Transcript The Telescopex

The Telescope
Hans Lipperhey
In October 1608, the national
government in The Hague discussed
a patent application for a device
that aided "seeing faraway things as
though nearby." It consisted of a
convex and concave lens in a tube.
The combination magnified objects
three or four times. The
government found the device too
easy to copy and did not award a
patent, but it voted a small award
to Jacob Metius and employed Hans
Lipperhey to make several binocular
versions, for which he was well
paid.
Galileo
By April 1609, three-powered spyglasses
could be bought in spectacle-makers' shops
on the Pont Neuf in Paris, and four months
later there were several in Italy. They were
made famous by an Italian professor and
experimenter named Galileo Galilei in the
summer of 1609 at the University of Padua
near Venice.
Galileo's first telescope was basically a tube
containing two lenses. His first attempt was a
three-power instrument; this was followed
by one that magnified objects approximately
nine times.
Newton
Newton designed a telescope that used
mirrors, rather than lenses, to bring the light
to a focus. It is interesting to note that
Newton did not invent the idea of a
reflecting telescope: the honour for this goes
to the Scottish mathematician James
Gregory, who designed such an instrument in
the early 1660s.
Hadley
To create a clear, sharp image, the mirrors
would have to be a different shape — a more
sharply rounded shape called a “paraboloid.”
The first person to actually create a parabolic
mirror was another English mathematician,
John Hadley. In 1721, he built a Gregorian
reflector whose mirror had very little
spherical aberration.
Johannes Kepler
A variation on the Galilean telescope was
suggested by Johannes Kepler in his 1611
book Dioptrice. He noted that a telescopic
device could be built using two convex
lenses, but the image it produced would be
upside down.
The advantage of this design, according to
Kepler, was its larger field of view and high
magnification.
More telescopes
The Huygens brothers also developed "aerial
telescopes." These featured an objective lens
mounted in an iron tube at the top of a tall
pole. The astronomer raised and lowered this
and found the image by trial and error. A
compound eyepiece on a little stand was
then positioned to receive the image cast by
the objective. Although astronomers made
some discoveries with these telescopes, their
usefulness was limited - alignment on windy
nights, for example, was difficult - and their
design cumbersome.
Radio Telescopes
The First Radio Telescope
In 1937, Grote Reber, an American
radio engineer, read about Jansky's
work and set out to construct the first
professional radio telescope. Reber
understood that radio waves were no
different from visible light waves
except for their longer lengths and
lower energy levels. With this
information, he realized the best
design for an efficient radio telescope
would be to copy designs of existing
optical telescopes.
Read more:
http://www.scienceclarified.com/scitech/Telesc
opes/Radio-Telescopes-Discovering-theInvisible-Universe.html#ixzz3jlsplKW1
X-Ray Telescope
An X-ray telescope (XRT) is a
telescope that is designed to
observe remote objects in the
X-ray spectrum. In order to
get above the Earth's
atmosphere, which is opaque
to X-rays, X-ray telescopes
must be mounted on high
altitude rockets or artificial
satellites.
Hubble Space
Telescope
The Hubble Space Telescope
(HST) is a space telescope
that was launched into low
Earth orbit in 1990, and
remains in operation. With a
2.4-meter (7.9 ft) mirror,
Hubble's four main
instruments observe in the
near ultraviolet, visible, and
near infrared spectra. The
telescope is named after the
astronomer Edwin Hubble.