It has been nearly 10 years since Penn State astrophysicist Tom Abel started his research on the early evolution of the universe, and his efforts have recently revealed how the first cosmological objects were formed.

"We are trying to create an understanding of an era of the universe that we can't understand observationally," he said.

Abel, assistant professor of astronomy and astrophysics, said he began his research as an exchange student at the University of Illinois in 1994 with his adviser, Michael Norman, and another of Norman's students, Greg Bryan.

"We use supercomputers to re-create what has happened since the Big Bang because it is a relevant stage in the history of the universe that allowed for life to form later on," he said.

These supercomputers use a three-dimensional grid to solve many equations at each point in space, he said. The equations quantify physical properties such as the temperature, density and molecular composition, so that astronomers can determine the movement of gases and the effects of chemistry and gravity at each point.

He said the supercomputers can follow these properties over time and across different length scales.

"The supercomputers are able to do this for objects the size of the sun and that are thousands of light-years across," he said.

He said the simulations start with the universe as it was observed about 10 million years after the Big Bang, when it was still very simple and very hot.

"At that time, material in the universe was distributed uniformly, except for small deviations in density," he said. Because of these deviations, some of the material started to come together due to gravity, forming the first cosmological objects.

The proceeding simulations show the formation of what Abel calls "microgalaxies," which were about one-millionth the size of our Milky Way Galaxy and were also the sites of the births of the universe's first stars.

These first stars, he said, were composed of hydrogen and helium, the only known elements in the universe at that time. They were about 100 times as massive as the sun and shined about 1 million times brighter. However, they only lived for about three million years, which is short by stellar standards. The sun, for example, is supposed to live for about 10 billion years.

"The first stars were like rock stars -- they would burn quickly and die young," he said. When these massive stars died, they exploded in supernovae. These phenomena created enough heat to produce other elements in addition to hydrogen and helium, and all of these elements were then ejected from the stars when they exploded.

"This explains why we have never seen a star only containing hydrogen and helium -- because all of them have already exploded," he said.

Furthermore, this means that all of the elements in the universe -- including the ones that make up all earthly objects -- must have been formed in stars and supernovae.

"A fraction of each of us was made in one of these stars," Abel said.

While this discovery was made before Abel's simulations, the procedure of using supercomputers to "observe" the evolution of the universe marks a transformation in the way astronomers are studying it. Until the simulations were developed, astronomers were unsure about how the whole process worked because it was so complex.

"It turned out to be quite different than what people thought initially," he said, although he added there were other theories that the simulations actually confirmed. For example, a satellite recently found evidence that the first light in the universe did not appear until about 100 to 200 million years after the Big Bang, which he said was precisely what the calculations in their simulations suggested.

Many other astronomers are taking note of Abel's research and applying it to their own studies. Peter Meszaros, professor of astronomy and astrophysics, studies gamma ray bursts, which are some of the oldest and most distant objects in the universe, and black holes, which result when extremely massive stars die. He said he is collaborating with Abel in these areas, comparing his own calculations with those from Abel's simulations.

"That's the way science works -- you test a theory with experiments," he said.

He also said he is involved in the Swift project, which will launch a new gamma ray satellite in December.

"We are excited to compare what it sees with the calculations [Abel] has been working on," he said.

Niel Brandt, associate professor of astronomy and astrophysics, studies black holes and X-rays. He said he thinks Abel's research will augment his own because it will allow him to see how black holes have evolved.

"Tom is simulating seeds that form the first black holes, which will ultimately grow into the massive black holes that I study," he said.

Abel has presented his findings all over the world, and National Geographic and Discover magazines have published articles about his research.