February 2015
Billie Silvey
This Christmas we got Katyana a telescope.  
Here she is, using it on the balcony of their
apartment to look at the stars.  

Before we shopped, we checked with a
scientist friend who told us he preferred
refracting (lens-based) telescopes over
reflecting (mirror-based) telescopes.

She has seen Orion's Belt and other stars
through it.  "It makes them look closer," she
says.  

Telescopes are a series of lenses encased
in a cylinder.  The lenses focus the light in
such a way that things that are far away
appear nearer.

Even larger is the telescope she saw on a
recent trip to
Griffith Park Observatory.  

Lenses are glass shaped into disks that
bulge in the middle.  They came into
common use with
Gutenberg's invention of
the
printing press in the 1440s.  
As people began to read, many realized that
they were farsighted and needed help to be
able to see clearly to read.  

Lenses are important to me.  I spend muchof
my time behind them.  In fact, often, to be
able to read and then look up and see things
further away, I wear contacts with reading
glasses over them.

In 1590, glasses makers experimented with
lining up two lenses to magnify objects,
creating  the
microscope.  Microscopes
allowed people to see the internal structure
of objects, leading to the discovery of cells
and transforming medicine.

Twenty years later, Dutch lensmakers
invented the
telescope, which brought the
distant near.  

Lenses went on to play a role in photography,
then movies and TV, creating the vast
entertainment industry--all because books
showed people that they needed glasses!
LENSES