******CHENG, Roger J******

By Don Rittner –TROY RECORD

I’ve been fortunate to meet and develop long friendships with some of the most interesting people on the planet Roger Cheng was born in Kaifung, east central China along the Yellow River in the Honan Province, one of the oldest inhabited regions with over 7 million people. During the Communist Revolution, it was the poorest farm country in China and millions of peasants died from hunger. Roger is the son of Chen-Yu and Shin-Nan Cheng, a farming family that goes back many generations. After passing a tough written exam, Roger attended the Nankai Middle School, Known for having the best and brightest students and where many of today’s top Chinese Government officers attended, including the former premier Chon En Lai. During one evening, a blind fortuneteller told his family that Roger would travel beyond China, work with small things, and marry a non-Chinese woman.

In 1957, Roger passed a stringent English exam for study in America. He borrowed $50 and air fare and landed at Florida State University doing graduate work with Seymour Hess, head of meteorology and an expert on the atmosphere of Mars. In 1964, Roger read the papers of Schenectady’s Vincent Schaeffer on ice and snow crystal research and wrote him asking for a job at Albany’s newly created Atmospheric Science Research Center (ASRC). Two years later, he began his first job as a technical assistant for Schaeffer for $1.25 per hour at 10 hours a week. He stayed at ASRC for 32 years.

Roger made several amazing observations in three major research fields all based on the study of single drops of water. His first research project, with Schaeffer, "Ejection of electrical charged ice particulates from a frost surface," helped explain how electric charges were generated in a thunderstorm cloud. This discovery was confirmed twenty years later by scientists from MIT. His photomicrographs capturing the activity became the Featured Cover in Science Magazine in 1970 and more than 160 scientists from 25 countries requested a reprint of the photograph and article. It also appeared in more than 30 international science magazines and 15 encyclopedias and yearbook.

Roger’s second experiment dealt with the formation of Acid Rain, marble erosion, and plant damage. He demonstrated in the lab that flyash from electric power plants catalyzed the reaction of sulfur dioxide in water droplets to form sulfates. By studying the marble in Schenectady’s City Hall he noticed that sulfur dioxide reacted with liquid water on the surface of the stone to produce sulfuric acid. Small pollutants like flyash act as a catalyst in the reaction making the marble change into gypsum, which crumbles. The Canadian EPA confirmed this experiment in 1995.

Finally, in 1986 he and colleagues discovered that sea salt particles (marine aerosols) were hollow and not solid as formerly believed. The sea produces marine sea salt aerosols by the bursting of bubbles at the surface. The small droplets are then carried high into the atmosphere by mixing and convection and can change phase to produce the sea-salt aerosol. Previous thoughts assumed they were solid and their mass could be calculated if their diameters were known. His discovery that they are hollow makes this calculation much more difficult. German scientists from the Institute of Meteorology confirmed his findings in 1997. He also noticed that seawater droplets ejected sulfate particles when they changed phase and that could be important in the global sulfur cycle.

As predicted earlier by the fortuneteller, he married Leida Sutt of Estonia in 1961, non-Chinese. They have two sons and one daughter. Their son Mark is a computer animator whose film credits includes Dinosaur and Mouse Hunt. I claim partial credit since Roger often brought Mark to my Mac user group meetings and I would set him up with my animation program to keep him busy!

I met Roger in the 80’s when I was a student in electron microscopy. I was so impressed with his energy and willing to share his knowledge; we’ve stayed friends. He consults for a number of places locally but has traveled extensively to Europe, Russia and homeland China, where he has given 14 seminars and visited more than 25 universities and other institutes. His photomicrographs have been in demand by popular and scientific publications worldwide for their art as well as content.

In 1978 he received the SUNY Chancellor Award for Excellence in Professional Service and retired from the ASRC in 2000. He is currently creating a CDROM that contains all his research papers, magazine covers, and hundreds of his photographs. We often have lunch; Chinese of course.


  • Don Rittner : Author and historian
  • Don Rittner is a historian, archeologist, environmental activist, educator,
  • and author living in the Capital District, Schenectady County, New York;
  • in December, 2004 he was named official Schenectady County Historian