Astronomy Professor Talks Green Flashes, Black Holes

FREWSBURG – A Jamestown native returned home Tuesday to discuss the color spectrum around the setting sun and the absence of color in space.

Dr. James LoPresto, a retired Edinboro University professor of astronomy and physics, returned to the area to present a lecture about green flashes and black holes. The presentation took place at the Martz Observatory, located at 176 Robin Hill Road, Frewsburg. About 25 people attended the informative discussion.

Over the years, LoPresto has given numerous talks at various colleges and universities, including Harvard, University of Michigan, University of Arizona, Penn State University, Kent State University and the University of Toronto. An expert in the field of solar astronomy, he has published 45 articles in various professional journals and magazines. Most of his research has taken place at the National Solar Observatory branch of Kitt Peak National Observatory near Tucson, Ariz. There he uses the McMath-Pierce Solar Telescope, the largest solar telescope in the world. He has been awarded permanent observing status at that site.

The green flash is one of the colors people can see around the setting sun. The color spectrum around the sun as it sets goes from red to orange to yellow to green to blue to violet. LoPresto said green is usually the last color on the spectrum people can see around the setting sun. He said blue and violet are very rare occurrences. The professor showed photos of the setting sun that included the green flash.

”It is the most beautiful emerald green you have ever seen in your life,” he said.

LoPresto said the green flash is similar to a snowflake because no two are exactly alike.

”That is what makes them so beautiful,” he said.

The astronomer said the green flash usually last between two to four seconds before it can no longer be seen. He said people don’t have to be looking over water to see the green flash. He said people can use a building to possibly see the green light around the setting sun. He said the key is being above the setting sun.

The professor then talked about black holes and famous physicist who have studied them. From Albert Einstein and his work on general relativity to Stephen Hawking and his work on theoretical physicist and cosmologist. LoPresto said black holes are space-time folded in on it self. He discussed event horizons, singularity and warped space. The astronomer said you can enter a black hole, but you can never get out. LoPresto said black holes have three dimensions of space and one dimension of time.

For more information on the Martz Observatory, visit