College of Sciences

Systems consisting of spheres rolling on elastic membranes have been used to introduce a core conceptual idea of general relativity: how curvature guides the movement of matter. However, such schemes cannot accurately represent relativistic dynamics in the laboratory because of the dominance of dissipation and external gravitational fields. A new study from School of Physics researchers demonstrates that an “active” object (a wheeled robot), which moves in a straight line on level ground and can alter its speed depending on the curvature of the deformable terrain it moves on, can exactly capture dynamics in curved relativistic spacetimes. The researchers' mapping and framework facilitate creation of a robophysical analog to a general relativistic system in the laboratory at low cost that can provide insights into active matter in deformable environments and robot exploration in complex landscapes. Researchers includes Hussain Gynai and Steven Tarr, graduate students; Emily Alicea-Muñoz, academic professional; Gongjie Li, assistant professor; and Daniel Goldman, Dunn Family Professor. 

The sudden buzz of a fly has most people flapping their hands wildly as if attempting to ward off an evil spirit. Seeing a wall or ceiling-hugger has others running quickly past or under, as if their mere shadow might prompt the insect to launch an aerial attack. Still others pick the fight response, choosing to squash the danger. But here’s the bug-zillion dollar question: Why do creepy-crawlies cause us to react this way? A 2018 Georgia Tech study that included Eric Schumacher, professor in the School of Psychology, found that the strongest neurological reaction elicited by bugs is disgust. It’s a result borne of a mix of things, from social conditioning and negative connotations to understanding their disease-carrying potential and, unfortunately, judging the book by its spindly, slimy, antennaed cover.

Diverse and full of sea life, the Earth’s Devonian era — taking place more than 370 million years ago — saw the emergence of the first seed-bearing plants, which spread as large forests across the continents of Gondwana and Laurussia. However, a mass extinction event near the end of this era has long been the subject of debate. Some scientists argue the Late Devonian mass extinction was caused by large-scale volcanic eruptions, causing global cooling. Others argue a mass deoxygenation event caused by the expansion of land plants was to blame. 
A recently published study in the journal Communications Earth and Environment now posits that both factors played a role — and draws attention to the environmental tipping points the planet faces today. Chris Reinhard, associate professor in the School of Earth and Atmospheric Sciences, contributed to the study.