Re: modern use of moon dust by YECs

Jonathan Clarke (jdac@alphalink.com.au)
Wed, 04 Nov 1998 17:04:08 +1100

Vandergraaf, Chuck wrote:

> > 1 - Moon dust. Ultraviolet light changes moon rocks into dust. It had long
> > been predicted that a thick layer of dust (20-60 miles
> > [32-96.5 km], caused by ultraviolet radiation on the moon's
> > 4-billion-year-old surface, must cover the moon's surface. But scientists
> > were astonished to learn that there is not over 2-3 inches [5.08-7.62 cm]
> > of dust-just the amount expected if the moon was only a few
> > thousand years.-pp. 15, 17.
> I don't get this. If UV light could indeed change rocks to dust (if may,
> for all I know), this should be a self-limiting process because the UV light
> would be eventually be totally absorbed by a layer of dust and the process
> should then cease. There is, as far as I am aware, no mechanism (wind,
> water) that would spread the dust around. In other words, a thin layer of
> dust would not prove a young moon.

As I understand it, this was Lyttleton's original thesis (although he regarded
X-rays as also eroding the surface. He though thermal effects would agitate the
resulting dust and allow it to flow to the low points in the lunar surface.
There is no evidence for erosion by UV or X rays, or such dust flow on the moon
that I now of.

> > 2 - Lunar soil. The dirt on the moon's surface does not show the amount of
> > soil mixing it should have, if the moon were very
> > old.-p. 17.
> See above. Without any wind, how could lunar dust be mixed?

Mixing can occur in lunar soil through the effects of meteorite impact.

> > 3 - Lunar isotopes. Short-term radioactive isotopes (uranium
> > 236 and thorium 230) have been found in the collected
> > moon rocks.
> Th-230 is a member of the U-238 decay series and should be in equilibrium
> with the U-238 parent. The presence of short-lived Th-230 is no evidence of
> a young moon. I don't have my references handy and cannot comment on U-236.

I concur. Is the author playing on the audiences ignorance of radioactive decay
schemes?

> > These isotopes do not last long and rather quickly turn into
> > lead. If the moon were even 50,000 years old, these short-life
> > radioisotopes would long since have decayed into lead. The moon cannot be
> > older than several thousand years.-p. 17.
> See my comment above.

ditto

> > Hey, I guess I was wrong about the moon, it is young! :-)
> >
> This is not to say that the moon could not be young; it's the arguments that
> are used to show that the moon is young are faulty.
>
> Chuck Vandergraaf
>

Jonathan