Today, we learn to live with electricity. 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.
Electricity is wonderful
stuff. I learned about electromagnets when I was a
child. Straightaway, I split a length of lamp wire
down the middle. I wrapped one half around a large
nail. Then I stuck the two bare ends in a wall
plug. The trouble was, I'd found out about
electromagnets before anyone had told me about
Ohm's law. It took five minutes for the blinding
blue flash to clear. It took much longer than that
to tell my father why our fuse box had all but
vaporized.
Now we face a new electrical threat. The Harvard
Medical School Health Letter tries to sift the
effects of electromagnetic waves. We live our lives
in electric fields. Are they hurting us? It's
possible that they are. Charged particles ride on
the membranes of every cell in our body. Electric
fields can affect them. After all, microwave fields
cook hamburger, X-rays are carcinogenic, and
ultraviolet fields burn our skin.
But the intensity of a man-made electric field
drops off rapidly as we move back from the source.
The danger drops off with the frequency. Power
lines, electric blankets, and hair dryers normally
expose us to weak fields. And 60 cycles per second
is a very low frequency, relatively speaking.
Studies disagree on the threat. Some show that
common electric fields can cause cancer, cataracts,
and dispepsia. Others show they don't. The ones
that say they're dangerous don't support each
another. They don't tell you which victims also
smoked or inhaled organic solvents.
My guess is that we'll have to build a whole new
set of protections against a minor, but real, risk.
In the meantime, I'll be a little more careful
about standing near electrical sources. I'll be a
little more careful, but not a whole lot.
And I shall lament the end of summer -- the passing
of childhood -- the days when I thought I could
stick bare wires in wall plugs. I shall remember
Ben Franklin harnessing lightning and living to
tell about it. His imitators didn't fare as well. I
shall look at pictures of the electric poineer
Nikola Tesla, with millions of volts leaping from
his hair. That was the same Nikola Tesla who
wouldn't shake your hand for fear of germs.
As a child, I ran through thunderstorms watching
lightning strike. As I child I knew I was immortal.
Now I fear to see children die. It took the minds
of children to corral electricity. It takes adults
to put the bit in its teeth. We could fly kites in
thunderstorms during the childhood of the
electrical age. But the stakes are much higher when
the empyrean life-giving ether of electricity flows
around us every moment.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
work.
(Theme music)
