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The speed of light in a vacuum is 186,282 miles per second (299,792 kilometers per second),and in theory nothing can travel faster than light. In miles per hour,light speed is,well,a lot:about 670,616,629 mph. If you could travel at the speed of light,you could go around the Earth 7.5 times in one second.

## Why is the speed of light 186,000 miles per second?

Special relativity is also based on a second assumption that gives the speed of light — 186,000 miles per second (300 million meters per second) — in a vacuum a special status. Einstein postulated that light always travels at the same speed for every observer, regardless of that observer’s speed, Galison explained.

## Can anything move faster than the speed of light?

So the faster something travels, the more massive it gets, and the more time slows – until you finally reach the speed of light, at which point time stops altogether. And if time stops, well then, so does speed. And so nothing can travel faster than the speed of light.

## What is the exact speed of light?

Put simply, light moves at incredible speeds and is the fastest moving thing in the Universe. Its speed is considered a constant and an unbreakable barrier, and is used as a means of measuring distance. But just how fast does it travel? Light travels at a constant speed of 1,079,252,848.8 (1.07 billion) km per hour.

## Why is "C" the speed of light?

Why is c the symbol for the speed of light? As for c, that is the speed of light in vacuum, and if you ask why c, the answer is that it is the initial letter of celeritas, the Latin word meaning speed. Isaac Asimov in C for Celeritas (1959) [1] A Short Answer

## What is a light-year?

A l ight-year is the distance that light can travel in one year about 6 trillion miles (10 trillion kilometers). It’s one way that astronomers and physicists measure immense distances across our universe.

## How did we learn the speed of light?

Aristotle, Empedocles, Galileo (illustrated here), Ole Rømer and countless other philosophers and physic ists in history have contemplated the speed of light. (Image credit: NASA)

## What is the invisible stuff that Michelson and Morley called?

This invisible, undetectable stuff was called the "luminiferous aether" (also known as "ether").

## What is the equation for the speed of light?

Einstein’s theory of special relativity unified energy, matter and the speed of light in a famous equation: E = mc^2. The equation describes the relationship between mass and energy — small amounts of mass (m) contain, or are made up of, an inherently enormous amount of energy (E). (That’s what makes nuclear bombs so powerful: They’re converting mass into blasts of energy.) Because energy is equal to mass times the speed of light squared, the speed of light serves as a conversion factor, explaining exactly how much energy must be within matter. And because the speed of light is such a huge number, even small amounts of mass must equate to vast quantities of energy.

## How fast is light?

Einstein’s theory of special relativity sets of the speed of light, 186,000 miles per second (300 million meters per second). But some scientists are exploring the possibility that this cosmic speed limit changes.

## How many times can you go around the Earth in one second?

If you could travel at the speed of light, you could go around the Earth 7.5 times in one second . Early scientists, unable to perceive light’s motion, thought it must travel instantaneously. Over time, however, measurements of the motion of these wave-like particles became more and more precise. Thanks to the work of Albert Einstein …

## How fast does light travel in a vacuum?

Light traveling through a vacuum moves at exactly 299,792,458 meters (983,571,056 feet) per second. That’s about 186,282 miles per second — a universal constant known in equations and in shorthand as "c," or the speed of light.

## Unit Conversion Example Problem

Todd Helmenstine is a science writer and illustrator who has taught physics and math at the college level. He holds bachelor’s degrees in both physics and mathematics.

## Problem

The speed of light in a vacuum is 2.998 x 10 8 m/sec. What is this speed in miles per hour?

## Solution

To convert this measurement, we need to convert meters to miles and seconds to hours.