On a foggy Saturday morning in 1953, a tall, skinny 24-year-old man fiddled with shapes he had cut out of cardboard. They represented fragments of a DNA molecule, and young James Watson was trying to figure how they fit together in a way that let DNA do its job as the stuff of genes.

Shakespeare’s entire catalog of sonnets and eight of his tragedies, all of Wikipedia’s English-language pages, and one of the first movies ever made: scientists have been able to fit the contents of all these works in a space smaller than a tiny test tube.

Standard laboratory tests can fail to detect many disease-causing DNA changes. Now, a novel 3D chromosome mapping method can reliably reveal these hidden structural variants and lead to new discoveries.