When can social change occur?

Somebody much smarter than I am was kind enough to read my little post on Endogenous Growth Theory.  At lunch today, they drew attention to this item that I mentioned:

I’m not aware of anything that tries to model the emergence of ground-breaking discoveries that change the way that the economy works (flight, computers) rather than simply new types of product (iPhone) or improved versions of existing products (iPhone 3G). In essence, it seems important to me that a model of growth include the concept of infrastructure.

The question was raised:

Could it be that times of significant social change have a tendency to coincide with with the introduction (i.e. either the invention or the adoption) of new forms of infrastructure? [*]  A new type of mobile phone hardly changes the world, but the wide-spread adoption of mobile telephony in a country certainly might change the social dynamic in that country.

It’s something to ponder …

[*] My intelligent friend is not an economist and would probably prefer to think of this as a groundbreaking discovery rather than just the development of a new type of infrastructure.