Posts Tagged ‘George Ellery Hale’

Last Thursday (24th of October 2013) I gave a talk to Swansea Astronomical Society. This is the third year in a row that I have spoken in the autumn to this wonderfully active society on a historical theme. Two years ago I spoke about the early history of Yerkes Observatory (I blogged about that talk here), and last year I spoke about George Ellery Hale (my blog on that talk is here).

This year I continued the Hale theme, speaking about the history of Mount Wilson Observatory, which Hale established in 1904 after resigning as Director of Yerkes Observatory. Mount Wilson Observatory is most famous of course for its 100-inch telescope, the telescope used by Hubble (and Humason) to discover that the Universe is expanding. The Observatory is located just outside Los Angeles, and despite the light pollution of LA, it is still a very active observatory. This is mainly due its exceptionally stable air, giving it image quality better than pretty much any other observatory in the continental USA.

My connection with Mount Wilson Observatory is not as strong as my connection with Yerkes, but I was lucky enough to be awarded a Mount Wilson Fellowship in late 1999 and so went to use the famous 100-inch on four separate observing runs in 1999/2000. I was using an adaptive optics system, the plan was to study in unprecedented detail the structure of the scattering of visible light from dust grains in reflection nebulae. Unfortunately we were not able to use the AO system to do this work, as the central stars illuminating the reflection nebulae were too far from the dust regions we wanted to study for the AO system to work. In addition, our primary target, NGC 7023, is located at too high a declination for the 100-inch with its yolk mount to be able to reach. I thus undertook an alternative observing programme of observing close binary star systems to determine their orbital properties, systems which were too close to be resolved with conventional telescopes not using an AO system.

During all of these four observing runs I do not remember seeing the stars twinkle when it was clear (which it was most nights), which is testimony to the incredible seeing the Observatory enjoys. Even way down towards the horizon, the stars remained rock steady to the naked eye. It is because of this exceptional seeing that Mount Wilson was the testing ground for Adaptive Optics systems, and is now the testing ground for optical interferometry, with projects like the CHARA project run by Georgia State University (see this link for more information).

Here are the slides from my talk. I hope you enjoy them, and of course if you have any questions please feel free to ask in the comments section.

Here is a video of my talk. Apologies for the quality.


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In November of last year (2011), I have a talk to Swansea Astronomical Society on the early history of Yerkes Observatory. I blogged about that talk here.

Last night (Thursday 8th of November) I gave a talk to the same society with the title “ George Ellery Hale : The greatest Astronomer of the 20th Century?“. The title is deliberately provocative. In the talk I attempted to show Hale‘s main achievements in his productive life. There were many, but this slide summarises the main ones :

A summary of Hale’s main achievements in his astronomical career

Here is a gallery of all the 32 slides in the talk.

My conclusion, in the last slide, is that maybe Hale wasn’t the greatest astronomer of the 20th Century, but probably the most important. Without Hale, Yerkes Observatory would never have existed, nor Mount Wilson Observatory.

Who do you think was the greatest astronomer of the 20th Century?

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Last Thursday (10th of November) I gave a talk to Swansea Astronomical Society. This is the 3rd or 4th time I have talked to them, and I was asked by Dr. Steve Wainwright to talk about the early history of the Universty of Chicago‘s Yerkes Observatory.


The great 40-inch refractor at Yerkes Observatory

I worked at Yerkes from 1995 to 2001, during my time there as a post-doctoral researcher I worked with Professor Al Harper on Airborne astronomy, initially on the Kuiper Airborne Observatory. In 1997 I started working on the HAWC far-infrared instrument for the Stratospheric Observatory For Infrared Astronomy (SOFIA). I feel very privileged to have worked at such an amazing place, so steeped in the history and development of 20th Century astrophysics.

Yerkes Observatory, which was founded by the University of Chicago, was home to the World’s largest telescope when it opened in 1897. This is the famous 40-inch refractor, which is still today the largest refracting (lens) telescope in the World. The Observatory gets its name from Charles Tyson Yerkes, the man who paid for the Observatory and the telescope. Its first Director was George Ellery Hale, a remarkable man who went on to establish Mount Wilson Observatory. I am giving a talk about Hale in a few months, so will write a longer blog about him then.

George Ellery Hale

George Ellery Hale as a young man

Hale left Yerkes in 1903 to try to set up Mount Wilson Observatory. Initially he wanted the University of Chicago to establish it as a remote observing station, but they refused. So, he resigned his position and struck out on his own. Mount Wilson became the premier observing site in the World for the best part of 50 years, being home to the 60-inch and then the 100-inch telescopes. It was the 100-inch which Edwin Hubble (who did his PhD at Yerkes in 1919) used to show in 1923 that the Andromeda Nebula was external to our Milky Way galaxy, and in 1929 that the Universe was expanding.

My talk was on the early history of Yerkes, from 1891 to 1903. I stopped at 1903 as this is when Hale left to establish Mount Wilson. I chart the appointment of Hale as Associate Professor of Astro-physics at the University of Chicago by its first President William Rainey Harper, the meetings they had with Yerkes to persuade him to fund the building of the Observatory and its massive telescope, and the trials and tribulations in bringing the dream to fruition.

Here is the first few minutes of my talk – filmed by my daughter Esyllt.

Here is a link to a PDF file of the slides I presented. There are 46 slides in the presentation, but many of them are just photographs from the Observatory’s early days.

I will also try and put them up as a slideshow, but so far I have not had much success in getting this to work on my blog.

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