👉 In physics and engineering, "antiphonical" refers to a specific type of flow line in a closed pipe system, where the pressure is at its highest point. This concept arises from the fact that the speed of particles in a fluid (like air) decreases as they move through a closed pipe, leading to a higher pressure drop across the pipe and thus a decrease in velocity. The term "antiphonical" comes from the Greek word "antihora," which means "against" or