How do mirrors work?
[ 2006-08-16 11:41 ]
童話里的魔鏡是不會撒謊的，現(xiàn)實中的鏡子也不會撒謊。那么，鏡子是怎么照見東西的呢？答案就在下面的文章里。
 We see objects in a mirror, because a mirror, when
hit by particles of light called photons, reflects the photons back to us and
some reach, and enter, our eyes. Photons that hit a rough surface will bounce
off of the surface in a haphazard manner, while those that hit a smooth surface,
such as a mirror, only bounce off of the surface at the same angle at which they
hit the object. The scientific term for this phenomenon is
reflection.
Not all smooth surfaces reflect photons back to us, even
though, technically, they should bounce back at the same angle at which they hit
the surface. This exception to the rule results, because some smooth surfaces
absorb the light particles hitting them, making it impossible for them to bounce
back.
Another apparent exception to this rule is that, although our
bodies are rough, uneven surfaces, off of which light bounces at random angles,
our images reflect off of a mirror. The reason for this apparent contradiction
is simply that when we stand in front of a mirror, some, but not all, of the
light particles bouncing off of us will hit the smooth surface of the mirror.
The ones that do reflect our images back to our eyes at exactly the same angle
at which they hit the mirror.
In other words, photons that bounce off of
any part of our bodies and hit the mirror reflect back to our eyes from only one
place on the mirror, and at only one angle. It follows that each point on our
bodies that reflects back to our eyes from one point on the mirror produces an
image in the mirror. All of the images together make up our reflections, like it
or not. And remember that mirrors don't lie!
particles:
微粒
photons: 光子
bounce: 反彈
haphazard: 偶然、隨機的
（英語點津 Annabel 編輯）
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