A 3-D Christmas!

We weren't sure we could pull it off - Melinda had some side effects from her last chemo a week earlier, and was feeling poorly. But after a swing past the Cancer Center for a liter of fluids, she perked up well enough for a short road trip to Mexico! The last couple Christmases it has worked out to get away for an exotic vacation less than 5 hour drive away. Our friend Margie takes good care of us, and having the Sea of Cortez and beach make it seem like a whole 'nother country (which it is)!

With out late start from Tucson on Christmas Eve (1pm), I figured we'd get into Rocky Point just about sunset, and that turned out pretty true. After brief bathroom and snack stops, we had an uneventful border crossing and arrived about 5:20. While we didn't get our luggage into the house in time for sunset, we did spot the moon rising over the desert to the northeast a few minutes later.

Margie was like the Jewish mother we'd never had - she had a stew ready for us when we arrived - the first of many meals she plied us with. After catching up our lives in the months since we had crossed paths, we watched a classic Christmas movie or two and actually headed to bed at an ungodly hour for me - 9:30!

I must have needed the sleep though, cause I didn't rise for 12 hours! With the full moon, Rocky Point has huge tidal swings - over 6 meters over this Christmas! I dressed and headed straight for the beach with camera to see low tide. The only company I had were a few fellow walkers, though ironically, I met another Tucsonan who grew up in Iowa and was a RAGBRAI regular!

When at the beach, one of my enjoyable activities is chasing down sea life, or the shells they leave. Since most of these are small, I usually pack the macro lens and tripod, and since I've perfected making anaglyph stereo images, I took a number of stereo pairs, where there is a couple-inch baseline to put the images back together to make 3D. So get out your red/blue anaglyph glasses to fully enjoy these!

On Christmas morning, the best views of the shells were near a lower level of the beach where gulleys in the sand evidently indicated where water was flowing to help expose these. These white augers are quite common - in fact, Margie points out you can get them by the 20kg bag for scattering near the entrance to her house, which she has done. At right is a small clam or scallop shell - rarely found fresh and still attached like shown here - and dramatic in 3D!

I'm not sure how it works out, but the water flow of the receding tide does a great job in concentrating different shells. It makes quite the colorful still-life in recording these, and I really like them in 3D, which helps differentiate the shells. Here at left is a wider shot of one concentration, and at right is a closeup of the upper part of the frame. There are obviously a wide diversity of shells, unfortunately, I haven't learned many types yet. Of course, tumbling around in the surf wears them down eventually into sand, yet, even the worn ones are quite interesting.


Case in point was this shell, well worn, and documented on the 3D shot as I found it. Picking it up afterwards, I found it makes a perfect natural pinkie ring! In the right image is how it is worn on my finger - the curved edge perfectly fits between pinkie and ring finger of my right hand...




We had a nice Christmas day - Margie made us scrambled eggs with shrimp, and just hung around telling stories all day, ending with more shrimp in garlic for dinner. There was a great sunset over the Sea, but taking it easy all day left me unprepared for sunset. I had to make-do with a shot with the kit lens set to 85mm to catch the "Omega Sunset", caused by warmer air near the water surface. Make sure you click on the image to see the broad base near the Sea's surface.

I had more plans to get out the morning of the 26th for more beachcombing at low tide, happening at a slightly later hour, but overnight a cold front had gone through, and a brisk wind made the beach really unpleasant! Plus the higher surf from the wind messed up the tide's shell distribution - really nothing to shoot at all... It was our departure morning, so packed up and left shortly after noon, arriving back to Tucson before 5pm. A nice break from reality, but it was good to see the cats, and they seemed glad to see us too! But it was a nice getaway, even if for 48 hours!

Five Sunsets!

We've just passed the Winter Solstice, and for those that know me, it's the season for imaging the setting sun past the silhouette of Kitt Peak National Observatory. Like the ancients gathered around Stonehenge for celestial alignments, I've been drawn to this one for well over 20 years, first recording the sunset behind the Observatory in 1988! Those days was with my 12" Newtonian telescope and film (!) camera pointed out of my old van! It is much easier now with portable refractors and digital cameras. I can park and be set up in minutes these days. At left is a GIF file I put together on the "optimum" date of 17 December - click for a larger version. At right is shown my current setup - TEC 140 triplet apochromatic telescope and the venerable Canon XSi camera. Note the home-built solar filter that we made in the TAAA filter workshop about a month ago - it has gotten lots of use lately!

The GIF image at left is quite remarkable. While it shows a few circular artifacts that I didn't see in the original files, what is amazing are the layers in the atmosphere. Formed from air at different temperature profiles, you can see their effect on the image both at the suns edge, and also in the appearance and spacing of the two sunspots. It looks like watching an image at the bottom of a wavy pool!

Why the "Five Sunset" title? Well it hit me that I really didn't know how the image correlated to Kitt Peak very exactly. I knew if you were at "the spot" a few days before and after solstice, you could catch the alignment. I wanted to learn a little more about the situation. About the time I decided to do this, it was 10 days before solstice, so went up alternate days 5 times. It really was an amazing experience! Every sunset was different. Most were clear, one had some clouds during sunset, the last night it completely clouded up 30 minutes after sunset.

The end result is shown here at left.  I started on the 13th, when the sun was still moving southward more than a fifth of its diameter every 2 days. Of course, its southward motion slowed and stopped on solstice day on the 21st, taken just a few hours before the start of Winter. While the casual observer might think the sun wouldn't cover the observatory on most of those dates from this image, note the suns sweeping left-to-right motion for us here in the Northern Hemisphere. Because of the horizontal motion, I caught the full Observatory silhouette on 3 of the 5 evenings, all observations from the exact same spot. As you can see at right, after the first alignment happens about the 17th, the sun continues to move southward, appearing to lower from day to day as it sweeps past the Observatory. On solstice day, it BARELY covers the full silhouette - it helps to move northward as far as you can along the curve to help you catch more solar disk.

But the silhouette wasn't the only thing to see! Like I said above, every one was different - the first day it was very hazy - at least the inversion layer was above the observed level of Kitt Peak and it appeared very hazy. The result was that when the sun dropped below the observatory profile, the peaks projected their shadows into the hazy air, shown at left. Similarly, the next trip up on the 15th, I was shooting the disk (Meade 80mm F/6) as it dropped below the mountain and I caught a bit of blue/green flash between a crack in the mountain, and at the same time, caught more rays being cast upwards and outwards from the suns position, shown at right.



It often paid to not to hurry home. On the evenings when there were clouds, there were spectacular sunsets. At left is a nice example - a 3-frame panorama taken with a 300mm lens plus a 1.4X tele-converter. On another night, I had planned to pause at "Bad Dog" (actually Babad Do'ag) overlook near the lower slopes of the Catalinas to shoot Kitt Peak silhouetted not by the setting sun, but with late twilight glow with the city lights in the foreground. At right is a 5 frame panorama taken with the Meade 80mm F/6 (480mm focal length) and 10 second exposures. I love catching the contrast of the dark-sky observatory within view of the urban lights of Tucson. Besides the lights of Tucson's downtown skyline, the bright lights are from the UA football practice field, where the team was practicing for their upcoming bowl game.

I've got some more items of interest here, but will have to wait for a subsequent post.

GMT4 Unveil!

About exactly 3 months ago, I posted about the latest high-profile event at the Mirror Lab - the renaming of the Lab to the Richard F. Caris Mirror Lab, and the latest casting for the Giant Magellan Telescope - GMT4! Well, the baking and cooling is completed, and yesterday the casting crew started disassembly of the oven revealing the latest mirror substrate for the first time. Of course, we'd been watching the video image through the high-temperature melting, but watching glass cool, where the anneal schedule has it dropping only .1C per day is worse than watching grass grow! At left is the oven with the lid and one section of the wall removed. With the glass still safely enclosed, the unpacking and mold removal will wait until after the holiday break.


While you would think that casting a disk of molten glass would be straightforward, there are lots of complications learned as the Lab started small, and slowly culminating in these present 8.4 meter mirrors. Between the upper image and this one at left, you can spot the Inconel bands that wrap around the outer tub walls to restrain the centrifugal force of the spinning molten glass. Each band wraps around 180 degrees of the mirror circumference, so there are 4 posts around the oven to ensure an even wrap around the mold. Note also that there are more bands near the bottom of the mirror as the hydrostatic forces of the mass of the glass plus the centrifugal force require more support. At right is shown the top of the cast surface, with marks on the machined edge indicating the thickness of the faceplate - 2 inches in this case. In all these images, the hexagonal shapes of the internal structure can be seen. These mold cores are made of a machined ceramic that are removed after casting to leave air hollows in the substrate, resulting in light-weighting. Also note the electrical resistance heaters in the walls for controlling the internal oven temperature. Heaters are also installed in the floor and top of the oven, controlled by feedback from the thermocouples that poke through some of the holes in the oven walls.

This mirror is GMT4, the 4th cast for the Telescope and is destined for the center position of the mirror array. As a result, it is the only mirror with a cast center hole - and an oversized one at that, 1.5 meters in diameter. All the other substrates are off-axis parabolas, and we're only allowed a small 3" hole in the center to allow drainage of fluid for fabrication stages - generating and polishing. These are machined in with diamond tools rather than cast. A close examination of the left image shows the reflection of the center tub wall off the fire-polished surface. Note that the reflection isn't perfect though! When the glass temperature first froze as the temperature dropped below its softening point, it was a near-perfect surface. However, as the temperature continued to drop from about 800C where that happens, to room temperature, the ribs continue to shrink, while the faceplate, supported by the cores, does not. That is why the ribs are about 1.5 to 2mm shorter than the faceplate...

To my eye the mirror looked perfect, and that was confirmed to me by the casting crew who was starting to unpack it and cleaned the upper surface for quick inspection.

The only other activity in the lab that attracted my attention with camera in hand was the Large Optical Generator working on the GMT3 backplate. Shown at left is a 3-frame mosaic showing the operation in progress. Flooded with coolant is the flat backplate, with each of the holes (each core has a 3.5" hole that supported the ceramic core) plugged with a baby-blue castable mold material that keeps the coolant out of the substrate. Shown in the left distance is the generator spindle enclosed in the ventilation system where the mist (contaminated w/glass particles) is exhausted to HEPA filters on the roof. The yellow frame is a safety rail to keep workers on the backplate from falling the 10 feet to the floor.

At right is a ground-level view of the base of GMT3. The mirror substrate, face down and glued to the spider via 36 annular pads, is mounted to the turntable for backplate fabrication operations. The spider is what lifted the GMT3 mirror out of the oven and held it vertically for mold removal. When this backplate operation is finished, it will be installed in the polishing cell for faceplate work, and the 36 pads, held on with RTV, will be wire-sawed off. I've posted about generating before, check this link for some images. On GMT3, backplate work is nearing completion - they are currently using a fine resin-bond wheel for closing out the backplate work.

A Sad Day...

It was about 3 months ago we brought a skinny, dirty, mat-covered feral cat we called Spitz to the Vet to see how bad of shape he really was in. His big problem was dental - she ended up pulling most of his teeth, and he was also FIV+, so would have to be isolated from our other cats till he was used to everyone - no fighting allowed! As per our usual routine, he lived in a dog crate in our living room where he could get used to everyone, and everyone could get used to him as well. At most, I think the longest anyone stayed in the cage was 3 weeks...

Well, he must not have gotten the memo, as it didn't go as planned. At first it was fine - he adapted to the cage ok, where there was a soft bed, food and liter box. When everyone was scarce, we'd close off the back bedroom and give him the run of the house and did fine - he bonded with us, sat with us and watch TV, even play with us as we chased him around the living room and hide-and-seek around the island in the kitchen. But as we added a cat to the mix, his mood would change and would stalk them, culminating in a fight. While one or two stood up to him and he would relent, the others feared him and would run, triggering a more vicious attack. The vet gave us a script for phenobarbital to "chillax" him, but it had little effect. When it was just us, he was great, but we couldn't trust him with any of the other cats without screaming - even with the drugs and frequent use of a squirt bottle. After 3 months of this, we decided it wasn't fair to continue having him spend 18 hours a day in a cage, nor have our others in fear that he was out and about, and locking them out of the living room where there dry food was waiting...

So we called our vet a few days ago and she called the shelter she works with - Hope Animal Shelter. They didn't have space, but by today she had found a foster home for Spitz where he will be an only cat, and hopefully serve as a bridge to an only-cat household where he'll be happy and peaceful. But even so, it was so sad to say goodbye to him, and sign away ownership to Hope. At least I know he will have a better life than what he had on the street just a few months ago.  If any of you out there need a great cat for your only-cat household, you can likely contact Hope and ask about adaption...

Not As Rare As I Thought!

Just a couple days ago I posted about what I thought was a pretty rare piece of stone that over a couple decades (!) I had fashioned and polished into a ball that shows off its pretty colors and internal structure. Literally the next day, my good optics and astronomy buddy Dick e-mailed saying he had one just like it, but bigger! I've been working on a sunset project that carries me past his house, so last night I stopped by for a look. Sure enough, shown at left is the same type "nebulastone" that appeared on my post - even using a piece of the original material as a base like I did! Evidently the material isn't rare, at least in this area. Some of the reading I've done indicates it is found in Mexico near the Sea of Cortez, so with its proximity to Southern Arizona, likely picked up by folks in their travels south of the border...


The neat thing about Dick's piece is that it was made for him by one of the opticians at the Optical Sciences Center (OSC) from back in the "olden days". The bottom of the base is inscribed "To Dick, Leo Elmore, Tucson, AZ 5-26-83". Don't quote me on those last figures, though... Leo was retired by then, and as I started at OSC in '84 and never knew him, he likely turned out this product in his garage, as Dick implies he and another optician were doing lapidary stuff about then. Anyway, it is quite beautiful and bigger (more valuable) than mine!




Of course, you can't go to Dick's without at least being invited to look through a telescope, and since he knew I was coming, had set up a Takahashi 4" APO triplet to look at the moon. With a 3mm focal length eyepiece, it provided over 270X and exquisite views of the skinny moon's craters. Shown at right is an image I'd taken in twilight with the TEC 140 an hour earlier in twilight (before stopping at Dick's) at full camera resolution with a nicely comparable view.

You'll shortly be seeing what I've been working on at sunsets, but sometimes it isn't always about the conclusions, but the little stops along the way - this time especially!

A LONG-Term Project!

While I don't usually go for knick-knacks, I thought this one was blog-worthy! It starts about 1988 when I discovered these pretty black rocks with green inclusions on a deserted Mexican beach literally in the middle-of-nowhere. There was a huge outcropping of them in this little cove and I loaded up the van likely with close to 50kg of them. I swapped the biggest pieces to a local rock shop in exchange for some diamond sawing of some glass boules that the astronomy club had - cut into manageable blanks, they were much more useful than 30kg chunks!

Anyway, about that time, the thing to do with pretty rocks was to make a sphere out of it and polish it. I picked out a nice one and intended to make about a 8cm sphere - even used the diamond generator I had access to at the time (Optical Sciences Center) to rough-in the shape. And there the project languished for about 25 years...

Fast forward to a couple weeks ago. One of the projects I can't tell you about has me making little glass spheres of various sizes. Shown at left, there are currently 3 diameters from 1" to 2.5".  These are in various stages of completion, but will eventually have a fine-ground finish. The link to our story today is that I've become pretty proficient at making these. You start with a raw chunk and use a tile saw to make it approximately spherical a little oversize. Then you get out or borrow the "Sphere maker" shown at right. It uses 2 counter-rotating cups of appropriate diameter, and slight angle between them with abrasive powder the operator adds to grind off the high spots, resulting in a smooth sphere. Grind down far enough to remove any irregularities, work through finer and finer abrasives, and eventually you end up with a polished surface.


So finally, after waiting about 25 years to finish smoothing out my partially finished pretty rock, I re-did the finest stages of grit and polished it up in no-time! I had even saved a corner off the original rock, ground a concave into it and use it now with a few spots of felt to make a holder for it. Final product is shown at left. As you can see, the raw rock is nothing much to look at, but when polished, or wet on a distant Mexican beach, it does indeed look impressive.

I've since found out that a popular name for the rock is "nebula stone" - so named for the green inclusions resembling telescopic views of green planetary nebula in the night sky. The other day I Googled "nebula stone" and found the name is copyrighted! You can follow the Google links yourself, or go to the Nebulastone company. Of course, they have all sorts of metaphysical effects attributed to these, and are charging outrageous fees - from something over $1/gm for tiny pieces to up to $4/gm for large polished pieces. I should rent a dump truck and go looking for that beach again!

DKIST Celebration!

While I wasn't involved in its fabrication, I got an invite to the celebration they held yesterday for the DKIST primary's completion. Formerly the Advanced Technology Solar Telescope (ATST), it was recently renamed the Daniel K. Inouye Solar Telescope (DKIST) after the long-serving senator from Hawaii. He led an amazing life and serves as appropriate namesake for an equally amazing telescope - be sure to check out the link about his life. Arriving a few minutes late, the crowd had already gathered and were milling about the optics fabrication lab at the College of Optical Sciences, having already hit the buffet line of sandwiches and veggie trays.

A few minutes later, the speeches started - at left is project scientist Jim Burge describing the many challenges of accurately polishing and testing the mirror - only 75mm (2.9" thick), extremely aspheric (8mm departure from best-fit sphere!), yet finished to a surface less than the size of a glass molecule! The mirror surface can actually be spotted behind his right elbow - more on it later...

After more speeches from the DKIST staffers, it was time for the group shot of those participating towards the successful completion. At left, associate director of Steward Observatory Jeff Kingsley, directs folks surrounding the 4.24 meter primary mirror of DKIST. What is interesting to me is that I used to work in this shop in the '80s, and there wasn't much of a safety culture then. Safety programs were really pushed hard at the Mirror Lab in the 90s, and evidently migrated BACK to Optical Sciences - check out Frank Gacon who was serving as photographer for the event. Forklift with man lift, harness safely tied off, and wrapped in caution tape at floor level! Even more interesting is that the woman at the bottom is Karen, who is in charge of the safety program at the Mirror Lab. She didn't have to do or say anything - it seems as though all this was set up well in advance for this event. But it did occur under her watchful eye!

After the official portrait, it was cake time! After a quick frame of the main cake, some of the DKIST staff got the job cutting and serving. It was fun wandering around chatting it up with folks I've not seen in a while, folks I used to work with, and meet a couple new ones. After working at the Mirror Lab for 25 years, the main lab here seemed small, but they have certainly found their niche, finishing both this mirror and the 4.3 meter Discovery Channel Telescope primary a few years back.


Being that the event was late in the day, there wasn't much going on in the lab, but as a partial demo, a few Mirror Lab staffers who have been lent to Optical Sciences for a few months were running on a large secondary mirror. At left, Sam is watching over the swing-arm polisher working on the convex aspheric of the TAO secondary.

I went on an amble over towards the DKIST primary and took a closer look at the mirror. The Zerodur mirror surface seems to have a higher reflectivity than the E6 mirrors of the Mirror Lab, but more likely, the darker glass-ceramic makes the reflection look brighter. Anyway, I always like getting down at near-grazing angles and examining the multiple reflections off the surface. At right I can spot reliably 5 reflections and reflections of reflections, easiest seen in the "block A" at left.

And, of course, knowing me, the edge of the DKIST primary is a perfect place for a 3D stereo image! Grab the red-blue anaglyph glasses and you can see the 3D effect using a pair of images I combined in Photoshop.

Another great photo-op was part of the test system that measures the shape of the telescope mirror. Similar to the big off-axis mirrors we're making at the Mirror Lab for the Giant Magellan Telescope, a fold sphere up in the test tower is used for folding the beam and used to make the highly astigmatic mirror look more like a sphere to facilitate testing with an interferometer. And similar to the fold sphere in our Mirror Lab test tower, the center of curvature (CC) is located down near ground level. While there was an actual interferometer located at the CC, by holding my camera a foot to the side, and me standing a foot to the other side, I could see my camera in the fold sphere, thus the camera could see me! Shown at right is the view the camera saw. Unfortunately, I was inverted (I've already forgotten if the camera was above or below the CC, so the orientation could be erect or inverted), so I rotated the image 180 degrees in photoshop so you wouldn't have to look at me upside down!

I was looking for the selfie taken in the Mirror Lab's fold sphere, and found that it has never been on the blog! Amazing! I've used it often in my presentations about the Mirror Lab and our projects there, so am showing it here for a comparison to the above. I feel like the Great and Powerful Wizard of Oz gazing down at the Lab in this shot! The fold sphere is considerably larger than the one at Optical Sciences, in fact the Mirror Lab version is nearly as big as DKIST, but mounted much higher in the tower. Anyway, now you've seen them both! It's like I work at the carnival and get to play with the fun-house mirrors every day!




UPDATE!  Since the party earlier in the week, Jeff Kinglsey forwarded everyone on the invitation list a copy of Frank's excellent portrait.  Don't bother looking for me - I got an invite, though my contribution was minimal and didn't line up.  I just came for snacks!  Anyway, thanks to Jeff and photographer Frank, I received and forward the official portrait (reduced to fit blog rules)!