Answers (2)
The speed of light is a basic unit used to define other things. The Earth's rotation changes all the time, but only a very small amount. For instance, the big quake in Japan changed the speed of rotation by a couple of microseconds.
The only thing anybody knows about time is that it only goes one way.
As the earth orbits the sun once a year the earth travels at a speed of about 66,600 miles an hour. That speed is just right to offset the gravitational pull of the sun and keep the earth at the proper distance. If that speed were decreased, the earth would be pulled toward the sun. In time, Earth could become a scorched wasteland like Mercury, the planet closest to the sun. Mercury’s daytime temperature is over 600 degrees Fahrenheit. However, if Earth’s orbital speed were increased, it would move farther away from the sun and could become an icy waste like Pluto, the planet whose orbit reaches farthest from the sun. Pluto’s temperature is about 300 degrees below zero Fahrenheit.
We should always trust God's word that he is the Creator of the heavens and the earth and the things in it. He is the only one who can give mankind answers concerning creation not evolution. The bible tells us at  Jeremiah 10:12
"He is the Maker of the earth by his power,The One who established the productive land by his wisdom And who stretched out the heavens by his understanding."
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