Knot to Speed of light Conversion Calculator: Free Online Tool
Convert knots to speed of light with our free online speed converter.
Knot to Speed of light Calculator
How to Use the Calculator:
- Enter the value you want to convert in the 'From' field (Knot).
- The converted value in Speed of light will appear automatically in the 'To' field.
- Use the dropdown menus to select different units within the Speed category.
- Click the swap button (⇌) to reverse the conversion direction.
How to Convert Knot to Speed of light
Converting Knot to Speed of light involves multiplying the value by a specific conversion factor, as shown in the formula below.
Formula:
1 Knot = 1.7160e-9 speed of lightExample Calculation:
Convert 60 knots: 60 × 1.7160e-9 = 1.0296e-7 speed of light
Disclaimer: For Reference Only
These conversion results are provided for informational purposes only. While we strive for accuracy, we make no guarantees regarding the precision of these results, especially for conversions involving extremely large or small numbers which may be subject to the inherent limitations of standard computer floating-point arithmetic.
Not for professional use. Results should be verified before use in any critical application. View our Terms of Service for more information.
What is a Knot and a Speed of light?
The knot (kn) is a unit of speed equal to one nautical mile per hour, which is exactly 1.852 km/h (approximately 1.15078 mph or 0.514 m/s).
The speed of light in vacuum, commonly denoted by 'c', is a universal physical constant important in many areas of physics. Its exact value is defined as 299,792,458 meters per second.
Note: The Knot is part of the imperial/US customary system, primarily used in the US, UK, and Canada for everyday measurements. The Speed of light belongs to the imperial/US customary system.
History of the Knot and Speed of light
The term knot originates from the 17th century practice of measuring ship speed using a "chip log". This device consisted of a rope with knots tied at uniform intervals (47 feet 3 inches or 14.4018 m), attached to a piece of wood shaped like a sector of a circle. The log was thrown overboard, and sailors counted the number of knots that passed through their hands in a specific time (usually measured by a 28-second sandglass). The number of knots counted in that time directly corresponded to the ship's speed in nautical miles per hour.
The concept that light travels at a finite speed has been explored since antiquity. Early quantitative estimates were made by Ole Rømer in 1676. Increasingly accurate measurements were made over centuries, culminating in the 1983 definition by the General Conference on Weights and Measures, which fixed the speed of light to its current value, thereby defining the meter based on 'c' and the second.
Common Uses for knots and speed of light
Explore the typical applications for both Knot (imperial/US) and Speed of light (imperial/US) to understand their common contexts.
Common Uses for knots
- Maritime Navigation: The primary unit for measuring vessel speed in maritime contexts worldwide.
- Aviation: Standard unit for indicating airspeed for aircraft globally.
- Meteorology: Commonly used to report wind speeds, especially in forecasts for marine and aviation purposes.
Common Uses for speed of light
- Physics: Fundamental constant in Einstein's theory of relativity (E=mc²), electromagnetism, and cosmology.
- Astronomy: Measuring vast cosmic distances (light-years).
- Telecommunications: Determining signal propagation speed in fiber optics and wireless communication.
- GPS: Accurate timing based on signal travel time from satellites.
Frequently Asked Questions
Questions About Knot (kn)
What is a knot based on?
A knot is equal to one nautical mile per hour. A nautical mile is based on the Earth's circumference (one minute of latitude).
Is the knot an SI unit?
No, the knot is not an SI unit, but it is accepted for use with the SI, especially in navigation.
Why are knots used instead of mph or km/h in navigation?
Knots are convenient because one knot is one nautical mile per hour, and a nautical mile directly relates to the lines of latitude and longitude on navigational charts (one nautical mile is approximately one minute of latitude).
How do you convert knots to mph?
Multiply the speed in knots by approximately 1.151. So, 20 knots is about 23 mph.
How do you convert knots to km/h?
Multiply the speed in knots by 1.852. So, 20 knots is exactly 37.04 km/h.
About Speed of light (c)
Is the speed of light always the same?
The speed of light in vacuum (c) is constant and independent of the observer's motion or the source's motion. However, light travels slower when passing through materials like water or glass. The ratio by which it slows down is the material's refractive index.
Can anything travel faster than the speed of light?
According to the theory of special relativity, no object with mass can be accelerated to the speed of light, and no information can travel faster than 'c' in a vacuum.
How is the speed of light related to the meter?
Since 1983, the meter is defined as the distance light travels in vacuum during a time interval of 1/299,792,458 of a second. This definition fixes the speed of light exactly.
Conversion Table: Knot to Speed of light
| Knot (kn) | Speed of light (c) |
|---|---|
| 1 | 0 |
| 5 | 0 |
| 10 | 0 |
| 25 | 0 |
| 50 | 0 |
| 100 | 0 |
| 500 | 0 |
| 1,000 | 0 |
All Speed Conversions
Conversion Formula
1 kn = 1.716002e-9 c
Where 1 Knot (kn) equals the calculated value in speed of light (c).