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Asking Questions About the Universe
An international crowd of cosmology experts descended on Warsaw in late August for a symposium on the universe, including such issues as dark matter and the evolution of galaxies. The symposium was held in honor of Polish astrophysicist Roman Juszkiewicz, a major contributor to international cosmology research who wrote nearly 100 research papers before his death in 2012. More than 70 experts presented their research projects at the event.

Cosmology is a discipline of science that seeks answers to questions about how the universe has evolved since the beginning of time, and how galaxies were formed. In short, cosmology seeks to understand the origin, evolution and ultimate fate of the universe.

Dark matter and dark energy

Scientists dealing with cosmology want to get an insight into issues such as the role of dark matter and dark energy—an unknown form of energy that is hypothesized to permeate all of space, tending to accelerate the expansion of the universe, says Agnieszka Pollo, Ph.D., a Polish cosmology researcher and a former student of Juszkiewicz. “Polish cosmology is strong and we can be proud of it,” she says.

Pollo is part of an international team of researchers working on the so-called Vipers survey, which focuses on distant galaxies and is managed by Prof. Luigi Guzzo of Italy. French and British researchers are taking part as well. A group of more than 40 scientists has been conducting observations for the project since 2008, using an eight-meter telescope at the European Southern Observatory in Chile.

“We have already measured almost 100,000 galaxies,” says Pollo. “We are preparing a detailed, three-dimensional map of the universe—the way it was 8-9 billion years ago. We are trying to answer questions about dark energy whose activity began to be visible in the universe around that time.”

In her everyday work, Pollo deals with a so-called large-scale structure of the universe. Single dots that we see as the Milky Way are each galaxies, which create a complex three-dimensional network and cluster into groups. How did this whole structure come about? How has it evolved? These are among the puzzles that cosmology is trying to solve.

Galaxies, quasars and gravity

Prof. Ewa Łokas from the Polish Academy of Sciences’ Nicolaus Copernicus Astronomical Center in Warsaw, another onetime student of Juszkiewicz, started out in the area of theoretical analysis in cosmology; today she studies the shape and evolution of galaxies.

Prof. Bożena Czerny, from the Astronomical Center, and Agnieszka Janiuk, Ph.D., from the Polish Academy of Sciences’ Center for Theoretical Physics in Warsaw, both research the role of quasars in cosmology. Quasars are the brightest objects in the universe. For a long time scientists had no clue as to what causes quasars to be easily seen from a distance of billions of light years despite their small size. Now there is general scientific consensus that a quasar is a compact region in the center of a massive galaxy surrounding a central supermassive black hole.

Meanwhile, Prof. Marek Biesiada from the University of Silesia in the southern city of Katowice focuses on what is known as gravitational lensing, a field of astrophysical research that involves the distribution of matter (such as a cluster of galaxies) between a distant source and an observer. Gravitational lensing is based on the observation that light passing near a massive body is attracted by it. On the basis of how the light of distant sources is deformed, scientists are trying to develop theories about the distribution of dark matter in the universe.

Scientific simulations

Researchers dealing with cosmology employ a variety of calculations and equations to answer such fundamental questions. However, not all equations can be solved in a simple way or written in a simple form. That’s where computer simulations are useful, because they can take into account more factors. Artificial universes are simulated like those that emerged shortly after the Big Bang, when matter began to clump together and evolve. A large part of the symposium was dedicated to simulations.

One of the world’s largest cosmological simulations is in progress at the University of Warsaw’s Interdisciplinary Centre for Mathematical and Computational Modelling (ICM). The project, called COpernicus COmplexio (COCO) and managed by Wojciech Hellwig, Ph.D.—who worked with Juszkiewicz at the University of Zielona Góra—seeks to answer questions about the nature of dark matter, which betrays its existence only indirectly. It does not emit light, and astronomers conjecture about its presence on the basis of gravitational interactions with normal matter.

The University of Warsaw’s Interdisciplinary Centre for Mathematical and Computational Modelling has extensive information and IT infrastructure, including powerful computers, data processing systems and a broad spectrum of scientific software and tools. The COpernicus COmplexio project is being carried out using the center’s Boreas supercomputer.

Karolina Olszewska


Prof. Roman Juszkiewicz (1952-2012) was a Polish astrophysicist whose work concerned fundamental issues of cosmology. He dealt with the theory of galaxy formation, gravitational instability and cosmic microwave background, the thermal radiation that fills the entire universe and is the remnant heat left over from the Big Bang.

Born in Warsaw, Juszkiewicz studied at Moscow State University under Yakov Borisovich Zel'dovich, where he graduated in 1976. In 1981, he obtained a Ph.D. at the University of Warsaw. From 1984 to 1986 he worked at the University of Cambridge and the University of Sussex in Britain; he spent 1986-1987 at the University of California at Berkeley, and 1987-1991 at Princeton. He also worked at the Paris Institute of Astrophysics and the University of Geneva.

Juszkiewicz was a professor at the Polish Academy of Sciences’ Nicolaus Copernicus Astronomical Center in Warsaw. His scientific interests included the theory of gravitational instability, the origins of the so-called large-scale structure, microwave background radiation and Big Bang nucleosynthesis. He wrote nearly 100 research papers, mostly in the area of cosmology.