Below is a short video of a 100 square metre space with packing increasing from 1 person per square metre to 10 people per square metre. This serves to illustrate how the crowd may look in low risk and high risk situations.
The word comes from the Greek euangelion, or good news. The gospel was considered the good news of the coming Kingdom of Messiah, and of redemption through the life and death and resurrection of Jesus, the central Christian message.
One theory: it came from the Greek phrase ola kala, which means all good. And then there's the Choctaw word okeh, which sounds like and means okay. President Woodrow Wilson reportedly thought it was the correct spelling of the word, and would OK documents with okeh..