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Re: DINO NEWSWIRES



I must be feeling Scrooge-ish right now...

Steve Cole (steve.cole@genie.com) forwarded some newswires this
morning.  Steve (being merely the messenger) is blameless of their
content.  The authors, however...

>  LONDON, Dec 17 (Reuter) - Days have been getting longer since the
> time of the dinosaur when days ran for just 23 hours, scientists
> say.  
>  With the earth now rotating more slowly, the world's time lords
> will add an extra "leap second" to the end of 1995.

There's a good piece of misinformation riding in this report.  While
it's true that the Earth's rotation is slowing down, it's not true
that this slowing is the only reason that leap seconds need to be
added.  I've just performed some crude calculations on the numbers
reported in the article, and if the Earth's rotation had been slowing
at a constant rate over the past 250 My (which is conservative since
the other numbers in the article indicate that the rate of slowing is
actually slowing down), then we would only need to add a leap second
around once every 200 years.  According to another news wire story I
just saw, leap seconds have been added 20 times over the last 25
years.  While it's true that the Earth's rotation (relative to it's
revolution) rate has been slowing over geological time, over the
shorter time spans more relevant to satellite positions and so on, the
Earth's rotation rate both speeds up and slows down due to all sorts
of interactions with other planets, the moon and due to the relative
motions of the Earth's different parts (i.e. oceans, magma
etc. sloshing around).  To claim that any one particular leap second
is being added because of the Earth's slowing rate of rotation is
nothing short of silly.

And since I'm complaining, did the following bother anyone else:

> searching for answers to the riddle of what killed the great beasts
> of the Cretaceous era.
                    ^^^

??  Maybe I just need to get a life for Christmas!

-- 
Mickey Rowe     (rowe@lepomis.psych.upenn.edu)