The reason why the earth's rotating speed is decreasing are the following.
1. Internal friction.
Inside the earth there is liquid. The earth is spinning, therefore the friction between the liquid and the earth slows the earth down. It's like if you would spin a ball that would have water inside, the water would slow it down. Plus, the surface of the earth is not smooth on the inside witch makes the friction even bigger.
2. Tidal friction.
Tides hit the beach all the time. If a tide comes up, it will push against the land and it will eventually slow the earth down. It is very minor, but it does contribute to the earth's spinning speed.
3. Wind currents.
The wind almost always blows the same way due to the Coriolis (spelling?) effect. This way it pushes against the mountains and slows the earth down a little.
The earth is slowing down. It's obviously that it was going faster. If you would go back in time, this will create a problem. If the earth, 4.6 billion years ago would be cooling down, and if it would be spinning much much faster, It would not be round. Take a ball and spin it fast, I mean really fast, you will see it will flatten out.
How would the evolutionists respond to this argument? Let's see talkorigins.com.
Presently, the earth's rotation is slowing down 0.005 seconds per year. At least Dr. H*vind doesn't use the horrendous rate of 1 second per year which Dr. Walter Brown employed as a result of a total misunderstanding of time keeping. I believe that Dr. Brown discarded that argument upon realizing his error, but don't expect it to disappear from the creationist literature. Only a towering optimist could expect that!
The actual rate of 0.005 seconds per year per year yields, if rolled back 4.6 billion years, a 14-hour day. The subject is a bit tricky the first time around, and I'm indebted to Thwaites and Awbrey (1982) whose fine article cleared away the cobwebs.
370 million years ago, the earth had 21.4 extra days per year.
The total days then per year were: (365.25 + 21.4)days/Year = 386.65 days/Year.
(8766 hrs/Year)/(386.65 days/Year) = 22.7 hrs/day
If you do the same calculations for 4.6 billion years ago, you'll get the 14 hrs/day given by Drs. Thwaites and Awbrey. Thus, there is no problem here for mainstream science. Indeed, the present rate may be too high:
...the correct present rate of slowing of the earth's rotation is excessively high, because the present rate of spin is in a resonance mode with the back-and-forth
motion of the oceans' waters in the ocean basins. In past ages when the rotation rate was faster, the resonance was much less or nonexistent, resulting in a much more gradual slowing of the rotation rate. The most recent calculations indicate that the earth could be 4 to 5 billion years old and not have been spinning excessively fast or requiring the moon to be any closer to the earth than 225,000 kilometers (140,000 miles).
A study of rugose corals from the Devonian (370 million years ago), initiated by John W. Wells of Cornell University in 1963, indicated that the year then had 400 days of about 22 hours each. For a discussion of coral clocks see Dott & Batten (1976, pp.248-249). Subsequent work with corals of Paleozoic, Mesozoic, and modern origin have produced highly revealing, if approximate, results.
Determinations of the same kind were made for algal deposits (stromatolites) of the Upper Cambrian (-510 m.y.) (Pannella et al., 1968). Plots of the collected data for the entire time span from Recent back through the Paleozoic Era showed a nonuniform increase in days per month going back in time, and from this it is inferred that tidal friction has not been uniform in that period.
Studies of the chambered nautilus, for a time, was also proposed as a geologic clock by Kahn and Pompea. However, that effort ran into problems. Creationists still cite it in their efforts to discredit the coral clocks. Each case, of course, has to be judged on its own merits. The nautilus is not a coral, and the coral clocks are good enough to destroy the young-earth claims.
From the present slowing down of the earth's spin we get a day of 22.7 hours 370 million years ago; 370 million years ago is the approximate radiometric date of those rugose corals. And, a study of the rugose corals confirms that the day then was about 22 hours long. In this example we have a remarkable, if rough, agreement between two, diverse dating methods.
These facts spell "Old Earth."
What that entire article is based on is that the earth's rotating speed is decreasing at 0.005 seconds per year. If that would be true, my question to them is: "Why do we add a leap second every 18 months?"
This means that the earth is spinning slower at the rate of 1 second slower per 18 months. Let's do some math - I hate this -.
So, The earth would be slowing down at the rate of 6 seconds per 9 years.
Let's see how fast was the earth spinning 50.000 years ago.
6 seconds ....................... 9 years
x seconds ....................... 50.000 years
x=(6 X 50.000)/9
So 50.000 years ago the earth was spinning 33.333 seconds slower than today. Let's transform that into hours. That would be 9 hours slower.
So, 50.000 years ago the day would be 15 hours long.
We can average and say that the earth is slowing down at the rate of 9 hours every 50.000 years. Therefore 100.000 years ago the day would be 6 hours long.
And 200.000 years ago the earth would be stopped.
I think we can conclude that the earth is young.
God bless you all.