��ӽ紫ý faculty member leads project to discover best measurement for ‘Big G’

Dipangkar Dutta (Photo by Russ Houston)

STARKVILLE, Miss.—A Mississippi ��ӽ紫ý physics professor will lead a multi-institutional, multi-discipline effort as part of a larger National Science Foundation (NSF) project studying the least precisely known, but very common, fundamental constant in physics.

Dipangkar Dutta, professor in ��ӽ紫ý’s Department of Physics and Astronomy, will serve as principal investigator with the help from a collaborating nuclear physicist and co-principal investigator from Indiana University. They will conduct research on an alternate material to measure G, Isaac Newton’s gravitational constant, also known as “Big G.”

According to Jeff Winger, acting head of the physics and astronomy department at ��ӽ紫ý, it is a great honor for the ��ӽ紫ý group to carry out their portion of the measurement. The Department of Physics and Astronomy recently received a grant for more than $148,000 from the NSF that will fund the research for potential improvements in the measurement of “Big G.”

Dutta said that all previous measurements have used large cylinders or spheres made from high-density metals that may have tiny hidden cavities in the metal and that this can lead to errors in measurement of G. Dutta and his collaborator hope to develop high-density transparent crystals that will make it possible to find the cavities easier, leading to more precise measurements of G.

According to Winger, G is unique compared to the many other fundamental constants that have been discovered since the time of Newton. “Everyone experiences gravity on a daily basis,” Winger said. “Yet, of all the fundamental constants, G is known with the least precision. In fact, several of the recent high precision measurements of G have been in disagreement.”

Because of this, Winger said that “an international effort is being put forth to make a precise and accurate measurement of G. It is exciting that ��ӽ紫ý can be a part of this effort.”

According to Dutta, measuring Big G is extremely challenging.

“Big G is one of the most important, yet finicky, numbers in astrophysics,” Dutta said. “Its value influences everything from rate at which galaxies are formed to the expansion of the universe.”

Big G is known as the Mount Everest of measurements – it is the supreme difficulty of the challenge that makes the pursuit itself worthwhile,” Dutta said.

Dutta explained how this opportunity also will provide an intellectually stimulating environment for many undergraduate and graduate students at ��ӽ紫ý.

“One of the most important impacts of this research will be the education of young scientific researchers,” Dutta said. “This challenging project will provide an excellent atmosphere for first-rate education in experimental physics.”

“This also will forge new collaborations with other universities and enhance the reputation of ��ӽ紫ý as a research powerhouse,” Dutta continued.

Dutta received his bachelor’s degree from the Indian Institute of Technology in 1992 and his doctorate at Northwestern University in 1999. He has taught at ��ӽ紫ý since 2006. His research focuses on the precision measurement of fundamental properties of nucleons. Dutta won the College of Arts and Sciences’ Henry Family Dean’s Eminent Scholar award in 2010, the ��ӽ紫ý ��ӽ紫ý Pride Award in 2010 and the College of Arts and Sciences Researcher of the Month citation in 2011.

Winger said that this grant brings prestige to the university, college and department.

“Professor Dutta has built a strong research program in medium-energy nuclear physics. This project builds on the techniques which were developed for nuclear physics research to work in a very different area of research,” Winger said. “Although just a small cog in the whole project, the effort put forth by the ��ӽ紫ý group and their collaborators will be instrumental in obtaining an accurate and precise measurement of G.”

The College of Arts and Sciences includes more than 5,000 students, 300 full-time faculty members, nine doctoral programs and 24 academic majors offered in 14 departments. It also is home to the most diverse units for research and scholarly activities, including natural and physical sciences, social and behavioral sciences, and the humanities.

Natural and physical science research projects have been supported over the decades by the National Institute of Justice, U.S. Department of Defense, National Institutes of Health and National Science Foundation, as well as the U.S. Department of Energy’s Office of Science.

Research expenditures in the humanities also are an important part of Mississippi ��ӽ紫ý’s overall research portfolio. Additionally, the NSF has ranked ��ӽ紫ý among the top 25 for research expenditures in the social sciences. For more information on ��ӽ紫ý’s College of Arts and Sciences, visit .

��ӽ紫ý is Mississippi’s leading university, available online at .

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