Toggle light / dark theme

Colossal Room Temperature Nonreciprocal Hall Effect

The Attosecond Science group at the Center for Free-Electron Laser Science has developed a novel light source capable of producing extremely short pulses for the investigation of UV-induced molecular dynamics with unprecedented temporal resolution. Scientists from the University of Hamburg and from DESY describe their unique observations in an article published in Nature Communications.

Mysterious 165-Million-Year-Old Minerals Found on Easter Island Defy Plate Tectonics

Easter Island consists of several extinct volcanoes. The oldest lava deposits formed some 2.5 million years ago on top of an oceanic plate not much older than the volcanoes themselves. In 2019, a team of Cuban and Colombian geologists left for Easter Island to accurately date the volcanic island. To do so, they resorted to a tried-and-tested recipe: dating zircon minerals. When magma cools, these minerals crystallize. They contain a bit of uranium, which ‘turns’ into lead through radioactive decay.

Because we know how fast that process happens, we can measure how long ago those minerals formed. The team from Colombia’s Universidad de Los Andes, led by Cuban geologist Yamirka Rojas-Agramonte, therefore went in search of those minerals. Rojas-Agramonte, now at the Christian Albrechts-University Kiel, found hundreds of them. But surprisingly, not only from 2.5 million years old, but also from much further back in time, up to 165 million years ago. How could that be?

The Mechanical World

This monograph examines the metaphysical commitments of the new mechanistic philosophy, a way of thinking that has returned to center stage. It challenges a variant of reductionism with regard to higher-level phenomena, which has crystallized as a default position among these so-called New Mechanists. Furthermore, it opposes those philosophers who reject the possibility of interlevel causation.

Contemporary philosophers believe that the explanation of scientific phenomena requires the discovery of relevant mechanisms. As a result, new mechanists are, in the main, concerned solely with epistemological questions. But, the author argues, their most central claims rely on metaphysical assumptions. Thus, they must also take into account metaphysics, a system of thought concerned with explaining the fundamental nature of being and the world around it. This branch of philosophy does indeed matter to the empirical sciences.

The chapters investigate the nature of mechanisms, their components, and the ways in which they can bring about different phenomena. In addition, the author develops a novel account of causation in terms of activities.