If you don’t update your website every 36 hours, you might as well not have one. Internet visitors consider a site “out of date” or “irrelevant” after that time period according to a NY Times piece this week. Good advice for bloggers, MySpacers or people who want traffic to their website. If you update it, they will come.

A new research paper seeks to answer a riddle for publishers, editors and even readers: when does new news become old news?

In the case of a news article on the Internet, the answer is surprisingly long: 36 hours on average, according to the paper, “The Dynamics of Information Access on the Web,” which appeared in the June issue of Physical Review E, the journal of the American Physical Society.

More precisely, 36 hours is the amount of time it takes for half of the total readership of an article to have read it, the paper found. The physicist who led the research, Albert-L