Written by the Fiveable Content Team โข Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 examโขWritten by the Fiveable Content Team โข Last updated September 2025
Definition
The speed of light is a fundamental constant in physics denoted by "c." It represents how fast light travels in a vacuum, which is approximately 299,792 kilometers per second or about 186,282 miles per second.
Related terms
Electromagnetic spectrum: This term refers to the range of all possible frequencies and wavelengths for electromagnetic waves, including visible light.