On the west coast of Washington State, 230 miles south of SPIE headquarters, stands a ghost forest of dead western red cedars along the Copalis River. Rooted as they are in a salty marsh, it’s no surprise that the trees are dead.
For decades, the prevailing theory was that the trees were slowly poisoned by salt as sea level rose. In the 1980s, however, geologist Brian Atwater and dendrochronologist—a.k.a. tree-ring scientist—David Yamaguchi found something altogether different.
By studying the rings of these trees, Yamaguchi determined that they had normal, healthy growth cycles that suddenly stopped. Using radiocarbon dating, Atwater pinned the death of the forest to within 10 years of 1700, and Yamaguchi was able to narrow it down even further: the trees’ last growth ring was dated to summer 1699, and they were dead by the following year.
The final piece of the puzzle came from Japan, where records indicated that an orphan tsunami—so-named because no corresponding earthquake near Japan was detected—decimated the Japanese coastline on 26 January 1700. We now know that the parent 9.0 magnitude earthquake originated from the Cascadia subduction zone across the Pacific. The massive quake caused the Washington coastline to suddenly drop, submerging an entire forest in saltwater and tidal mud overnight.
The most haunting thing about the ghost forest isn’t the sight of the skeletal trees; it’s the fact that a system can be perfectly stable, repeating predictable cycles for centuries, until one cataclysmic event causes the entire record to shift permanently.
We’re seeing a similar cataclysm right now in scholarly publishing. AI has fueled a dramatic increase in research output, much of it low quality or even blatantly fake. Editorial systems that have for centuries relied on expert peer review are buckling under the sheer volume of marginal AI-generated papers being submitted. In 100 years, will researchers look back to the scholarly record and see an AI growth spurt, followed by normalized cycles of scholarly output? Or will they find a ghost forest where the human signal died out?
While the shifts in scholarly publishing feel seismic, our ability to measure and manage interruptions to the world’s rhythms remains a core human strength. In this issue of Photonics Focus we explore cycles of all kinds, beginning with a look at the daunting challenges of recycling optical glass and the innovative ways optics companies are tackling sustainability. We examine the photonic techniques used to monitor the solar cycle from space, where high-precision sensors help us predict the temperamental rhythms of our closest star. Finally, we dive beneath the surface to see how researchers are deploying optical sensors to track marine nutrient cycling, providing a window into how warming oceans are altering the foundations of the global food web.
Soil layer analysis of the Washington coast reveals that major earthquakes have occurred on average every 300 to 500 years. Because we now know the last one happened on 26 January 1700, those of us who live in the Pacific Northwest are anxiously aware that the next Big One is statistically due. It is a reminder that we can’t afford to mistake a wide parabola for a straight line. Whether we are monitoring the sun, the oceans, or the integrity of the scientific record, the goal is the same: to ensure that when the next cycle comes, we aren’t caught stuck in the mud.
Gwen Weerts, Editor-in-chief
