I'm surprised you think that margins decrease the signal-to-noise ratio. I find generous margins make text easier to read - which is why print magazines and newspapers will split text into columns even when the entirety of a page is taken up by one story.

Aren't columns actually used because it's easier to read shorter lines of text than long ones?

That was what I just said, yes.

You seemed to be suggesting that it had something to do with margins, which is actually a different issue than column width. In a newspaper, you can have a lot of columns with small margins, for example.

You also seemed to be suggesting that it had something to do with separating different stories on the same page.

When you have one column of text, as in the frontpage of HN, large margins implies a narrow column of text.

My point about separate stories is that it is independent of them. Magazines and newspapers layout their stories in columns. I was anticipating someone saying "Yes, but they also show multiple stories on one page." But magazines and newspapers still use narrow columns of text even when they have a single story on the page.

Thanks for the clarification.

"foofy" margins actually have a purpose - to improve legibility. Something that HN is in desparate need of.

If I set my browser window to a reasonable width I can have legibility without foofy margins and I can use the rest of my 1280 pixels for something else. Window systems - they rock