Think the Dobsonian revolution could happen again?

Mel Bartels, Jan 2014


Before the revolution amateurs had small reflectors and refractors on shaky equatorial mounts. Star atlases were limited and observing manuals few and far between, listing only a handful of objects. After the revolution amateurs peered into large aperture altazimuth reflectors using a plethora of observing manuals and atlases.

How did this revolution come about?

John Dobson in the 1950’s and ‘60’s had a vision: show the public the skies. He called it Sidewalk Astronomy. People should see and understand the universe that they inhabit - all the people of Earth. What were his requirements and their solutions?

   1. Bright views at the eyepiece with large aperture.
   2. Easy to transport telescopes that had to be simple, rugged.
   3. The telescope must be easy to setup: no tricky adjustments (push-pull adjustments and movements only).
   4. And the telescope has to be easy to use. This means no tracking because the viewing time is relatively short at the eyepiece as the public shuffles through.
   5. Finally the telescope should be assembled from inexpensive low precision parts, recycled if possible.

To accomplish his vision, John invented a new telescope. Named by others the Dobsonian, the telescope could have been invented immediately after WWII, even before, but wasn’t.

Think of it: the Dobsonian revolution could have happened 20, even 30 years earlier. Or could it have? Did the thinking of that era preclude such a telescope? Or was the idea simply waiting there, decade after decade, waiting for the right person to champion it?

John used parts that he could find; as a monk living in a monastery he had no money. He found porthole glass from salvaged ships, remnant wood and surplus binocular eyepieces. John largely ignored existing telescope designs, no doubt finding them unsuited because of their small aperture, expense and many adjustments. Telescopes of that era were also rather shaky at the eyepiece and took a great time of time to setup and cool down, not to mention being rather heavy.

Others joined in leading to the formation of the San Francisco Sidewalk Astronomers. This greatly multiplied Dobson’s efforts and spread the word to amateur telescope makers.

It’s fair to say that John was taken aback by the established experts’ rejection. They didn’t see the compelling vision; in particular, the lack of tracking was judged crippling. Recycled and non-precision parts went against thinking of the day (more engineering is better, inspired by the Space Race to the Moon). It didn’t help that John Dobson and some of his followers were counter culture; in the 1960’s they and their ideas were suspect. Suspicion was cemented by John’s psychedelic paint schemes.

But the vision was too compelling to be ignored. Starting at the Riverside Telescope Makers Conference, and ending up with myriad articles in Telescope Making and Astronomy magazine written by new group members and students, the revolution become an irresistible force. Vive la révolution!

It wasn’t long before commercial interests took note of the compelling big aperture views. Coulter, Star Optics and others that came and went brought the Dobsonian design to market.

The knock-on effects cannot be underestimated.

   1. Big views begged for big eyepieces: Al Nagler had the answer with their astonishing unheard of 80 degree apparent field of view eyepiece (an innovation in its own right).
   2. Larger scopes needed to be faster for convenience, eventually leading to the coma corrector and focal ratios plunging from f7 to f4 to f3.
   3. Better star charts and object lists and manuals proliferated.
   4. Star parties grew in popularity, littered by Dobsonian telescopes.
   5. A new community of makers and observers joined the hobby.

Refinements in the design have transformed John Dobson’s original telescopes into modern telescopes that bare hardly any resemblance.

   1. Truss tubes replaced the cardboard Sonotube.
   2. Pyrex took over for WWII plate glass portholes.
   3. Computerized tracking and equatorial platforms appeared.
   4. Minimalist, ultralight and folding designs brought more aperture and one person transportability.

Can it happen again?

If the Dobsonian idea could have been developed decades earlier, is the next revolutionary idea already out there, waiting for its champion?

Do you have a compelling idea that amateurs will find irresistible? Have you worked up an unusual design, maybe even built a telescope or two based on this design?

Have you ruthlessly stripped your idea down to its bare essentials, sharpening the compelling idea, discarding any and all items and accessories that burden and obscure?

Willing to build a community of early adopters?

Willing to commercialize the product?

What are you waiting for?

 EOD