Editorials

Time is a big deal for us geologists. Rates of Earth processes range from the mind-numbingly slow (mantle convection) to the catastrophically fast (volcanic eruptions) with everything in between. Geologists move effortlessly from units of seconds to giga years in a way that often confounds scientists in other disciplines; no geologist is unaware of humanitys’ fleetingly brief tenure of the planet in the grand scheme of things.

One of the pleasures of serving as a principal editor of Elements is working with people from across the whole Earth science community, many from places, subjects and institutions who I wouldn’t encounter in the rest of my professorial life. This issue is a good example: its contributing authors and editors include men and women from four continents and seven countries, studying everything from isotope geochemistry to mining to advanced batteries to medical biochemistry, while working in universities, national labs, technology and mining companies, consulting agencies, and a medical center. This breadth reflects the efforts Elements makes to assure that the words in our pages capture the full range of insights and experiences of the diverse minds that are engaged in the Earth sciences. We are proud that many issues of Elements have authors and editors that almost represent a cross section of the world.

The concept of oxidation as the process that turns iron metal into rust is familiar to all of us. We might be equally familiar with reduction, the “reverse” of oxidation, by which iron metal is produced by heating iron ore with coke in a blast furnace. Rusting and smelting of iron are just two examples of reduction–oxidation (“redox”) reactions. As one species (e.g., the iron ore) becomes reduced, so the other (e.g., the coke) becomes oxidised. In redox, there is always something being oxidised and something else being reduced; it’s the yin and the yang of geochemistry, as the guest editors of this issue of Elements refer to it (cover).