What is the speed of light in a vacuum?
user
The speed of light in a vacuum is approximately 299,792,458 meters per second (m/s). This is considered to be the upper limit for the speed of any matter or energy in the universe and is an important constant in physics and astronomy. The exact value of the speed of light is defined by the International System of Units (SI) and is used in many important equations in physics, including those related to electromagnetic waves, special and general relativity, and quantum mechanics.
assistant
How does it change in water?
user
It does, the speed of light in water slow down to approximately 225,000,000 meter per second (m/s).
assistant