'Invention that Will Change Astronomy'

That's fascinating, Richard! Thank you so much for posting this.

There are a couple of people at the Observatory that I will email in the hope that they can point you in the right direction.

Good luck with your book!

Andy Sawers

Chair, Flamsteed Astronomy Society

Thanks Andy. I appreciate your offer to email 'a couple of people at the Observatory' and hope they can tell me if Arnold Tustin's invention was successful or not.

Fingers crossed!

I've just checked and see that the article appeared in the Birmingham Gazette on 3 Feb 1950, and not in 1959. as I incorrectly said

Success!!! Richard, I've received the following reply from Tom Kerss, one of the astronomers at the Observatory and an expert astrophotographer…..

I read about this in a book published in the 80s called ‘History of Astronomy Technology’ or something. I’m afraid it was almost 10 years ago that I stumbled on it, but yes it does appear that the first Active Optics system was invented in the UK and piloted at RGO. Sadly this is a very poorly told story, so I’m glad you are trying to bring it to light!

I would suggest getting in touch with Gerry Gilmore at IoA to see if he can illuminate the details: https://www.ast.cam.ac.uk/~gil/

Gerry is a true legend in this area, and has been involved in the development of the most accurate optical systems ever created (notably Gaia’s interferometry bench and the VLT/E-ELT)

By the way, the last paragraph in the article is quite prophetic. Early Active Optics system worked by moving a small optical window near focus. Since then the design has evolved into what we would now call Adaptive Optics, and it is indeed used all over the world by the most powerful ground-based telescopes!

Clear skies,

Tom Kerss
P.S. Say hello to Gerry from all of us at the ROG!

Thanks Andy. That's great to hear! I'll contact Gerry Gilmore at IOE via the above link and report back to you on his response, assuming I get one. Meanwhile, let me know if you receive further information on this topic.

Richard

Hi Andy,

I said I'd report back on Gerry Gilmore's response. He has kindly emailed me and says he has not been able to find out anything more. He added that:

'There is nothing recorded in any Adaptive Optics history book in our library. A good reference to the history of the INT is F Graham Smith and J Dudley, Journal for the History of Astronomy 13, 1, 19, 1982.'

Babcock's article does however make clear that the concept here - essentially fast-guiding - was used on telescopes in the 1930's.

I also checked with the surviving old hands involved with the early days of the INT. Nothing there. Except the delay in this reply.

They are adamant that there was no effort  involved in trying wavefront correction on the INT. Indeed the local image quality was so very poor none of the plausible seeing-correction systems would have worked very well. One gets better results by starting with already good conditions.

The only relevant experiment people recall is as follows (Richard Gregory was a very notable physics person at Bristol, with wide interests). "The only image sharpening I can remember is a programme with Richard Gregory which was a lucky imaging concept, using a beam splitter to send a fraction of the image through a photographic negative and then triggering a shutter with the amount of light that spilled around the edges of the black parts of the negative.  He had some success with a test programme with the 36 inch that I helped him with and went on to the INT."

So, this implies that my Great Uncle Arnold's gadget may not have been fitted to the INT telescope at Greenwich, or was perhaps not as effective as anticipated. The article I attached that mentions his  invention does seem curious however. I'm also left wondering about Tom Kerr saying that 'the first Active Optics system was invented in the UK and piloted at RGO', which I had rather hoped was true. He mentioned reading about it in 'a book published in the 80s called ‘History of Astronomy Technology’ or something', which is intriguing. Please pass this email on to him. I expect he'll be interested and may have further thoughts.

Richard

Many thanks, Richard, I will indeed pass this on!