Archive for the 'Bowen Island' Category

Reflections on the Dobsonian Telescope

Today I am remembering the great gift of astronomy that came to all of us from John Dobson, the inventor of the Dobsonian telescope. John died yesterday at the age of 98.

During my lifetime, one of the most profound developments in the technology of telescopes was made by John Dobson. In 1968 telescopes for non-professionals were either cheap and crummy, or precision optical and mechanical devices that were either very expensive, or required a sophisticated workshop to construct. Telescopes with a main lens that was more than 8 inches in diameter were almost too heavy for one person to carry, and they were beyond the means of most. Dobson changed all that.

John Dobson had a passion for showing people the sky. He founded the San Francisco Sidewalk Astronomers. And to see some of the great celestial celebrites, he realized observers needed a huge telescope. His discovery, and invention, was that if all you wanted to do was have an awesome nighttime view of galaxies, nebulae, and other wonders, you could strip away most of the technology that professional astronomers must have, and make a telescope with only a big glass lens and a few sheets of plywood. The cost was mainly that lens.

While I call this an advancement in technology, most of what he did was simplify the construction of a telescope, and re-think how it would be used. One of his (many) breakthrough discoveries had to do with the telescope bearings. He found that if the ‘scope moved by Teflon sliding on Formica, the coeficient of sliding friction was the same as the coeficient of starting friction. What that means is that if you have a telescope with no clock drive (to follow the stars), and had to push it by hand to keep the highly magnified target in the eyepiece, with Dobson’s bearings, the telescope would move smoothly and stop smoothly.

In 1985 a group of us build a Dob with a 17-1/2 inch mirror to be able to observe the return of Comet Halley. At the time, it was the largest telescope in Manitoba (in terms of the size of the lens). Here is the story of a group of us having our first glimpse of the Comet Halley. In the months that followed, thousands of people observed the comet with that telescope.

That Dobsonian telescope is now here on Bowen Island.

A group of people on Bowen Island observing Mars with the 17-12 inch Dobsonian telescope

A group of people on Bowen Island observing Mars with the 17-1/2 inch Dobsonian telescope

It’s beginning to look a lot like…

Garden Snowfall on Bowen Island I know it won’t last. What this tells me is that there is some new snow arriving high on the local mountains (where it will stay for a while). And someday soon I may be able to ski the backcountry.

Amanita Muscaria spotted on Sunday

Amanita Muscaria family at 2310 ft elevation on Mt. Gardner, Bowen Island

Amanita Muscaria family at 2310 ft elevation on Mt. Gardner, Bowen Island

Howe Sound Fog Lifting

Before sunset the fog was lifting on Howe Sound

Before sunset the fog was lifting on Howe Sound

Even when it is not foggy at the house, which is a 300 feet, I know when there is a fog bank on the Sound. I hear the ferry horns bellowing. This afternoon the fog seemed to be clearing so, for exercise, I walked down to the beach.


Here on Bowen Island, on Canada’s wet west coast, we expect some rain in September. Last year during September we had only a trace of precipitation. Today, as I write this entry, we are having a downpour.

Cheap easy compost bin

In Winnipeg we had a large vegetable garden, and I maintained three big compost piles. They were really cheap and easy: for each I’d buy 18 feet of 4-foot welded stucco wire and form a cylinder with it. That’s all I did — other than throw compostables into it. The compost was turned once/year, if that. It made lots of great compost.

That design failed here on Bowen Island. The deer think that my compost pile is their dining room table, and they stamp down the sides to access their meal. I see many elegant compost bins that either use lots of plastic, or require many hours of carpentry. We are talking about the recycling of waste, not constucting a family heirloom. So, here is what I am trying now. (This is what I made today.)

Sketchup 2x2 cedar for frame of composter

The frame will be 2″x2″x4′ cedar connected with galvanized carriage bolts. Diagram made with Sketchup. It will support 18′ of stucco wire

Completed Compost Bin

This is the completed compost bin.

The stucco wire is attached to the frame with stainless wire. I will use more before it is deployed. The front is on the left, and can be removed by taking off 2 nuts & washers. In a year or so, I’ll let you know how it works. If it does, I’ll make more. It is very big… I might try something smaller.

Thunderstorm over Bowen Island

If you enjoy the pyrotechnics of a thunder storm, the event on the evening of August 29, 2013 was the most dramatic I’ve seen since I left Winnipeg in 1990. Here is a 20 minute stereo recording of the event. To experience it fully, play it at high volume with some good speakers.

For the record, here is how the storm appeared on local weather radar.

That weather information is available at Ballantyne Mountain Weather Resources.

The audio file is posted to I recorded it in stereo with a Zoom H1, mp3 128kbps with a ‘dead cat’ wind screen. I was on a dome of land called Millers Landing on Bowen Island. The recorder is facing North. Mt. Collins is on my left, and across Howe Sound are the mile high hills that form the east wall of this fjord. I suspect that the hills form part of the soundscape. The line of clouds that made this storm ran from North to South and were moving eastward. Play this at high volume to experience the event.

Robert's professional sites:
Ballantyne and Associates

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