Baher Ghosheh showed two photographs of women and asked which were the Muslims.
In one photo, the women were covered from head to toe in black cloth, not even their eyes were visible. In another, the women had on suits, like they might wear to a business meeting or a job interview.
While many in the crowd at his Wednesday lecture on "Women in Islam" guessed that the group in black was Muslim, Ghosheh revealed that all the women were followers of Islam.
In his talk, which was part of Women's History Month activities at Edinboro University of Pennsylvania, Ghosheh pointed out the diversity among Muslim women. He also spoke about the oppression of female Muslims and women in general.
Ghosheh, a professor of geosciences whose specialties include Middle Eastern studies, said that according to the Quran, Islam's holy book, "women are the twin halves of men" and "the rights of women are sacred."
They include the right to earn a living and to own and inherit property, he said.
He said that Mohammed, the prophet of Islam, worked for an international businesswoman. He married her and continued to work for her, Ghosheh said.
"The precedent set by the prophet is very clear that women should be allowed to work," the professor said.
He showed more photos of Muslim women, whose styles of dress varied somewhere between the pictures he'd shown earlier. Cultural influences are responsible for the differing degrees of cover and the use of various colors, he said.
"Islam only talked about modesty in dress," Ghosheh said. "Different people interpret it differently."
In Iran, he said, women can be arrested by the "morality police" for being "insufficiently veiled."
Ghosheh said some governments and men use the religion to justify their own policies or chauvinism.
In Saudi Arabia, for example, he said men dress in white, which is cooler in the heat, while women are required to cover themselves in black.
"This is male chauvinism disguised as religion," Ghosheh said.
He shared the story of a woman in Saudi Arabia who was gang raped and then sentenced to six months in prison and 200 lashes.
"She was the victim," one female in the audience said. "Why was she sentenced?"
Ghosheh said it was because women can't leave their houses there without being accompanied by a male and the victim had been unescorted. She eventually was pardoned.
"You must not confuse religion for male chauvinism," Ghosheh said. "This has nothing to do with religion."
He also pointed out that not all Muslim women are oppressed, and women aren't only oppressed in Muslim societies.
He said that in America, women in general don't earn as much money as men.
Ghosheh told the students that the three largest Muslim countries -- Indonesia, Pakistan and India -- have already had a female president or prime minister.
In the U.S., which has never had a female head of state, women make up 52 percent of the population but just 24 percent of the national and state legislative bodies, Ghosheh said.