the australian museum society fred watson, aao 17 may 2005 the australian museum society fred...
TRANSCRIPT
The Australian Museum SocietyFred Watson, AAO17 May 2005
The Australian Museum SocietyFred Watson, AAO17 May 2005
Well, this is
rubbish…
Prologue…On 2nd October
2008, we will celebrate the 400th birthday of this document.
It records the first appearance of a telescope.
But by 2008, we will also be on the brink of a new generation of unbelievably large telescopes.
What lessons can we learn from the 400-year history of telescope making…?
The secret obsessions of astronomers
The secret obsessions of astronomers
Characteristics of astronomy today• Huge range of instrumentation• Infinite computing power• Access to every part of the
electromagnetic spectrum:-rays, X-rays, UV, visible (optical), IR, mm-wave, radio
The Universe through different eyes...
What’s so good about optical astronomy?
• Visible light is emitted by ‘ordinary matter’ in the Universe—i.e. stars
• The visible spectrum is rich in the ‘bar-code’ of atomic and molecular features
• Optical observations bridge long and short wavebands
• You can do it with your feet on the ground
The Schematic Ground-Based Optical Telescope
• Something large to collect and focus the radiation
• A complicated bit in the middle for analysis
• An optical detector
• A ground-based mounting
Now essentially perfect
To gather more light from faint sources, telescopes need to become ever bigger
Bigger telescope mirrors can also reveal finer detail in the sky…
Cautionary tales:the bad telescope
casebook
Cautionary tales:the bad telescope
casebook
Andrew Barclay and the ‘Unrevealed Wonders of the
Heavens’
Andrew Barclay and the ‘Unrevealed Wonders of the
Heavens’
Andrew Barclay (1814-1900)Andrew Barclay (1814-1900)Locomotive builder from Kilmarnock Became hooked on building telescopes on the side.
While they were beautifully engineered, his telescopes were small and old-fashioned by the standards of the day.
And his mirrors were absolut-ely hopeless.
But Barclay refused to believe they were…
Barclay also described a ‘blue, spherical-looking mountain’ in Mars’ southern hemisphere (1893)
Andrew Barclay’s Mars…Andrew Barclay’s Mars…
Barclay’s ‘egg-shaped protruberances’ were later reported to have brown smoke issuing from them.
His version of Jupiter…His version of Jupiter…
And Saturn…And Saturn…
Barclay’s results appeared in the English Mechanic and were received with utter derision:
‘I can only say that if I had a telescope that exhibited the great planet as depicted in Mr B’s Fig.1, I would dispose of the optical part for what it would fetch, and convert the tube into a chimney cowl straightway.’ (And that’s one of the kind ones.)Barclay protested that he had spent £10,000 learning how to make telescope mirrors. How could there be anything wrong with them?He was clearly not only obstinate, but also stupid.
The response to Barclay’s work…The response to Barclay’s work…
Moral number one: Make your mirrors good ones (and listen to people who tell you they aren’t…)
Johannes Hevelius (1611-87) and his telescopes
Johannes Hevelius (1611-87) and his telescopes
The wealthy brewer of DanzigThe wealthy brewer of DanzigHevelius spared no expense in equipping his state-of-the-art optical workshop…
…and working with his young (second)
wife Elisabetha, who was:
‘the faithful Aide of my nocturnal
Observations’.
The wealthy brewer of DanzigThe wealthy brewer of Danzig
His early instruments were stylish (and stylishly used). This one dates from 1647.
But then he caught galloping megalomania.
First, he built a 60-foot (18-m).
Then a 150-foot (46-m)…
But in the end, his quivering telescopes were destroyed in the Great Fire of
1679:
‘The cruel flames have consumed all the Machines and Instruments’.
Moral number one: Make your mirrors good ones (and listen to people who tell you they aren’t…)Moral number two: Understand the mechanical limitations of your telescope…
Sir James South (1785–
1866) and the telescope that
sparked a feud
Sir James South (1785–
1866) and the telescope that
sparked a feud
South was a gifted amateur astronomer of independent means (a surgeon by profession).He was knighted for his services to astronomy (the measurement of double stars), but was outspoken in his criticism of the establishment.He was president of the RAS, 1829–31.
Secretary of the RAS at the same time was
Rev. Richard Sheepshanks, the
forthright son of a Yorkshire mill-owner.
Get a brain,South.
With degrees in mathematics,
theology and law, he was scornful of those
less talented than himself.
Especially Sir James…
Just watch it,Sheepshanks.
Woof!
Late in 1829, South bought an exquisite 12-in telescope lens.He placed it in the hands of his then-friend, Edward Troughton, asking him to construct Britain’s most powerful telescope.They disagreed on the design…
By 1832, Troughton’s telescope had failed to satisfy South.He accused Troughton and his partner, William Simms, of building “a useless pile”.Troughton took legal action to recover his firm’s costs.Guess who he hired as his lawyer?Troughton & Simms won in 1838, enraging South.
So, in 1839…
The scene at Sir James South’s, 8th July 1839…
“…the useless 20ft equatorial invented by Troughton and Simms, and cobbled by their
assistants the Rev. R. Sheepshanks and Mr. G. B. Airy…”
And, in 1842…South attempted to complete the humiliation of Troughton & Simms and their allies by addressing the humblest categories of tradesmen in the district…South’s vitriol continued even after Sheepshanks’ death in 1853…The great lens was never
properly used by South.
Moral number one: Make your mirrors good ones (and listen to people who tell you they aren’t…)Moral number two: Understand the mechanical limitations of your telescope…
Moral number three: Agree on exactly what you want - before you start…
And one final moral:
Put your telescope in the right place…
Against the odds: how icons are
created
Against the odds: how icons are
created
The 100-inch Hooker telescope (1917)
Why did it become an icon…?
The Eagle Nebula—stellar birthplace
The Eagle Nebula—stellar birthplace
But – the Hubble cost $US 2 billion
to build, launch and fix.
That would buy 20 of today’s
ground-based 8-metre telescopes…
A 3.9-metre mirror can see detail of 0.03 arcsec…
Stars should look like this…
This is very depressing indeed
1 arcsecond
But unusual things happen in Australia…
Multi-object spectroscopy with fibre optics
The answer to life, the Universe and everything...
Detector
Spectrograph
Slit
Galaxies…
Basic building-blocks of the Universe
If this was our Galaxy,we’d be here •Around 100,000,000,000 stars
•Lots of gas and dust (in spirals)•Around 100,000 light years across (or 1,000,000,000,000,000,000 km)
Applying the lessons…
Applying the lessons…
Beyond the VLT, the thinking goes like this:
VLT: Very Large Telescope 4×8 m (16 m equiv.)ELT: Extremely Large Telescope 25 mCELT: California Extremely Large Telescope 30 mGSMT: Giant Segmented-Mirror Telescope 30mTMT: Thirty-metre Telescope (US + Canada + ?)Euro50: formerly SELT…
Future plans for large telescopes...
OWL—Sharp-eyed and OverWhelmingly Large
But could OWL go
bad…?
But could OWL go
bad…?Or will it become an
icon?
Or will it become an
icon?
Earth-like planets out to about 75 l.y. by direct
imaging
What might we study with OWL?
Individual stars in moderately distant galaxies – galactic archaeology
Galaxies forming at look-back times up to 10 billion years
Exploding stars at look-back times up to 12.5 billion years
For the full story of telescopes and the crazy people who created them…“A rollicking good yarn” (Sky & Space Magazine)
“A lively, entertaining, can’t-put-it down history” (Aust. Sky & Telescope)“A fine piece of science writing…” (Kirkus Reviews, USA)
“As riveting as watching paint dry…”(Wayne Webb, xtramsn entertainment website, NZ)