[quote="apodman"][quote="[url]http://en.wikipedia.org/wiki/Airy_disk[/url]"]The diffraction pattern resulting from a uniformly-illuminated circular aperture has a bright region in the center, known as the Airy disk which together with the series of concentric bright rings around is called the Airy pattern. Both are named after George Biddell Airy, who first described the phenomenon. The diameter of this pattern is related to the wavelength of the illuminating light and the size of the circular aperture.[/quote]
[list][b]Up the airy mountain
Down the rushy glen
We daren't go a-hunting
For fear of little men[/b] - William Allingham 1824–1889[/list]-----------------------------------------------------------------
[quote= http://www.uh.edu/engines/epi1006.htm"]
THE NEPTUNE AFFAIR by John H. Lienhard
.
<<The convoluted story of Neptune begins in 1841
when John Adams, a brilliant Cambridge student, took
an interest in the irregular movement of Uranus. Maybe
the irregularity was caused by another, yet undiscovered, planet.
In 1843, Adams went to the Cambridge astronomy professor,
James Challis, with a computational scheme. Challis got the
data Adams needed from the royal astronomer, George Airy.
Adams went to work. Two years later, he knew where to aim
a telescope to find the mystery planet. He asked Challis
to look for it. Challis didn't want to take on the job.
He sent Adams to Airy.
Airy read Adams's work and sent back a note with a minor
question. The question struck Adams as too simple. He figured
the great Airy was writing rhetorically. He didn't bother
to answer. Airy thought the young man was snubbing him.
He wrote an angry letter to Challis, and he wouldn't
even to speak to Adams.
Months later, a young French astronomer, LeVerrier, made the
same calculation Adams had. He also went to Airy. Airy heard
him out, then went to Challis and said, "Let's look for the
planet." Challis finally began looking. But so did German
astronomers. On September 23, 1846, the Berlin Observatory
found the planet we call Neptune. It lay very near
the spot both young men had predicted.
Airy wrote congratulations to LeVerrier. The French Academy
cheered a French triumph and tried to name the planet after
LeVerrier instead of naming it after yet another Roman god.
Then the great English astronomer, John Herschel, announced
that Adams had actually done the calculation first.
The French were furious at Herschel. The English Royal Society
was equally furious at Airy and Challis for dropping the
ball. They subjected them to a public humiliation from
which neither ever fully recovered.
. And what of Adams and LeVerrier?
Well, those two level-headed young men became close friends.
After all, they'd discovered Neptune, hadn't they? This
nationalistic stuff wasn't their fight. But then, a few years
later, a Harvard astronomer showed that their calculations had
been incomplete. They'd both been lucky to find anything at all.
Maybe the crowning irony was the discovery, in 1980, of notes
that Galileo had made in 1612 and 1613. He'd clearly identified
Neptune, but he hadn't realized it was moving in relation
to the stars behind it. He thought it was another star.>>[/quote]-----------------------------------------------------------------
[quote=" http://www.u-net.com/ph/lassell/adams-airy.htm"]
Adams, Airy and the Discovery of Neptune in 1846 by Allan Chapman
<<Popular interpretations of this incident place a great deal
of responsibility upon Airy, for not having taken the initiative
to secure a British discovery. Yet this is unjust, and
several key factors must be born in mind:
1. It was not the job of the Astronomer Royal to undertake searches.
2. As an extremely over-worked man, Airy cannot be blamed for being
unavailable when Adams chanced to call upon him without first
having made an appointment. He was abroad on the first occasion,
and at dinner with his family on the second.
3. After Adams left his figures for Neptune's place, when the Airy
family were at dinner on October 21st, 1845, Airy was prompt in writing
to Adams in Cambridge, requesting crucial pieces of mathematical
information about the basis of his computations. Adams never
replied to Airy's letter, nor supplied the requested information.
4. Why was Adams not admitted when Airy was at dinner? We should bear
in mind that at the time Mrs. Richarda Airy was within a week of giving
birth to their ninth child. Her previous pregnancies had been difficult,
and as Airy was deeply attached to his wife, he saw no reason to have
their dinner interrupted by a stranger who wished to see him on a
business matter. There is no evidence to suggest that Adams was willing
to wait until the meal was over in spite of the fact that the Airy
family dined not in the evening, but in the late afternoon.
5. Airy's voluminous surviving correspondence makes it clear that
everyone - from Cabinet Ministers and Admirals, down to servant-girls
wanting to have their fortunes told - wrote to, and occasionally
called-in upon the Astronomer Royal. A man who was so much in the public
eye had to defend his privacy.
6. While all of this was going on, the Royal Observatory was being
rocked by the disclosure of an awful incident. A senior Greenwich
Observatory Assistant, William Richardson, had just been exposed for
having committed an appalling murder. From late October 1846, onwards,
Airy and his Chief Assistant, the Revd Robert Main, made appearances
before the courts at the beginning of Richardson's trial. Airy was
acutely embarrassed by the regular appearance of his name, as
Richardson's employer, in the newspaper columns reporting
the details of a crime which hinged upon sex, incest,
and the burial of a body in a shallow grave.
7. And if this was not enough, the year 1845-1856 was probably the
busiest in Airy's professional life. For in addition to astronomy,
he was immersed in the business of the Railway Gauge Commission.
As the Scientific Commissioner, he was travelling around Britain
testing trains & interviewing engineers. It was this Commission, and
Airy's scientific advice, which settled British (and, later American)
railway gauges at the "Standard Gauge" of 4 feet 8 1/2 inches.
..........................................................
John Couch Adams, while a brilliant mathematician, was rather naive
socially, and was said by a senior Cambridge colleague to have behaved,
regarding Neptune, not "like a man who made a great discovery, but like
a bashful boy." In 1846, however, the "bashful boy" was 27 years old.
Urbain Le Verrier, the French co-discovery of Neptune was an older, and
much more business-like individual, and had the determination to see his
computations put to effect. Yet even he was not able to find a French
Observatory that was willing to undertake the search, and was forced
to write to colleagues in Berlin. We often forget that the French
scientific establishment let Le Verrier down no less than the British
was accused of having let down Adams. Once the Berlin sighting
had been made, however, the French were quick to turn it
into a French National discovery.>>[/quote]
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