Vacuum Speed of Light

The vacuum speed of light is the fastest possible speed at which all electromagnetic waves, including visible light, can travel through empty space. It’s approximately 299,792 kilometers per second (about 186,282 miles per second). This constant speed is fundamental to physics because it affects how we understand space, time, and the universe. In a vacuum, light isn't slowed down by anything, making it the universal speed limit for how quickly information or signals can move. This concept underpins theories like Einstein’s relativity and helps explain the structure of the cosmos.