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Why do you always hear about curved lenses?
I have a magnifying lens that's flat. Explain that!
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The
surface of the
lens is the most
important part
because that’s what
bends light as it
moves into and out
of the lens. In 1820,
Augustin Fresnel
made this discovery
and then created
lenses that eliminated
the glass in the
middle, making a lens
that was all surface.
Today you can buy
flat, plastic Fresnel
magnifying lenses.
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A
drop
of water
makes a fine
magnifying
lens.
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HERE’S
WHAT YOU NEED
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Clear plastic
wrap
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A newspaper
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An eyedropper
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Water
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HERE’S
WHAT YOU DO
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1.
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Tear off a piece of plastic
wrap and put it on top of a sheet of newspaper.
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2.
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Using the dropper (or
your finger if necessary), put different-sized drops of
water in random spots on the plastic wrap.
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3.
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Look at the words on the
newspaper through the drops. Do the words appear bigger?
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4.
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Look at the drops from
the side. Notice that they’re curved out. You just
made yourself a bunch of convex, or magnifying, lenses.
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