system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: why are scientific paper on two columns?

It seems all papers use this format...
gpt
Ease of reading, as a carryover from the days when they could only be printed rather than available to read on a controllable screen such as a monitor.

Most scientific papers pack a lot of information into a small-typefaced article, and include terminology and concepts that can make them a bit harder to read than, say, a cheesy romance novel which is full of short paragraphs where people are speaking. Quite often journals involve very long paragraphs too. So you want to do what you can to make them easier to digest, even if only by a little bit.

By breaking long lines into two columns, you are less likely to lose your place every time you finish reading a line and start the next one, because your eyes don't have to travel as far. Your  eyes only have to return halfway across the page, making it less likely to either start rereading the same line or accidentally skip a line, which is something that's easy to do when reading long paragraphs.