Letters Rediscovering the roots of our work

Acknowledging the priority of ideas in the scientific literature can be difficult. One can hardly be faulted for not being aware of all papers on a topic. The problem is hard enough with the many foundational papers that get cited but rarely read; it is much worse with the masses of others that have faded into obscurity along with their precocious insights.

Charles Day’s editorial “Crediting our predecessors” (Physics Today, September 2018, page 8 ) and Ray Goldstein’s article “Coffee stains, cell receptors, and time crystals: Lessons from the old literature” in the same issue (page 32 ) remind us of the pleasurable thrill (and for those who thought their ideas were original, the disappointment) of rediscovering those old gems.

My favorite example of the form is a not-so-obscure paper, “Gravitational machines,” by Freeman Dyson. ¹ That brilliant article, ostensibly about the limits of power generation by a spacefaring civilization, is occasionally cited for its insights into the gravitational-wave radiation of binary systems.

But Dyson’s article made a series of other remarkable scientific leaps that are rarely cited. He offered what is apparently the first published speculation on the existence of tight binaries comprising two neutron stars; his comment predated the discovery of pulsars by five years. He also calculated the gravitational-wave signal strength of those binaries and identified them as an observable source of gravitational waves, even at intergalactic distances. He did not imagine that such binaries could form naturally, but he speculated that they could be the by-product of deliberate energy extraction and argued that the detection of a merger event would constitute evidence for alien technology.

Despite having presaged the discovery of gravity waves from the inspiral of binary neutron star GW170817 by more than 50 years, Dyson’s work is not cited in that paper ² or any other paper I can find on that topic, presumably because most people are unaware of that particular aspect of Dyson’s publication. Many who cite his paper thus apparently do so without reading it, which is a shame because it is a model of clarity, simplicity, and brevity and is a joy to read.