Experts in the News

Pushing a shovel through snow, planting an umbrella on the beach, wading through a ball pit, and driving over gravel all have one thing in common: They all are exercises in intrusion, with an intruding object exerting some force to move through a soft and granular material. Predicting what it takes to push through sand, gravel, or other soft media can help engineers drive a rover over Martian soil, anchor a ship in rough seas, and walk a robot through sand and mud. But modeling the forces involved in such processes is a huge computational challenge that often takes days to weeks to solve. Now, engineers at the Massachusette Institute of Technology and Georgia Tech have found a faster and simpler way to model intrusion through any soft, flowable material. Daniel Goldman, Dunn Family Professor in the School of Physics, joined MIT researchers for this project. 

Is science better when it disrupts or when there are just incremental improvements to previous knowledge? The topic was analyzed in a recent study, and it seems that researchers have spent these past years improving things rather than trying to revolutionize everything. The study suggests that the level of "disruptiveness" in scientific research has gone way down in the 2000s compared to the last half-century. Yian Yin, a computational social scientist at Northwestern University in Evanston, Illinois, highlights how disruptiveness is not inherently good, and incremental science is not necessarily bad. Yin cites the first direct observation of gravitational waves, a landmark discovery that was both revolutionary and the product of incremental science. Georgia Tech researchers, many from the School of Physics, worked with researchers at the Laser Interferomoter Gravitational Wave Observatory (LIGO) on the gravitational wave observations. (This coverage also appeared in Nature and Inside Higher Education.)

Henry Segerman, a British American mathematician and mathematical artist at Oklahoma State University, has invented a puzzle to help explain the Earth's annual trip around the sun: Continental Drift, a 3-D sliding puzzle that made its debut earlier this year. The underlying geometric concept is holonomy: When you travel a loop on a curved surface and return to the starting point, you arrive somewhat turned around, rotated, perhaps by 180 degrees. It's just one of Segerman's inventions that help visualize mathematics. A few years ago, Dr. Segerman demonstrated Extensors: a construction kit for making extending mechanisms from scissor-like hinged parts. Sabetta Matsumoto, an associate professor in the School of Physics, applied mathematician, and Dr. Segerman’s partner, gave input into the contraption’s development and came up with the name Extensor. Between them, math is “a pretty common conversation,” said Matsumoto, who was featured in a 2019 New York Times story about her project to investigate the mathematics and mechanics of knitting. (This story also appears in Yahoo! News.)

The Artemis 1 mission to the Moon, launched from Kennedy Space Center on Nov. 16, did not have astronauts on board. It did have what NASA is calling "moonikins" — dummies wearing special spacesuits that will measure data on vibration, acceleration, and cosmic radiation. Thomas Orlando, professor in the School of Chemistry and Biochemistry, and an adjunct professor in the School of Physics, will study that data. Orlando is also the principal investigator for Georgia Tech's REVEALS (Radiation Effects On Volatiles And Exploration Of Asteroids And Lunar Surfaces), which will help NASA design the next generation of spacesuits and astronaut habitats. 

Most people may think of bacteria, regardless of species and shape, as a single cell, or maybe several free-living cells. The problem with this image, according to microbiologists, is that it doesn’t reflect how most bacteria are likely to live. Often, bacteria use sticky molecules to anchor themselves to a surface, growing in collectives called biofilms. A new study shows that even bacteria floating in the open ocean, which lack an anchoring point for forming large conglomerates, exist in multicellular forms. The study builds on 2021 published research from Georgia Tech scientists that showed unicellular yeast forming multicellular clusters. The School of Biological Sciences researchers include Ozan Bozdag, research scientist; William Ratcliff, associate professor; Kai Tong, Ph.D. Quantitative Biosciences student, and Penelope Kahn. School of Physics researchers involved include Peter Yunker, assistant professor;  Thomas C. Day, graduate student; and Seyed Alireza Zamani-Dahaj, Ph.D. student.