Author and professor Clay Shirky has an amazing essay posted on his blog about what he calls the “cognitive surplus” – all the extra time and mental energy we have in our society, and why we don’t realize it.

Thanks to his new book, Here Comes Everybody, he was being prepped by a producer to appear on a TV talk show. He was talking about the participatory nature of Wikipedia, and the amount of activity on the discussion pages, and so on…

She heard this story and she shook her head and said, “Where do people find the time?” That was her question. And I just kind of snapped. I said, “No one who works in TV gets to ask that question. You know where the time comes from. It comes from the cognitive surplus you’ve been masking for 50 years.”

So how big is that surplus? So if you take Wikipedia as a kind of unit, all of Wikipedia, the whole project—every page, every edit, every talk page, every line of code, in every language that Wikipedia exists in—that represents something like the cumulation of 100 million hours of human thought. I worked this out with Martin Wattenberg at IBM; it’s a back-of-the-envelope calculation, but it’s the right order of magnitude, about 100 million hours of thought.

And television watching? Two hundred billion hours, in the U.S. alone, every year. Put another way, now that we have a unit, that’s 2,000 Wikipedia projects a year spent watching television. Or put still another way, in the U.S., we spend 100 million hours every weekend, just watching the ads. This is a pretty big surplus. People asking, “Where do they find the time?” when they’re looking at things like Wikipedia don’t understand how tiny that entire project is, as a carve-out of this asset that’s finally being dragged into what Tim calls an architecture of participation.

I have that tingly feeling that I only get when a new, clear articulation of an idea has been introduced into my noggin. I love that feeling. Thank you, Clay!