How fast does light travel?

That’s a great question! Light travels incredibly fast – at a constant speed of 299,792,458 meters per second (approximately 300,000 kilometers per second). This speed, often represented by the symbol “c”, is a fundamental constant in the universe and serves as the upper limit for the speed of any matter or energy.

To put this into perspective, here are some comparisons:

  • A car traveling at 100 miles per hour (160 kilometers per hour) would take over 177 years to reach the Sun, which is about 149.6 million kilometers away.
  • Light can travel around the Earth in just over one-eighth of a second.
  • In one second, light can travel to the Moon and back about 237 times.

The incredible speed of light has profound implications for our understanding of the universe. For example, it explains why we can’t see stars that are farther away than a certain distance – their light simply hasn’t reached us yet. It also plays a key role in Einstein’s relativity theory, revolutionising our understanding of space, time, and gravity.

Here are some additional facts about the speed of light:

  • Light travels at the same speed in all directions, regardless of the motion of the source or observer.
  • Light can travel through empty space but slows down when it passes through matter, such as water or glass.
  • The speed of light is one of the most precisely measured constants in physics.