The speed of sound in air at sea level is about 343 meters per second (1,235 km/h or 767 mph). At this speed, circling the Earth’s equator (roughly 40,075 kilometers or 24,901 miles long) would take about 32 hours without stopping. In contrast, the speed of light in a vacuum is about 299,792,458 meters per second (186,282 miles per second). At this speed, a beam of light could circle the Earth more than 7 times in just one second. This difference comes from the fact that light travels almost 900