I've not blogged about the Mirror Lab in an age, so after this, you will officially be up to date! It has been over 2 months (!) since last blogging about the Large Synoptic Survey telescope (LSST). We at the Mirror Lab (Steward Observatory Mirror Lab ) are working on the primary mirror fabrication, and since the last post on 20 February, we've finished the backplate generation to the proper thickness, edged the mirror to the proper outer and inner diameter, polished edges and fine ground the bevels and boss reference surfaces. All that is left before loose abrasive grinding and polishing is to machine 24 of the backplate holes for stress relief.
The LSST Telescope is unlike any other telescope in a number of ways. The most important point for the tasks at hand is that after the brief sky exposures, the telescope has only a few seconds to reposition to it's new location in the sky as the previous exposure downloads from the 3.2 gigapixels. The potentially large sky movements in a few seconds puts huge loads and stresses into the telescope and mirror, and as a result, the hard points defining the mirror position must be as strong and stress-free as possible. A mill head has been mounted to the Large Optical Generator (LOG), and with an assortment of diamond tools we are attacking the backplate. The crew and I are going through the 6 areas where the hard points will be mounted, cleaning up the as-cast backplate holes and generating radii into the extra-thick cast backplate (for extra strength). With 6 locations and 4 backplate holes per location, and several hours per hole, nearly a couple weeks will be required for this work before moving on to conventional grinding and polishing of the rear surface.
The coolest part is that they've installed a webcam to either monitor progress or keep an eye on the employees! You can check in to see what is happening real time in the lab by going here. You should see an image update every 2 seconds. I'm currently working 6am till something after noon (Mountain Standard), at which time the second shift comes in till about 8pm. Of course, most everyone is off weekends, and I'll also be gone early next week with Melinda for a short Midwest trip. But do check in and at least wave to me if I'm there working hard!
We're glad to see you here! Come and share our daily lives with us, we welcome your company and your comments. We hope there is something here for everyone!
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Thursday, April 30, 2009
Wednesday, April 29, 2009
Buds and Blossoms
As the Arizona cactus flowering season continues, I've been keeping an eye out for interesting blossoms. I've mentioned before in these posts (check here for the 5 April post, or here for the 9 April post) that the flowers only last a day in the heat and dryness. While a large, branching cacti may have enough buds to flower for a week or two, some only have one or two buds, so you've got to have good timing to catch them! Anyway, here are a few of the recent photogenic results.
I'm not sure why this prickly pear appeals to me so much - probably because the pads are so small and cute. Images of the pads and buds have appeared in both the above posts, but finally the spreading bush of this cactus is finally flowering (it is mostly in shade, so is a little slower than those in the sun). Some pads only have flower buds on them and some have new pads AND buds. The large pads here are about 10cm (4") across, so buds, flowers and the new pads are tiny!
This is another prickly pear behind my neighbor Leenie and Mike's house. In all my years here, I've never seen a cactus quite like this (I need to get a book!). Huge thorns protruding from nodule-like bumps. These flower buds appeared a couple weeks ago, and I'll be watching for them to pop out soon.
This gorgeous flower is from a potted hedgehog cactus in the backyard of neighbor Jack (with the Cereus cacti flower post of 24 April). The hedgehog name generically applies to a large number of cacti species, but locally, if you see the bright cup-shape flowers, that is the name that you use. I've seen these at 7,000 feet elevation at Kitt Peak when I worked there decades ago growing out of seemingly solid rock. And of course, they are common to the desert floor as well.
This cholla (pronounced choy-ya) cactus has also made a previous appearance in our posts above, though the first time for the blossom. I remember years ago when I got a book on Arizona flowers that the ONLY green flower in the book was from the cholla cactus. And while not precisely not a green flower, it is definitely on the green side of yellow. But even if they are not a showy desert bloom, the bees still seem to find them, and the big bushy plant, over 2 meters (80") tall, has seemingly an endless supply of new ones every day.
The last image of today is actually from a mistreated Bishop's Cap cactus in our back yard - potted over a decade ago and rarely watered (and mostly under the eave of the house to boot!), it is the last survivor of the pot, yet every month or so in the Spring it sends out a set of buds with small 2cm (.75") diameter flowers. Melinda wants to reward it with a replanting in the front of the house - who knows how it would respond to some reasonable treatment!
I'm not sure why this prickly pear appeals to me so much - probably because the pads are so small and cute. Images of the pads and buds have appeared in both the above posts, but finally the spreading bush of this cactus is finally flowering (it is mostly in shade, so is a little slower than those in the sun). Some pads only have flower buds on them and some have new pads AND buds. The large pads here are about 10cm (4") across, so buds, flowers and the new pads are tiny!
This is another prickly pear behind my neighbor Leenie and Mike's house. In all my years here, I've never seen a cactus quite like this (I need to get a book!). Huge thorns protruding from nodule-like bumps. These flower buds appeared a couple weeks ago, and I'll be watching for them to pop out soon.
This gorgeous flower is from a potted hedgehog cactus in the backyard of neighbor Jack (with the Cereus cacti flower post of 24 April). The hedgehog name generically applies to a large number of cacti species, but locally, if you see the bright cup-shape flowers, that is the name that you use. I've seen these at 7,000 feet elevation at Kitt Peak when I worked there decades ago growing out of seemingly solid rock. And of course, they are common to the desert floor as well.
This cholla (pronounced choy-ya) cactus has also made a previous appearance in our posts above, though the first time for the blossom. I remember years ago when I got a book on Arizona flowers that the ONLY green flower in the book was from the cholla cactus. And while not precisely not a green flower, it is definitely on the green side of yellow. But even if they are not a showy desert bloom, the bees still seem to find them, and the big bushy plant, over 2 meters (80") tall, has seemingly an endless supply of new ones every day.
The last image of today is actually from a mistreated Bishop's Cap cactus in our back yard - potted over a decade ago and rarely watered (and mostly under the eave of the house to boot!), it is the last survivor of the pot, yet every month or so in the Spring it sends out a set of buds with small 2cm (.75") diameter flowers. Melinda wants to reward it with a replanting in the front of the house - who knows how it would respond to some reasonable treatment!
Sunday, April 26, 2009
A Friendly Native
While scouting the trail head of the Finger Rock Canyon area yesterday looking for some IR photos to take, I ran across this fellow. I've tried to image lizards lately, but they are always too fast for me - just as I push the shutter release, they are typically on their way at a high rate of speed. But this guy was much slower, and larger (and brightly colored) than those in the back yard (perhaps the cats have eaten all the slow ones!). I thought for a bit that he might have been someones pet, because I could get my hand to within a few inches. But I wasn't quite motivated enough to catch it, and I was content to grab a couple frames. It looked to be at least 30cm (12 inches) long, mostly tail. From the description and other photos on various websites, it appears to be a native, not a pet, likely an Eastern Collared Lizard, Crotaphytus collaris. Tucson is on the edge of it's range, tending towards rocky woodland areas, which certainly describes the edge of the Catalina Mountains where found. He was certainly a beauty - I'll need to keep an eye out in the future!
Saturday, April 25, 2009
A New Window On The Universe - IR!
I've been a bit of an infrared (IR) nut since I started doing photography in high school. Infrared light is just past our limit of visibility in the red part of the spectrum. By using a red-transmitting filter and infrared sensitive film (generally available till a few years ago), you could record some interesting effects, that we'll get into in a few minutes.
As digital imaging came into popularity and film use slipped a few years ago, many scientific and special-use films disappeared, including IR. Fortunately, the new digital sensors had some sensitivity in the infrared band which was generally bad for normal imaging, and is filtered out. Some had a "red leak" where the filter still passed some IR - my first digital camera, a Sony, could be used with an IR filter and LONG exposures of .5 second or so. Here is a shot of Melinda in her pre-engagement days in her tie-dye t-shirt and sunglasses. Note the IR image loses the shirt color, as well as the tinting in the sunglasses! My newer Canon cameras didn't have a similar red leak, so were not able to be used for IR.
But where there is a need, there is a solution! There are cottage industries showing up to remove the normal IR blocking filter in the new digital cameras and replacing them with clear or specialty filters. Amateur astronomers for several years have been modifying cameras to better transmit the red hydrogen wavelength to better show gas clouds in space. Similarly there are also folks who can install the IR transmitting filters. Jim Chen, of San Diego was recommended by a friend, and after finding a used, reconditioned Canon 20D camera on E-bay, sent it off to him for modification. It came back the other day and I've been having fun with IR! So what Jim does is change the normal filter in front of the sensor with a deep red (almost black) filter that transmits light just beyond the range of vision. The advantage of this over using a clear filter over the sensor, and an IR filter over the lens is that you would not be able to focus and compose with an IR filter - the field would be pitch black. The viewfinder looks normal, auto focus and auto-exposure still works fine, but you get the full IR effect.
Some of the effects you get with IR - since the clear sky is blue, it is quite dark in the infrared part of the spectrum. So the sky is dark, while live vegetation is brightly reflective, or white. Many dyes used in clothes and paints do not reflect well beyond red, so results can be unexpected. A stop sign will not show the "stop" printing. As above, tie dye and sunglasses some out uncolored. When viewing long distances, small atmospheric particles scatter light in the blue -longer IR wavelengths are less affected, so better visibility results. Check out Jim Chen's site for more results, or Google "IR Photography" - I just got 56.5 million hits! Well, that is good for an intro - here are some IR-visible comparison pictures taken this afternoon near the trail head of Finger Rock at the top of Alvernon.
As digital imaging came into popularity and film use slipped a few years ago, many scientific and special-use films disappeared, including IR. Fortunately, the new digital sensors had some sensitivity in the infrared band which was generally bad for normal imaging, and is filtered out. Some had a "red leak" where the filter still passed some IR - my first digital camera, a Sony, could be used with an IR filter and LONG exposures of .5 second or so. Here is a shot of Melinda in her pre-engagement days in her tie-dye t-shirt and sunglasses. Note the IR image loses the shirt color, as well as the tinting in the sunglasses! My newer Canon cameras didn't have a similar red leak, so were not able to be used for IR.
But where there is a need, there is a solution! There are cottage industries showing up to remove the normal IR blocking filter in the new digital cameras and replacing them with clear or specialty filters. Amateur astronomers for several years have been modifying cameras to better transmit the red hydrogen wavelength to better show gas clouds in space. Similarly there are also folks who can install the IR transmitting filters. Jim Chen, of San Diego was recommended by a friend, and after finding a used, reconditioned Canon 20D camera on E-bay, sent it off to him for modification. It came back the other day and I've been having fun with IR! So what Jim does is change the normal filter in front of the sensor with a deep red (almost black) filter that transmits light just beyond the range of vision. The advantage of this over using a clear filter over the sensor, and an IR filter over the lens is that you would not be able to focus and compose with an IR filter - the field would be pitch black. The viewfinder looks normal, auto focus and auto-exposure still works fine, but you get the full IR effect.
Some of the effects you get with IR - since the clear sky is blue, it is quite dark in the infrared part of the spectrum. So the sky is dark, while live vegetation is brightly reflective, or white. Many dyes used in clothes and paints do not reflect well beyond red, so results can be unexpected. A stop sign will not show the "stop" printing. As above, tie dye and sunglasses some out uncolored. When viewing long distances, small atmospheric particles scatter light in the blue -longer IR wavelengths are less affected, so better visibility results. Check out Jim Chen's site for more results, or Google "IR Photography" - I just got 56.5 million hits! Well, that is good for an intro - here are some IR-visible comparison pictures taken this afternoon near the trail head of Finger Rock at the top of Alvernon.
Friday, April 24, 2009
A Distraction On The Way To Work...
Heading in to work this morning, I had a brake-screeching moment as I passed neighbor Jack and Delia's house. I've mentioned them the last couple days - he and his sons run a landscaping business and he was showing me some of his blooming and about-to-bloom cacti a few days ago. He was long gone to work this morning at 7:45am when I happened by, but this cactus was hard to miss - literally covered with 15cm (6") blooms. After a chat yesterday, he was trying to tell me what kind of cacti they are - I believe they are all Cereus - which also explains their night time activity - they tend to be night bloomers. In any event these flowers were quite incredible, with one branch containing 6 of them, and the entire plant with 11 today! Yesterday there were white flowers, he had an identical-looking one in back of the house with yellow, and today these pink ones. There was a lot of bee activity, they likely know in advance to stick around Jack's place!
Wednesday, April 22, 2009
Occultation Images
I've been looking all day for some Venus Occultation images good enough to post on our blog. Sure enough, buddies Tom and Jenn Polakis of Phoenix have posted some great images from this morning. It also includes a nice high resolution video of the Moon moving over the Venus crescent. Look here to go to their photo album. The video was taken with a 10" diameter telescope, the wider views with a 70-200 zoom, the medium field views with a 4" telescope. Enjoy!
The Feral Family Out Front
People are always asking how many cats we have... We sometimes don't know how to answer that question. We've got 9 inside the house - I had seven before our wedding last June, and added Melinda's two from Illinois. They've been documented here before, and though there were some tough times last summer when I brought up two from Arizona to intrude into the Illinois territory, they are all getting along surprisingly well here in Arizona.
The reason we sometimes don't know how to handle what seems a simple question is that there are three feral cats out in front of the house (outside our "catproof" fence), that we feed on a daily basis. Part of pet ownership responsibility is that once you start feeding animals, you can't arbitrarily stop, and that extends to our regular "wild" cats. Almost all of my 7 cats started out as walkups to the front of the house, so the ferals have the potential of moving inside at some point. In fact, I've got several calls in to my vet to find out the next dates they will spay/neuter ferals. Before exposing our inside cats to any new ones, they need to be neutered and assured disease-free. Here are the current regulars:
This is Scruffy. He first showed up about a year ago before the summer move to Illinois. He was in such poor shape - barely more than skin and bones. I put off taking him to the vet thinking he would likely get put out of his misery! He was very shy and untouchable, but he came around for regular feedings (which continue with the cat/house sitter when we're not here), and while he has filled out some, he is covered with matted fur and walks like he is old and arthritic. I'm pretty sure it is just so painful to move with the mats, so the vet has agreed to a shave as well as a neuter job when the time comes. He has such pretty green eyes, and after regular food and water, tolerates petting at feeding time, away from the mats, anyway. He is an insatiable eater and I suspect he likely has parasites and a skin condition, as well as the coat issues. I'm always careful to wash my hands after handling him, but I have high hopes for his integration.
Yellow Cat is our "newest" feral. While he has been a regular through the Winter and Spring, he was only seen rarely before then. He appears pretty healthy, though always seems to have a mournful or worried look on his face. Like Scruffy he started out extremely shy, but with regular feeding he better tolerates human contact - with a bowl of food in your hand, he allows his head to be scratched, but that is about the extent he permits at the moment.
We call this black cat "Hootie2". He appears a virtual clone of our inside cat Hootie. He has been around for a long time - in fact, I'm pretty sure he is a feral that Vicki and I trapped and had neutered about 7 years ago. He may well be a close relative of Hootie - besides their exact appearance (color and size), many of their mannerisms are also the same. While far from being tame, he also allows his head to be scratched, and also rolls on his back as illustrated here - showing (I believe) that he trusts us. He is healthy as a horse, so far as I can see, and like Hootie is one muscular little dude.
So that is our "outdoor" family. So do we have 12 cats or 9? It makes little difference - we accepted them a long time ago by feeding them. Taking the next step by moving them inside will certainly extend their life span (regular vet care) and make them safer (from traffic and roaming dogs and coyotes). We've never had 12 cats here before, but perhaps we already do!
The reason we sometimes don't know how to handle what seems a simple question is that there are three feral cats out in front of the house (outside our "catproof" fence), that we feed on a daily basis. Part of pet ownership responsibility is that once you start feeding animals, you can't arbitrarily stop, and that extends to our regular "wild" cats. Almost all of my 7 cats started out as walkups to the front of the house, so the ferals have the potential of moving inside at some point. In fact, I've got several calls in to my vet to find out the next dates they will spay/neuter ferals. Before exposing our inside cats to any new ones, they need to be neutered and assured disease-free. Here are the current regulars:
This is Scruffy. He first showed up about a year ago before the summer move to Illinois. He was in such poor shape - barely more than skin and bones. I put off taking him to the vet thinking he would likely get put out of his misery! He was very shy and untouchable, but he came around for regular feedings (which continue with the cat/house sitter when we're not here), and while he has filled out some, he is covered with matted fur and walks like he is old and arthritic. I'm pretty sure it is just so painful to move with the mats, so the vet has agreed to a shave as well as a neuter job when the time comes. He has such pretty green eyes, and after regular food and water, tolerates petting at feeding time, away from the mats, anyway. He is an insatiable eater and I suspect he likely has parasites and a skin condition, as well as the coat issues. I'm always careful to wash my hands after handling him, but I have high hopes for his integration.
Yellow Cat is our "newest" feral. While he has been a regular through the Winter and Spring, he was only seen rarely before then. He appears pretty healthy, though always seems to have a mournful or worried look on his face. Like Scruffy he started out extremely shy, but with regular feeding he better tolerates human contact - with a bowl of food in your hand, he allows his head to be scratched, but that is about the extent he permits at the moment.
We call this black cat "Hootie2". He appears a virtual clone of our inside cat Hootie. He has been around for a long time - in fact, I'm pretty sure he is a feral that Vicki and I trapped and had neutered about 7 years ago. He may well be a close relative of Hootie - besides their exact appearance (color and size), many of their mannerisms are also the same. While far from being tame, he also allows his head to be scratched, and also rolls on his back as illustrated here - showing (I believe) that he trusts us. He is healthy as a horse, so far as I can see, and like Hootie is one muscular little dude.
So that is our "outdoor" family. So do we have 12 cats or 9? It makes little difference - we accepted them a long time ago by feeding them. Taking the next step by moving them inside will certainly extend their life span (regular vet care) and make them safer (from traffic and roaming dogs and coyotes). We've never had 12 cats here before, but perhaps we already do!
Astronomical Disappointment
When going out to observe, I've forgotten key pieces of gear, had transportation issues, and had equipment problems that have prevented observing. But rarely, does it seem, that you get clouded out here! True, it is cloudy occasionally, but you can generally wait a day or two and get out to look at that comet or collect a night under the stars.
This morning, however, waking up early to observe the lunar occultation of Venus, There was a thick cloud exactly where the crescent Moon slowly moved over the smaller crescent Venus in the dawn sky. In the picture at left, the thickest part of the cloud is where the moon was located. By the time a clear spot finally passed over, Venus was already hidden behind the Moon's disk (right image). If I was located a couple miles to the west, it might have been a great image!
Believing that when life deals you lemons, make some lemonade - I walked over to neighbor Jack's yard to check on some cacti I was shooting yesterday to see if the blooms had opened - they had! These normally diminutive-looking cacti had some huge flower buds, and opened to nearly 5 inches diameter during the night. Most native cacti open during the day and an individual flower only lasts that one day. I shot a sequence of it yesterday afternoon, hoping to make an animated gif of it opening, but other than the buds slowly tracking the sun, they made no attempt to open, though it was obvious that after returning from dinner last night, it would be a morning debut. I shot another sequence this morning, to see if the other buds would open, but again, little or no daytime activity. Like astronomers, they must be mostly active at night!
So walking home after collecting the gear from Jack's yard, I went looking for the Moon in a cloud gap and was able to spot Venus next to it, now some distance to the west (the moon moves about it's diameter in an hour). I grabbed my little Meade scope and was able to grab a shot before being swallowed by clouds again - be sure to click the image to enlarge it and see the little crescent of Venus. You can also immediately notice how much brighter the clouds of Venus are than the dirt of the Moon. I'll look on the 'net to see if i can find a good occultation pic to post later...
This morning, however, waking up early to observe the lunar occultation of Venus, There was a thick cloud exactly where the crescent Moon slowly moved over the smaller crescent Venus in the dawn sky. In the picture at left, the thickest part of the cloud is where the moon was located. By the time a clear spot finally passed over, Venus was already hidden behind the Moon's disk (right image). If I was located a couple miles to the west, it might have been a great image!
Believing that when life deals you lemons, make some lemonade - I walked over to neighbor Jack's yard to check on some cacti I was shooting yesterday to see if the blooms had opened - they had! These normally diminutive-looking cacti had some huge flower buds, and opened to nearly 5 inches diameter during the night. Most native cacti open during the day and an individual flower only lasts that one day. I shot a sequence of it yesterday afternoon, hoping to make an animated gif of it opening, but other than the buds slowly tracking the sun, they made no attempt to open, though it was obvious that after returning from dinner last night, it would be a morning debut. I shot another sequence this morning, to see if the other buds would open, but again, little or no daytime activity. Like astronomers, they must be mostly active at night!
So walking home after collecting the gear from Jack's yard, I went looking for the Moon in a cloud gap and was able to spot Venus next to it, now some distance to the west (the moon moves about it's diameter in an hour). I grabbed my little Meade scope and was able to grab a shot before being swallowed by clouds again - be sure to click the image to enlarge it and see the little crescent of Venus. You can also immediately notice how much brighter the clouds of Venus are than the dirt of the Moon. I'll look on the 'net to see if i can find a good occultation pic to post later...
Tuesday, April 21, 2009
Evening Ambles
After a couple months of inactivity (I was under doctor's orders to stop exercising after a December infection, and never returned...) a week or so we started evening walks in the neighborhood. I've got a quickie that is about 3/4 mile and another that is about 2 miles. Melinda has been game for the shorter distance, but calls the longer one "a deathmarch". My pace is a little faster than hers, but she also has circulation issues, so I'm a little understanding. Regardless, a regular exercise routine would be good for both of us.
As Melinda blogged earlier, it was the warmest day of the year so far - the 5pm weather said it got up to 97F, but our thermometer said 104+F. As we were leaving the house tonight, it had cooled to 95F, and the humidity was 3%! The dew point was 4F - in other words, if you had a glass of ice water, it was far too dry for any humidity to condense on the outside of the glass! It felt pretty comfortable, though, and I brought the camera to catch any cacti blooms we might cross.
We ran into neighbor Jack, also on his walk. He works as a landscaper with his sons, and with the onset of warm weather, heads in to work at 5am, and is off by lunchtime. The other day he pointed out some of his cacti buds about to pop, and you may see some of the results here soon.
Melinda opted for the quickie walk, and I continued on, partially to see the progress construction crews had accomplished at our nearest major intersection (Prince/Mountain), that was actually shut down for installing new sewer lines all weekend. Even with signs up for days, people were driving through our cul-de-sac all weekend looking for the secret shortcut around construction (there aren't any). It will be about 6 months of heck around here as work continues.
The walk continued, and I finally tried a couple self-portraits while walking with the camera and monopod... Normally the walk is later and I get to see the stars come out and Mercury reign in the northwestern sky, so I've rarely seen my shadow while walking. Will work on getting one of the two of us soon... No cacti shots tonight, but I've got a good supply built up - check back soon!
As Melinda blogged earlier, it was the warmest day of the year so far - the 5pm weather said it got up to 97F, but our thermometer said 104+F. As we were leaving the house tonight, it had cooled to 95F, and the humidity was 3%! The dew point was 4F - in other words, if you had a glass of ice water, it was far too dry for any humidity to condense on the outside of the glass! It felt pretty comfortable, though, and I brought the camera to catch any cacti blooms we might cross.
We ran into neighbor Jack, also on his walk. He works as a landscaper with his sons, and with the onset of warm weather, heads in to work at 5am, and is off by lunchtime. The other day he pointed out some of his cacti buds about to pop, and you may see some of the results here soon.
Melinda opted for the quickie walk, and I continued on, partially to see the progress construction crews had accomplished at our nearest major intersection (Prince/Mountain), that was actually shut down for installing new sewer lines all weekend. Even with signs up for days, people were driving through our cul-de-sac all weekend looking for the secret shortcut around construction (there aren't any). It will be about 6 months of heck around here as work continues.
The walk continued, and I finally tried a couple self-portraits while walking with the camera and monopod... Normally the walk is later and I get to see the stars come out and Mercury reign in the northwestern sky, so I've rarely seen my shadow while walking. Will work on getting one of the two of us soon... No cacti shots tonight, but I've got a good supply built up - check back soon!
It's a dry heat my @#%!!
Yes, yes, it's a dry heat and all of that rot. But, hot is hot. We're having "warmer than usual" weather (so they say). Dean says he's not totally believing of the home weather station temperature (though it's a weather station approved by The Weather Channel, for crying out loud!). All of that aside; today's temp on our weather station was as high as 104.1 F. The neighbor's shaded porch thermometer read 95 as we were in their back yard taking cactus flower pictures. And yes, it's dry. 5% humidity, to be exact. There's no sweating involved, it evaporates too quickly to form beads on your forehead. Oh boy!
Monday, April 20, 2009
Monday recovery
It has been a busy past several days. The retirement parties, remember? Last Thursday we weren't able to make it to Jane's retirement reception from her department (Dean has a cold that was/is kicking his butt these days); but we did attend the 'official' retirement dinner that evening. Dean and Jane were both retirees in the past year, so it was a nice celebration for all of the 2008/2009 retirees. Jane didn't stay for the dinner (continuation of the day party was going on at her house), but was there for pictures, salad, a glass of wine, and received her gift. Dean and I stayed for the dinner, which was quite good, and the presentation of gifts. All of the years of service, represented that evening, added up to over well over 1000! In addition to the gifts, they had a raffle drawing. Dean won two tickets to a dance presentation. We need to call to reserve our seats for that (reminder to self).
Jane was disappointed that we hadn't made it to her party Thursday, but I went over to have coffee with her on Friday morning. Ron, her honey, was in town for all of the festivities so it was good to see him, and even more exciting was being able to see Jane's son, Matt, and his wife Carla! Matt has been in the Army for the past 5 years, and has recently arrived home (safely) from his second tour in Iraq. I get tears in my eyes just thinking about how fortunate we all are to have Matt home safely! His wife, Carla, is a little slip of a thing, and cute as a button. She stayed in Tucson while Matt was in Iraq, but then met him in Texas, on his arrival back to the US. They are here only for a short time, then will have to return to Texas until Matt's discharge in the fall. They will return to Tucson after his discharge.
Saturday's party for Jane was held at her friend, Melissa's, house. She lives in the foothills, near Sabino Canyon. There were lots of friends there, including the fellow who introduced Jane to Ron. It was a great party! Several people shared stories about Jane, from her early days in Tucson, when Matt was a baby, and I was able to share stories from when we were in Junior High together. Matt and Carla brought Carla's mom, Maria, with them to the party also. That was our first time meeting her. She and Jane have become friends as well as in-laws. It was a fun evening for all!
Sunday we relaxed, went to the movies (we saw "Sunshine Cleaning", which we enjoyed). His cold is still really getting him down, and he was up most of the night - coughing. He's home today, and hopefully will benefit from the nap he's taking right now.
Jane was disappointed that we hadn't made it to her party Thursday, but I went over to have coffee with her on Friday morning. Ron, her honey, was in town for all of the festivities so it was good to see him, and even more exciting was being able to see Jane's son, Matt, and his wife Carla! Matt has been in the Army for the past 5 years, and has recently arrived home (safely) from his second tour in Iraq. I get tears in my eyes just thinking about how fortunate we all are to have Matt home safely! His wife, Carla, is a little slip of a thing, and cute as a button. She stayed in Tucson while Matt was in Iraq, but then met him in Texas, on his arrival back to the US. They are here only for a short time, then will have to return to Texas until Matt's discharge in the fall. They will return to Tucson after his discharge.
Saturday's party for Jane was held at her friend, Melissa's, house. She lives in the foothills, near Sabino Canyon. There were lots of friends there, including the fellow who introduced Jane to Ron. It was a great party! Several people shared stories about Jane, from her early days in Tucson, when Matt was a baby, and I was able to share stories from when we were in Junior High together. Matt and Carla brought Carla's mom, Maria, with them to the party also. That was our first time meeting her. She and Jane have become friends as well as in-laws. It was a fun evening for all!
Sunday we relaxed, went to the movies (we saw "Sunshine Cleaning", which we enjoyed). His cold is still really getting him down, and he was up most of the night - coughing. He's home today, and hopefully will benefit from the nap he's taking right now.
Thursday, April 16, 2009
A new computer and parties to attend...
No pics today, sorry to say! I'll have to procure some from Dean, or get out and take some to put on here. While my usual HP workhorse of a laptop has loads o' pictures on it....it bit the dust two days ago. Yesterday was spent seeking out diagnostics, and dare I hope, easy repair??? Is there such a thing for a computer? After trips to two places, it was confirmed - my hard drive was damaged by "unknown causes". While it would be possible to put a new hard drive in, reload Windows, and then pay someone $100 for each GB of files rescued - all for a 5 year old laptop; I decided that it might be best if I moved forward and purchase a new machine. That took us on a shopping excursion to Sam's (best deals around on computers, if you didn't know!). A few hours later we were unpacking my slick new HP laptop, complete with lots of GB's, a built in webcam and microphone (!), and .... Microsoft Vista. This is pushing my learning curve to the max. As our live in student, Jason, says "It's just a prettier version of XP - trying to look more like Apple." It's a challenge, I'll say that! I am getting used to it, but it will take a while - not to mention figuring out the ins and outs of the machine itself. It does have a lot of features that I like. Even though Dean's laptop is only slightly newer than my previous one, his has a lot of features that I didn't have on mine. I especially like having a port to put a camera card in, for ease of transfer of pictures. Nice touch!
Parties! Yea!!! We love parties!!! This week will bring two, maybe three! This evening is the U of A retirement dinner in one of the ballrooms at the Student Union. Dean missed out on going last year, so we were delighted to receive an invitation to this years dinner! The invitation states "Business attire". Dean said he would wear shorts and a t-shirt, as that is what he has worn to work (to do his business) for the past 24 years! He was trying on dress shirts tonight though, so I guess the tie dye and shorts will stay at home this time. Also, this afternoon is the reception that the U is giving our friend, Jane, on her retirement after 30+ years. We aren't sure if we will make it to that event or not, though we wouldn't think of missing her retirement party given by her friends on Saturday! Somewhere in all of the fun I will have to fit in a night of work. But I won't let that deter us from enjoying our soirees!
Parties! Yea!!! We love parties!!! This week will bring two, maybe three! This evening is the U of A retirement dinner in one of the ballrooms at the Student Union. Dean missed out on going last year, so we were delighted to receive an invitation to this years dinner! The invitation states "Business attire". Dean said he would wear shorts and a t-shirt, as that is what he has worn to work (to do his business) for the past 24 years! He was trying on dress shirts tonight though, so I guess the tie dye and shorts will stay at home this time. Also, this afternoon is the reception that the U is giving our friend, Jane, on her retirement after 30+ years. We aren't sure if we will make it to that event or not, though we wouldn't think of missing her retirement party given by her friends on Saturday! Somewhere in all of the fun I will have to fit in a night of work. But I won't let that deter us from enjoying our soirees!
Monday, April 13, 2009
Fisheye Fun!
I love fisheye lenses! With a field of view (FOV) of 180 degrees, you can be assured you can get everything in the picture! Back in my Kitt Peak days, they had a 6mm fisheye that actually had a 220 degree FOV - it was difficult to keep your shoes out of the photo. Not that you would ever hand hold it at nearly 10 inches diameter and close to 15 pounds! I've got slides somewhere, but I've never seen one other than the one I used at the Observatory. Here is what it looked like with a standard film camera - remember what those were?
More modern fisheyes are much more manageable in size. The Tucson Amateur Astronomy Association (TAAA) has an 8mm Nikon on long term loan from Steward Observatory, and since I still work at Steward, I'm it's current keeper, so get to use it a lot. It is the size of a telephoto and weighs about 2.5 pounds, but is about 4 decades old, so optical and coating quality are a little suspect, especially when shooting stars - always a difficult task because of their infinitely small size.
Manufacturers are also currently making fisheyes - Sigma makes one pretty much indistinguishable from a normal lens. At F/4 it is a little slow for astronomy, but just the lat year they started making an F/3.5. Friend Tom Polakis has the F/4 that he has allowed me to borrow several times - and in fact, images have appeared here before. This one on the left appeared in November when Tom, Jenn and a friend stopped by the Mirror Lab for a tour. Set down on the ground at our feet looking straight up, it still caught all of us and is a pretty cool shot. The 8mm fisheye is designed to give a circular image covering horizon to horizon (if pointed straight up) if you used a full 35mm format. With the APS sized sensors I use, it gets the full FOV horizontally, but crops a little vertically. Still, the 8mm is a nice field if it is sharp enough for astronomy.
A couple weeks ago at the Messier Marathon, I knew Tom and Jenn would likely be there, so I again asked to use it under a dark sky. They were more than willing, so I was finally going to be able to use it in a direct comparison with the older Nikon 8mm fisheye. In the early evening, I was busy with the 14", capturing Comet Lulin in the western sky, so put off the fisheye tests, though I did take a self-portrait with the lens a couple feet behind me in the Messier Marathon post.
Finally, with that sequence done, I took a set of 4 frames of the setting Winter Milky Way, and of the gegenshein to the south. The brightest glows visible are of urban origins. In the first one to the left, the brilliant glow to the right is that of Phoenix and Casa Grande to the north. The more celestrial glow is of the Milky Way, and of course, nearly all the Winter constellations are visible in the west, the most obvious being Orion, trailing the Hyades and Pleiades star clusters. A fainter nearly vertical glow, brighter at the base, is the Zodiacal Light - the reflection of sunlight off dust particles in the ecliptic plane (where the planets and asteroids orbit). Total exposure is 15 minutes with the lens wide open at F/4.
This next shot is of the gegenshein. This is a very faint, diffuse glow, again, reflected sunlight from dust particles (in fact, the gegenshein is part of the Zodiacal Light), this time from enhanced reflection on the sky exactly opposite the sun. Difficult to see or image unless from a very dark site, a wide angle lens like the fisheye is just about perfect for capture. The urban glow is from Tucson to the southeast this time, and the layering effect of that edge is from the stacking of the 4 frames as the Earth rotated between frames. The constellations in this part of the sky are less spectacular than the bright winter ones, but Saturn is brightest to the upper right of the gegenshein, and Leo above Saturn. Sixteen minutes total exposure with the Canon XSi.
Unfortunately, the clouds over Tucson moved in, and I wasn't able to take photos for a direct comparison with the older Nikon fisheye, so it will have to wait for another time under a dark sky. But the fisheye view will always have a place in my photographic heart!
More modern fisheyes are much more manageable in size. The Tucson Amateur Astronomy Association (TAAA) has an 8mm Nikon on long term loan from Steward Observatory, and since I still work at Steward, I'm it's current keeper, so get to use it a lot. It is the size of a telephoto and weighs about 2.5 pounds, but is about 4 decades old, so optical and coating quality are a little suspect, especially when shooting stars - always a difficult task because of their infinitely small size.
Manufacturers are also currently making fisheyes - Sigma makes one pretty much indistinguishable from a normal lens. At F/4 it is a little slow for astronomy, but just the lat year they started making an F/3.5. Friend Tom Polakis has the F/4 that he has allowed me to borrow several times - and in fact, images have appeared here before. This one on the left appeared in November when Tom, Jenn and a friend stopped by the Mirror Lab for a tour. Set down on the ground at our feet looking straight up, it still caught all of us and is a pretty cool shot. The 8mm fisheye is designed to give a circular image covering horizon to horizon (if pointed straight up) if you used a full 35mm format. With the APS sized sensors I use, it gets the full FOV horizontally, but crops a little vertically. Still, the 8mm is a nice field if it is sharp enough for astronomy.
A couple weeks ago at the Messier Marathon, I knew Tom and Jenn would likely be there, so I again asked to use it under a dark sky. They were more than willing, so I was finally going to be able to use it in a direct comparison with the older Nikon 8mm fisheye. In the early evening, I was busy with the 14", capturing Comet Lulin in the western sky, so put off the fisheye tests, though I did take a self-portrait with the lens a couple feet behind me in the Messier Marathon post.
Finally, with that sequence done, I took a set of 4 frames of the setting Winter Milky Way, and of the gegenshein to the south. The brightest glows visible are of urban origins. In the first one to the left, the brilliant glow to the right is that of Phoenix and Casa Grande to the north. The more celestrial glow is of the Milky Way, and of course, nearly all the Winter constellations are visible in the west, the most obvious being Orion, trailing the Hyades and Pleiades star clusters. A fainter nearly vertical glow, brighter at the base, is the Zodiacal Light - the reflection of sunlight off dust particles in the ecliptic plane (where the planets and asteroids orbit). Total exposure is 15 minutes with the lens wide open at F/4.
This next shot is of the gegenshein. This is a very faint, diffuse glow, again, reflected sunlight from dust particles (in fact, the gegenshein is part of the Zodiacal Light), this time from enhanced reflection on the sky exactly opposite the sun. Difficult to see or image unless from a very dark site, a wide angle lens like the fisheye is just about perfect for capture. The urban glow is from Tucson to the southeast this time, and the layering effect of that edge is from the stacking of the 4 frames as the Earth rotated between frames. The constellations in this part of the sky are less spectacular than the bright winter ones, but Saturn is brightest to the upper right of the gegenshein, and Leo above Saturn. Sixteen minutes total exposure with the Canon XSi.
Unfortunately, the clouds over Tucson moved in, and I wasn't able to take photos for a direct comparison with the older Nikon fisheye, so it will have to wait for another time under a dark sky. But the fisheye view will always have a place in my photographic heart!
Saturday, April 11, 2009
New Optician In Training
On Friday Cindi (our metrology engineer Mike's wife) brought young son Jack past the Mirror Lab for a visit. He was born on Thanksgiving, so has just passed 4.5 months. Normally, infants take a look at me and start crying - likely because of my beard, so it was nice for a change to have Jack eye me with detached curiosity with nary a tear in sight. Looks like Dad has him desensitized to beards...
Is it me or does he resemble the baby star from the '30s Swee'Pea???
Thursday, April 9, 2009
Word of the day - Cladophylls
It was a beautiful day when I got home after lunch (I'm working half days this week). You don't often get April days with perfect blue skies and highs of 78F, though that is the normal for this time of year. Seems to always be warmer than "normal", and though we've been in the 90s already this season, I feel the need to get out and enjoy the 70s while they are still here!
So I grabbed the digital camera and retraced the neighborhood ramble Melinda and I took last weekend, looking for interesting photos. Melinda's comment from our walk is that I needed a sense of scale in the photos, which may be valid, but it almost made me rebel and go even closer to the objects, so mounted a Nikon macro lens on the Canon XSi (with inexpensive adaptor ring). The lens is so old, it isn't even an AI lens, let alone auto focus, but with the XSi's magnified live view, it is easy to check focus, and a monopod helped steady the view, so I really didn't have to throw out many images.
Looking back on the photos, the young pads of the prickly pear cacti seem to be the main subject. Their official name is cladophylls (clad-o-fils) - "flattened photosynthetic branches assuming the form of and closely resembling ordinary foliage leaves". Locally, they are also known as nopales (no-pah-lehs), and you can buy them in Safeway in the canned vegetable aisle. Supposedly all varieties of the cactus are edible, but there must be certain kinds raised for food - all of these looks pretty prickly, even these that are from this Spring's growth. Scrape off the spines, cut into strips, steam for a bit and you're eatin'! No, I've not tried the canned or fresh versions - perhaps someday...
My first shot was about 80 feet from our front door - our neighbor Susan has what I think may be a Santa Rita prickly pear. The flash of bright purple and green caught my eye from a good distance (the green spicules fall off as the pad ages). The only problem was that I had to (carefully) shoot under another branch of the cactus to get the shot. The other thing I discovered is that many of these shots were made from my knees, and Arizona soil is rocky at best, and covered with cactus spines at worst - I need a cushion or pad to carry with me on future trips. To placate Melinda, I should say that this cladophyll is about 7cm wide (2.5 inches).
This next shot is from the same cactus as the flower shot from Sunday. The red tips of the tubercles attracted my attention, as well as that of the honeybee as well, even though there were open flowers nearby on the plant. Since Arizona is now in the "Africanized" bee zone, you can likely assume any bee you see is a "killer bee", though there isn't much to be concerned about unless you threaten or disturb a hive. It is easier than you think, though - they tend to collect in unusual places, like the water utility meter chambers or even mailboxes, so utility workers and the public have to be a little cautious doing even routine tasks... Anyway, the bee serves as size reference! I do not know what the black substance is at the base of the tubercles - parasites, mold or what. The stuff is not visible in older pads.
This next shot is a favorite because of the gentle curves formed by the glochids (spine clusters). Is it a real pattern or a desire for the brain to want to "connect the dots" to make the curves? While they look soft and fuzzy, they definitely stiffen with age, and eventually become dangerous!
And while these cladophylls look similar to the last, the cactus is definitely different - more of a ground cover than an upright shape, and the pads are considerably smaller. A shot of the flower buds made it into Sunday's post, so am including the pads today. They are only a little over a centimeter across (about .75"), so are quite small. The full-size pads are about 10cm (4" diameter). There has been almost no change in the flower buds the last 4 days, so these desert plants are in no hurry to bloom, though I did notice some saguaros that had flower buds (normally bloom in May or June). Will have to figure out how to photograph some of those when they are 20 feet or more off the ground!
So I grabbed the digital camera and retraced the neighborhood ramble Melinda and I took last weekend, looking for interesting photos. Melinda's comment from our walk is that I needed a sense of scale in the photos, which may be valid, but it almost made me rebel and go even closer to the objects, so mounted a Nikon macro lens on the Canon XSi (with inexpensive adaptor ring). The lens is so old, it isn't even an AI lens, let alone auto focus, but with the XSi's magnified live view, it is easy to check focus, and a monopod helped steady the view, so I really didn't have to throw out many images.
Looking back on the photos, the young pads of the prickly pear cacti seem to be the main subject. Their official name is cladophylls (clad-o-fils) - "flattened photosynthetic branches assuming the form of and closely resembling ordinary foliage leaves". Locally, they are also known as nopales (no-pah-lehs), and you can buy them in Safeway in the canned vegetable aisle. Supposedly all varieties of the cactus are edible, but there must be certain kinds raised for food - all of these looks pretty prickly, even these that are from this Spring's growth. Scrape off the spines, cut into strips, steam for a bit and you're eatin'! No, I've not tried the canned or fresh versions - perhaps someday...
My first shot was about 80 feet from our front door - our neighbor Susan has what I think may be a Santa Rita prickly pear. The flash of bright purple and green caught my eye from a good distance (the green spicules fall off as the pad ages). The only problem was that I had to (carefully) shoot under another branch of the cactus to get the shot. The other thing I discovered is that many of these shots were made from my knees, and Arizona soil is rocky at best, and covered with cactus spines at worst - I need a cushion or pad to carry with me on future trips. To placate Melinda, I should say that this cladophyll is about 7cm wide (2.5 inches).
This next shot is from the same cactus as the flower shot from Sunday. The red tips of the tubercles attracted my attention, as well as that of the honeybee as well, even though there were open flowers nearby on the plant. Since Arizona is now in the "Africanized" bee zone, you can likely assume any bee you see is a "killer bee", though there isn't much to be concerned about unless you threaten or disturb a hive. It is easier than you think, though - they tend to collect in unusual places, like the water utility meter chambers or even mailboxes, so utility workers and the public have to be a little cautious doing even routine tasks... Anyway, the bee serves as size reference! I do not know what the black substance is at the base of the tubercles - parasites, mold or what. The stuff is not visible in older pads.
This next shot is a favorite because of the gentle curves formed by the glochids (spine clusters). Is it a real pattern or a desire for the brain to want to "connect the dots" to make the curves? While they look soft and fuzzy, they definitely stiffen with age, and eventually become dangerous!
And while these cladophylls look similar to the last, the cactus is definitely different - more of a ground cover than an upright shape, and the pads are considerably smaller. A shot of the flower buds made it into Sunday's post, so am including the pads today. They are only a little over a centimeter across (about .75"), so are quite small. The full-size pads are about 10cm (4" diameter). There has been almost no change in the flower buds the last 4 days, so these desert plants are in no hurry to bloom, though I did notice some saguaros that had flower buds (normally bloom in May or June). Will have to figure out how to photograph some of those when they are 20 feet or more off the ground!
Wednesday, April 8, 2009
Back to the project at hand...
It seems that we had a big rush on getting things done around here in early March (in preparation for Carolyn's visit), but since then we've been 'taking it easy'. I know my pattern, I can live with chaos and unfinished projects, but only for so long. Then I hit a "I've got to get this done - I'm sick of this mess!" stage and get back to work. I hit that stage this week, though it was complicated by having to go to class on Monday afternoon, and then work on Monday night. That means that Tuesday was a total wash....must have sleep!
Today, however, I woke up ready to get back into the bathroom ceiling project! We left off with it being mudded with drywall mud, to repair the gypsum exposed area left with the scrapping and stripping of the termite damaged areas. Those areas extended from the ceiling down into areas of wall above the shower tile, as well as the wall above the toilet. I wasn't looking forward to sanding it smooth, thus the procrastination on my part. When I sanded the ceiling in the guest bath it was like being continually hit in the face with loose flour, as the mud dust cascaded down. Not fun, and it really can't be good for one to be inhaling that dust. That sent me to the local Ace Hardware to pick up a dust filtering mask. While it was hot wearing the mask, it was so nice to not be breathing that stuff in while I was working! The sanding was punctuated with multiple rest breaks - but eventually it was done. I tried to put off painting the primer/sealer coat (Kilz), but Dean convinced me it would be better to get that part done today too, while it was dry in the bathroom (before showers steam it up again). Painting was a breeze after doing all of the sanding! Mind you, I only have the Kilz coat on in the areas that were repaired, no finish coats yet. I like the result so far though! I'm still trying to figure out what color to paint the bathroom (the light green colored accessories are temporary until decisions are made). Our goal is to put in colorful Mexican tile, new sink, etc. The project continues, though this repair work was a major hurdle. I'm glad this part is behind me!
Sunday, April 5, 2009
A Walk in the 'Hood
I talked to my sister Kathy this morning - the Midwest is under a winter storm warning today! So just to prove it is springtime somewhere, we took a late afternoon walk with the camera to see what was photogenic. We had a pretty dry winter, so didn't have much of a wildflower season this spring, so we are jumping directly into the cactus flowers, though it is still a little early for them too. Temperatures have been seasonal lately - mid 70s mostly - today's high was a normal 78F.
Our first stop was a mere 60 yards or so from our house - one of our neighbors had a huge cholla cactus laden with flower buds, but no flowers yet. Note that the proper pronunciation follows the Spanish, so cholla is pronounced Choy-ah (double l makes a "Y" sound). There are about 20 species of cholla, nearly a half dozen we spotted on our amble. While all take the generic form of branching cylinders, there is a wide variety of thorn density, branching types and flower colors. We'll have to repeat our walk at regular intervals to catch them in bloom as well, but for now, shape and form will have to do. You can see from the 3 types shown here there are distinct differences. The one at left is sometimes called "Teddy Bear " cholla - from a distance it looks soft and cuddly, but the closeup shows it's sharp teeth! There is another common type called a "jumping" cholla - the segments break off easily (some say they "jumped" onto them), and when they are pried off the passerby later (human or beast), the segment takes root to propagate a new plant. Again, flower pictures in a future post...
Another common type of cactus is the prickly pear, and similar to the cholla, there are numerous species in the area. Notably, some have nasty looking thorns, some look to be thornless, but close examination shows clusters of fine, tiny barbed spines called glochoids. Brushing past the pad of a prickly pear, you might think you escaped harm, only to later discover from the burning pain that you got a few dozen of these spines in you that need a tweezer to remove. The pictures here are from 2 plants - the first had both buds and a few flowers that were still open (and were popular with the bees). The second plant had much smaller pads, but was covered with buds that should be a spectacular sight in a week or so. Again, you can see the wide variety in appearance, though the general form is the same. Interestingly, cholla and prickly pear are related - instead of branching cylindrical forms for the cholla, the latter have interconnecting pads.
The last plant to show off tonight is not a cactus, but is a native desert shrub. The creosote bush has numerous yellow flowers this time of year, which transform to seed balls for dispersal in the wind. Fortunately, both are visible this time of year, and it makes a striking plant. The creosote bush makes a pungent fragrance, especially in the summer rainy season, and is perhaps the most characteristic scent of the Sonoran Desert. There is a very good book about the Sonoran Desert and the local population of Tohono O'Odham called "The Desert Smells Like Rain" - well it is the creosote that makes that smell!
Our first stop was a mere 60 yards or so from our house - one of our neighbors had a huge cholla cactus laden with flower buds, but no flowers yet. Note that the proper pronunciation follows the Spanish, so cholla is pronounced Choy-ah (double l makes a "Y" sound). There are about 20 species of cholla, nearly a half dozen we spotted on our amble. While all take the generic form of branching cylinders, there is a wide variety of thorn density, branching types and flower colors. We'll have to repeat our walk at regular intervals to catch them in bloom as well, but for now, shape and form will have to do. You can see from the 3 types shown here there are distinct differences. The one at left is sometimes called "Teddy Bear " cholla - from a distance it looks soft and cuddly, but the closeup shows it's sharp teeth! There is another common type called a "jumping" cholla - the segments break off easily (some say they "jumped" onto them), and when they are pried off the passerby later (human or beast), the segment takes root to propagate a new plant. Again, flower pictures in a future post...
Another common type of cactus is the prickly pear, and similar to the cholla, there are numerous species in the area. Notably, some have nasty looking thorns, some look to be thornless, but close examination shows clusters of fine, tiny barbed spines called glochoids. Brushing past the pad of a prickly pear, you might think you escaped harm, only to later discover from the burning pain that you got a few dozen of these spines in you that need a tweezer to remove. The pictures here are from 2 plants - the first had both buds and a few flowers that were still open (and were popular with the bees). The second plant had much smaller pads, but was covered with buds that should be a spectacular sight in a week or so. Again, you can see the wide variety in appearance, though the general form is the same. Interestingly, cholla and prickly pear are related - instead of branching cylindrical forms for the cholla, the latter have interconnecting pads.
The last plant to show off tonight is not a cactus, but is a native desert shrub. The creosote bush has numerous yellow flowers this time of year, which transform to seed balls for dispersal in the wind. Fortunately, both are visible this time of year, and it makes a striking plant. The creosote bush makes a pungent fragrance, especially in the summer rainy season, and is perhaps the most characteristic scent of the Sonoran Desert. There is a very good book about the Sonoran Desert and the local population of Tohono O'Odham called "The Desert Smells Like Rain" - well it is the creosote that makes that smell!