Center of Earth

Zero.

Well, there would be some relative motion between a point at the surface equator and a point at the equator of the planet's core. One degree of latitude at the equator measures 60 nautical miles - in statute miles, its a tad more than 68.7 miles, in feet, 362,760. Now, the Earth's core - the roughly 1500 mile diameter Iron-Nickel mass at the center of the Earth - has been seismographically determined to rotate 0.4º +/- 0.1º per year faster than the surface of the planet (the rate of super rotation evidently varies by +/- 0.1º over time, with a periodicity on the order of centuries). Taking the 0.4º per year midfigure, that works out to a little less than 242 feet per year. Anyone who cares to work that out in terms of miles per hour is welcome to play with all the zeros that'd take; I ain't gonna do it. In any event, by that criteria, the nearest (although absurdly remote) half-mile-per-hour would be one half mile per hour, though a closer approximation would be more like one half mile per couple dozen millenia.

However, that point, regardless how many zeroes fall to the right of the decimal point before the first significant digit, is moot if one takes as "center of the Earth" a geometric point; reference the absolute center of rotation there would be no difference in rotational velocity if one considers that point to be an integral component of the rotating mass.

If on the other hand, one takes that point to be stationary, independent of the rotating mass, the equatorial circumference of the Earth being 24,902 miles give or take a few yards, and the rotational speed of the earth being one revolution in 24 hours give or take a few seconds a year, a point at the equator would be be rotating at 1,037.58333 miles-per-hour relative to that stationary point - to the nearest half-mile, 1,037.5 miles-per-hour.

So now you know folks what Anti-IDarianism is like in its blowtorch mode.

All you need do is learn it off by heart, enter into the space marked "Answers" and you are a peer. The absence of rhyme and rhythm is deliberate so that only those with determination can join the annointed circle.

The centre of the earth is stationary relative to the surface although I think it is moving at about 60,000 mph relative the centre of the sun, something faster than that relative to the unknown centre of the galaxy and goodness knows the velocity at which we are rushing inwards towards a pile-up or outwards towards a diffusion of unknown lukewarmedness. Irrespective of how fast it itself is rotating. And according to what I've heard there are more suns in our little galactic back yard than there are grains of sand in all the deserts of the earth. How fast the galaxy is moving is subject to profitable dispute which, when resolved, will turn its attention to the universe.

Given that,I think that the speed of a pair of kecks being driven towards a suspect assignation at sea level relative to the stationary centre is about 1,000 mph in old money plus or minus some fractions depending on whether the object in question has been thrown out of the window or is going up a twisting mountain road or down a gentle gradient which entails some vector analysis I'm not qualified to comment on.

It is not irreducibly complex because it can all be worked out on simple scientific principles.

Such a point on the Earth's surface travels a distance equal to one circumference of the Earth in 24 hours. Circumference is pi * D. From this, it's a simple matter to get miles per hour.