August 8 1974
I had the opportunity on July 31 of seeing over the
Glomar Challenger, which was in Dublin port for a few days
en route from the Azores to the Arctic. There was a report
in the news columns by Dick Grogan on August 1 which
highlighted the existence of US-Soviet collaboration in this
basic work.
This ship was designed specifically to sample cores
from the ocean bottom, in order to study the process of
continental drift. It makes use of position-finding and
position-control technology refined from off-shore petroleum
practice; the drilling techniques are similar but by no
means identical. The object is to keep the core intact and
to raise it to the surface for scientific analysis in the
ship's laboratory.
This analysis involves geologists, geochemists,
palaeontologists, physicists and other disciplines. The
various teams which have worked on the ship since its
commissioning have succeeded brilliantly in unscrambling the
historical record; detailed maps are now available which
show the locations of the boundaries of the various discrete
shell-like plates which constitute the Earth's crust. These
plates are being prized apart by convective forces in the
Earth's mantle; this takes place at the mid-ocean ridges.
Elsewhere they are being forced together; when this
happens, one plate goes under (giving an oceanic trench, as
off the west coast of the American continent) and the other
goes upwards (eg the Andes).
This 'continentaal drift' process was first put forward
by Wegener in 1912, on the basis of evidence derived from
comparing the flora and fauna of Africa and South America;
their evolution could be traced back to a common stock about
100 million years ago. This was ignored until in the 50s
the geophysicists started working out the apparent wandering
of the poles, as derived by analyses of the directions of
magnetisation of marine sediments and volcanic rocks. The
hypothesis of continental drift has now been triumphantly
vindicated by the work of the Glomar Challenger, to the
satisfaction of all disciplines. They have an excellent
film which explains very clearly the processes at work and
how we have come to understand them. This, I understand, is
being made available to RTE through the US Embassy.
July 15 1975
I am not usually starry-eyed about space technology,
but I am tempted to display a flicker of interest by a
Boeing project (Gordon L Woodcock and Daniel L Gregory at
Seattle) to produce 10 Gigawatts of net useful electrical
power from a 22 square mile array of mirrors deployed to
dcapture solar energy, in geosynchronous orbit 22,000 miles
out in space. A heat engine would work between a high
(solar image) temperature source and a three square mile
dissipator of low-grade heat. The whole would weigh 71,000
tonnes and would be assembled in space in low orbit and
subsequently shunted out. Power would be sent down by
micro-wave beam.
The cost of the project, which is considered to be
feasible by the end of the century with existing technology,
would be $60Bn, which would pay off at 2.5c per KWh.
This to me sounds credible and exciting(18), suggesting
that solar power in worthwhile quantities is closer than I
had thought.
Another landmark in the co-ordinated exploitation of
space will be the Apollo-Soyuz link-up, scheduled for July
15 (ie today!). There has been very little press publicity
given to this important evidence of 'detente' and developing
peaceful co-operation between the USSR and USA. One of the
experiments they will do jointly will be to cast magnetic
alloy under gravity-free conditions. On earth,
high-coercivity alloys have to be produced by a multi-stage
powder-metallurgy process, because under gravity you do not
get an even distribution of the magnetic particles in the
casting process. This may seem a relatively trivial piece
of showmanship, until you realise that the key to the
success of large-scale economic satellite projects, such as
that described by the Boeing team, is the carrying out of
many complex engineering operations in situ. Space will, I
think, again become fashionable.
NOTES