Geoscience Reference
In-Depth Information
In science, good luck can be as important as good judgement. When Brian Harland first came up
with the Snowball idea, he was too far ahead of his time. But Paul Hoffman became obsessed by the
ice rocks in Namibia at the perfect moment. The Snowball stage was set when he and Dan experien-
ced their eureka, and the key criticisms that had long dogged the Snowball idea were already solved.
There was no ice there? Virtually everyone now believed Brian's argument that the rocks were formed
from the action of grinding glaciers, and dropped by overhead icebergs. There was no way out of the
ice catastrophe? With his super-greenhouse, Joe Kirschvink had found a way that the Earth could go
into a deep freeze and still recover. All the continents had been huddled around the frigid poles at the
time the ice appeared? Thanks to the magnetic records from the Flinders Ranges, everyone now be-
lieved that in at least one place, in what is now the South Australian outback, there was ice within a
few degrees of the equator.
For Paul and Dan, it could hardly have been more perfect. Their predecessors had each, individu-
ally, solved the arguments
against
the theory. Now they themselves had produced evidence
for
the
theory. Paul's isotopes were evidence that large numbers of living things perished before the Snow-
ball, and Dan's carbonates were evidence for the super-greenhouse that came after the ice.
Coming up with the Snowball story—understanding how the new evidence fitted in with the work
that had already been done—took a particular combination of capabilities. Paul had the deep know-
ledge of Precambrian geology, the long years of fieldwork in Canada and Namibia. Dan had the un-
derstanding of how oceans work.
Telling the story would require yet another important combination, but this time of personalities
rather than knowledge. Paul had the vehemence, the stubbornness, the single-minded obsession. Dan
had the social network, the grace, the names and phone numbers of smart, imaginative scientists in
many different disciplines. Unlike Brian Harland, Joe Kirschvink, or any of the other people who had
worked on the glacial rocks in the past fifty years, Paul and Dan were prepared to run with the Snow-
ball idea. Having put the theory together, they wanted to taste it, test it and spread it around. Paul in
particular. This idea felt different from any others he'd been involved in. This was his chance, finally,
to make a world-class difference to the way we all understand the Earth.
