Carl%20Sagan%20-%20The%20Demon%20Haunted%20World

No Such Thing as a Dumb Question
atomic number 6 (which is carbon) and atomic number 7 (which
is nitrogen)?
• Yes, the new preservative causes cancer in rats. But what if you
have to give a person, who weighs much more than a rat, a
pound a day of the stuff to induce cancer? In that case, maybe
the new preservative isn't all that dangerous. Might the benefit
of having food preserved for long periods outweigh the small
additional risk of cancer? Who decides? What data do they
need to make a prudent decision?
• In a 3.8 billion-year-old rock, you find a ratio of carbon isotopes
typical of living things today, and different from inorganic sediments.
Do you deduce abundant life on Earth 3.8 billion years
ago? Or could the chemical remains of more modern organisms
have infiltrated into the rock? Or is there a way for isotopes to
separate in the rock apart from biological processes?
• Sensitive measurements of electrical currents in the human
brain show that when certain memories or mental processes
occur, particular regions of the brain go into action. Can our
thoughts, memories and passions all be generated by particular
circuitry of the brain neurons? Might it ever be possible to
simulate such circuitry in a robot? Would it ever be feasible to
insert new circuits or alter old ones in the brain in such a way as
to change opinions, memories, emotions, logical deductions? Is
such tampering wildly dangerous?
• Your theory of the origin of the solar system predicts many flat
discs of gas and dust all over the Milky Way galaxy. You look
through the telescope and you find flat discs everywhere. You
happily conclude that your theory is confirmed. But it turns out
the discs you sighted were spiral galaxies far beyond the Milky
Way, and much too big to be nascent solar systems. Should you
abandon your theory? Or should you look for a different kind
of disc? Or is this just an expression of your unwillingness to
abandon a discredited hypothesis?
• A growing cancer sends out an all-points bulletin to the cells
lining adjacent blood vessels: 'We need blood,' the message
says. The endothelial cells obligingly build blood vessel bridges
to supply the cancer cells with blood. How does this come
about? Can the message be intercepted or cancelled?
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