As the speed of light is thought to be an absolute speed (it is not, but close enough) we use it and a time frame, usually a year, to describe how far things are away.The term is: Light Year (the distance light will travel in a year) roughly 6 trillion miles. Divide the total distance by the total time to get the average speed. Or, when you need the speed at a certain time, you can differentiate the fuction of distance(t) over time. This can be compared with dividing the distance (of a really really really short timespan) by the same really really really short timespan). The speed of light is about 186,000 miles or 300,000 kilometers per second. So, in one year light travels a distance of about 5,880,000,000,000 miles or 9,460,000,000,000 kilometers or 63,240 A.U.. This distance is 1 light-year.
By measuring this angle, it was possible to measure the speed of the light. Foucault continually increased the accuracy of this method over the years. His final measurement in 1862 determined that light traveled at 299,796 Km/s. 1728 James Bradley: 301,000 Km/s. In 1728 James Bradley, an English physicist, estimated the speed of light in vacuum to be around 301,000 km/s. He used stellar aberration to calculate the speed of light. Thus both the distance and the time light takes to travel this distance can bemeasured. From these measurements the speed of light can be determined. Figure 1 General arrangement of the equipment used to measure the speed of light. For clarity, thereturn path of the light from the fixed mirror is displaced slightly, and the angle of the rotating mirror forthe return reflection is exaggerated. If the average speed and the time of travel are known, the distance travelled can be calculated by rearranging the definition to. Using this equation for an average speed of 80 kilometres per hour on a 4-hour trip, the distance covered is found to be 320 kilometres. Different from instantaneous speed, average speed is defined as the total distance covered over the time interval. For example, if a distance of 80 kilometres is driven in 1 hour, the average speed is 80 kilometres per hour. Answer by Clindberg4. Confidence votes 627. As the speed of light is thought to be an absolute speed (it is not, but close enough) we use it and a time frame, usually a year, to describe how far things are away. The term is: Light Year (the distance light will travel in a year) roughly 6 trillion miles. Divide the total distance by the total time to get the average speed. Or, when you need the speed at a certain time, you can differentiate the fuction of distance(t) over tim … e. This can be compared with dividing the distance (of a really really really short timespan) by the same really really really short timespan). The finite speed of light also limits the theoretical maximum speed of computers, since information must be sent within the computer from chip to chip. The speed of light can be used with time of flight measurements to measure large distances to high precision. In 1983, the metre was redefined in the International System of Units (SI) as the distance travelled by light in vacuum in 1/ 7008299792458000000♠299792458 of a second. As a result, the numerical value of c in metres per second is now fixed exactly by the definition of the metre. Astronomers measure the distance to a galaxy in the same way we estimate the distance to an oncoming car by the brightness of its headlights. We know from experience how much light a car's headlights emits, so we can determine how far away the car is. To measure the distance to a galaxy, we try to find stars in that galaxy whose absolute light output we can measure. We can then determine how far away the galaxy is by observing the brightness of the stars. Instead, astronomers measure distances to objects which are outside our solar system in light-years. A light-year (ly) is the distance that light can travel in one year in a vacuum (empty space). The speed of light is about 186,000 miles or 300,000 kilometers per second. So, in one year light travels a distance of about 5,880,000,000,000 miles or 9,460,000,000,000 kilometers or 63,240 A.U.. This distance is 1 light-year. For example, the nearest star to us is about 4.3 light-years away An astronomical unit (A.U.) is the average distance between the Earth and the Sun, which is about 93 million miles or 150 million kilometers. Astronomical units are usually used to measure distances within our solar system. The speed of light is about 186,000 miles or 300,000 kilometers per second. So, in one year light travels a distance of about 5,880,000,000,000 miles or 9,460,000,000,000 kilometers or 63,240 A.U.. This distance is 1 light-year. For example, the nearest star to us is about 4.3 light-years away Speed of Light 1 Measurement of the Speed of Light in Air Measuring the speed of something is a familiar process, just measure the time it takes to travel agiven distance. But as Galileo discover, light is much faster that anything else encountered in everydaylife. From these measurements the speed of light can be determined. Figure 1 General arrangement of the equipment used to measure the speed of light. For clarity, thereturn path of the light from the fixed mirror is displaced slightly, and the angle of the rotating mirror forthe return reflection is exaggerated.
http://speed-light.info/measurement.htm http://www.physics.arizona.edu/~haar/ADV_LAB/SPEED_C.pdf https://en.wikipedia.org/wiki/Speed http://www.answers.com/Q/How_can_the_speed_of_light_be_used_to_measure_distance https://en.wikipedia.org/wiki/Speed_of_light http://hubblesite.org/reference_desk/faq/answer.php.id=45&cat=galaxies http://coolcosmos.ipac.caltech.edu/cosmic_classroom/cosmic_reference/distance.html http://coolcosmos.ipac.caltech.edu/cosmic_classroom/cosmic_reference/distance.html http://www.physics.arizona.edu/~haar/ADV_LAB/SPEED_C.pdf
how can the speed of light be used to measure distance