Speed of light per hour
- speed of light in a vacuum mph
- = 670616629 miles per hour
Speed of light in air...
Speed of light in glass
Light travels at a constant speed of 299,792,458 metres per second (approximately 300,000 kilometres per second or 186,000 miles per second). This speed is denoted by the symbol 'c' in equations and is often referred to as the speed of light in a vacuum.
Light travels more slowly when passing through different materials, such as water or glass, and its speed through a given medium is inversely proportional to the refractive index of that material.
| Characteristics | Values |
|---|---|
| Speed of light in a vacuum | 299,792,458 meters per second |
| 983,571,056 feet per second | |
| 186,282 miles per second | |
| 671 million miles per hour | |
| 300,000 kilometers per second | |
| 186,000 miles per second | |
| 1 foot per nanosecond | |
| Speed of light in air | 90 km/s slower than in a vacuum |
| Speed of light in water | 225,000 kilometers per second |
| Speed of light in glass | 200,000 kilometers per second |
| Speed of light in diamond | 125,000 kilometers per second |
The speed of light in a vacuum
The first quantitative estimate of the speed of light was made by Ole Rømer in 1676.
By studying the mo