An interview with John Dobson
John Dobson, creator of the Dobsonian telescope, passed away on 15 January 2014
The renowned telescope maker passed away on 15 January 2014
John Dobson, creator of the Dobsonian telescope and lifelong advocate of public astronomy, sadly passed away on 15 January 2014.
Before Dobson, serious deep-sky observing was only for professional astronomers. But in 1956 he revolutionised amateur astronomy by hand-building a powerful telescope out of nothing more than scrap materials – the world’s first Dobsonian.
Then in 1968, Dobson founded The Sidewalk Astronomers. His idea was to bring astronomy to the streets so that interested passers-by could look through a telescope. Along the way, he passed on his knowledge and passion, and can now be credited with inspiring a future generation of telescope builders and sky-watchers. We were lucky enough to meet and interview the great man back in 2006.
Why are you sometimes called the ‘MacGyver of astronomy’?
MacGyver [from the American TV series] always finds himself in a pickle and he finds a way out of it with what’s available to him. So people call me the ‘MacGyver of astronomy’ because I make telescopes out of what’s available. I use cardboard tubes made for pouring cement columns as telescope tubes, and I make mirrors from porthole glass – I’ve got 4.5 tonnes of ship windows. This is junk! So MacGyver means to make-do – I’m a make-do astronomer.
What originally motivated you to build your own telescope?
I wanted to see what the Universe looked like and I had only used a little refractor before I built my own. So I built a 12-inch Dobsonian, which was about 7.5ft long – now that’s a good size for a telescope and you can see just about everything with it.
Is it true you built it in a monastery?
Yes, when I was a monk [in the Vedanta Monastery in San Francisco] a friend told me you could grind your own glass. I said “you’re nuts”, I didn’t believe him, but he showed me you really could. A friend of ours had a sheet of glass on his kitchen table and we decided to make a mirror with it. We needed another piece of glass to grind it against, which we got from a marine salvage shop down the street for $5.
How did you come up with the design for the Dobsonian telescope?
The telescopes that people were using were tiny ones set up for photography. When you’re doing photography you need to track objects across the sky, and so you need a motor. I wasn’t interested in photography; I’ve never had a camera in my life. So I just made a telescope that moved up and down, and left and right. I just wanted to be able to see the sky and aim it anywhere above the horizon. You can run a bigger telescope without all of the machinery needed for photography; if you had all that machinery on a 12-incher it would be an observatory.
Why do you think no-one thought of the Dobsonian design before you?
They were too busy taking pictures. Their telescopes were so tiny that they weren’t very good for seeing galaxies with their own eyes, so they took pictures and looked at them in the daytime. In the daytime they can see them with their cone cells [cells in the eye that function best in bright light]. Now that’s cheating – nobody ever saw a galaxy with his cone cells, you see them with your rod cells [responsible for night vision]. If I want a picture I buy it from an observatory.
Was your telescope-making encouraged within the monastery?
No, because it wasn’t part of our curriculum. When I was in Sacramento building a retreat, I even came up with a code to talk to my friends at the main monastery in San Francisco about it. A telescope was called a geranium, and if it was a 12-inch telescope you would say you had a 12-inch geranium. If you said it had been potted, it meant the telescope had been put in the tube and in the rocker. If it had been aluminised or silvered, it was said to be in bloom. So if I said I’ve got a 12-inch, potted geranium in bloom, they knew I had a finished telescope.
Why did you leave the monastery in 1967 after 23 years of being a monk?
I was asked to leave the monastery, and that whole thing was an accident. I was weeding plants next to the monastery wall and a man was asked to look for me. He couldn’t find me and so he reported that I was missing, but I wasn’t. So I was asked to leave.
How did the Dobsonian become commercially successful?
Jim Braginton, who ran Coulter Optics, looked through a 24-incher on the top of a mountain in California, and thought ‘if he can do it, I can do it’. He started selling Dobsonian telescopes, and modelled them on my 24-incher. I don’t get royalties or anything like that, but he always treated me very well.
How did The Sidewalk Astronomers come about?
There was a nine-year-old boy who made a telescope with me. It was a big telescope, 7.5ft long with a 10.5-inch diameter mirror. His mother called me and said he needed someone to talk to about astronomy and telescope making, as the San Francisco astronomy club wouldn’t let him join until he was 14. He was five years too young to join the club, even though he had a bigger telescope than they did. So we talked it over and decided that we should start a club, and that’s how The Sidewalk Astronomers was started. To begin with there were only three members, and we got two telescopes out on the sidewalk every clear night. It was known all over the San Francisco Bay area that if you wanted to look through a telescope, you went to Jackson and Broderick streets on a clear night. The Sidewalk Astronomers has grown a lot bigger since then.
Why did you bring astronomy to the streets?
The public needs to know where they were born. People think they were born in the city, but they were actually born in the Universe. Most people have never even seen the Moon through a telescope and they are shocked when they see it so close up.
What do you think about theories of how the Universe was created?
I’m allergic to the Big Bang theory. They get the whole Universe from nothing – how likely is that? The Big Bang people have all kinds of trouble with their model, and so they change the physics to clean it up – ‘oh there’s dark matter’. And then they see the expansion of the Universe seems to be speeding up and so they invent dark energy to explain that. These are just inventions to patch the model.
This article first appeared in the December 2006 issue of BBC Sky at Night Magazine.