You may find this interesting!

https://web.archive.org/web/20080604020024/http://www.hereco...

> 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.

> 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

I'm not sure one can compare an hour of watching TV to an hour of researching and writing, the former is essentially mindless idling that does not take any mental effort. I wonder if there's a measurable difference in brain energy consumption, but probably not.