Amateur Telescope Making’s Bright Future

by Mel Bartels

The best prediction of future weather is today’s weather. ATM weather locally and globally looks sunny. In Oregon cities, astronomy clubs are on par with other clubs - club membership ratio to general population is perhaps 1 to 5,000. Mirror making classes are more popular than ever - attendees regularly include high school students, a few of which complete large mirrors up to 16 inches. Oregon Star Party telescope walkabout participants include young new members showing off their just finished in time for the star party telescopes. Globally there’s a good deal of ATM activity in Europe. In fact, the French, German and Spanish amateurs are leading the way in aperture, speed and portability.

The Apollo bubble ended two decades ago. One of the greatest, if not the greatest achievement of mankind, it sparked a titanic interest in astronomy and telescopes. Short spikes occurred during Halley’s Comet and the Mars opposition shortly after. Any downside from the passing of the Apollo bubble has long since passed. It’s high time that we stop lamenting its passing and looking down on newbies with stories of how special we once were.

People grow up slower and take longer to acquire money to fund hobbies.  Taking this into account, I do not see a change in demographics of ATMers. I do see a marked change in how younger ATMers access information. I can’t recall the last time a budding mirror maker said that they read one of the reference books on telescope making. Instead, information is sucked up from YouTube and online discussion groups. Books, magazines and other traditional media are fading while social networking is increasing.

We don’t live in an era of information overload; we live in an era of trivially acquired information. Information access is overwhelming easy but trivial access comes at the expense of being stripped of context, the hard won experience and the qualifiers. Sifting through information is low commitment while learning through experience is high commitment. Low commitment information is quickly consumed and discarded because of the lack of meaning and context. We are poor consumers of low commitment information: we retain and process it less well than we believe. Further, the relationship between facts and the physical world is missing. Tacit knowledge and wisdom and original thinking are as hard to acquire as ever.

When we lived in an oral culture, memory was prized. When books appeared, prophets foretold the end of wisdom. When television appeared, the ritual was repeated. Originally knowledge expanded at the rate that people walked. Then at the speed of horses. Knowledge began traveling at the speed of railroads, then wireless. Previous generations faced increased knowledge and faster rates of dissemination. Today we are in the midst of yet another transformation. Intelligence and skill is increasingly judged on the ability to quickly search vast information repositories in order to create contextual tacit knowledge. This takes high commitment. As a deeply satisfying activity involving our brains and tool making, ATM’ing will continue to be a high commitment hobby. 

The night sky is disappearing. The severe impact of light pollution on amateur telescope making is sadly outweighed by its  impact on culture and on our health. One-fifth of the Earth's population has lost sight of the Milky Way. In the USA two-thirds can no longer see the night sky. Worse, latest studies find a correlation between light pollution and cancer. And it's devastating for birds and insects. Some gentle tapping of the brakes on this headfirst plunge are being applied, but people won't miss what they can't see. Of all the factors considered here, the fortunes of amateur telescope making seem most directly tied to light pollution.

The Dobsonian: a tale of reverse innovation and disruptive technology.
Reverse innovation is the process of creating low cost simplified products in a resource starved environment informed by high end products and then making these low cost products available in the high end market. A prominent early practitioner was John Dobson who created a low-tech, high-tech telescope designed from recycled material. His reverse innovation was a classic case of disruptive technology because his design for sidewalk astronomy was co-opted by the larger ATM community.

The Dobsonian telescope could have been invented three decades earlier. Amateurs living in the resource rich world thought of improving their technologies, not starting over using only meager resources. It took John's genius and perseverance and his ascetic lifestyle to turn upside down the world of the amateur telescope maker.

I remember a note in Sky and Telescope magazine from the late 1960's mentioning John Dobson's 24 inch at the Riverside Telescope Makers Conference. This scope was so much larger than the amateur scopes of its era. Surely it would have garnered an exclamation point or two if it was for real? Consequently I didn't think about the matter again until that breakthrough article in Sky and Telescope's Jan '73 article by Lee McDonald. McDonald spoke in measured yet breathtaking phrases about the Sidewalk Astronomers and Dobson's 24". Seeing pictures of the 24" coupled with mention of Lord Ross and a description of observing the Corona Borealis Galaxy Cluster seared my mind. The circle was completed in 1980 when I observed through Dobson's 24 inch at Crater Lake. The views were everything that Lee said they were. Within months I was building my own 24 inch: I never looked back.

McDonald describes the essential feature of Dobson's telescopes as thin plate glass mirrors held in slings which succeeds because of the altazimuth mounting. The core reverse innovation was salvaging portholes from WWII era ships. Dobson taught himself how to figure the thin plate glass using the star test: both quite unconventional. I regard his star testing methods as reverse innovation because he resuscitated a testing method first described by John Hadley two centuries ago, using it to test very large optics. He mounted his mirrors in a sling and choose an altazimuth mounting to keep the sling properly oriented. His final reverse innovation was to use Teflon to build sticky bearings, where the scope stayed pointed after letting go. Altazimuth mounts all used clamps to lock down the telescope once the object was acquired: a frustrating exercise in watching the object jump out of position as the clamp was tightened, then repeating the ordeal a few moments later when the object drifted too far afield.

Though it took years for the amateur telescope making community to create sufficient domain knowledge (Dobson's telescopes violated most every rule of thumb of telescope making), amateurs were quick to try new ideas: Pyrex mirrors figured by other than glints off of telescope poles, truss systems for Sonotube, rack and pinion focusers for sliders, ventilated mirror cells for Dobson's closed hinged back plates, thin vaned spiders for wooden vanes and computer control to bring back motorized tracking. Today's Dobsonian bears little resemblance to John's telescopes. In fact, many amateurs think a Dobsonian is about the mount, having forgotten about the porthole plate glass mirrors that were replaced with precision Pyrex decades ago.

Further, the original purpose of John's telescopes of  bringing the universe to the public was co-opted by amateur astronomers for their own deep sky observing enjoyment. This is a well known story in the world of invention and product development. See the book, "The Myths of Innovation" for a good exposition of this view. Consequently, I cannot talk about the Dobsonian telescope for very long without weaving in the story of the Sidewalk Astronomers.

The longevity of the Dobsonian speaks to its success in bringing big aperture along with tolerant and easy to build mounts to the amateur astronomical community. The impact on telescope making is clear: telescopes are evolving. They are becoming simpler, more direct, higher quality and more delightful to use. The state of the art Dobsonian is the simplest and most dazzling design yet. The quality and size of the optics and the ease of transporting the telescope to dark skies means the greatest observing experience in human history. 

An amateur creating a new telescope design has a formidable threshold to overcome: delighting and turning the heads of Dobsonianites. It's not sufficient that a superior optical design is developed: it has to be better than the Dobsonian from the viewpoint of comprehension, observing results, utility and cost to build. The alternative is to continue to innovate within the Dobsonian design.

ATM’s future will be the intersection of cultural with technical forces and what we make of it all.  Nothing’s set irrevocably. Those that grok reverse innovation and are willing to learn with high commitment just might lead us into an even more wonderful era.

Mel Bartels, Feb 2011