courtesy of http://www.what-is-the-speed-of-light.com/
The speed of light in vacuum is exactly 299,792,458 m/s (metres per second)
In 1983 the SI (Systeme International) defined a metre as:
The metre is the length of the path travelled by light in vacuum during a time interval of 1/299 792 458 of a second.
When people refer to the speed of light, they refer to the definition above - the speed of light in a vacuum.
The speed of light is normally rounded to 300 000 kilometers per second or 186 000 miles per second.
Light from the Travel time
Earth to the moon 1.28 seconds
Sun to Earth 8.5 minutes
Sun to Mercury 3 minutes
Sun to Venus 6 minutes
Sun to Mars 12.5 minutes
Sun to Jupiter 43 minutes
Sun to Saturn 1 hour
Sun to Uranus 2.6 hours
Sun to Neptune 4 hours
Sun to Pluto 5.4 hours
Sun to the nearest star 4.3 years
Sun to the furtherest stars 18 billion years]
BTW- The speed of light can be determined through several methods. Many of them are discussed on the cite provided above.
It’s speed is also variable, depending on different sets of circumstances and has been contained (trapped) in a “box” and released minutes later in a Harvard experiment recently.
“food for thought”…