30 seconds per century? (was Re: Evolution and Creationism)

[John Mallinckrodt <ajmallinckro@CSUPOMONA.EDU>]

On Fri, 20 Aug 1999, Michael N. Monce wrote:

>         I'll take a stab at this one.  I have no idea if the 30 second
> value is correct.  However, the conclusion assumes the rate of slowing has
> been constant over the lifetime of the earth.  I believe the slowing is
> due to tidal effects and it would seem that the the 30 sec/century figure
> could have been much different in the past.  I have no evidence of such,
> which I hope someone can supply.  The conclusion makes an assumption about
> the rotational slowing rate that may not be valid.

I think the answer is far simpler: The 30 second figure--like many of the
other "facts" in the originating post is simply wrong or misinterpreted.

The interpretation seemed to be that days were growing longer at the rate
of 30 seconds each century.  This would correspond to 1/3 of a second per
year.  If days were 1/3 of a second longer today than they were last year
and we based the standard second on what it was last year, we would now be
having leap seconds every three days.  Two years from now we'd be having a
leap second every day and in just three decades we would have reached the
point where we would need to be having 10 leap seconds every day.  T'ain't
so.

John
 ----------------------------------------------------------
 A. John Mallinckrodt        http://www.csupomona.edu/~ajm
 Professor of Physics      mailto:ajm@csupomona.edu
 Physics Department         voice:909-869-4054
 Cal Poly Pomona              fax:909-869-5090
 Pomona, CA 91768-4031     office:Building 8, Room 223