How Science Looks on Instagram: "The candle clock is a fascinating historical invention that shows how humans measured time long before the age of digital watches or mechanical clocks. Used in ancient China, Japan, the Middle East, and medieval Europe, the candle clock was a simple yet ingenious device: a tall candle was marked with evenly spaced lines down its length, and as the candle burned at a steady rate, the passage of time could be measured by how far the wax melted past each mark. Some