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The speed of light can be measured in miles (as we do here in the US) as: 186,000 miles per second (which means light can circle the earth over seven times every second!), or 5,865,696,000,000 miles per year (which, to spare you from counting the digits, is just under 6 trillion miles per light year!).

THE SPEED OF LIGHT is 299,792,458 meters per second - in a vacuum or 186,282 miles per second in a vacuum. And according to the theories of motion - nothing can travel faster than the speed of light. If it does - it bends time and time will slow down and eventually - as the speed increases - time will start going backward - and you will travel back in time!!! And of course this is theory - it has never been tested - as the fastest movement - relative to the person measuring the movement) has never even approached 50% (93,000 miles per hour) of the speed of light!!!!

The speed of light - as all speeds are measured - is determined by the distance travelled - divided by the amount of time it took to travel that distance. A race car, for example, measures it's speed by the amount of time to travel a specific known distance (quarter mile - or 500 miles) divided by the time it took to travel that distance.

The speed of light is something we've figured out only in the last 100 years, right? Well, once more, our forebears surprise us. It turns out we've known the speed of light since before the birth of Johann Sebastian Bach.

That knowledge came close on the heels of the invention of the first telescopes in the early 1600s. In 1644, Ole Roemer was born in Jutland, Denmark. He took up the new study of astronomy with the early greats of that field.

By 1675 Roemer was 31 and working in Paris with Picard. He was interested in the movement of Jupiter's nearest moon. He tracked it as it orbited in and out of Jupiter's shadow. It entered the shadow, then reemerged exactly 42 hours, 28 minutes, and 35 seconds later. It moved with constant and exact regularity.

So Roemer measured 100 cycles and found that in one hundred cycles, Jupiter's moon could be relied upon to emerge EVERY TIME - right on schedule - to the exact second!! So he measured different lengths of time!! One was six months -- 100 laps -- and it was then that Roemer set his clocks and focused his telescope on Jupiter in the winter. In the spring - he waited and waited - but no moon appeared!! Finally it danced out of the shadows a full 15 minutes late. But why was the moon late - there MUST be a reason!!

After much discussion, Roemer concluded that the moon was still appearing at the same time - and it was the earth that had moved!! The earth had swung hundreds of millions of miles away from Jupiter during the long winter months so light had to travel that vast distance to see Jupiter's moon!!! It had obviously taken the extra time to do so. (Also discovering that earth's orbit around the sun is egg-shaped - NOT a circle!!)

He put pencil to paper and concluded that light had to move 192,500 miles per second to lose just those fifteen minutes. Not bad at all! Roemer was within three percent of the right value (186,282 miles per second). And that was less than 70 years after we first had telescopes.

Just to be sure, Roemer calculated when we'd get that 15 minutes back, as the earth moved back toward Jupiter and spring began. He was right again.

Today the speed of light is measured - and found to be accurate - by pointing a laser to one of the many groups of mirrors and reflectors that were set up on the moon by the 1970's moon landing missions. Now computers accurately measure the speed light with a laser - and can determine the exact speed of light to within 1/quadtrillionth of a second!!! These mirrors also measure the movement of earthquakes on the earth - from the moon - to within 1/10,000,000,000th of an inch!!!!

Hope this helps - and hope you enjoy science!!!!!

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Q: What is the formula for the speed of light?

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The formula relating the speed of light (c), frequency (f), and wavelength (λ) is: c = fλ. This formula shows that the speed of light is equal to the frequency multiplied by the wavelength.

The formula for the speed of light, in vacuum, isc = 299,792,458 meters/second . where ' c ' is the speed of light.In any material substance, the speed of light isc/(the index of refraction for that substance) . Gamma rays, radio waves, and all other members of the electromagnetic spectrumbetween those, all have the same speed.

The formula used to calculate the speed of light is c = fλ, where c is the speed of light, f is the frequency of the light wave, and λ is the wavelength of the light wave. The speed of light in a vacuum is approximately 299,792 kilometers per second.

To find the wavelength of light in Plexiglass, you need to take into account the change in speed of light. Since light travels at 67% of its speed in air in Plexiglass, you would need to calculate the wavelength using the formula: wavelength in Plexiglass = wavelength in air / refractive index of Plexiglass. Refractive index of Plexiglass is calculated as speed of light in air / speed of light in Plexiglass.

The formula to calculate travel time at the speed of light is distance divided by the speed of light. The nearest star to Earth is Proxima Centauri, which is about 4.24 light-years away. Therefore, the travel time to Proxima Centauri at the speed of light would be 4.24 years.

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The formula relating the speed of light (c), frequency (f), and wavelength (λ) is: c = fλ. This formula shows that the speed of light is equal to the frequency multiplied by the wavelength.

Refractive Index= Speed of Light in Vaccum / Speed of Light in the material

Speed of light in water = speed of light in vacuum/refractive index of water

Celeritas means 'at the speed of light'. In Einstein's formula E=MC2, the 'C2' stands for 'the speed of light times the speed of light, or, the speed of light times itself, or, the speed of light squared.

speed of light

The formula for the speed of light, in vacuum, isc = 299,792,458 meters/second . where ' c ' is the speed of light.In any material substance, the speed of light isc/(the index of refraction for that substance) . Gamma rays, radio waves, and all other members of the electromagnetic spectrumbetween those, all have the same speed.

wavelength = c/frequency of light where c is the speed of light.

In the formula E=mc², c represents the speed of light in a vacuum, which is approximately 3.00 x 10^8 meters per second.

energy=mass times speed of light squared (times by itself) (e=energy m=mass c=speed of light) *This formula calculates the energy that an object can release when its atoms are split (Same process used in atomic bombs). The formula means Energy is equal to mass times the speed of light times the speed of light again. In other words energy = mass x speed of light x speed of light. In numbers it would be energy = mass x 299'792.456 x 299'792.456 (Speed of light = 299'792.456 km/s)*

from a purely mathematical stand point, if something were to reach the speed of light the time dialation/length contraction formula would yield something over 0. This is beacuse the formula is: constant/[(1-(velocity/speed of light)^2] as you can see, if velocity=speed of light, you get something over zero.

The formula to calculate wavelength is: Wavelength (λ) = Speed of light (c) / Frequency (f) Where the speed of light in a vacuum is approximately 3 x 10^8 m/s.

His formula was E=Mc2 which stood for; Energy equals mass times the speed of light squared. C=Celeratis which is Latin for "speed of light". He chose this word because he excelled in Latin in High school.