Oh Say Can You See...

Just a quicky post tonight - we were out looking for the Space Shuttle (last night in orbit tonight - landing tomorrow, 31 July), and the International Space Station, both making a pass close to 8pm. We never saw the Shuttle - it likely is maneuvering for it's landing tomorrow and passed too early for us to spot. But the Shuttle was bright, even though it only rose 19 degrees off the SW horizon and was over 900 km (550 miles) downrange of us, and was easily spotted in the bright twilight. I tried an exposure, but was late getting out and didn't do a good job of recording it - I promise better in the future!


But in the deepening twilight, other bright stars played peek-a-boo with a few light clouds softly lit by the rosy glow of the sunset nearly an hour earlier. Here is an exposure (cropped from a 24mm lens, 30 seconds, F/4, ISO 400) of an asterism everyone knows currently high in the Northwest. Can you spot it (click the image for a larger view)?


For those who need a little help, the giveaway is the arc of 4 stars above leading to a bowl of 4 stars among the clouds. Yes, the Big Dipper is high in the NW sky and is easily spotted even from town. The Dipper is an asterism - a pattern of stars that is not a constellation. What's that you say - the Big Dipper is a constellation? Actually no, it is part of the much larger constellation Ursa Major, or Big Bear, the dipper and handle forming part of the Bear's hindquarters and long tail. To see all of Ursa Major, you need a pretty dark sky, but the dipper is easy to spot, and is visible all year long from the northern part of the country. From here in Arizona it will dip below our northern horizon in the early evening in a few months, thanks to our southern latitude and the curved surface of the earth....

Neighborhood Portrait

While visiting Elinor last week on our swing through Texas, she asked for our assistance in helping clear some of her husband David's estate. I've found homes for most of his photo gear with a donation to the scholarship fund of the local camera collectors, and took a couple boxes of books for my own library (a small percentage of what remains!).

One of her offerings this trip was a small telescope in the corner of David's computer room - a 70s vintage 5" Celestron telescope. Elinor always believed that our mutual friend Bob Goff, who worked for Celestron then, was responsible in some way in it's construction, so held on to it. Since he was just about my best friend in Tucson, Elinor thought I should provide a home for it, which I'm proud to do. David had tricked it out - mounting it on a sturdy tripod with very smooth altazimuth movements. It makes a perfect grab-and-go scope to keep near the back door.

To that end, I set it up to take a peek at the quarter moon tonight. It needs a touch of collimation alignment work, which I'll leave for another night, but thought I'd snap a shot of the moon with the Canon XSi. Here is a 250th second, ISO 400 with the F/10 telescope. Not bad for untracked tripod mount!

Glass Sorting!

One of the more interesting operations at the Steward Observatory Mirror Lab is the glass sorting before casting one of the mirror projects. Coming up next month is the spin casting of the 6.5 meter diameter substrate for the San Pedro Martir Observatory. To make as perfect a mirror as possible, over 11 tons of glass must be inspected and sorted before loading it into the mold to form the lightweight casting. My last couple posts about the Mirror Lab have talked about the mold making, so refer back for that info.


Besides handling large quantities of the magical looking blocks of glass, the sorting crew is a wonder to behold - everyone has their job and move as if part of a smoothly oiled machine. The boxes of glass individually wrapped in foam are unpacked, cleaned of particulates, inspected under crossed polaroid filters (more about that in a minute), sorted by seed content, reboxed and weighed. Meanwhile the scraps of foam are corralled and boxes recycled. Sorting the 10 tons of glass took a day and a half, so they were quite efficient indeed. Note that everyone wears gloves - the cleaved blocks are extremely sharp and gloves help keep that nasty blood off the glass!


Randy, head of the casting crew, individually inspects every piece of glass. Using a light box with a polarizing filter, the crossed polarizer in his glasses reveal stress in the glass. Usually associated with localized impurities or stria (index of refraction variations), remelting the glass doesn't always relieve the stress, so there is a reject box. If the stress is in a small area or near an edge, it can be cleaved out of the block. What does it look like under the polaroids? A "clean" chunk is featureless as shown at left. In the presence of stress at right, the plane of polarization is rotated, so appears as a bright spot or zone with the analyzing filter (click to enlarge images). This example was quite bad so was rejected.





The glass is also sorted for seeds - tiny bubbles or impurities within the blocks. The glass with fewest defects is set aside for placement on the top of the casting. These blocks will help form the faceplate of the telescope mirror and using the clearest glass correspondingly helps form a mirror surface with fewer defects.


And yes, as can be told from the name (Ohara Glass Corporation), it is a Japanese product. They go to a lot of work for the lab making a consistent batch-to-batch product, then cleave the batches into these blocks so that they melt together cleanly without trapping a lot of air bubbles. No other manufacturer has offered to go to that effort to assure the consistency of results on which we depend. We've had excellent results in the past, and expect to continue to use them in the future...

It Really is a Dry Heat!

As I come in from my evening walk tonight it is a comfortable 98F. Of course I'm in Tucson where the dewpoint is 43F and the humidity 16%. I was reminded of our time just over a week ago in San Antonio, TX where just standing, let alone going on a vigorous walk, you almost needed to hold your arms out to keep rivulets of sweat from running down your arms! BTW, current conditions there (1030pm CDT) are 88F with dew point of 71F and 60% humidity.

One reason it is more comfortable in Tucson is that the monsoon circulation has left us for the moment. Normally starting around July 4th and lasting about 10 weeks, rain comes to the desert, delivering about half our annual rainfall (about 12") in that time. The reasons are complicated, but with the subtropical "Bermuda High" in the right place and another high pressure area near the 4-corners area, air circulation is right to bring up moisture from the Gulf of Mexico, and with the daytime heating in the desert, sometimes violent thunderstorms result. During this time, the air is more humid, but it also doesn't get as hot as it can while dry. As a result, yesterday and today were cloudless for the first time since our return, and for my commute home it was a toasty 106F!

The photos above were shot from our roof yesterday - the infrared shots show off the thunderheads of the July storms, which have, for the moment, moved off to New Mexico, which I verified with a satellite image. The lower image shows a few fair weather cumulus hanging down towards old Mexico past the Santa Rita Mountains south of town.

I've gotten into the habit of taking evening walks after Melinda takes off from work. Five weeks ago it was common to see folks and families out for an evening stroll about sunset. But the last couple nights not a soul - 98F must be over their limit!

The Ketelsen's are: IN

We arrived home from the "Tour de Texas" this evening, thus concluding our official 'summer vacation'! While I was back in Tucson for a 7 night visit (6 nights of work to break up the vacation); Dean has been gone from home for a full month. Needless to say, it was a joyful reunion between him and the cats!

We had an uneventful driving trip (an improvement over last year when the wheel fell off about 50 miles from home) today, sharing the task of driving. Fortunately, we both enjoy driving. During my 'riding' time I explored learning to play the harmonica that our friend, Elinor, gave to me! I was a little too self-conscious to seriously try at it, but plan to practice and serenade Dean with "Red River Valley" (one of the songs in the accompanying booklet) as soon as possible!

We don't have many pictures to post from our visit with Elinor, however, we had a wonderful time with her! We visited with Elinor last year, on our trek to Tucson with the four cats along for the ride. She was disappointed that we didn't have any cats with us this time, though she now has 'joint custody' of a sweet little kitty named Missy. Missy started as her neighbors cat, but now travels between the two houses - spending most nights with Elinor. Our first night at Elinor's I came upon my first scorpion. I was so excited that I grabbed Dean out of the bathroom to kill it! I had never seen one (they sneak into houses when no one is the wiser) alive, and I'm told by Dean and Elinor that this one was 'big'. It was about 2.5 - 3 inches long. Did I stretch it out on a ruler to verify....NO. You'll have to take my (and Dean's) word on it!


We also, with Elinor, spent an afternoon in Marfa, Texas - a small town about 26 miles west of Alpine. Marfa is a growing artist community, though many of the galleries were closed on Monday, the day we chose to spend there. This picture is the county courthouse, as Marfa is the county seat. In a 'rough and tumble old west town' it was a delight to see this pristine Victorian jewel! We ate at a nice little cafe, having wonderful Mexican food, before taking in the shops in El Paisano Hotel.






El Paisano Hotel is noted for having been the place that some of the cast of the movie "Giant" (1955-Eliazbeth Taylor, Rock Hudson, James Dean) stayed during the local filming of that movie. For you movie buffs out there, that was James Dean's last movie before his death in a car crash (1955). The first floor of the hotel is filled with galleries and shops, though the lobby, dining room, and swimming pool are very elegant in the 'grand old hotel' sense of the word.

Marfa is also known for a phenomenon called "The Marfa Lights". The lights are unexplainable 'orbs of light' that sometimes show up in the sky (oh so scarey!!!), and 'dance' around! There have been articles about them, they have been studied, and they date back to over 100 years, or so some sources report. We did not go out in search of the Marfa lights, opting instead to relax and enjoy dinner and a nice glass of wine (and/or beer) at home with Elinor.

We both agreed that while it's nice to get home from a vacation, we enjoyed being able to spend a couple of nights with each of the relatives/friends we stayed with in Texas. One night is never enough, so two nights was just about perfect! To the family/friends we visited who are reading this blog entry: thank you! We had a great time and are so happy to have been able to spend some time with you!

Hotter than %$!! in Texas

It is a mite warm here in Texas - supposedly only 98F today, but considerably more humid than we are used to in Arizona. Yesterday we left Dallas, and the comfortable confines of sister-in-law Susan's house. We had a great time with her and nephew Brian, mostly hanging out, enjoying some great meals, going to the movies, but mostly stayed inside where it was cool. Brian is taking a break from all the summer camps he has done this Summer, but his brother Rhett and Dad Bill were on a camping trip in New Mexico, so didn't get to see them. Here is a shot of Susan and Brian before we departed for San Antonio.


The trip down was uneventful, but traffic was bad both getting out of Dallas and passing through Austin at the peak of rush hour. Almost easy to predict, but what can you do? We got in about 6:30 - just in time to jump back in the car and head out to a local steakhouse for dinner.


This is our first trip to San Antonio and my sister Sheri was carefully planning our every hour to get a taste of the place. First stop this morning (after a breakfast of fresh-and-hot coffee cake!) was a stop at the Alamo. It is smaller than you expect - at least the mission shrine is quite small. Interestingly, no fee was charged for any part of the visit, though the gift shop (with some exhibit space) is larger than the mission. And of course, the downtown development has built up skyscrapers across the street, so I guess we are lucky any of the Alamo still exists at all! Sheri's husband Tim is off on a family trip to Indiana, so we don't get to see him. In the photos are their 14-year-old Brittany, and 7 year-old Colton.


Our visit downtown seemed mostly to consist of ducking into buildings to get out of the oppressive heat. After the Alamo visit, we headed west a block or two to the Buckhorn Saloon and the "Hall of Horns". Rated a "Must-See" by Susan, we did lunch at the Saloon and paid the premium price for the museum which really was a very entertaining 90 minutes and well worth it. On display over the dining area was every sort of stuffed horned or antlered animal and many that didn't have horns. In the museum were also displays of African interests, finned creatures (mostly fish), unusual displays of all sorts of natural and historical interests.



We spent the hottest part of the day there, and left for the famed "Riverwalk" area - really a subterranean man made river that goes for seemingly miles. It exists under street level, connecting bars, restaurants and other shopping areas - almost like a pedestrian mall under street level, with trees, gardens, and river with guided boat excursions! I'm not sure if the trees and water made it seem cooler or if there was a real effect, but the return to street level seemed to increase the misery again.


As we headed for home, while we stopped for a DVD to watch, the dark clouds that had formed dumped, and the view out the window reminded us of the hurricane coverage from the Gulf of Mexico with sheets of horizontal rain. But the storm did cool things off dramatically and the evening was pretty pleasant, though we mostly stayed inside and enjoyed "The Coneheads" (remember - family friendly) brought to mind from the hall of mirrors at the Buckhorn Saloon.


After an all-too-brief visit, the plan is to hit the road again tomorrow, heading west towards Alpine, Texas. It will be a longer day driving, but shouldn't have any problem making it...

Back on the Road...

Just a quick note why we've not posted lately. Well, between the driving and the visiting with friends and family, there just aren't enough hours in the day. So be assured we are fine and currently somewhere between Dallas and Tucson. Today (Friday) we are leaving sister-in-law Susan's delightful home in Dallas, and headed to sister Sheri's house near San Antonio. Then Sunday we head towards Alpine, Texas for a stop to visit friend Elinor. Supposed to be home by Tuesday. We will likely have Internet access at our stops, so we may post, but it may wait till home too. See you down the road!

Meanwhile, Back in Tucson...

I was on the road all day today - but made it the 650 miles to Oklahoma City in about 11 hours. A little warmer down here - 70s in Iowa, about 100 here in Oklahoma! That leaves about 210 miles for tomorrow morning. Melinda flies into Dallas tomorrow evening for the last leg across Texas.

Meanwhile, I've not posted about the Mirror Lab in a long time. No, I'm not thinking too much about work, but they did call me while I was driving today to get my opinion on something. And I've got these pictures from June 23rd, the day before leaving Tucson that I never posted, so it makes for an easy blog entry!

There are three main projects in which Steward Observatory Mirror Lab is heavily involved. I've posted about the LSST and SPM Telescopes recently, but there has been lots of progress lately, so will update those as well. In this uppermost shot of the Polishing Lab, you can see both the GMT mirror at left, and the LSST mirror across the room.


Mostly I've been helping out on the LSST (Large Synoptic Survey Telescope) finishing the backplate generating and edging this Spring, but now we are using a 2 meter diameter grinding tool to get through the loose abrasive grinding and polishing to fully stress-relieve the backplate. We had just started the grinding on the flat rear of the mirror. As shown in earlier posts, the backplate has a hole over each core that is temporarily plugged to keep the mirror interior clean. You can see a PVC arm holding an array of brushes that sweep up the grit out of the holes to recycle the abrasive grit. Leslie is rinsing off the edge of the 8.4 meter diameter mirror.

Across the room, the GMT (Giant Magellan Telescope) has just started the polishing process on the front surface. I've not posted about GMT since my earliest Mirror Lab post last winter, and really need to describe it in more detail. It has a complicated surface figure - unlike most mirrors that are parabolic, or just rotationally symmetric for that matter, this mirror, designed to be mounted in the telescope with 6 other 8.4 meter mirrors is actually an off-axis parabola, the largest one in the world that has ever been attempted by far. Here Bill keeps an eye on the Stressed Lap Polisher - which changes to the ideal mirror shape, as the operation continues. As the mirror surface becomes more polished, we can start optical testing, but the testing is complicated by the off-axis shape.



The first part of the test setup, is a 4 meter "Foldsphere" now permanently mounted in the top of our new test tower. The Foldsphere was the last mirror I finished before "retiring" over a year ago, and in the interim, it has been aluminized and lifted to the highest point in the lab. Note that the image of my Canon camera pointed into the test tower is reversed in the mirror. My camera is very near the center of curvature of the concave sphere, so is magnified greatly. The center of curvature is also where an interferometer will be permanently mounted to monitor the shape of the Foldsphere during GMT testing. The main interferometer test of the GMT will bounce off this Foldsphere and will contribute the majority of the aspheric correction of the GMT mirror. Will include some diagrams and further discussion at a later point!


Also since my last post, the casting crew has finished the mold for the 6.5 meter diameter San Pedro Martir Telescope. They really worked hard and finished mold construction in a record 4 or 5 weeks (I lost count). In this image from 23 June, Damon and Phil were using the dust collection system, and dowel rods to plug the rib gaps of the mold to generate enough air flow through the backplate gap to vacuum up dust and contaminants. While I've been gone, they have started a mold prefire to "set" the mold. After cooling and another inspection, the mold will be ready for glass loading and a mirror casting in early Fall. You are now as up to date as I am!

A Stop In Iowa City

After yesterday's family function, I headed out to Iowa City to stay for a day or so. It is the home of the University of Iowa and I must say it is about the most beautiful campus I've ever seen! I'm biased some as I went to school there, but built into the banks of the Iowa River, it really is scenic. And not only is it scenic, it is integrated perfectly into the downtown commercial district, so classical stone institutional classroom buildings are across the street from bars, restaurants, bookstores and art galleries. Of the half dozen university towns I've spent time in, it is by far my favorite!

The Iowa River splits the university - athletics, medical and nursing schools on the west side, and most everything else on the east. The crest of the east bank of the Iowa is dominated by the Pentacrest - the original 5 buildings of the University, with the Old Capitol Building at their center. Old Cap served as the territorial capital and the State Capital for the first decade until the legislature voted to move it to the more central Des Moines. The building then became the first permanent University building back in 1857. It was used for classes for over a century and used for offices since. Unfortunately, during external renovations in 2001, an open flame torch accidentally set the wooden dome on fire and the dome was destroyed. Rebuilt and recovered with gold leaf, the building was reopened in 2006 and currently serves as a museum. The Pentacrest is a natural meeting and demonstration location - I remember well my first semester at Iowa when presidential candidate George McGovern made an appearance just before the '72 election. With the expanses of green trees and lawn, I think this Arizonan took more pictures of it today than in the previous 35 years!

I'm staying (as with most overnight stays at UI) at the hotel located at the Student Union. Called the Iowa House, it is a perfect location to stay - very reasonable walks to athletic events, food and functions in Iowa City without using the car. I've not moved the van since parking it in the ramp 24 hours ago! Unfortunately, unbeknownst to me, today starts incoming freshman orientation, and I was lucky to snag a room for tonight. Everyone and their family is walking around campus today, and there were literally dozens of guided tours in small groups wandering around in the morning.

There are a few pilgrimages I make nearly every trip I go to Iowa City, though it has been nearly 3 years since staying overnight. I usually look up my friend Ann - I think the only connection to my student days 30-some years ago. She was actually my supervisor for a semester when I drove for the Cambus bus system after I graduated and wasn't working towards a degree. Miraculously, we've stayed in touch over the decades - she works at the UI Library and we get together to chat over lunch as I pass through. I knew her small son those decades ago, and now Ann shows pictures of her grandchildren. Today we were joined by my nephew Jeff and his sister Sarah, both living in the area, who joined us for lunch.


Another trip I must make every time is a visit to Prairie Lights Bookstore. Located a block from the Physics building, where I took most of my classes, it is perhaps the best independently owned bookstore in the Midwest. While smaller than your typical Borders or Barnes and Noble megastore, it is amazing at the selection of books you WANT to read, and it is a rare trip I can get out the door without spending $100. The staff is great too - I went in once with a book I'd heard about on a long-ago NPR segment, but had forgotten the title, and they were able to connect my verbal book description to the book without title or author. Now THAT is knowing your product! The store also promotes authors by hosting readings and festivals. One of the employees saw one of my book selections and asked if I knew the authors were going to be in the store Saturday! It really is one of the true destination attractions in Eastern Iowa!


Another pilgrimage I made was to my favorite bar/restaurant from 35 years ago - The Sanctuary. Located a few blocks from the center of the business district, it was known for it's cheesy pizza back then - I wasn't so much of a beer drinker back then (don't forget the drinking age was 18 then!). I had stopped in 3 years ago with Melinda, and did a solo trip today, getting a small Sanctuary Special Pizza (most all of the top 6 or 7 ingredients) and a pint of Dead Guy Ale from Oregon's Rogue Brewery - a great combo! Not only was the food good, but they had some great music in the background (a little jazzy for my 70s taste, but Tony Bennett seemed perfect this trip). Also, the waitress had a copy of the Sunday New York Times travel section for me to peruse while my food was being prepared - now THAT is full service!

Hitting the road in the morning towards Dallas - first west to Des Moines, then south to Kansas City, Wichita, and Oklahoma City. Hoping to get to the latter before stopping for the day...

The Return To Arizona Starts...

After some packing, organizing and cleanup of the house in St Charles, Illinois, it was with some sadness that I headed west towards Iowa in the trusty van. Today's plan was to join family in DeWitt, Iowa for a combination farewell (mine), and early birthday parties(for Stepmom Diane and Uncle John). The "event" was held at brother Jim's house - always the most popular sibling in summer with the pool in the back yard. He installs pools and spas for a living, so his place is a real showcase of what can be done, even in the short summers of the Midwest. The 2 comparison shots are taken from near the same spot in standard color, and with the IR-modified camera showing the darkened sky, light foliage, and dark water of the longer wavelengths being used.



The star of the show was little Alivia, who turns 3 years old in less than 2 weeks. She was quite the social jabberbox. She is shown here during consumption of "Snickerdoodles" (sort of a chocolate-frosted peanut buttery Rice Krispy bar), and after cleanup. As you can surmise, she is not camera-shy at all, similar to most of my nieces and nephews around their camera-toting Uncle Dean.



Also similar to our family functions where at least 4 of the brothers and sisters are present, a group shot was taken. Missing is little sister Sheri, who arrives in a couple weeks after I'm back in Tucson (and who I visit in a few days!). Shown from the back left is me, Brian and Jim, with Kathy and Linda in front (also in order of age from left-to-right in case anyone wondered). With Melinda and me splitting our time between Tucson and Chicago, and Sheri's family now living in San Antonio, TX, at least I'm not the only one preventing a full reunion any more!

But Is It Art?

While we get the New York Times at home (turned off while we are away), it is often hard to find on the road, even in St Charles in the Chicago suburbs. If leaving the house early enough (before 10am), I can usually find one at local grocery stores. Even when we are busy running around and I don't have the hour or so to go through one, I like to get it for my favorite sections in each day's edition. Tuesday has the can't-miss science section, Wednesday has the food and cooking section, Thursday has style and home, Friday has new movie reviews, and of course, every day has an original crossword puzzle that we both enjoy doing, though as they grow harder during the week, I can usually only finish a Monday or Tuesday, while Melinda gets much deeper into the week. In any case, every day has great articles you rarely see anywhere else and draw your attention.

While at the mechanic's on Thursday, I caught up on editions from earlier in the week. There was an interesting article in the Tuesday paper about an art project in London called "One and Other", a piece designed by artist Antony Gormley. You can read the article here. In short, volunteers occupy a vacant plinth on the NW corner of Trafalgar Square. Normally designed to support statuary of kings or generals, a statue was never built on the "Fourth Plinth", but is the stage of "One and Other", where volunteers can do pretty much whatever they want for an hour, webcast live, 24 hours a day for the next 100 days. From the website, "One & Other is an extension of the exploration of the connection between individuals. The volunteers on the plinth become both representations of themselves and of the human population of the world, viewed by fellow members of the wider society which they inhabit."

So, in effect, there is a continuous performance piece ongoing. I find myself frequently checking in - currently there is a well dressed man in suit and tie standing in the rain, striking the pose of an explorer, eyes wordlessly fixed on the horizon. I've seen a woman dressed as a pigeon (in celebration of the pigeons in the square), a dancer who performed with ribbons, a woman with 2 bubble machines who blew soap bubbles for her hour, and others who interact with the crowd. Besides the live video, you can also hear the volunteer and crowd noise as well. So go to the website link above and you can witness the ongoing art project.

More Homework!

Melinda missed out on all the fun today! Maj and I (and Jack the wonder dog)attacked the "scary" room for really the first time. The scary room really isn't that scary, but it is called that because at some point in the past, there were major roof leaks and there was resultant floor rot - resulting in a bouncy floor. At some point the floor was replaced with particle board, but the bounciness remains, so one of the next steps is to remove the floor and see what sort of joists remain. Regardless, there will need to be some reinforcing work done.

I mentioned in our last post that we are moving the wall in our guest room enlarging it a bit to become the master bedroom. The "scary" room will become a little smaller, and really, just become a walk-in storage room. To facilitate the wall move, Maj and I removed the beadboard from the ceiling, the wall that is shifting, and also removed it back to the new wall position. With the previous roof damage, there was a lot of crap falling down as we pulled off beadboard, and we both looked a mess by the time we finished. We cleaned up before the picture taking, so you get no sense of the mess we made. We actually tried to keep up with it as we made it so it didn't get tracked into the house so much, and we mostly succeeded.

Since the wall about to be moved was at one time an exterior wall, a door exiting to the porch was actually boarded up, but is now open again! In the vertical format shot, Maj is examining the roof around the chimney where she assumes the roof leaks were originally located. The wood is soft there, but while we worked today, there was some steady rain, nothing got into the house, though.


When Maj's carpenter is available, they will remove the floor, reinforce floor joists as needed and replace floor, jack up some dips in the roof and reinforce any damage from the old leaks, take down the old wall and move it to it's new position. If we are lucky, it might be done in a day - we'll see! Otherwise, most of the work of insulating, wiring, reinstalling beadboard and general finish work will wait till our return for another "vacation".

Homework!

It hasn't all been fun and games in our all-too-brief visit here in St Charles. Melinda's sister Maj has done a lot of work on the house in our absence, almost to the point where she was asked to "save some stuff for us"! Recent work has concentrated on the "guest room", which needed the ceiling removed to reinforce the roof supports. Maj doesn't do electrical work, but Melinda does, so we've been wiring in new outlets, a ceiling light with hardware for an anticipated fan, and reconnecting power to the closet and other house outlets beyond. A complicating factor is that we are moving one of the walls over 2 feet, so we are leaving enough cable so we don't need to do any other rewiring then.


The guest room used to be an external porch that was enclosed at some time in the past. You can see in this shot the white upright posts that were original roof supports on the porch. Melinda is pretty fearless with her wiring skills - checks the book occasionally, but does good work. I think the girls' plan is to get a real electrician to split the circuit that goes to the back of the house with the stuff we are adding, since we have 3+ rooms on the one circuit...

Both she and Roger are leaving today, Melinda back to Tucson to work, and Roger on to his conference in South Bend, Indiana. I'm staying a few more days working on the house some - Maj says I'm putting in insulation! Towards the end of the weekend I'll swing through Iowa visiting family once again, then head towards Dallas, where Melinda will rejoin me for the return swing through Texas and visits with more friends and relatives. Back to Tucson about the 22nd...

Yerkes Observatory Day Trip

Our friend Roger is visiting us from Vancouver - on his way, actually, to an antique telescope convention on the campus of Notre Dame later in the week. One of the side trips he wanted to take in the area was to Yerkes Observatory, one of the world's great observatories 100 years ago. Run by the University of Chicago on the shores of Lake Geneva, Wisconsin, it still holds the record for the largest refractor (lens-type) telescope - 40 inches (1 meter) in diameter.This telescope, and in fact, many of the premier telescopes of the 19th century were built by Alvin Clark and Sons, a source of research for Roger, so of particular interest. Refractors were soon superseded by much larger reflecting (mirror-type) telescopes and astronomers never looked back... Research is still ongoing, but mostly involving comparison observations taken decades ago with the same telescope. Of course, southern Wisconsin was never a great location for a large telescope, and there is considerable light pollution from metropolitan centers along the western shore of Lake Michigan.


So last Friday, the day before the 4th holiday, Roger arranged a tour of the facility and we did the 75 mile drive north, joined by Melinda's sister Susan as well. Our tour was given by Richard Dreiser, who has been there for 30 years. Melinda and I have been through the place before, but it is an interesting place and we learn something new every time. The tour starts on the outside of the building with the architecture and exquisite stonework before moving into some of the historic offices, library, and eventually, the cavernous dome of the great refractor.





The dome is huge! It almost seems larger from the inside that it appears from outside. Of course, the size of the dome is driven by the length of the telescope - one of the reasons the Mirror Lab where I work makes very short focal length telescopes - to ultimately lower the cost of the telescope enclosure. But partially because of the refractor optics, the color error they generally suffer from is minimized if the focal length is made longer, so refractors are generally long, this one being about 65 feet (20 meters) long. And as it moves around the sky, the instrument or eyepiece varies a huge amount in height, so the floor, a full 75 feet (22 meters) in diameter, moves vertically about 30 feet (9 meters). And as a precision device, it is built massively, capable of tracking a star without errors for hours. Some friends of mine have actually been part of a group to observe with the telescope, but that opportunity comes rarely, if at all.


The telescope was dedicated in October of 1897, after being on display at the World's Columbian Exhibition in Chicago in 1893. The included cartoon is on display in the hall of the Observatory, from the front page of The Daily Inter Ocean, a Chicago newspaper, on dedication day. It champions the use of industry and technology for research even while in Europe there was a buildup in the war machine.