How can a cell record its own history without sending any data out? · Grey Matter

It grows a molecule that keeps a timeline.

How can a cell record its own history without sending any data out?

It grows a molecule that keeps a timeline. In the protein recorders published in 2023, cells assemble long chains from subunits carrying fluorescent tags, and a gene switched on by the signal being recorded changes which tag is added, so the order of tags along a chain stores when that signal was on. After days or weeks the tissue is fixed and the chains are read under a microscope, which removes the bandwidth problem entirely at the price of hours-scale time resolution and a single readout at the end.