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1. Accumulation of Helium in the atmosphere

The creationst argument goes something like this:  Helium-4 is created
by radioactive decay (alpha particles are helium nuclei) and is
constantly added to the atmosphere.  Helium is not light enough to
escape the earth's gravity (unlike hydrogen), and it will therefore
accumulate over time.  The current level of helium in the atmosphere
would accumulate in less than two hundred thousand years, therefore
the earth is young.  (I believe this argument was originally put forth
by Melvin Cook, in a letter to the editor which was published in
_Nature_.)

To the best of our knowledge, the state of helium in the atmosphere is
at or near equilibrium.  In order to "get" a young age from their
calculations, creationists "handwave away" mechanisms by which Helium
can escape.  For example, Morris says:

 "There is no evidence at all that Helium 4 either does,
  or can, escape from the exosphere in significant amounts."
  (Morris, 1974, p. 151)

But Morris is wrong.  Surely one cannot "invent" a good dating
mechanism by simply ignoring processes which work in the opposite
direction of the process which the date is based upon. Dalrymple
says:

 "Banks and Holzer (12) have shown that the polar wind can
  account for an escape of 2 to 4 x 10^6 ions/cm^2.sec of
  [4]He, which is nearly identical to the estimated production
  flux of (2.5 +- 1.5) x 10^6 atoms/cm^2.sec.  Calculations
  for [3]He lead to similar results, i.e., a rate virtually
  identical to the estimated production flux.  Another possible
  escape mechanism is direct interaction of the solar wind with
  the upper atmosphere during the short periods of lower
  magnetic-field intensity while the field is reversing.
  Sheldon and Kern (112) estimated that 20 geomagnetic-field
  reversals over the past 3.5 million years would have assured
  a balance between helium production and loss."
 (Dalrymple, 1984, p. 112)

Dalrymple's references:

(12) Banks, P. M. & T. E. Holzer.  1969.  High-latitude plasma
     transport: the polar wind.  Geophys. Res. J. 74: 6317-6332.

(112) Sheldon, W. R. & J. W. Kern.  1972.  Atmospheric helium and
      geomagnetic field reversals.  Geophys. Res. J. 77: 6194-6201.

This argument also appears in the following creationist literature:

 (Baker, 1976, pp. 25-26)
 (Brown, 1989, pp. 16 and 52)
 (Jansma, 1985, p. 61)
 (Whitcomb and Morris, 1961, pp. 384-385)
 (Wysong, 1976, pp. 161-163)

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References:

Baker, Sylvia, 1976.  _Evolution: Bone of Contention_, New Jersey,
 Evangelical Press.  35 pp.  ISBN 0-85234-226-8

Brown, Walter T., Jr., _In The Beginning..._, Arizona, Center for
 Scientific Creation.  122 pp.

Dalrymple, G. Brent, 1984.  "How Old Is the Earth?  A Reply to
 ``Scientific Creationism''", in _Proceedings of the 63rd
 Annual Meeting of the Pacific Division, AAAS_  Volume 1,
 Part 3, California, AAAS.  pp. 66-131.

Jansma, Sidney J., Jr., 1985.  _Six Days_, Michigan, Jansma.

Morris, Henry, 1974.  _Scientific Creationism_, California, Creation-
 Life Publishers.  217 pp.  ISBN 0-89051-001-6

Whitcomb, John C., and Henry M. Morris, 1961.  _The Genesis Flood_,
 New Jersey, Presbyterian and Reformed Publishing Company.
 518 pp.  ISBN 0-87552-338-2

Wysong, R. L., 1976.  _The Creation-Evolution Controversy_, Michigan,
 Inquiry Press. 455 pp.  ISBN 0-918112-01-X
-- 
Chris Stassen      stassen@alc.com