Hey, I figured Something Out!

No; don’t laugh. I don’t mean I figured out how to tie my shoe or hit a forehand. I mean I think I discovered something that no one has though of before. At least, I’ve read a lot on this subject and I’ve never seen this mentioned by anyone else.

As you know from a previous post, I make telescopes. Because of the sensitivity of the particular lens I used for this one, I made both the objective mounting cell and the diagonal mirror collimatable. This allows me to adjust all the parts so that their optical axes are aligned precisely and I can see the sharpest possible images.

Most telescopes allow such adjustments, and there are lots and lots of instructions out there that tell how to collimate a telescope. If you’re so inclined, you can purchase gadgets ranging from a simple cylinder with a peephole and a crosshair to a complicated laser projector to help you collimate more easily and precisely. But how do you know when to collimate?

Poor collimation causes imperfect images in the eyepiece, and it can keep you from seeing objects that are as small and faint as you should. But there are plenty of reasons that your views may appear less-than-sharp, and most have nothing to do with optical alignment. Most often, turbulence at some layer of the atmosphere bends the light from the object and distorts the view. This is known as bad seeing. But maybe you have eyestrain; maybe you had beer with dinner and your optic muscles are too relaxed to focus well; maybe your telescope and eyepiece haven’t cooled down yet. Without being sure, should you pull out your collimation tools and take time tinkering that could be spent actually looking at the universe, even though it’s not tack-sharp?

The other night, I (to my knowledge) invented what I’m calling the Curmudgeon Test. When I pointed the red-dot rifle sight I use as a finder, I noticed that the star I sought was off to the side of the view in the main scope. That can happen. Who can always point within a fraction of a degree to a star? This particular star was a close double that I have, in the past, been able to see as two distinct stars. But this time, try as I might, I could not see them. I put it down to atmospheric turbulence and moved on. Saturn was up next, and once again the image was offset in the main scope after I lined up my finder carefully. I then had a hard time seeing details on the planet that I usually can. Well, it’s not a good night for high-power, finely-detailed observations, I thought, and sought out a galaxy instead. Bad seeing matters less on diffuse objects. I pointed the telescope to a nearby star to begin the step-by-step hop to the galaxy, and, wouldn’t you know it, the star was off-center in the eyepiece. But all of a sudden, the scales fell from my eyes as I realized that each object had been displaced by the same amount in the same direction!

This was no random error; the finder and the telescope were not pointing at the same spot in the sky. It could have been that the finder was mis-aligned, but I quickly ruled that out because it fastens securely to the telescope and is placed such that it never gets knocked around once set. This left collimation as the likely culprit. Even a small bump when putting away a telescope or shifting lawn equipment next to it in the shed can move a lens or mirror system enough that its axes no longer align. And when that lens or mirror tilts, it moves the image it produces in a corresponding direction. I checked it and, sure enough, the lens was canted slightly in the exact direction each star was off-center. With a couple of turns of a screw, I was back in business. To my relief, I noted that all of the details I had been missing were suddenly visible and sharp. The rest of the night was a true pleasure.

So, here is the test: If your telescope images are consistently displaced from those in a previously-aligned finder, check the collimation. Otherwise, don’t sweat it and look at something else, or try another night.

But at least you’ll know.

P. S. Only align your finder with a telescope in perfect collimation. Otherwise the world will little note nor long remember what I’ve said here today.

Advertisements

Hobbies and Such

Last Sunday,  the weather forecast indicated the temperature would reach the mid-to-upper 50s. AND IT DID. I could not pass up the opportunity, so on the last day of January I went for my first bike ride of the year. I know what some of you are saying. It has been such a mild winter that you never stopped riding. Plus you have your “smart” blue-tooth toe heaters in your new graphite shoes, so you’ve leveraged the performance parameters by uploading your blood flow numbers from the monitor in your crank to the heads-up display in your sunglasses, which indicated it was all right to keep pedaling.

But, seriously, there have been plenty of opportunities for all sorts of outdoor recreation this winter. It’s just that they are not the usual ones. It has made me observe the way I engage in my hobbies, and I can describe it best as “streaky.” I seem to concentrate on one particular pastime for a while, and as long as I get to do that thing, I don’t get cranky or impatient with life. Then, suddenly, I feel like doing something else for a while, and I concentrate just as hard on that. While I’m doing it, I think to myself, “Hey, I’d forgotten how much I enjoy this.” I suppose it keeps me fresh.

You may remember that I was a competitive cyclist when I was younger, but for about the last five years, I was all about tennis. I decided to make practice time count, and actually teamed up with some hitting partners who would work on skills with me rather than want to play for points all the time. I learned to string my own racquets so that I could experiment with different types, gauges, and tensions of string. I even joined a club so that I would face different levels of competition. It was thoroughly satisfying, and I hardly thought about cycling.

Then, my wife’s youngest daughter graduated from high school. Being an avowed Anglophile, she wanted a three-speed bicycle with a basket to ride to class. While there were some new, retro-type models out there, we knew she wanted an actual vintage machine, so we searched classifieds and ordered her one. When it arrived, I started putting it together, and began again to smell the unique bouquet of road grit, leather, old rubber, and 3-in-1 oil that is peculiar to vintage bicycles. I felt the grunge under my fingernails, and it felt good. I realized how much I missed riding, and I have not picked up a tennis racquet since.

Last summer, I rode nearly every day. For the first time since I was in college, cycling became the activity I needed to feel as though my day was complete. My wife began to notice that, no matter what we were doing, I was checking my watch to calculate if we could make it home in time for a ride. We incorporated bicycles into lots of activities, like touring historic homes and visiting our favorite tea importer, but more often than not I wound up handing her the keys to my truck and riding the extra thirty miles home.

Then one day, I was done. I wasn’t burned out or injured, but I’d had enough. As fall progressed and the nights began earlier, all I could think about was setting up my telescope and searching for galaxies I had never seen before. In the same way that I had looked forward to a bike ride every day in the summer, now I planned my time to avoid the moon and made sure I had time for naps in the afternoon if my targets were going to keep me up until all hours. I did not even crave the exercise I was no longer getting, because my mind was completely wrapped up in astronomy.

I wrote in a previous post about following the Mets through the playoffs, but to get an accurate view of how that happened, picture someone sitting in pitch darkness in the yard with the radio tuned to a ball game in the background, staring through a telescope at tiny, faint patches of light whose photons began their journey toward me before human beings even existed on the Earth. For me, that’s a perfect evening.

On one hand, the mildness of this past winter made stargazing more comfortable than in most winters. Lots of my archived sketchbooks and log pages are smeared from the tears the wind has forced from my eyes. On the other hand, mild winters tend to be cloudy, and lately there have not been many opportunities to see stars. I was just beginning to feel cabin fever coming on when I received word of an estate sale arranged by the antiques dealer down the street. So last Saturday, as I browsed through the re-homing of someone’s worldly possessions, I came across a work stand that holds bicycles while you work on them. I purchased it for a song, brought it home, tinkered with my brakes, swapped some pedals between bikes, and suddenly I wanted to take a ride. And that’s what began on Sunday.

I wonder how long this streak will last.

Ad Astra per Aspera- Chapter One

In Which I Find the Object of My Search, Only to Wonder if it was Better Not to

     As I ascended the slight grade on the sun-dappled forest path, I had a hard time believing I was finally here.

Millbrook01

For twenty years, I had looked forward to this day, seeking relevant volumes in dusty used bookstores, poring over topographic maps, driving through this place while trying to look nonchalant. No Howard Carter in the Valley of the Kings, no Indiana Jones in an Amazon jungle, had ever felt more anticipation than I did that August morning. The fact that I was probably trespassing only added to my tension, and I have never been one to break rules, but a slight tingle of thrill drove me onward.

As I rounded a bend, a clearing materialized before me, and at the far end, the object of my quest gleamed white like some long-forgotten temple. Millbrook School Observatory, at last.

Millbrook02

As soon as I recognized the building from photos in fifty-year-old books, part of me wished I hadn’t. This incredible structure, built entirely by the blood, sweat, and tears of high school boys, lay abandoned and neglected in a corner of the campus now given over to the storage of machinery and scraps of lumber, themselves seemingly long-forgotten. A dumpster out in front of this facility? Really? Is that all the respect they can muster for what these young men accomplished?

Millbrook03

The small clearing was surrounded by tall trees, which made it difficult to recognize where everything I thought I knew so well was situated. Weren’t some of the photos I had seen taken from this spot? I thought they had been, but where was the concrete patio on which the nice young men in jackets and ties displayed their home-made telescopes? Had this three-foot-high mound of earth always been here? Had the site of the observatory once lauded by Scientific American magazine become a landfill? How had they even seen the sky from here?

I waded through thigh-high weeds, moving ever closer to what had been a center of science, community outreach, and geophysical research a few short decades ago. Vines had overrun and started to penetrate the doors covering the dome’s slit. They seemed to force it open, making it appear rather more vulnerable to the ravages of time than it ought.

Millbrook04

The whitewashed finish of the building’s cinder block exterior had crumbled away in places, revealing construction details that should, by right, have remained seamlessly incorporated into the facade.

Millbrook26

A blue tarp that had once protected equipment that did not even belong here now hung forlornly in tatters, exposed in its impotence against the elements.

Millbrook05

I found myself wishing the school had demolished the observatory years ago, rather than let it be shamed like this.

I approached the door that sat forlornly open, feeling more than ever like an archaeologist about to enter the burial chamber of an ancient monarch. It seemed to invite my approach.

Millbrook06

I can see they don’t value this, but will they mind if I do? After all, not having found anything marked as visitors’ parking, I had left my truck on the other side of the campus and walked all the way over here, feeling as conspicuous as a fox among the hens. But nobody seemed to pay me any heed, so after glancing over my shoulder one last time and listening for the sounds of maintenance or security personnel, I ducked inside and entered.

Immediately, my mood improved a bit. There was the student astronomers’ masterpiece, a 12″ reflecting telescope pointed to the south at an angle that meant it could be looking at the rich Milky Way star fields in summer or star birth regions in Orion during winter. The floor was relatively uncluttered, allowing me to examine the scope closely from all angles. Although its paint was flecked and peeling, the instrument gave off a feeling of solidity and dignity, as if it knew its own power.

Millbrook07

Cautiously, I reached out a hand and attempted to slew the magnificent structure in right ascension. It complied without a sound, with just the right amount of friction to prevent an observer from overshooting his target. I did the same with the declination axis, pointing the massive framework tube ever-so-slightly more northward, and once again the instrument responded perfectly, almost with pride in the quality of its construction. So far, so good mechanically; what about optically?

I located the knob used to remove the primary mirror’s wooden cover and decided to lift it off. This was really my Rubicon. If anything went wrong now, I could easily be prosecuted for trespassing and destruction of private property. Hang on! This telescope deserves to have someone care about it. My righteous indignation fueled me on.

Millbrook15

As I reached for the cover, I became aware of an almost-invisible inscription. What ancient knowledge would its decipherment give me? Raised slightly from the mirror cell’s surface, but painted in the same gloss black, were the words “MILLBROOK SCHOOL FOR BOYS.” I chuckled for a moment, trying to imagine how the makers of this behemoth expected it to go missing and need identification. Then it dawned on me: this was not meant to help recover a stolen telescope. It was written by a group of people feeling pride in their accomplishment, and wanting future generations to know about it.

I removed the cover to reveal a slightly tarnished surface, no worse than others I had successfully cleaned in the past, with…a postage stamp stuck to the middle of it?!

Millbrook17

Someone has vandalized…no; wait a minute. The stamp, I realized, had once been a reference mark for the collimation of the mirror in the optical train. While it’s customary to place a tiny magic marker spot on the center of your mirror for this purpose, I had never seen one an inch by three quarters in size. Still, as long as it was smaller than the portion of the mirror shadowed by the telescope’s secondary mirror, it was no problem.

All of a sudden, I was back in archaeologist mode. Stamps change. If I could find out when this particular specimen was issued, I would have an earliest limit on when someone had last maintained the observatory’s equipment. On further inspection, it was in the denomination of 32 cents, and carried an illustration of a man with a glorious Victorian mustache, in a military band uniform, playing a trumpet. Across the bottom near the perforations was the inscription, “The Stars and Stripes Forever.” Sousa. 32 cents. That should not be hard to track down.

I replaced the mirror cover and in doing so noticed the crudely-bent metal strips and cardboard spacers holding the mirror in place.

Millbrook18

I could not imagine that Neale Howard, the science teacher who had inspired the creation of this observatory, would stand for such shoddy workmanship. After all, his students had machined every metal part of the tube themselves. What could account for this deviation from his usual standards? I glanced at the eyepiece end of the telescope and observed that the secondary, directing the light to the eyepiece at the side of the tube, was a mirror.

Millbrook23

That’s strange. Didn’t Howard’s book specify that a prism was a better choice in this particular configuration? Something was afoot. People had tampered with this telescope!

Feeling appalled, I next examined the clock drive mechanism. I don’t remember being able to see the drive gear from his pictures. And what’s with these twist-on plastic connectors?

Millbrook09

When I had first found that the mount’s bearings were in good shape and the mirror was cleanable without needing re-aluminizing, my mind immediately leapt to thoughts of Millbrook Observatory’s glorious re-opening. How many people had been introduced to the wonders of the universe through this instrument? Why could this not continue? Now, seeing some of the other problems, including the infestation of the sun-warmed dome by wasps and hornets, I wasn’t so sure.

Millbrook10

Two decades after my quest to see Millbrook Observatory had begun, I had finally accomplished that objective. But, like all scientific and historic investigations, mine had left me with many more questions than answers.

Millbrook28

I retreated down the forest path still hoping not to be discovered.  As I walked back to my truck, I reflected on my life in amateur astronomy. It had begun in the days of robotic planetary probes, led to an unsuccessful attempt to make astronomy my career, driven me to create my own equipment, and revealed to me the educational oasis that was and is Millbrook. Its history was meaningful to me because of my particular interests and hobbies, but the more I learned about it, the more I realized it was a paradigm of how education should happen. America needed Millbrook as much as, or more than, I did.

I knew my involvement with this place had just begun.