Yi Zhang
yqz5135
Caijia Liu
cvl5213
Jiayu Fang
jqf5138
While it is the human nature to
explore the mystery of
macrocosm and microcosm, this
is limited by the lack of
appropriate tools in the early
time. The invention of telescope
and microscope offered an
opportunity for people to know
better about the world.
Let’s start from convex lens and concave lens
History:
 1608: the earliest telescope appeared in Netherlands
 In 1668 Isaac Newtown build the the first reflecting
telescope.
 In 1733 Chester Moore Hall made achromatic lens
 In 1931 radio telescope (along with radio astronomy)
was born with Karl Guthe Jansky's discovery of an
astronomical radio source
There are a lot of types of telescopes, but the most
common ones are Keplerin telescope and Galieo’s
telescope.
Principles of telescopes
 Keplerian telescope
 The combination of an objective lens 1 and some type
of eyepiece 2 is used to gather more light than the
human eye could collect on its own, focus it 5, and
present the viewer with a brighter, clearer, and
magnified virtual image 6.
 Galileo’s telescope
Galileo telescope uses a convergent (plano-convex or biconvex) objective lens and a divergent (plano-concave or
bi-concave) eyepiece lens. Galilean telescopes produce
upright images.
 Parallel rays of light from a distant object (y) would be
brought to a focus in the focal plane of the objective
lens (F' L1 / y’). However, the (diverging) eyepiece (L2)
lens intercepts these rays and renders them parallel
once more, but travelling at a larger angle (α2 > α1) to
the optical axis. This leads to an increase in the
apparent angular size.
 The final image (y’’) is a virtual image, located at
infinity and is the same way up as the object
Microscope
 There are many types of
microscopes, the most
common and first to be
invented is the optical
microscope which uses
light to image the
sample.
Principles of microscopes
 According to the different distance of the objects, the
image formations of the lens are different.
 Specifically,1) When Do>2f,then the image will be
inverted, real and smaller. f<Di<2f 2) While Do=2f,
then the image will be inverted, real and same size as
the object. 3) While f<Do<2f, then the image will be
inverted, real and larger, Di>2f. 4) While Do=f, then
the image cannot be formed. 5) While Do<f, then the
image will be erected, virtual and larger on the object
side, Di>Do.
 The distance of object in the microscope is larger than
twice of the focal length, but smaller than one focal
length of the tube lens, thus, the image will be
inverted, real and larger. The image is then be
magnified by the lens of eyes, so that eyes are able to
see the image. The function of the lens of eyes is the
same as the tube lens, the difference is that what the
eyes see is not the real object, but the image that
magnified by the tube lens.
Effects on people’s lives
 Telescopes have changed
the way man views himself
in relation to the Universe.
It is responsible for many
important discoveries like
determining the orbits of
the planets in our solar
system. The Hubble
telescope shows us billions
of galaxies, with billions of
stars in each one. We can
see the birth and death of
stars, so we know what will
happen to our own star in a
few billion years.
We could never reach out
as far as we have in the
Universe without our
telescopes.
 Microscope provides us with
chances to discover the
microscopic world.
Microscopes improve our
lives by allowing scientists to
study the smallest forms of
life. These lifeforms include
disease causing pathogens
such as bacteria. The
inventon of microscope has
played an important role in
the Medical Field.
References:

http://www.google.com.hk/images?hl=zh-cn&newwindow=1&safe=strict&client=aff-cs360se

channel&channel=bookmark&q=microscope%20change%20people's%20lives&um=1&ie=
UTF-8&source=og&sa=N&tab=wi&biw=1349&bih=580

http://en.wikipedia.org/wiki/Telescope

http://en.wikipedia.org/wiki/Refracting_telescope

http://www.google.com.hk/images?hl=zh-cn&newwindow=1&safe=strict&client=aff-cs360se-channel&channel=bookmark&q=telescope&um=1&ie=UTF8&source=og&sa=N&tab=wi&biw=1349&bih=580

http://en.wikipedia.org/wiki/Microscope

http://telescope.kingyar.com/?tag=%E6%9C%9B%E8%BF%9C%E9%95%9C%E5%8E%8
6%E5%8F%B2

http://www.bjhwx.cn/xsxwj006.htm

http://scholar.google.com/