Tuesday, April 7, 2009

WYSIWYG - Mount Wilson Observatory

Mount Wilson, California
Copyright 2009 by Andrew Alden, geology.about.com,
reproduced under educational fair use.

Those handy Dutch people played around with variously ground pieces of glass set on line so that light passes through them all. Hans Lippershey made one in 1608. Galileo Galilei somehow heard from the idea and - as a handy man by himself - constructed next year a 130 cm long tube from wood and paper and set a piece of ground glass on one and an eyepiece to the other. Voila! 14x magnified view and humanity moved to another era of space exploration with these artificial eyes, telescopes.

Galileo made a telescope like this in 1609
and got into lots of troubles with the authorities!

Everything in the United States is so big. They even say that the flies in Texas have such big dogs in their hair.

So it came to the mind of some very ambitious American people to build the largest telescope in the world. Nothing less than that would do.

At the end of the 19th century the biggest telescope in the world was in Chicago - a Clark type refracting telescope with 18 1/2-inch lens. But California wanted to do better.

The man with the big bug was Edward F. Spence (1832-1892), a banker in First National and a politician who served two terms as the major of Los Angeles. Spence promised the whopping $50.000 to UCLA for building the largest telescope in the world. He requested a 40 inch lens which is at the practical limits of refractors, nothing less than that.

According to the interesting web pages of Mount Wilson Observatory a specialist team from Harvard recommended that this mammoth telescope could be built on of the mighty and hard to reach 1740 meters high top of Mt Wilson in California.

In January 1889 the first telescope had been set up there for testing - a 13-inch Clark refractor five and half inches short of the Chicago telescope. But it soon turned out that conditions were really tough up there and the ambitious project was about to collapse in practical and financial troubles.

However, in the initial enthusiasm, a 40 inch lens had already been ordered from Alvan Clark and Sons and eventually the world's largest telescope was constructed using it by George Ellery Hale (1868-1936). No, not the Hale whose name was given to the exceptionally bright Hale-Bopp comet C/1995 O1 mentioned in this blog in the tragic Heavens' Gate text. The comet was discovered on 23 July 1995 by two independent observers, Alan Hale (Cloudcroft, N.M.) and Thomas Bopp (Stanfield, AZ), so Hale-Bopp it is!

Young George E. Hale
a man with big dreams that came true

Mr Spence had certainly got things moving with his generous donation and world's largest telescope was indeed built - but in Wisconsin because Mount Wilson seemed way too difficult for the project. Even more importantly, Spence had ignited the astronomic ambitions of a very gifted and dedicated telescope builder, George E. Hale, who would not stop dreaming about a really big telescope that could provide some answers to a new science he called "astrophysics".

John Hooker financed Mt. Wilson 100 inch telescope, the Hooker.

The next big bug came from a financier called John Hooker (1833-1911) who was a hardware millionaire. G.E. Hale had told him that with 40 inches the practical diameter limits of a glass lens had been reached. The only way beyond this size and ability to collect light would be to create a reflector type telescope - and duly Mr Hooker assigned the money needed to start a fund to build a 100 inch reflecting telescope. He requested that the instrument would be named after him - and so it was. Mt Wilson's Hooker it is.

In 1906 George E. Hale had made his preparations and world wide research and decided to order the glass for 100-inch mirror from Saint-Gobain glass works in France. They made the special glass and it was shipped to USA where it reached Pasadena December 7, 1908.

Not just any piece of glass. This French glass when properly ground and set in place of a huge system on the high mountain top of Mount Wilson. The artificial eye from earth to the space would forever change the way humanity understands the entire universe.

It took some time - with such a massive object and such demands for precision! Fore River Shipyards was given the job and it began working on the glass May 12, 1912 i.e. about four years after the glass had been shipped to California.

They worked on the single piece of glass for five years. Grounding, washing, measuring, checking... manual work of highest possible accuracy. To get it right. This was very expensive special glass material and the customers would not forgive serious problems on its surface.

Carefully boys, it is glass! July 1 1917

July 1st, 1917, when First World War was at its worst, this marvellous piece of glass was finally brought up to Mount Wilson and the construction of the rest of the telescope could begin. First light was seen through the monstrous thing on November 2.

Hooker 100-inch reflecting telescope.
Mount Wilson Observatory, California

What's the big deal? you may ask.


WYSIWYG - what you see is what you get.

Galileo in his time was the first man on this planet to see the four biggest moons of Jupiter with his own eyes. Similarly, nobody on this planet had ever seen anything like what those guys saw who took photos of the night sky using the Hooker telescope up there on top of Mount Wilson.

You know, on October 5, 1923 Edwin Hubble was looking through Hooker at a cloud on the sky in the constellation of Andromeda and noticed a Cepheid variable star in it.

Imagine that!

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