# The speed of the Earth

**The speed of the Earth** in its orbit is quite large - 30 km/s. It is 1/10000 of the speed of light. You can spend an interesting experience, using an enormous speed of the Earth as it moves in its orbit.

If we move in the direction of the light source, the light signal can be taken faster than away from it. Michelson and Morley constructed plant and measured the speed of light in the direction of motion of the Earth and against him. We already know that the Earth's speed is 1/10000 the speed of light. However, it turned out that the effect of the study is determined by the square of this fraction, that is one hundred millionth. This value is not beyond the ability of extremely sensitive methods. To his great surprise Michelson and Morley found that the speed of light in both cases was the same!

Thus, the speed of the Earth does not have any effect on the speed of light. This has led to serious difficulties, but Michelson came up with an interesting idea! And, if at the moment when an experiment, the speed of the Earth in space could be equal to 30 km/s. To confirm his thoughts, he pointed to the following reasons. Indeed, the speed of the Earth around the Sun becomes 30 km/s. But then, the whole solar system moves in space in any direction. And it is possible that the sun moves in space is also at a speed of about 30 km/s. Now imagine that the Earth moved along its orbit in the opposite direction of the sun during the experiment. What then? In practice this means that the velocity of the Earth in space was zero.

So, if all the conditions are right, six months later, when the Earth will pass half of its orbit, the direction of movement of the Earth and the Sun would coincide, and velocity of the Earth in space became equal to 60 km/s. To avoid errors, Michelson repeated his measurements of the whole year. But it's time to get the same result. The speed of light was always the same, regardless of the direction of motion of the Earth.