Today, let's try to drill a hole through to China.
The University of Houston's College of Engineering
presents this series about the machines that make
our civilization run, and the people whose
ingenuity created them.
I was recently at a national
teachers' convention. People had rented space to
sell educational materials. One man was pushing his
new book. He'd proved, he said, that Earth's center
isn't molten after all. He claimed the temperature
is really absolute zero.
I doubt that he had much luck in rewriting science
curricula, but he makes a point. When we haven't
actually been somewhere -- in this case to the
center of the Earth -- it's all too easy for laymen
to bend scientific inference wherever they want it
to go.
But we have been drilling ever deeper to see what's
there. Commercial drilling for oil and gas
typically goes down a mile or so. It rarely gets as
deep as three miles. Still, one commercial bore
hole in Oklahoma went to a depth of six miles.
Then, like a scene from Dante's Hell, it hit molten
sulfur.
We've also been doing research drilling, but
funding for that hasn't been lush. No American
research hole has gone down more than two miles
yet.
German and Russian research rigs have gone much
deeper than we have. The Russians hold the record
with a hole north of the Arctic Circle, near
Norway. In 1984 they reached a depth of seven and a
half miles. There they found hints of deep-lying
mineral wealth.
Such deep holes are hard to drill. Guiding a
seven-mile drill only a foot or two in diameter is
like trying to steer a thread through a concrete
pier. Drill bits have to carry their own guidance
systems.
And we find strange things at such depths. We've
brought unknown bacteria up from depths of almost
two miles. The Swedes expect to locate deep natural
gas that doesn't come from organic material.
Researchers are trying to sort out plate tectonics.
They're trying to find out more about the San
Andreas fault.
And what about temperature? Well, it certainly does
go up as the drill goes down. A research drill two
miles under California's Salton Sea reached an
environment of almost 700 degrees.
The United States leads the technology of drilling
at high temperature. Drillers sent one bit straight
into a subterranean lake of lava under Hawaii. Its
temperature was 2000 degrees. They did it by
circulating coolant to freeze the lava around the
drill. Then they bored a regular hole through
solidified lava.
So just when you thought Earth had run out of
frontiers, we've found a new one. There are more
things in Heaven and Earth -- more things just
under our feet -- than we ever imagined. And we're
creating some dazzling high tech to take us there.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
work.
(Theme music)
