[syhprum (OP)]

leap seconds cause confusion , could all the windmills be run in reverse to get the rotation speed correct ?

[alancalverd]

"Correct" is undefined.

The earth's rotation speed is not constant or easily predictable as it is influenced by every other celestial body, continental drift, volcanoes, shellfish....But it is useful to adjust our clocks occasionally so that the stars (particularly the sun) appear at the same time on a given date.

[evan_au]

how much energy would take speed the Earths rotation that no leap seconds needed?

The definition of the second is based on the year 1900. Effectively, you want to:
1)  speed up the Earth's rotation so that it spins as rapidly as it did in the year 1900.
2) And, once it is spinning that fast, you want to fire rockets or similar, to keep it going at that rate.

Q1: Speed up the Earth's rotation
We would need to speed up the Earth by about 1ms per day.
I'll leave calculation of the energy required as an exercise for the student []

Q2: Keep it spinning
It is estimated that the Earth loses 3.7 TeraWatts to tidal friction.
Effectively, you would need to make up for that loss.
The world's electricity production in 2008 averaged 2 TW, so we are not too far away from 3.7 TW.
However, rockets are horribly inefficient (< 0.01% of the thrust makes it outside the atmosphere), so I can't see any known technology that would allow us to apply this power to overcoming tidal friction.

could all the windmills be run in reverse to get the rotation speed correct ?

Stirring the atmosphere (or even the ocean) does not overcome the energy lost to tidal friction in the oceans.

[syhprum (OP)]

My back of a fag package calculation works out at 430 TW for a year rather a strain on our generating capacity

even_au I think the definition of the second has been updated now to an atomic standard 

[evan_au]

I think the definition of the second has been updated now to an atomic standard 

That's true...

I guess I was trying to say that when they changed over to an atomic clock definition of the second, they tried to make the new definition as close as possible to the old definition - and the old definition for the second was based on the length of the average day in the year 1900.

[syhprum (OP)]

I was pleased to see that my calculation of 430 TW for a year was close to the figure of 3.7 TW for 116 years that you posted, I guess we will have to put up with our leap seconds until our nuclear fusion reactors get going.

[evan_au]

rockets are horribly inefficient (< 0.01% of the thrust makes it outside the atmosphere)

The rocket must be firmly attached to the Earth, otherwise the rocket will accelerate, but not the Earth's rotation. So I am imagining a big tower (150km high), with rockets at the top.
It's not enough to just fire rockets into space - you have to ensure that the rocket exhaust leaves Earth's gravity well. Otherwise, the rocket exhaust will return to crash back into the Earth's atmosphere, neatly cancelling any angular momentum gained by firing the rocket in the first place. So you need a rocket with an exhaust velocity greater than Earth's escape velocity of around 11 km/second.
That means an incredibly hot chemical rocket, or more likely an ion rocket or magnetic fusion jet.
I suggest that we take the technology to build a 150km-high tower, and use it to build a space elevator. That way, we can get off Earth at a much lower cost.

And if we are off the Earth, leap seconds will be the least of your concerns - a day on Mars is 24 hours and 40 minutes. Don't worry about a spare millisecond per day...

Its just as well that our smartphones can take leap seconds into account!

[syhprum (OP)]

Experiments have been done confining people in an artificial environment where they had a 25 hour day and they soon adapted so its one thing you will not have to worry about when you join the Mars colony

[Atomic-S]

The Earth's rotation is affected not only by the drag of the tides, but also by the distribution of the Earth's mass. The more mass moves to the equator, the greater the moment of inertia, and the slower it spins. So, to speed it up, move mass from the equator to the poles.