From:    Rick Mcfarlane
To:      Mark Fox                               Msg #2234, Jun-01-94 23:20:00
Subject: Magnetic fields

 -=> Quoting Mark Fox to David Rice <=-

 DR> Mark claimed that the Earth's magnetic field is "decaying," when
 DR> in fact it is not.

 MF> 1835...8.558 x 102 amps per meter
 MF> 1945...8.065 x 102 amps per meter
 MF> 1965...8.017 x 102 amps per meter

It's getting smaller, alrighty.

 MF> Measuring by a consistent rate, the magnetic rate it is declining
 MF> at a half life rate of 830-1400 years (26 nanoteslars per year)--
 MF> half life every 830 (Magstat)-1400 years (Barnes).

Unstated assumption alert!

Any evidence at all that this is a decay phenomenon?

 MF> At this rate it
 MF> will be ineffective in a few thousand years.  Using P=RI, since
 MF> the resistance of rock would be a constant (R), Power generated would
 MF> be millions of times greater just 10,000 years ago as current (I)
 MF> increases arrhythmically.  10,000 years ago the planet would have been
 MF> to hot to sustain life.

Oh, Mark, the planet is much less than 10,000 years old, but it started off
very cold, not very hot.  Consider:

Feb. 20, 1994,    -15 C
March 30, 1994,    -1 C
May 31, 1994,      +5 C

(Above observations are nighttime low temperatures at my home locale,
Goulais River, Ontario, Canada.)

Obviously, the tempreature has been rising rapidly.  Probably due to the
sun heating the planet.  In the last 100 days the nighttime low has gone up
by 20 Celcius degrees.  At that rate, the nighttime low will be above the
boiling point in 450 days, and all life will be destroyed.

Going the other direction, the nighttime low was less than absolute zero
(-273 C) about 1400 days ago.  Since less than absolute zero is an
impossibility, obviously, the earth is only about 4 years old.

Silly?  Of course.  But your argument is just as silly.  There's lots of
evidence that the magnetic field of the earth varies in both direction, not
just down.  Take a look, before you make yourself look even sillier.

And there is certainly no evidence that it is "decaying" with any kind of a
"half-life" at all.  A linear approximation would fit through those three
points you stated just as well as the exponential curve you chose.

Next, a word about extrapolation: Ask any statistician (you can start with
me, if you'd like) whether he considers it safe to fit a straight line to
130 years of data, and then extrapolate it 10,000 years into the past.
He'll laugh his head off.  Then ask him if an exponential curve would be
safer.  You'll have to scrape him off the floor!

Extrapolating at all is dangerous (without good theoretical proof that you
have the right curve).  The farther you extrapolate, the more dangerous it
is.  I can't imagine anyone seriously extrapolating more than the range of
the base data, under any circumstances.  You just extrapolated 70 times
that far.  And all of this applies to a straight line, which is a well
behaved curve.  An exponential decay curve is very ill behaved (unless it
really is a decay phenomenon).

Actually, your argument is even sillier than mine.  I used a straight line,
and extrapolated 14 times the range of my base data (a ludicrous thing to
do).  You used a very ill-behaved curve (exponential) and extrapolated 70
times the range of your base data (an incredibly humourous thing to do!)

 MF> Time will tell the correct model.

Come on, Mark.   I read your posts accusing others around here of
intellectual dishonesty.  Now it's time to check your own.  The above
argument is so ludicrous, so contrived, that it qualifies 100% for that
same label.  It is clearly devised to "get the right answer", and it does
so by making unwarranted assumptions, and brutally dangerous
extrapolations.

Think it over.  Do you still maintain this is a good argument?  That it has
any validity at all?  Show us YOUR intellectual honesty.

 MF> Cosmic dust theory--there are particles of dust that settle to the
 MF> earth, and moon all the time.  Patterson of the Swedish Oceanographic
 MF> Institute calculated that 14 million tons of meteoritic dust settles on
 MF> the earth year as a fine powder.  (Such dust can be calculated and
 MF> eliminating the  terestrial sorces based on the nickel content.)

The amount of meteoric dust in space can also be observed in space.  And it
has been.  With no need to try correct for terrestrial contamination.  Why
not quote those studies?  Because they don't support your point of view,
perhaps?  Back to the honesty question.

Instead, you reference terrestrial studies:

 MF> filled in?  Hans Petersson, COSMIC SPHERICALS AND METEORITIC DUST,
 MF> Scientific American p 202, February 123.

What year was that?  1960?

And:

 MF> --Gold, ROYAL ASTRONIMICAL  SOCIETY OF
 MF> LONDON, Monthly notic 115:585 1955 p 598.

Earth based studies from a period when access to space was impossible.
We've got better, more recent data, but you insist on quoting the old,
inaccurate ones.  Why would that be?

 MF> Pattersons, it would be closer to 630 centemeters.  NASA's best
 MF> calculations led them to believe that lots of dust should be on the
 MF> moon when they landed  on the moon (hence the big saucer feet on the
 MF> ship).

NASA had been to the moon (remember Surveyor?) before the Eagle landed.
They knew from direct experience how much dust there was there when they
designed those feet.  They may have had some concern about dust of lunar
origins (caused by thermal spalling, and the impact of meteors), but they
knew full well that the amount of meteoric dust would be very small.

 MF>  Dust was only inches deep suggesting an age of 8,000 yrs or
 MF> less.

You have a source for this observation?  NASA you say?  Must be, they're
the only ones who've been there.

Let's see if I got this straight.  You go to NASA for space based
observations on how much dust there is on the moon, but you forget to ask
them how much dust they have observed in space (ie. the rate at which dust
will collect on the moon?).  And having forgotten to ask them, you go
looking through 40 year old issues of Scientific American for a source of
data?  Do I look that credulous?  This isn't just an honest oversight.  You
know where good data can be obtained, yet you ignore it in favour of
outdated inaccurate data.  Why?  Back to that intellectual honesty question
again.

You question the intellectual honesty of others (possibly quite rightly, I
don't know), but you aren't demonstrating a whole lot of it here yourself.

Take care.