CHRISTMAS 2002 This year I would like to tell you about my ventures into astronomy. When Robin was in sixth grade Erlys met another mother at a PTA meeting. The woman said that her son was interested in astronomy and was eager to make an astronomical telescope but her husband lacked knowledge to help him. Erlys spoke up and said that she knew that I would be willing to help him build a telescope. Later that evening she told me what she had said. When I told her that I had no knowledge in this field she said that Michael was so enthusiastic that surely I would help him. The next afternoon when I got home from work I had an 11-year old boy waiting for me. He had brought a catalog describing a telescope making kit. His kit would consist of a heavy piece of Pyrex glass, 6" in diameter and about 1-1/2" thick for the main reflector, another piece of plain glass 6" in diameter and about 1" thick for a grinding tool, and maybe 8 kinds of abrasive for hollowing out the Pyrex and then polishing it. The next day Michael put in an order for the kit and I stopped in at the optics lab at NASA to see what I had gotten myself into. They laughed and told me that I had a lot of learning ahead of me. On later reflection I decided that this was an understatement. They told me to study 3 hardbound volumes put out by the Scientific American entitled, Amateur Telescope Making, and another thick book, entitled Standard Handbook for Telescope Making. For the next several weeks while awaiting the delivery of the kit I spent every evening and most of Saturdays and Sundays studying the books. This is what I learned.
Success would depend on making a precise, concave mirror from the Pyrex blank. You start by erecting a post about table height and then nailing on it a piece of wood with cleats on its edges so it will hold the Pyrex securely. Now you are ready to start the process of making the mirror. You begin by sprinkling some water on the Pyrex, add a pinch of the coarsest abrasive and then you cover this with the glass disc. Now you are ready to begin work. You rub the glass back and forth over the top of the Pyrex, all the while walking slowly around the post. The glass disc needs to overhang the Pyrex one quarter of its diameter on each stroke. The object is to grind a concave cavity in the Pyrex, as it might look if it were made of soft wax instead of glass and you pressed a basketball into it. The actual hollow needs to be about the thickness of a penny at its center. But this depth needs to be accurate to a fraction of the thickness of a human hair. Michael and I took turns walking in circles for many evenings, perhaps a total of 8 hours, before removing the Pyrex for its first test. The final surface must be parabolic and smooth within 3 millionths of an inch, one thousand times smaller than a human hair. This is far beyond the limits of accuracy of mechanical measuring instruments; instead you must use an optical setup that was invented by a Frenchman named Foucault in 1840. As you might imagine we were miles off and went back to grinding for many evenings before the next test. After maybe 6 extended periods of evening grinding we got in the ballpark. Another 4 secessions and we were getting close enough to use a finer grade of abrasive and were making Foucault measurements each hour. The final polishing was done with rouge (iron oxide). The books warned us that while this stuff is harmless if ingested, it makes a permanent, conspicuous stain on clothes. We did the rouge grinding wearing throwaway clothes. The only problem arose because we took a cocoa-and-graham-cracker break in the middle of each evening. This resulted in permanent red stains on wash cloths, towels and worse, walls and chair cushions. Later I thought about the red stains. In flea markets you sometimes see vendors pitching their carpet cleaning solutions. They have a piece of clean carpet on which they smear some sticky black substance. Then they rub in some of their patented solution and voila, the carpet is again clean. Now if they were to permit me to substitute some rouge... The remainder of the telescope offered only normal problems, and all of these seemed trivial compared to the mirror grinding. With the telescope project over I thought that would end my ventures in astronomy. I was wrong.
Dad had always been interested in astronomy. He bought himself an astronomical telescope and joined the Peninsula Astronomical Society. The group was made up of a professor from Stanford and maybe 25 others, mainly retired professionals. They welcomed him into their group, saying that he was a gift from heaven. One of their members had a beautiful piece of property a few hundred feet below Skyline Highway on the ocean side. He donated an acre or so at the best spot for an observatory. From an astronomer's viewpoint this was close to heaven as anyone on earth would get. It was shielded from the night light of the bay area, smog free and high enough to always be above the fog around the ocean shore. Another member had offered to permanently install his huge 12" Newtonian telescope in the observatory. They had made plans to build a smaller version of the big observatories, with a concrete floor and pier for the telescope and cylindrical walls of concrete blocks. Their plans called for a rotating hemispherical roof with a hatch that could be opened for the telescope. No one in the group had the necessary experience to do the concrete and masonry work so the project was dormant until dad appeared. With his direction and largely his labor the floor was poured and the concrete blocks were laid but not grouted. At this point dad died. The project stopped. Months later I attended one of their meetings and said that it is a matter of family honor for me to finish the work that dad had started. They were overjoyed. They said that if I were to lead them they would provide the manual labor. I remembered dad complaining to me that typical of a club they were largely accomplished talkers but few doers. I inspected the site and decided that the first thing we would need is electric power; to get this we would need approval and building permits from the largely rural Monterey county. A delegation was elected to go to the county offices and apply. When they said that they wanted to build an astronomical observatory the clerk said that they didn't have any requirements on file for such land use so he couldn't proceed. One of our delegates thought quickly and replied that we knew all about observatories and would be happy to help the county by writing the requirements and restrictions. Their offer was accepted. They described what they had written at the next meeting. One of the problems that observatories have is the interference from lights from buildings. They wrote restrictions for surrounding landowners, such that no building within a mile was to have light showing at night brighter than Betelgeuse, the brightest star in the sky. A few years later the University of California decided to give up Lick Observatory on top of Mt. Hamilton because of the interference from lights in San Jose. They chose a plot of land in Monterey County. When they applied for permits they were shocked when the clerk of this rural area pulled out requirements and restrictions for observatories.
On the first Saturday work party I filled the hollows in the walls with mortar. I stood on a ladder within the walls and one of the members, the professor, stood on a ladder outside at the same spot. My job was to direct the mortar within the cavities with my trowel. I was wearing carpenter's overalls over my clothing. Someone handed the professor a heavy bucket of mortar. He poured the whole bucket with one quick motion, overshooting the wall. The mortar poured over me, much of it going between my overalls and my clothing. All we had on the job was a broom with which a futile attempt was made to brush the mortar from my clothes. After this first session of hard labor the Saturday turnouts diminished. I remembered dad's comment about talkers and doers. I had to do most of the remaining work by myself with help from Michael and my daughters.