Usefulness of Math Topic of February Science Cafe

UM professor Sandra Spiroff to discuss applications of mathematics

UM mathematics professor Sandra Spiroff explains complex mathematical equations in the classroom. Photo by Robert Jordan/Ole Miss Communications

OXFORD, Miss. – Practical uses for mathematical concepts is the topic for a monthly public science forum organized by the University of Mississippi Department of Physics and Astronomy.

The spring semester’s second meeting of the Oxford Science Cafe is set for 6 p.m. Tuesday (Feb. 20) at Lusa Pastry Cafe, 2305 W. Jackson Ave. Sandra Spiroff, UM associate professor of mathematics, will discuss “When are we ever going to use this?: Some Applications of Mathematics.” Admission is free.

“In 1623, Galileo Galilei wrote, ‘Philosophy is written in this grand book (meaning the universe), which stands continually open to our gaze, but cannot be understood unless one first learns to comprehend the language and interpret the characters in which it is written,'” Spiroff said. “‘It is written in the language of mathematics, without which it is humanly impossible to understand a single word of it.'”

Spiroff’s 40-minute presentation will explore the mathematics behind some of our everyday experiences.

“In addition, we will use technology to model the behavior we wish to understand,” she said.

Spiroff earned her doctorate at the University of Illinois at Urbana-Champaign. Her research area is commutative algebra, which includes the study of rings, modules, fields, groups, and the maps and invariants associated to these constructions.

She holds a five-year grant from the Simons Foundation and is an advocate for underrepresented groups in the study of mathematics, including women and minorities. Spiroff is organizing a research conference at the Banff International Research Station in Canada for the former and participating in national and regional conferences in support of the latter.

Active in the university’s globalization efforts, Spiroff will be traveling to China with a UM delegation to pursue partnerships with universities in Beijing and beyond. She is vice president of the UM Chapter of Phi Beta Kappa and faculty adviser of the American Mathematical Society Graduate Student Chapter.

For more information about Oxford Science Cafe programs, go to For more information about the Department of Physics and Astronomy, visit or call 662-915-5311.

Second Law of Thermodynamics Topic for January Science Cafe

UM researchers Randy Wadkins and Nathan Hammer to discuss mysteries of entropy

UM chemistry and biochemistry professors Randy Wadkins and Nathan Hammer will share ‘Harrowing Tales of Entropy’ at the monthly Science Cafe Jan. 30. Submitted photo

OXFORD, Miss. – The second law of thermodynamics is the topic for a monthly public science forum organized by the University of Mississippi Department of Physics and Astronomy.

The spring semester’s first meeting of the Oxford Science Cafe is set for 6 p.m. Jan. 30 at Lusa Bakery Bistro and Bar, 1120 North Lamar Blvd. Randy Wadkins and Nathan Hammer, UM professors of chemistry and biochemistry, will discuss “Harrowing Tales of Entropy.” Admission is free.

The second law of thermodynamics holds that entropy, basically heat lost during a chemical or mechanical transformation, can never decrease in an isolated system, such as the universe. The second law puts a limit on the transformation of heat into work.

“Entropy is a mysterious phenomenon that has puzzled scientists since its discovery by Rudolph Clausius in the 1850s,” Wadkins said. “Did it drive Clausius mad? Perhaps. But it led to his development of the Second Law of Thermodynamics.

“Nearly 200 years of scientists have struggled with this mind-blowing, senses-shattering physical phenomenon.”

Wadkins and Hammer’s 45-minute presentation will address several questions about the nature of entropy and how it affects everything.

“Found in refrigerators, automobiles and even our bodies, entropy will eventually destroy the universe,” Hammer said. “We can promise you one thing from this evening of thrills and sensations: you will never look at a snowflake the same way again.”

Marco Cavaglia, professor of physics and astronomy and the forum’s organizer, said he expects a most interesting discussion.

“I’m eagerly waiting their presentation,” Cavaglia said. “Entropy has fascinated researchers for generations, so I’m sure the general public will be fascinated as well.”

Wadkins received his bachelor’s and doctoral degree froms UM in 1986 and 1990, respectively. He held a postdoctoral fellowship with the National Institutes of Health, a Gesellschaft Postdoctoral Fellowship at the Max Planck Institute for Biophysical Chemistry in Goettingen, Germany, and a postdoctoral fellowship at St. Jude Children’s Research Hospital.

He also has been a science and technology policy fellow with the American Association for the Advancement of Science in 2015-16, sponsored by the Biophysical Society.

A member of the Ole Miss faculty since 1990, Wadkins’ research interests are biophysical chemistry, molecular dynamics, fluorescence microscopy and imaging, DNA structure and structural transitions, and biosensors.

Hammer received an honors bachelor’s degree in chemistry and a doctorate in physical chemistry and chemical physics from the University of Tennessee in 1998 and 2003, respectively. He was a postdoctoral researcher at Yale University and an Intelligence Community Postdoctoral Fellow at the University of Massachusetts.

He joined the UM faculty in 2007 and received tenure in 2013. He was honored as an Ole Miss Faculty Research Fellow in 2008 and received a Faculty Early Career Development Award from the National Science Foundation in 2010 to spectroscopically track the evolution of noncovalent interactions from the single molecule level to the condensed phases.

Hammer also directs the NSF-funded Ole Miss Physical Chemistry Summer Research Program for Undergraduates.

For more information about Oxford Science Cafe programs, go to For more information about the Department of Physics and Astronomy, visit or call 662-915-7046.

Wild Mushrooms Topic for November Science Cafe

Biologist Jason Hoeksema will discuss ecology and culinary potential of fungi

Several varieties of wild mushrooms will be discussed during the November Oxford Science Cafe. Submitted photo by Jason Hoeksema

OXFORD, Miss. – The ecology and edibility of wild mushrooms is the topic for a monthly public science forum organized by the University of Mississippi Department of Physics and Astronomy.

The fall semester’s third meeting of the Oxford Science Cafe is set for 6 p.m. Nov. 14 at Lusa Bakery and Cafe, 1120 North Lamar Blvd. Jason Hoeksema, UM associate professor of biology, will discuss “Wild mushrooms: Ecology, edibility and more.” Admission is free.

“What is a mushroom? What is its natural function for fungi? Which ones are delicious and which ones will make you ill or worse?” Hoeksema said. “In this presentation, we’ll answer all these questions.

“We’ll start with a discussion of fungal ecology, especially focusing on how fungi obtain food and the really interesting ways that fungi can change the ecology of plants and nutrient cycling.”

Hoeksema’s 45-minute presentation also will examine the role of mushrooms in the life cycles of fungi.

“Finally, we’ll discuss strategies for finding and safely enjoying wild mushrooms in northern Mississippi,” he said.

A Science Cafe organizer said Hoeksema’s discussion should be most interesting.

“I’m eagerly waiting for Dr. Hoeksema’s presentation,” said Marco Cavaglia, professor of physics and astronomy. “The world of mushrooms is so fascinating.

“When I was a kid, I spent many weekends mushroom hunting with my dad. Nowadays, when I hike in the woods of Mississippi, I’m still mesmerized by the variety and beauty of wild mushrooms.”

Hoeksema received his bachelor’s and doctoral degrees from the University of Michigan and the University of California at Davis, respectively. A member of the Ole Miss faculty since 2006, he teaches courses in ecology, evolution, statistics, microbiology, mycology and ornithology. He also occasionally leads mushroom field trips for the public.

His research addresses questions regarding the ecological and evolutionary consequences of species interactions – such as mutualism, parasitism and competition – on populations and communities, with a focus on interactions between plants and mycorrhizal fungi.

For more information about Oxford Science Cafe programs, go to For more information about the Department of Physics and Astronomy, visit or call 662-915-7046.

Physics Department Offers Ghoulish Fun

Spooky Physics Night provides frights and excitement with a side of science

An Oxford Elementary School student lies on a bed of nails as a volunteer places a weight on her while other Spooky Physics Night participants observe. Photo by Nathan Latin/Ole Miss Communications

OXFORD, Miss. – Frights, food and fun are the order of the evening when the University of Mississippi Department of Physics and Astronomy presents Spooky Physics Night on Friday (Oct. 27) in Lewis Hall.

The program, which runs 7-9 p.m., includes a stage show at 7:45 p.m. Hands-on activities through the evening include freezing objects in liquid nitrogen (at minus 320 degrees), generating sound waves with Bunsen burners and tubes, and levitating magnets with superconductors. Other fun presentations include optical illusions with mirrors, a Van de Graaff generator, a bed of nails and other contraptions.

Physics department personnel also will prepare ice cream with liquid nitrogen and award prizes for the most original, scariest and cutest costumes to children 12 and under. It’s all in the name of making learning about science fun and exciting, said Marco Cavaglia, professor of physics and coordinator of the evening’s activities.

“We at the Department of Physics and Astronomy really look forward to this event,” Cavaglia said. “As in the past years, there will be shows and a lot of hands-on science demonstrations with a Halloween twist to experience weird physics phenomena, from electricity to heat and pressure to the ultracold.

“And to make the evening ‘sweeter,’ guests will be able to taste our world-famous liquid nitrogen ice cream!”

Parents and children should be able to find plenty to enjoy at the event, said Luca Bombelli, chair and professor of physics and astronomy.

“Spooky Physics Night is an opportunity for the public to come and enjoy what we do all the time in a relaxed and refreshing manner,” he said. “For our faculty and students alike, it’s something everyone looks forward to each October.”

Parking for the event is available near Lewis Hall in the areas alongside or behind the Turner Center and the old athletics administration building, in the Pavilion garage or in the Tad Smith Coliseum parking lot.  All vehicles must be off campus by midnight.

For more information or for assistance related to a disability, call the Department of Physics and Astronomy at 662-915-5325.

Scientists Detect Gravitational Waves Produced by Colliding Neutron Stars

Joint LIGO-Virgo discovery marks first cosmic event observed in both gravitational waves and light

An artist’s illustration of two merging neutron stars. The narrow beam represents the gamma-ray burst, and the rippling spacetime grid indicates the isotropic gravitational waves that characterize the merger. Swirling clouds of materials ejected from the collision are a possible source of the light that was seen at lower energies. Graphic courtesy National Science Foundation/LIGO/Sonoma State University/A. Simonnet

OXFORD, Miss. – For the first time, scientists have directly detected gravitational waves – ripples in space and time – in addition to light from the spectacular collision of two neutron stars. This marks the first time that a cosmic event has been viewed in both gravitational waves and light.

The discovery was made using the U.S.-based Laser Interferometer Gravitational-Wave Observatory, known as LIGO, the Europe-based Virgo detector, and some 70 ground- and space-based observatories.

Neutron stars are the smallest, densest stars known to exist and are formed when massive stars explode in supernovas. As these neutron stars spiraled together, they emitted gravitational waves that were detectable for about 100 seconds; when they collided, a flash of light in the form of gamma rays was emitted and seen on Earth about two seconds after the gravitational waves.

In the days and weeks following the smashup, other forms of light, or electromagnetic radiation – including X-ray, ultraviolet, optical, infrared and radio waves – were detected.

“This is really the beginning of multimessenger astronomy,” said Marco Cavaglia, professor of physics and astronomy at the University of Mississippi and principal investigator of the Ole Miss LIGO group. “Since the time humans have first gazed at the sky, people have just relied on light to learn about the universe.

“Today, we proved we can simultaneously observe a cosmic event using two different carriers of information: electromagnetic waves and gravitational waves. This is a revolution in astronomy comparable to Galileo’s first telescopic observations.”

The observations have given astronomers an unprecedented opportunity to probe a collision of two neutron stars. For example, observations made by the U.S. Gemini Observatory, the European Very Large Telescope and NASA’s Hubble Space Telescope reveal signatures of recently synthesized material, including gold and platinum, solving a decades-long mystery of where about half of all elements heavier than iron are produced.

The LIGO-Virgo results are published today in the journal Physical Review Letters; additional papers from the LIGO and Virgo collaborations and the astronomical community have been either submitted or accepted for publication in various journals.

The gravitational signal, named GW170817, was first detected at 7:41 a.m. Aug. 17; the detection was made by the two identical LIGO detectors in Hanford, Washington, and Livingston, Louisiana. The information provided by the third detector, Virgo, situated near Pisa, Italy, enabled an improvement in localizing the cosmic event.

At the time, LIGO was nearing the end of its second observing run since being upgraded in a program called Advanced LIGO, while Virgo had begun its first run after recently completing an upgrade known as Advanced Virgo.

The National Science Foundation-funded LIGO observatories were conceived, constructed, and operated by Caltech and MIT. Virgo is funded by the Istituto Nazionale di Fisica Nucleare in Italy and the Centre National de la Recherche Scientifique in France, and operated by the European Gravitational Observatory. Some 1,500 scientists in the LIGO Scientific Collaboration and the Virgo Collaboration work together to operate the detectors and to process and understand the gravitational-wave data they capture.

Each observatory consists of two long tunnels arranged in an “L” shape, at the joint of which a laser beam is split in two. Light is sent down the length of each tunnel, then reflected back in the direction it came from by a suspended mirror. In the absence of gravitational waves, the laser light in each tunnel should return to the location where the beams were split at precisely the same time. If a gravitational wave passes through the observatory, it will alter each laser beam’s arrival time, creating an almost imperceptible change in the observatory’s output signal.

On Aug. 17, LIGO’s real-time data analysis software caught a strong signal of gravitational waves from space in one of the two LIGO detectors. At nearly the same time, the Gamma-ray Burst Monitor on NASA’s Fermi space telescope had detected a burst of gamma rays.

Rapid gravitational-wave detection by the LIGO-Virgo team, coupled with Fermi’s gamma-ray detection, enabled the launch of follow-up by telescopes around the world.

The LIGO data indicated that two astrophysical objects located at the relatively close distance of about 130 million light-years from Earth had been spiraling in toward each other. It appeared that the objects were not as massive as binary black holes – objects that LIGO and Virgo have previously detected.

Instead, the inspiraling objects were estimated to be in a range from around 1.1 to 1.6 times the mass of the sun, in the mass range of neutron stars. A neutron star is about 12 miles in diameter and is so dense that a teaspoon of neutron star material has a mass of about a billion tons.

“The scientific community has been eagerly awaiting this moment,” says Kate Dooley, UM assistant professor of physics and astronomy and a member of the LIGO team that designed and built the detectors.

“Coalescing neutron stars provide such an exciting laboratory for new physics. We can study how neutrons behave when they’re packed so closely together, and even make an independent measurement of the expansion of the universe. We are tremendously lucky this event was relatively close by and could also be so precisely pinpointed in the sky.”

Theorists have predicted that when neutron stars collide, they should give off gravitational waves and gamma rays, along with powerful jets that emit light across the electromagnetic spectrum. The gamma-ray burst detected by Fermi, and soon thereafter confirmed by the European Space Agency’s gamma-ray observatory INTEGRAL, is what’s called a short gamma-ray burst.

The new observations confirm that at least some short gamma-ray bursts are generated by the merging of neutron stars – something that was only theorized before.

“This result is a great example of the effectiveness of teamwork, of the importance of coordinating and of the value of scientific collaboration,” said Federico Ferrini, director of the European Gravitational Observatory. “We are delighted to have played our relevant part in this extraordinary scientific challenge: Without Virgo, it would have been very difficult to locate the source of the gravitational waves.

Each electromagnetic observatory will be releasing its own detailed observations of the astrophysical event. In the meantime, a general picture is emerging among all observatories involved that further confirms that the initial gravitational-wave signal indeed came from a pair of inspiraling neutron stars.

Approximately 130 million years ago, the two neutron stars were in their final moments of orbiting each other, separated only by about 200 miles and gathering speed while closing the distance between them. As the stars spiraled faster and closer together, they stretched and distorted the surrounding space-time, giving off energy in the form of gravitational waves before smashing into each other.

At the moment of collision, the bulk of the two neutron stars merged into one ultra-dense object, emitting a “fireball” of gamma rays. The initial gamma-ray measurements, combined with the gravitational-wave detection, also provide confirmation for Einstein’s general theory of relativity, which predicts that gravitational waves should travel at the speed of light.

Swope and Magellan telescope optical and near-infrared images of the first optical counterpart to a gravitational wave source, SSS17a, in its galaxy, NGC 4993. The left image is from Aug. 17, 11 hours after the LIGO/Virgo detection of the gravitational wave source, and contains the first optical photons of a gravitational wave source. The right image is from four days later. SSS17a, which is the aftermath of a neutron star merger, is marked with a red arrow. On the first night, SSS17a was relatively bright and blue. In only a few days, it faded significantly and its color became much redder. These observations show that heavy elements like gold and platinum were created in the merger. Photos courtesy 1M2H/UC Santa Cruz and Carnegie Observatories/Ryan Foley

Theorists have predicted that what follows the initial fireball is a “kilonova,” a phenomenon by which the material that is left over from the neutron star collision, which glows with light, is blown out of the immediate region and far out into space. The new light-based observations show that heavy elements, such as lead and gold, are created in these collisions and subsequently distributed throughout the universe.

In the weeks and months ahead, telescopes around the world will continue to observe the afterglow of the neutron star merger and gather further evidence about various stages of the merger, its interaction with its surroundings and the processes that produce the heaviest elements in the universe.

“Gravitational wave astronomy continues to provide exciting new ways to observe our universe,” said Josh Gladden, UM interim vice chancellor for research and sponsored programs. “A particularly exciting aspect of this discovery is that this event could be observed by both traditional electromagnetic (light) astronomy as well as by gravitational waves, which allows for direct comparisons.

“We are proud that our gravity group at Ole Miss continues to provide important contributions to the LIGO effort.”

LIGO is funded by the NSF, and operated by Caltech and MIT, which conceived of LIGO and led the Initial and Advanced LIGO projects. Financial support for the Advanced LIGO project was led by the NSF with Germany (Max Planck Society), the U.K. (Science and Technology Facilities Council) and Australia (Australian Research Council) making significant commitments and contributions to the project.

More than 1,200 scientists and some 100 institutions from around the world participate in the effort through the LIGO Scientific Collaboration, which includes the GEO Collaboration and the Australian collaboration OzGrav. Additional partners are listed at

The Virgo collaboration consists of more than 280 physicists and engineers belonging to 20 different European research groups: six from Centre National de la Recherche Scientifique in France; eight from the Istituto Nazionale di Fisica Nucleare in Italy; two in the Netherlands with Nikhef; the MTA Wigner RCP in Hungary; the POLGRAW group in Poland; Spain with the University of Valencia; and the European Gravitational Observatory, the laboratory hosting the Virgo detector near Pisa in Italy, funded by CNRS, INFN, and Nikhef.

UM communications specialist Edwin Smith contributed to this report.

UM Physicists Celebrate Nobel Prize-Winning Discovery

Historic gravitational wave observation made in 2015 recognized as breakthrough in modern physics

UM physics professor Marco Cavaglia, right, shares a T-shirt with Kip Thorne, one of three recipients of the 2017 Nobel Prize in physics. Submitted photo.

OXFORD, Miss. – Physics researchers at the University of Mississippi are elated over news that colleagues involved in the groundbreaking discovery of gravitational waves in 2015 were awarded the prestigious Nobel Prize in physics Tuesday (Oct. 3).

Rainer Weiss, a professor at the Massachusetts Institute of Technology, and Kip Thorne and Barry Barish, both of the California Institute of Technology, were awarded the prestigious honor for the discovery of ripples in space-time known as gravitational waves, which were predicted by Albert Einstein a century ago but had never been directly seen.

In announcing the award, the Royal Swedish Academy called it “a discovery that shook the world.”

“Kip and Rai are two of the most clever and kind people I ever had the honor of working with,” said Marco Cavaglia, UM professor of physics and astronomy and head of the Ole Miss Laser Interferometer Gravitational-wave Observatory team. “Kip and Rai are always easy to talk with, and humble although they are among the best scientific minds of our time.

“They both remain very active, especially Rai, who, at 85, is still one of the driving forces behind LIGO.”

Cavaglia met Weiss and Thorne more than a decade ago and credits the former for his LIGO connection.

“Over 10 years ago, I was invited to LSU to give a colloquium at the physics department by Jorge Pullin, a professor at LSU working on quantum gravity,” he said. “At that time, I was working on quantum gravity, particle colliders and cosmic rays.

“Gaby Gonzalez, LSU professor and later spokesperson of the LIGO Scientific Collaboration, arranged for me a guided visit to the LIGO Observatory in Livingston, Louisiana, on my way back to Oxford.”

Much to Cavaglia’s surprise, it was Weiss who gave him the tour.

“He spent several hours with me, showing the detector and the lab to me,” Cavaglia recalled. “I was so amazed with the LIGO project and researchers that I started planning to join the LIGO Scientific Collaboration and work on gravitational wave astrophysics. I’ve been working within the LSC ever since then.”

Other UM officials shared their reflections about the prize recipients.

“Rai wrote the first detailed document for the design of the LIGO interferometers in 1983,” said Katherine Dooley, UM assistant professor of physics and astronomy. “We call it the ‘Bluebook’ because of how accurately he predicted all of the noise sources for the detector.

“Rai, himself, is also remarkable for his energy and ability to continue playing an integral role in the detector commissioning to this date.”

Dooley worked at the LIGO Livingston site for four years, installing hardware and commissioning the full interferometer. Weiss was a regular, long-term visitor.

“He always had his pet projects, from tirelessly tracking down leaks in the vacuum system – the largest-volume vacuum system in the world and the most valuable part of the entire detector – to tackling head-on the ‘mystery noise’ that most impeded our progress in commissioning,” she said. “He suspected Barkhausen noise – magnetic domain-flipping – was a culprit and set up experiments to measure it.”

Weiss also played a special role in Dooley’s path to earning her doctorate, she said

“He was the first person to sit me down and make me write an outline for my thesis,” Dooley said. “Rai was always an advocate for us students, and we appreciated that greatly. He wouldn’t hesitate to step in to protect our interests.”

Josh Gladden, UM interim vice chancellor of research and sponsored programs, congratulated the LIGO team on their honor.

“As a physicist, the most exciting moment in my professional career was being on hand in Livingston, Louisiana, for the announcement of the first detection of gravitational waves,” Gladden said. “We are so proud of the contribution that our physics colleagues have made to the LIGO effort and that the Nobel committee has honored this discovery with the highest prize in physics.

“As subsequent discoveries have shown, gravitational waves are going to be an entirely new tool for humans to observe our universe.”

Weiss, in a live phone call with the Nobel Committee minutes after the announcement, said, “I view this more as a thing that recognizes the work of about 1,000 people,” referring to the LIGO Scientific Collaboration.

“We are so pleased that our physics department and research faculty have been an integral part of LIGO since 2007,” Chancellor Jeffrey S. Vitter said. “It is quite an honor for the University of Mississippi to play a role in this international collaboration of talented scientists and engineers, which is producing such astounding breakthroughs and now the Nobel Prize in Physics.

“Our participation in this collaboration is a stellar example of UM’s transformative impact upon our understanding of the world.”

The Royal Swedish Academy of Sciences, founded in 1739, is an independent organization whose overall objective is to promote the sciences and strengthen their influence in society. The academy takes special responsibility for the natural sciences and mathematics, but works to promote the exchange of ideas between various disciplines. Nobel Prize is a registered trademark of the Nobel Foundation.