J Ding

Two different microphones are recording the same concert. One microphone stands by the stage and mostly picks up the loud sounds from the front row; the other hangs from the ceiling and hears the whole hall, but with the bass muffled. If you compare the recordings, you can figure out how much of the noise in them comes from the microphone and how much from the orchestra itself.

In a print shop, every page of a book used to be set by hand. One mistake, and the whole print run is at risk. RNA sequencing of the brain looked much the same until recently: each sample demanded hours of manual work, and short reads, like torn scraps of pages, could not be pieced together into the full text of a gene. Now there is a production line that reads every page from start to finish.