Late Summer Cactus Fun!

Since some of our regular readers are NOT from Arizona, I thought a post about some of our native plants is about due. While our "rainy" season is just about over, most cacti do not show many external signs of the extra moisture. Most bloom in the spring, and those blooms have long since gone to fruit and long since eaten by birds and bugs.

One exception to the above are some varieties of barrel cactus. We've got a large one in our yard that is still blooming and are some months yet from ripening to fruit and seeds. The flowers are large and striated, and attract a lot of insects. The shots here show both flower buds that have opened days previously and if pollinated, will develop into fruit, as well as some buds that have yet to flower. Interestingly, we've a second fishhook (so named because of the bend in the needles) barrel cactus that, except for size (smaller), looks identical to this one. The smaller one however, which is from Mexico, blooms early in the Spring, a good 5 months ago!

While shooting the blossoms here, a bee loaded down with pollen, was having fun swimming through the sea of stamens - only his pollen laden rear legs and striped abdomen are visible (right photo). I wanted a firm identity of the bee because the high contrast stripes didn't look like a honey bee, and sure enough, Carl Olson, an entomologist at the University of Arizona identified it as Diadasia rinconis, also known as the Cactus Bee, a solitary bee (doesn't live in a hive) that builds a nest in the ground.

Though I don't have any before pictures, there was a 7' (2 meter) tall prickly pear that was encroaching on our secondary parking spot in front of the house - not something you want to walk into at night! The end of July, I hacked off it's upper half and severely trimmed it, knowing it would sprout new pads. Sure enough, here we are 5 weeks later, and tiny little growths are dotting the edge of the pads I trimmed.


And like many cacti, I swore I didn't come close to it, but I must have, as evidenced by the tiny glochids stuck in my finger after taking the above pictures. They are so small that you generally don't feel them initially, but they work their way in with time and are irritating, if not painful. Painful is when you get an armful of hundreds of them, not just a couple as shown here. That is why standard equipment when out walking or hiking in the desert should include a good set of tweezers for pulling out the tiny barbs.




The last pair of pictures is of a beetle that spends a lot of time on a prickly pear over in our neighbor's yard. Most every night when I go out on my walk I see a few of them out on the cactus, but never during the day. One clue to that behavior is that late one afternoon I saw a 10" (25cm) lizard searching through the branches of this particular cactus - looking to make a meal of these guys! I never paid much attention to what the beetles were doing, but they didn't move much, staying in the same approximate place during my nearly hour walk.

In taking their picture the other night, their mission became more obvious - the photos are of the same beetle, with slightly different perspectives. The one on the right shows he has eaten off a bit of skin off a pad, and apparently spends time there lapping up the ooze the plant exudes!

These guys are a pretty good size, 5 or 6 cm (2" to 2.5") long. Note the ant for scale on the left image. They look formidable too - check out the grappling hooks at the end of it's legs - perfect for hanging on to cactus spines... Melinda claimed she got the willies and would get nightmares after seeing the shots, so she will likely not read these last paragraphs!

Again, I bow to Carl Olson at the U of A for identification and he notes that it is a Moneilema gigas, identified by the horns at the side of the thorax and the white antenna segment. The common name, as could be expected, is the Cactus Longhorn Beetle. Evidently, besides the adults damaging the cactus skin, the larvae work on the roots of the plant as well, placing it in some danger with long term infestation. Fun stuff!

Tonight's Deathmarch...

Melinda won't walk with me anymore - she says I'm too fast (it is exercise, after all!), so mostly I go out on the nights that she works, like tonight. Normally I don't bring my camera along, but this time of year, Melinda heads off to work right about sunset, and as I headed out, what I spotted made me go back in to get it!


This time of year as the monsoons wind down and the thunderstorms dry up, you still get widely separated thunderheads, and with the right conditions, you can get some spectacular effects. Tonight a thunderhead formed right over the setting sun, and even though the sun had gone down, the sun's rays cast a shadow into the upper atmosphere, where scattering made it visible. Called crepuscular rays, they appear to diverge from the sun. of course, the rays are parallel and their apparent divergence is a trick of perspective, like the rails of a railroad track appear to converge into the distance. Here you can see the thunderhead on the western horizon, lit up by the already-set sun casting a shadow into the sky.


Oh, and another thing I like to watch on my walks - do you see the shadowy spots against the sky (I see 4)? They are bats that also come out at sunset, feeding on flying insects, blurred by the longish exposure.


Of course, if you have crepuscular rays, there is also a chance of seeing anticrepuscular rays! As the clouds projected shadow continues in the direction opposite sunset, it appears to reconverge in the east. Sure enough, you can see the anticrepuscular rays tonight as well in this shot looking east. And as a bonus, if you look at the full-resolution image (click on the image), the caret marks the bright planet Jupiter, now low in the SE at sunset. It appears here over the palm tree.

The Latest Home Improvement Projects

Now that Melinda has a taste of tiling in her blood, we are racing forward with similar projects. Just last week she took hammer and chisel to the guest bathroom. We finally got sick of what could generously be called a pinky-fleshy color and got it down with some difficulty. The cement board backer stayed firmly attached to the drywall, which varied in quality, so we caved and contacted a contractor who will remove drywall and backer board, and install and mud a new set ready for us to set tile against. That will happen on Wednesday of this next week.

We have visions of Mexican Talavera tile through the entire bathroom, and have been shopping through Tucson for selection and pricing. Melinda likes the busier patterns, while I prefer the solids with accents of patterned tiles. I don't care a lot, though, so she can do what she likes! There are a few stores in town with fired ceramic sink basins, and even toilets, but I think we'll stop at walls and perhaps a basin...

And while waiting for the contractor next week, Melinda wanted to dabble, so tiled the little entry to the house between security door and entrance. She used the leftovers from the bathroom floor, and ended up with only 1 - 6" square left, so did very well! She also wants a border of Talavera under the rim of blue tile, but ran out of mastic, so will have to wait a day. Then late tomorrow comes the familiar routine of sealing grouting and sealing again... Stay tuned for more of the transformation!

Another Optics Facility and Arizona Telescope Project!

While some of you may yawn when I talk optics, it is what I do for a living, and actually, it is big business here. Tucson is sometimes referred to as "Optics Valley" with all of the associated industry. One of the main reasons is the University of Arizona's College of Optical Sciences, formerly known at the Optical Sciences Center (OSC). Located on the SE corner of Cherry and University, it is shown in an IR shot here. Developed in the mid-1960s, if there is an experimental application of optics, research is likely going on here. From thin film applications, optical computing, materials research, it all goes on here. And like the Mirror Lab and the National Optical Astronomy Association (NOAO) another block to the north, it is home to an precision optical shop capable of making large optics.

Of the 3 optical shops within a few blocks of each other, Steward Observatory Mirror Lab has specialized in the 6.5 and 8.4 meter diameter mirrors for large telescopes. NOAO's shop, active in the late '50s and '60s for development of telescope mirrors and instrumentation for Kitt Peak National Observatory (here near Tucson) and Cerro Tololo (down in Chile), is mostly inactive now. The OSC shop is very diverse and usually finds work that no one else will bid on - deemed too difficult or impossible to build by other optics shops. I actually got my start in optics at the OSC shop back in the '80s doing precision metrology and surface generating. The multiple shops are not in competition - in actuality they cooperate and borrow equipment and supplies back and forth quite frequently.


At the moment, the highlight of the OSC optics shop is the 4.2 meter diameter mirror for the Discovery Channel Telescope. The project is a partnership between Lowell Observatory, a private observatory located in Flagstaff, Arizona and yes, the company that brings the Discovery Channel to your cable TV system. The new Observatory will be located in Happy Jack, Arizona, an excellent site near 7,800 feet elevation 45 miles SE of Flagstaff. There are a number of interesting features of the mirror, probably the biggest challenge in fabrication is that it is only 10cm (4") thick. Because the large mirror is so thin, it is flexible, so it is extremely difficult to make into a precision surface. The solution OSC uses is 100+ passive supports to overcome the flexibility. In a recent visit, these pictures show Norm working on a zone near the center of the mirror. The thin mirror and numerous supports are seen.


The latest news I've heard is that the mirror is nearing completion in the next few weeks. The image at left shows a posted map of the surface errors as of the end of June. Opticians use interferometers to measure the surface profile of mirrors. Like a carpenter uses a ruler to measure a structure, an interferometer uses wavelengths of light as a ruler to measure mirror errors. Using these devices, errors of millionths of a millimeter can be reliably obtained. One of the neat aspects of the north end of the OSC shop is that the machine is built under a test tower, so after a polishing run, the mirror is washed and dried and can be measured without moving the mirror or support system.

Ok, enough about optics and telescopes - I promise our next post will NOT be about glass, astronomy or telescopes!

This N That

In my post Sunday about our trip out of town, I showed a side view of a distant thunderhead, with a swath of rain below. Last night we had a closer, more oblique view. Right at sunset, as I walked out to get the mail, the rumblings of thunder woke me to the close proximity of this thunderhead that was certainly photo and blog-worthy. Even with the wide-angle lens (10mm) I could barely get the uppermost sweep of the cloud. No rain to report here...


With the end of the month upon us, the monsoons are also winding down and with them the forecasters promise of a wet summer storm season. The nightly weather dutifully reports we are upwards of 4" behind our normal annual rainfall, which doesn't sound like a lot, but is nearly half our yearly total! Of course, with the passing wet season brings with it the promise of clear cooler nights, and in fact, Jupiter shines brightly in our southeastern sky tonight, but after a long day at work (more about that in a sec...), no scope set up tonight. Of course, those of us living in the desert (even the astronomers!) would likely prefer a drenching rain, but it is looking more and more like that won't be happening anytime soon...


Today was high temperature day of the latest Mirror Lab casting - that for the San Pedro Martir 6.5 meter telescope. The day started early with representatives from this project's partners, from other current telescope projects, and dignitaries from south of the border (I spotted several from the mayor's office of Ensenada, Mexico). In this photo the Steward Observatory director, Peter Strittmatter, facing the camera in center, talks to attendees, with the spinning oven containing 11 tons of molten glass behind. At this moment (2130 local time) the oven is well past the peak temperature of 1165C to 1125C, and will continue to drop about 30 degrees/hour or more until the glass freezing point is reached at about 800C. The oven will continue to spin at 7.4rpm until 700C, which is scheduled for sometime Friday at the moment... Cooling slows considerably to prevent internal stresses from building, with the oven staying sealed until mid-November - a long time to wait for a cake to come out of the oven! I haven't heard of any issues or problems, not that casting these is routine yet. This is the 12th (by my count) casting over 3.5meters diameter and it still attracts a lot of attention!

Blog Stats...

We went out to see "Julie and Julia" yesterday, the new movie about the lives of Julia Child - the woman who brought French cuisine to America 50 years ago, and blogger Julie Powell, who used Julia's tome "Mastering the Art of French Cooking" to add purpose and drive to her life. The movie is very good - I absolutely love ANYTHING Amy Adams is in (portraying Julie Powell), and Meryl Streep truly channels Julia Child's voice and mannerisms.

The story is a compilation of 3 books - Child's cookbook as well as her book "My Life in France" describing her postwar years in France while her husband works as a diplomatic envoy, in addition to the Powell book "Julie and Julia" based on her year-long blog cooking her way through Child's cookbook. Nora Ephron as screenwriter and director does a great job combining the women's stories yet provide strong roles for the movie husbands as well.

So after thoroughly enjoying the movie, I went looking for source material, reading the original New York Times article that publicized Powell's goal of cooking her way through Child's book in a year, as well as checking out her current blog. Now we've been doing this little blog thing too for 14 months, compared to the 6 year following Julie has built up, but it was still a little depressing to look at her comment totals - two of her last 3 posts have garnered an average of over 350 comments! We're lucky to get a couple per week... Oh well, as long as we are having fun, and our sparse readership does the same!

Time To Melt Some Glass!

This shows the lowering of the oven top onto the now-loaded mold almost 2 weeks ago. After hooking up circuits and testing along with some new training proceedures thrown in, time to cast the 6.5 meter mirror for the San Pedro Martir Observatory.

If you can't be there to feel the heat of the nearly 1200C temperatures on your face, or feel the wind tousel your hair as the oven and mold rotate at 7rpm, the next best thing is to check out the nearly-live pictures from the website one of the project scientists has thrown up. In addition to weblinks to the principle partners, the latest photos of the melting glass, temperature profiles, video files will be available as well. The peak temperature will come sometime Wednesday midday.

As of this moment (4pm Monday) , there is a normally scheduled hold at 500C for checking out systems. Much hotter and the glass will start melting, so is the last chance to stop the casting if there are issues.