Prior to the 17th century scientists believed light travelled in (no time). Since, none were successful in measuring the speed of light the conclusion was the speed of light could not be determined. However, in1667 Galileo determined to prove the speed of light could be measured. With the help of his assistant, two lamps and a water clock, Galileo using deductive reasoning concluded, light travels ten times faster than sound.
In 1675 Ole Roemer, a Danish astronomer, used a different method to determine the speed of light is 200,000 Km/sec. His conclusion was reached by studying the Jupiter moons and their orbital velocities in relation to the Earth's orbit.
In 1728 James Bradley, an English physicist, using stellar aberration, meaning he using the apparent positions changes of stars to be due to the motion of the Earth as it moved around the sun. His theory was the ratio of the earth orbits of the sun, to the speed of light, proved the speed of light in vacuum, is 301,000 Km/sec.
Next came, Hippolyte Louis Fizeau who said in 1849 the speed of light is 313,300 Km/sec. Fizeau was a French physicist and by the speed of a toothed wheel, rapidly spinning the reflection light beam off a mirror five miles away made determining the speed of light a simple task.
In 1926, Leon Foucault also a French physicist using a method similar to Fizeau's method, however he used two mirrors to prove his theory. Faoucault used a rotating mirror and a stationery mirror and measured the light as it bounced from one to the other. He concluded light travels at 299, 796 Km/sec. Today, 299,792.458 Km/sec is believed to be the speed of light.
Sir Isaac Newton, first to analyze the speed of sound and determined the are variables in the speed of sound. Newton tested the speed of sound, at sea level air in ambient temperatures. His calculation, 99ft/sec was corrected by Laplace whose test measured 1116 ft/sec. Weather disturbances can interfere with testing results. There is not just one speed of sound, speed is determined by many variables, no one answer suits all.
The speed of sound means the distance sound waves will travel in a given number of seconds. Not all sound waves travel at the same speed, the properties of the medium determine the speed of sound travelling through the medium. Sound will travel faster through an open door, than through a closed door, the medium affects the rate of speed.
Sound waves travelling through solids, liquids and gases will travel at different speeds in the same amount of time. The speed of sound can be determined in relation to thunder, lightening claps and all sorts of sounds, but the speed of sound for each is not the same. The speed of sound varies. For more information go to
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