You have to feel sorry for those whose birthdays happen to fall on 25 December.
More often than not, the celebration of their birthday is eclipsed by other festivities.
However, this 25 December marks a special occasion for all astronomers,
as it celebrates the 370th anniversary of the
birth of the creator of the
Newtonian
reflecting telescope.
Galileo died on January 8th, 1642 and somewhat fittingly Newton was born
in that very same year.
At the age of 25 in late 1668, Newton constructed the first known reflecting telescope.
Earlier, Newton had performed his celebrated work on optics and the theory of colours.
Quote:
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Originally Posted by Newton writing to Henry Oldenburg, the secretary of the Royal Society
"To perform my late promise to you, I shall without further ceremony acquaint you,
that in the beginning of the Year 1666 (at which time I applied my self to the grinding
of Optick glasses of other figures than Spherical,) (I procured me a Triangular
glass-Prisme, to try therewith the celebrated Phenomena of Colours".
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Newton had observed that refracting telescopes at the time suffered from
chromatic aberration. If you study the edge of a lens, you will notice it forms
a little prism. He had theorized that a reflecting telescope would be free of
this defect and his first reflector employed a a spherical speculum metal mirror
and was a 1.3" f/5. He used it to make observations of the Galilean moons and of
the phases of Venus.
In 1671, a second reflector was presented to the Royal Society and demonstrated
to Charles II in 1672. Newton was then admitted as fellow to the Society.
A replica of that second telescope can be seen in this image here -
http://upload.wikimedia.org/wikipedi...opeReplica.jpg
As a telescope, its purpose and function is instantly recognizable to any
amateur astronomer today.
So this 25th December, be sure to go out and pat your faithful Dob and spare
a thought for that genius of geniuses that conceived and built the very first
reflecting telescope.
25 Dec 12 - celebrating 370 years since birth of Newtonian telescope inventor
Thanks Gary , that is so cool .
