OASI: John Dobson

John Dobson, inventor of the Dobsonian telescope mount, honoured OASI with a visit to Orwell Park Observatory on Sunday 29 September 2002. In late September 2002, he had begun a "world/whirlwind tour" starting in the Eastern Russian town of Irkhutsk (near the Chinese border) and ending at the Whirlpool Star Party, Ireland one week later. During the tour, he stayed largely with amateur astronomers and his closing comment at the Whirlpool Star Party echoed his heartfelt thanks to all those amateur astronomers who helped me get here! Neil Parker and Lesley Vertue from the Green Witch Astronomy Centre in Cambridge hosted John during the English leg of his tour and, while hosting him, contacted Pete Richards regarding a visit to Orwell Park Observatory.

The lure of meeting John Dobson could not be missed and we were delighted to accommodate a visit at very short notice! On Sunday 29 September 2002, Pete called to advise that Neil, Lesley and John had set off from Huntingdon and were due to arrive at Orwell Park about 4.45pm. I packed everything I could think of into the car and set off for the observatory. The visitors arrived on time.

Despite being aged 87, John is fully mobile: he had no difficulty whatsoever in ascending the observatory stairs, even counting them (111 in total) on the way! He comes across as a humble man, approachable, a mystic, an environmentalist, an eccentric with a great sense of humour, but also a pragmatist with strong views on what is right and wrong including what makes telescopes work at their best. His mission is to make astronomy as accessible as possible to the general public, particularly the younger generation who can't afford expensive instruments. Scrap and recycled materials are used as much as possible in his telescopes. At the same time, he is passionate about raising the profile of global threats such as asteroid impacts to the general public and is clearly frustrated by the lack of funding from governments and agencies across the world to address such risks.

John's tour of Orwell Park Observatory started in the belvedere with the history of the observatory then moved upstairs to the equatorial room to inspect the Tomline Refractor and transit instrument. Thanks to Pete for an excellent exposition of the history of the observatory! John took a keen interest in the observatory and instruments, listening attentively and interposing many questions and comments. I learned that the mirror of the Mount Palomar 5 m instrument was made from "French wine bottles". And also that John regularly sleeps in his telescope tubes! In fact the 45 cm instrument that he regularly carts around the USA, and which has covered 150,000 km already, has slept three people on more than one occasion. In John's words: the neatest thing about sleeping in a telescope is that you can't roll out of bed!

When told about the OASI Millennium Telescope project, John's first question was What's the focal ratio? On being told F/4.5, he looked slightly quizzical for a moment then said That's too short! His preference is for much longer focal ratios as they provide higher contrast images at higher magnifications than shorter focal length equivalents and this can aid viewing some of the less diffuse deep sky objects which is why the refractor people got it right. However he acknowledged that our 48 cm F/4.5 telescope will be over two metres tall so that a longer focal ratio would be problematic!

After we had descended the stairs from the observatory and were walking around the grounds, John suddenly displayed an interest in the "bush tucker" to hand. Perhaps this reflects the days when he was a monastery gardener. The conversation went something like this...

At this point, almost before anyone else could speak, John disappeared into a clearing behind the tree and started picking and eating yew berries and spitting out the odd stone or two.

I tried a yew berry myself and found it to have a strong sweet flavour but I can't see them appearing in Delia Smith's Summer Pudding for quite some time! John also admitted having a liking for nightshade berries. Surely not deadly nightshade? I enquired. Well, I don't know of that particular variety! John responded.

In the belvedere discussing the history of Orwell Park.

In the belvedere discussing the link between the observatory and Sir G B Airy.

In the belvedere examining the 250 mm Dobsonian reflector.

In the equatorial room.

Examining yew berries in the grounds of Orwell Park.

Biography of John Dobson

John Dobson was born in China in 1915 to missionary parents. His family returned to San Francisco in 1927 and he attended Lowell High School and later the University of California at Bezzerkly (his term for Berkeley) to study biochemistry. Displaying the traits described above at a young age, he rejected conventional institutions and joined the Carol Beals dance group! However, a lecture by Swami (chief monk) Ashokananda changed his mind, igniting his interest in astronomy and cosmology and sending him on a lifetime quest to establish the reality behind the universe. The Swami advised returning to school to gain qualifications and, in 1943, John graduated with degrees in chemistry and mathematics. Shortly afterwards, he found work at Berkeley, later transferring to Caltech then the Berkeley Radiation Laboratory.

However, the lure of astronomy was never far away. In 1944, John quit his job and entered the Vedanta monastery as a monk of the Ramakrishna order. At the monastery, Swami Ashokananda assigned him the task of uniting the ancient thinking of India with atomic physics and astronomy, the sciences that deal most closely with the "first cause" of the universe!

In 1956, whilst at the monastery, John built his first telescope. The mirror was made from a 30 cm disk of porthole glass using the instructions found in Allyn Thompson's book Making Your Own Telescope. The sight of the Moon through this instrument helped John to decide that everyone in the world had to see the heavens through a telescope. In 1958, John was transferred to the Vedanta Society's monastery in Sacramento where he served as gardener and surreptitiously built instruments with cardboard hose-reel barrels and porthole glass mirrors. At night, he trundled the instruments on wagon wheels around the neighbourhood of the monastery and taught local children how to build telescopes. But monastery rules forbade leaving the monastery grounds without permission and, in 1967, after 23 years as a monk, John was expelled. At the time, he had constructed fifteen 30 cm and two 45 cm telescopes from salvaged junk.

On his own again, John returned to San Francisco. On every clear night, he rolled his 30 cm "Stellartrope" to the corner of Jackson and Broderick Streets and showed the heavens to anyone who would look. One of the thousands of passers-by realised that John could teach others how to make telescopes and arranged for him to begin teaching telescope making and astronomy, initially at the Jewish Community Center and later at the Lawrence Hall of Science and the California Academy of Sciences.

The following year, two of John's friends insisted that he join them in forming a club to be named the San Francisco Sidewalk Astronomers. The club met at Jackson and Broderick Streets, on the sidewalk (American term for pavement), and brought telescopes for public stargazing. Among the telescopes were Cyclops (40 cm aperture) and The Little One, one of his original 45 cm instruments from Sacramento. During the 1970s and 1980s, the Sidewalk Astronomers toured national parks in the West, showing tens of thousands of people the sights of the universe.

Dennis di Cicco had seen John's large telescopes at the 1978 Riverside Telescope Makers Conference, and had been so impressed that he based a 40 cm telescope on John's ideas and exhibited it at Stellarphane. Richard Berry, the editor of Telescope Making, saw di Cicco's telescope and that autumn re-mounted his own 31 cm F/7 Newtonian on an alt-azimuth mount. Although neither of these telescopes was a true Dobsonian, they confirmed to Berry that John's concept worked for large instruments.

After another decade passed, the Dobsonian design finally received nation-wide exposure with two short articles in the newly founded American magazine, Telescope Making. It became ever more popular and the rest, as they say, is history....