate to two or more distinct groups, and each group may be separately tipping out or tipping