Silvia raised her hand. "I think sundials can still be useful. We might not need them to tell time anymore, but they can be a visual tool when teaching about how the field of astronomy developed in the past. And during the day, they may be more accurate than clocks, because clocks can stop working suddenly. They aren't very helpful at night or when it's cloudy, but couldn't you use the position of the stars to tell time at night?"