My life with chemistry

Yep, I've been there, too.

As a child, my main recurring Christmas gift was a chemistry set. That was back when chemistry sets were "dangerous", with real chemicals that you could actually get to. I preferred the "experiments" that changed colors and exploded.

I once made a batch of gunpowder. My father was skeptical as to whether it would actually burn or not so he placed a little pile on the wooden floor in our walled-in back porch and lit it.

It burned.

In school, I was fond of labs. Show-and-tell was often a chemistry experiment. It often resulted in an evacuation.

In elementary school, I set up a demonstration of how crude oil was cracked to make different compounds. The science teacher did the actual demonstration. There was fire involved so they didn't let a little kid perform it. That would be dangerous.

I told him the tube was getting blocked. He didn't listen.

When it blew, the cork in the test tube hit a girl in the front row and knocked her out of her chair.

Oh, I continued my mayhem into college. I once spilled some concentrated hydrochloric acid on the floor of a class laboratory. The correct response is to neutralize the acid with a base and then wash the spot. My choice of base? Concentrated ammonia solution.

Unfortunately, the gases given off by ammonia solution and hydrochloric acid, ammonia and hydrogen chloride, will combine in air to form a white, solid, particulate substance, ammonium chloride.

Soon, I couldn't see a foot in front of my face. Another evacuation.

My first ten years at Auburn University was a five year curriculum in Pharmacy. I wanted it for the physiological background that I could take into a double major with psychology. I was interested in neurophysiology before neurophysiology was cool. But there was also a lot of chemistry to keep me happy. 

For the first ten years at Auburn (I spent twenty years there alternately studying and working my way through a double major and graduate school.) I variously commuted from home in Valley, Alabama and lived in a dormitory. I didn't drive, though. For awhile, I tagged along with a chemistry professor who lived in Valley. I paid for the lift working as his lab assistant. He collected amino acids, synthesizing one after another and determining their properties. There wasn't much color or explosions. There could have been explosions but I would have lost my ride.

But I did get to watch him run his tests and I washed a lot of glassware.

Occasionally, there was a class (for credit) that was basically students helping a professor with their project. I jumped on those.

It's been awhile since I've played around with chemicals. Chemicals for home exploration became scarce about the time I graduated from college. Blowing up buildings full of people became a thing and the only way you could order a laboratory grade chemical was if you had proof that you had some professional or occupational reason to have it. Chemistry sets became safe (lame). You couldn't actually get at the chemicals; you could only transfer them from one closed container to another. And even if you could get at them, they were all very dilute solutions and there was only enough to perform the "experiments" in the manual.

Things  have loosened up now and you can buy reasonable chemistry sets and individual chemicals online (for instance, from Home Science Tools) and, in larger cities, from local dealers who cater to hobbyists. 

I'm not sure how I want to approach chemistry next year. I don't want to rely too much on laboratory grade chemicals so as to keep close to the portable and inexpensive philosophy of the blog, but we can't really avoid some chemical purchases. It would also be hard to avoid some level of chemistry hardware - glassware, heating equipment, supports, those sorts of things, but all that tends to be pretty inexpensive.

Two resources I keep close are: 

American Science and Surplus

and

Home Science Tools

They have a lot of the basic material at prices that adventurers can afford.

The blog is basically for introducing adventurers (including myself) to different fields. For more in-depth study, I am writing the LabBooks, and I do want to start one on Chemistry. Like the astronomy and physics LabBooks, they will be a long term project and I'll be working on very basic topics for a good while. But they'll be available at the Timeline as they progress.

In the meantime, have a fun and satisfying New Years Eve and New Years Day, and may all your future years be better than any that has gone before.

Years

If you've been following this blog, you'll have noticed that I've slowed considerably. The pandemic has had a lot to do with that, along with...aging, I guess. But I'm still on the trails.

This last picture is appropriate. It's the National Mining Museum in Leadville, Colorado. It should be on the bucket list of anyone interested in geology. Housed in a retired high school, it displays everything mining and mineralogy.

A close friend wanted to drive to Vale to hike around this picture postcard tarn...

Despite two feet of snow, we finished early and decided to go into Leadville. Glacial topography and mining...a perfect lead-in to next year when I will segue from physics and astronomy to chemistry and geology, mostly geology because the Denver area is a geotourists dream.

I won't be leaving physics and astronomy behind. I'll keep working on the LabBooks, but my trail adventures will carry me from the margins of the Rockies into the mountains.

I'll be focusing on my back yard and I invite you to join me in exploring your own back yard. You might be surprised by what you find there.

And, as always, I wish for you a greater future than any that has gone before.

The Mosquitoes

When I take a vacation, I devote all of my time to learning about new surroundings...

Wrong!

I enjoy myself, but learning is a part of that. I live within sight of the Rocky Mountains, but I don't get into them that often, so I appreciate what opportunities I get.

Some tribe members came down from Michigan to spend a week in the mountains and our House stayed with them.

The Mosquito Range separates Fairplay, Colorado from Breckenridge. Fact is, we saw one mosquito the whole week and, although Colorado has a diversity of biting flies, there aren't many mosquitoes. I found some of the history of the Mosquitoes here: 

https://freeskier.com/stories/chasing-history-in-the-mosquito-range

But where the name came from...I haven't the foggiest.

The drive from Denver was spectacular, bringing us over Kenosha Pass, but we didn't see any of it because it was night and we were driving through storm clouds.. an adventure in itself. The mountains open up into one of the great high altitude valleys, called parks. Fairplay is in the northwest corner of South Park, and, yes, this is the South Park of television fame/infamy (according to how you like your comedy.) Our destination was in the mountains above Fairplay.

Colorado is tricky. If you were taken from some other part of the world and placed, blindfolded, near Denver, your eyes might tell you that you are somewhere near sea level. The ground is relatively flat. The mountains are right there to the west but an unobstructed view to the east would stretch far. Your lungs would tell you something else because the land actually slopes up from the Mississippi River, over 800 miles away, to Denver, and Denver is a mile over sea level, which means that there is less atmospheric pressure and oxygen.

Fairplay is similar except, ignoring how flat the ground is, Fairplay is almost 10,000 feet above sea level, and even people from Denver might have some difficulty breathing there (I did!)

The Mosquitoes are high peaks. In the twenty miles between Fairplay and Breckenridge are four fourteeners and several other summits above thirteen thousand feet. Our lodge was at a little over ten thousand feet. It was up the side of the valley over the middle fork of the same river that flows through Denver, the South Platte.

The first morning I was at the lodge, I just missed a herd of elk tramping across the property. I missed a lot, but my camera wasn't idle so I'll share what I managed to photograph.

Aspen and evergreens dominated the fall foliage. Aspens are closely related to poplars, in fact, the scientific name for the genus is populus. They like the cold but can survive the short Colorado summers. We have one in our back yard in Centennial.

They are rathers vicious. They secret a toxin that keeps undergrowth from around their roots, which spread out to form other trees. There is a grove of about twenty aspens uphill from the lodge. They are all one tree. Individual trees might live over 100 years but there is a colony in Utah that has a root system estimated to be 80,000 years old.

Crystal Lake Trail carried some of us a few hundred feet above Alma, Colorado, A small town in the Mosquitoes. Alma was getting some snow. We were in the clouds and were getting pelted by blocky, hexagonal crystals of ice called "graupel". We persevered.

We began our 4+ mile trek out in mountane forests of evergreen and aspens but the trees quickly shrank to bushes and brambles. This stuff was all over the place.

My companions asked what it was and I didn't know, so I took a picture and later subjected it to Google Lens. (Although the lodge had WiFi, there was no Internet where we were.) All the willows I had ever seen were trees but, in montane environments, they adapt to form these low, cottony bushes. We were taken by the aromatic leaves. 

Willows were one of the early sources of pain relieving salicylates. Modern aspirin is acetylsalicylic acid, but methyl salicylate is the aromatic ester in wintergreen and other salicylates smell good also. The reason for tagging the acetyl group onto salicylate is that the other compounds are rough on stomach linings. Nevertheless, if you have a pain, you can use willow bark or wintergreen tea to get some relief. Just don't overdo it.

We crossed the treeline at around 12,000 feet and none had passed out from a lack of oxygen. One of us was used to diving around the coast of North Carolina before joining us in Colorado and it seems to help. The rest of us were a little out-of-breath. Big trees need more air to thrive than shrubs so they like lower elevations.

Our destination, Crystal Lake (and, by the way, there are at least three Crystal Lakes between Fairplay and Breckenridge. It's easy to get confused.), resides in a scooped out depression in the side of the mountain. It's pretty obvious that there was once a glacier here. These glacial depressions are called "cirques" and the lakes are called "tarns".

What drew people to these mountains was gold that is washed out of the granite by streams and collected in gravels, the gold being heavier than the other stuff in the stream beds. It's called placer mining and the above photo was taken from a mound of rock left by a mining operation. It sloped down to a marshy area that had claimed a Jeep (?!?) and, then, the lake. This place is probably packed with wildflowers in the spring.

The mountains that form the eastern wall of the Rockies can be a scrabble of metamorphic, sedimentary, and igneous rocks, but the Mosquitoes are in the heart of the Rockies and all that has been scraped off by wind, rain, and lots of ice. These are granite mountains.

The Continental Divide runs through here. The waters of the South Platte, running through Fairplay, end up in the Mississippi River and continue to the Gulf of Mexico and, thus, to the Atlantic Ocean. The waters around Breckenridge drain into the Blue River, which is a tributary of the Colorado, so they end up in the Pacific Ocean (well, they would if they were not intercepted for drinking water and irrigation by folks west of here.)

The next day, a few of us walked down to the river below the lodge. Here, the valley carved out by the South Platte broadens as it approaches South Park, itself a wide valley swept out by the South Platte and it's tributaries. The rivers pours out of the hard granite of the Mosquitoes into softer sedimentary rocks of a faulted and folded bowl between the higher mountains. The softer rock allows the river to meander more and more.

The broken thunderstorms afforded us with a nice valley rainbow.

The area is surrounded by several of the local fourteeners, like Mt. Sherman.

It was gravel beds like these that drew pioneers to the area. The granite washed out of the mountains carried with it gold. 

These streams are not like the ones I'm used to back east...or the ones where I currently live at the edge of the Great Plains. Those streams have a thick bed of soft material to dig into. The ones in the Rockies meet hard bedrock quickly so their beds tend to be shallow with vertical shoulders.

That night, I pulled out several scopes to look at the sky. The first few days were too cloudy to allow any sky gazing, but we finally got some clear skies and I saw the Milky Way for the first time since the early seventies. It's hard to find dark skies today. But the heart of the galaxy and Orion were low behind the mountain so I didn't try very hard for astrophotographs.

It was a nice week away from the faster pace of Denver.

On the way back to Denver, we pulled over to get a photo of this lady.

I've seen moose tracks around but this is the first moose that I've seen.

I advocate for learning where you are. We lose our anchor in the universe when we don't appreciate our own, personal universe. Every place has it's attractions and values. And it's easier to learn in your back yard. But travel opens new vistas and opportunities.

Grass

For lifelong learning, most of your time will probably be spent in your own neighborhood, and that's okay. The same things that make the universe go, that create stars and make atoms spin, are the same things that make your local world go. And all places have their points of interest.

I live at the western edge of the great plains. We have some nice wildflowers including my favorite, milkweed. The plains are home to spectacular sunflowers and there's a patch of solanum rostratum, buffalo bur, that had taken up in our back yard.

But the headliners of the plains are the grasses and their relatives, the sedges and rushes.

Most people aren't that impressed with grasses. They aren't very colorful. "Hey. I have a lawn. What's so special about grass?"

What grasses lack in color, they more than make up for in patterns. Take the three grasses I spotted the other day on a grocery run.

Setaria grasses include some of our  grains like millet and korali. These wild ones are little puffs.

These silky grasses are called bromus or cheat grasses. I identified them using Google Lens, an app that will take a photo and give you options to identify what's in the picture. I've found it very useful for identifying everything from wild plants and animals, to architecture, to landscapes. 

Blue Grama, the state grass of Colorado, puts out feathery blooms. 

Different grasses bloom and seed at different times so any hike down the Little Dry Creek trail will give me something different to see.

What's special about your area?

Three shades of twilight

It's hard to pinpoint when twilight - dawn and dusk - begins or ends. If I hike to the top of the hill, right around where I stop in at Milano's Coffee for a milkshake, I can see the horizon out on the plains and, as soon as the center of the sun clears the horizon, that's the end of twilight. But dawn begins as a gradual lightening of the skies.

I can't see the geographic horizon to the west since the massive mount Evans blocks my view, so I have no visual indication of when dusk begins or ends. 

Astronomers can be much more precise. There are three stages of twilight. Say that you are on a hike along a trail and you expect it to turn into a night hike. You will notice that, even after the sun has set, you will have some time before you have problems seeing what's around you. That's called "civil twilight." Astronomers peg it from the time the center of the sun drops below the horizon to when it is 6° below the horizon.

As you continue to walk, you can still see pretty much where you're going but it's harder to see objects at the side of the trail. And you can see some of the brighter stars. This is the time of "nautical twilight". This was prime time for ancient mariners because they could see both the horizon and navigational stars like Polaris and navigation was easy. For astronomers, nautical twilight is the period when the center of the sun is from 6° below the horizon to when it is 12° below the horizon.

Pretty soon, you have to pull out your flashlight to see where you're going. Keep the red light mode on so you don't destroy your night vision. There's still a little light but the stars are beginning to really put on a show. You might see tiny stars shining back at you from the undergrowth, eyes reflecting your light back at you. This is "astronomical twilight" when the center of the sun is from 12° to 18° below the horizon. After that is night proper until the sequence reverses in the east with the beginning of dawn.

You can pinpoint the three stages of dawn and dusk by pulling up the Time and Date website:

https://www.timeanddate.com/

and type the name of the nearest town into the search bar at the top of the home page. You'll get a lot of information including a link entitled "Show more twilight and moon phase information". It will take you to a page that gives you all the times of day (and night, and all the twilights.)

Between day and night is a band of half-light, called the "terminator", that moves across the globe as the Earth rotates. If you have Google Earth, you can see it. There's a button in the toolbar at the top labeled something like "Show sunlight on the landscape."

How broad is the band? That varies according to the time of year and your latitude, but with those two pieces of information, you can calculate it. Start by figuring out how long your twilight lasts from the times at Time and Date. You can get your latitude from Google maps or Google Earth, or by finding your location in Wikipedia. If it has an article, it will tell you the geographic coordinates. You will want the degrees latitude as a decimal fraction (instead of degrees, minutes, and seconds).

You can figure out the circumference of the circle around the Earth at your latitude using the following equation:

c=2πR(cos l)

where R is the radius of Earth (6371 km or 3959 mi.) and l is your degrees latitude. You know that there are 360° in a circle, and you know (or now know) that it takes one hour for the Earth to rotate 15°. Can you figure out how broad the terminator is in kilometers or miles?

Give it a try, and while you're on your night hike, take in the beauty of the sky and trail, but watch your step!

When you can't see the stars...

Astronomy is a sometime thing (apologies to George Gershwin). Light pollution, haze, clouds, so many things can sabotage a night of stargazing, so what do you do when you want to see a star but can't.

Well, study the thing that blocks your view. I've been impressed with how well phone cameras can perform after the sun goes down. For instance, sunset doesn't necessarily end when the sun goes down. The sun may have set on you but the clouds above you are still in line if sight of a low, red sun.

Here are some low clouds over Centennial, Colorado about half an hour after sunset. 

Recently, we've been having some very uncharacteristic thunderstorms in the area. It's difficult to impossible to capture a lightning strike in a photograph, but a video is a different thing entirely.

Thunderstorm

Fog, smog, clouds are all interesting in their own light and they show a different face at night than they do during daylight.

The Foundation

That's what physics is...the foundation of science. It's at the bottom of every material and energetic process in the universe from the exotic heart of a supermassive black hole, to your car's engine, to your own metabolism. So, physics is important.

I still plan to shift my focus to chemistry and geology next year. I'm really looking forward to exploring the spectacular geology in my area. But I don't want to drop physics and astronomy, so I will continue working on the physics and astronomy LabBooks.

It will be awhile before I've finished the introductory section of the Astronomy LabBook but I've completed the first two brief, introductory sheets of the Physics LabBook and an indepth exploration of measurement, precision, points, graphing, and geometry with lots of hands on excursions. You can find it here:

Physics LabBook

The first few sheets will be concerned with the fundamental measurements and methods that physicists use to explore the world. I make sure to bring it home to do it yourself projects and survival techniques.

Like the other LabBooks, this one is a LibreOffice spreadsheet, so download and install the free LibreOffice suite before trying to view it.

Catch the sun

You've probably read that you can't look directly at the sun without damaging your eyes. At an approximation, take that as a fact.

It's not exactly true, though. You can actually look at the sun briefly without burning a hole in your retina. A little longer and you will temporarily wipe out the part of your retinas that the image of the sun fell on. Longer than that and that part of your retina will be permanently out of operation. 

The problem is that everyone is different. If someone tells you that they looked at the sun for three seconds without lasting effects, your eyes might be able to take only one second. And that is why I suggest that you never look directly at the sun.

Your vision is precious. Don't risk it.

The image of the sun on the light sensitive part of your camera will also destroy it in a very short time.

But there are ways to observe the sun. You can get a blurry image with little cost. It's acceptable for viewing solar eclipses but not for detailed solar observation. For that, you will have to put out some cash.

I only do the inexpensive stuff here. This is my solar observation tool kit.

The most common means of viewing the sun is with a pinhole. That's what the silver rectangle is. I cut a small square out of two pieces of card stock (index cards are perfect, and folded a piece of light weight aluminum foil over one side. In the middle of the square hole, I used a pin to punch a tiny hole in the foil. To punch the hole, I placed the foil side down on a hard surface (I used a craft cutting board but a marble table top or similar surface will work fine) and pressed a pin point against it.

Holding the pinhole over another card and using it to project the sun's image, I got the following.

It's...uh, that tiny dot in the center of the black circle...you might have to enlarge the photo. You can move the pinhole nearer and further from the card. When you move it away, the dot gets bigger. The problem is that it also gets dimmer.

A large hole will provide a larger image but it will be dimmer and fuzzier. The main problem is that light from the surrounding area will wash out any details.

I have two inexpensive (but very cool) science kits that include pinhole projects. The white box is from the ScienceWiz: Light kit. I cut a hole, about a half centimeter, into one wall of the box opposite the side that isn't there (the box only has five sides. The missing side has been replaced with wax paper.) When I aim the pinhole at the sun, the sun's image is cast onto the wax paper. The box shields the image from glare.

The hole wasn't very round so the image came out sorta whompsided. A paper punch would have given me better results. But, if you do this project, don't expect to see a lot of details. The big hole is better suited as a pinhole camera for landscapes.

I got a much nicer image by replacing the lenses from a simple refractor telescope kit (the Project STAR telescope bought from Home Science Tools) with a foil pinhole (I punched a pushpin completely through the foil to create a larger pinhole) at one end and wax paper at the other (the kit instructions tell how to build the pinhole tube). 

With a pinhole tube, you can slide the telescoping cardboard tubes in or out to sharpen the image.

You can also use telescoping mailer tubes to create a pinhole tube.

A second way to inexpensively look at the sun is to use a #14 welder filter. It cuts out more than 99% of the sun's light. Eclipse glasses (which are really inexpensive) do much the same thing. Old science kits suggest that you use a candle to coat one side of a microscope slide with soot to create a solar filter. The problem is that it's very easy to scratch away a tiny section of soot and that's all the sunlight you need to blast your retina or a camera CCD into oblivion...not a good idea.

The second photo is zoomed. Zooming with a digital camera won't give you any more details but it will make the image larger (and fuzzier).

The pinhole phenomenon produces an interesting effect during an eclipse as spaces between leaves on trees act as pinholes to cast images of the sun onto the ground.

These methods will give you great images of an eclipse. (See the blog for August 21, 2017 for images of the last total eclipse in Colorado.) For observing the sun in detail, you need something that will either project a cool image (a lens will just start fires), or a special filter. You can buy a special telescope called a sunspotter for a little over a hundred dollars. With it, you can see sunspots and flares.

You can use a sun filter (or welder filter) with a scope but the filter has to go over the objective lens and it has to cover the objective completely. You can get a sun filter for most telescopes and some binoculars. Here's my Carson telephoto lens on my smartphone with a #14 welder filter between it and the sun.

Here, you can see the sun's corona. The bubble at the upper right of the image is an artifact, but you can just see a solar flare below it. This is about the best I can do with my set up. Any sunspots would be masked by the general brilliance of the sun's image.

You can project the image if the sun through a scope but keep in mind that things (the scope's optics, the surface you project onto, whatever's under that...) will quickly heat up.

If you want to seriously get into solar observation, the sunspotter telescope is one way to go.

Another is an H alpha filter. It filters out all light except a very narrow band from the hydrogen spectrum (thus, it's name). It's expensive but it will show you incredible solar details. It will also block light pollution in urban settings.

Professional astronomers use radio, ultraviolet, and infrared telescopes (in addition to their regular telescopes) to get their solar images. For a lot of cool images of our hot sun, check out Wikipedia (https://en.m.wikipedia.org/wiki/Sun).

As a curious astronomy observer, you don't have to spend a lot of money to watch space and most of the inexpensive pieces of equipment are also very portable so you can easily carry them on the trail. With a little more money, you can turn astronomy into a hobby that can grow to any level.

The sun is a fascinating object to track but be safe and enjoy it.

I am a camera

Actually, I am not a camera. That was a quote from "Into the Lens", a song by Yes. You should find it on the Internet and listen to it while you read this blog.. or not.

Astrophotography is a fun hobby. To get great photos, you need to put out some substantial funds, but to get nice shots, like my shots of Venus...

You just need a phone camera, a way to connect it to a tripod, and an inexpensive telephoto lens.

You also have to have an intimate knowledge of your scope and your camera.

For any photographic work, you need to know your camera's field of view and resolution, and if you don't have this in your phone's specs, you can easily determine them like I did for my phone camera. Here's my setup.

I carried my portable podium onto the patio with a half meter ruler held up by optical bench stands (those are from an inexpensive set I bought from Home Science Tools. Great company. You could probably make your own.) Under the podium, I stretched out 20 feet of a tape measure.

On the bottom photograph above, there's a plumb bob I threw together using a random piece of plastic I had lying around. I hung it from my phone tripod clamp with a 1/4 20 wing nut and cord. I clamped that to my phone so I could tell how far away I was from the ruler using the tape measure.

To figure out the angular field of view, I stood back until the ruler filled the camera view from one side of the frame to the other. 

That was right at 2 feet (27 inches).

Next, to determine the camera's resolution, the distance at which two close objects at a specified separation can just be seen as two separate objects, I moved back until the millimeter markings on the ruler just blurred into indistinguishable marks.

That was at 28 inches.

So, why would I want an angular field of view? Many terrestrial scopes, including binoculars, give their field of view in terms of width in feet at 20 feet. That's okay when you're working at distances that can be expressed in feet, or even miles, but astronomers work in distances from astronomical units (1 AU is the average distance from Earth to the sun) to light years (a light year is about 6 billion miles) to billions of light years.

If you draw a great circle around the Earth, at any distance, it is composed of 360 degrees. The moon, as seen from Earth, has a diameter of about half a degree (we say it "subtends" an arc of 0.5 degree.) So does the sun, although the sun is much bigger. That's why the moon can block out the sun in a total eclipse. Astronomers work with arcminutes (an arcminutes is one sixtieth of a degree) and arcseconds (60 arcseconds make up an arcminute, 3600 arcseconds make up a degree). Binary stars, as seen from Earth have a separation of from 20 to less than one arcseconds.

Next...the math.

I have set up a right triangle here. The angle from one end of the ruler to the camera, back to the center of the ruler is half the angular field of view. I know the distance from the ruler to the camera (d), and I know that the half ruler is 250 millimeters long (it's a half meter ruler). I can use trigonometry to figure out the angle.

I need everything to be in millimeters, so 27 inches is 685.8 mm. The tangent of my angle is 250 mm/685.8 mm, so the half angular field of view works out to be 20° and the full field of view is 40°.

Mount Evans, pictured here, is 40 miles away. The tangent of half my view angle is the half width of my view field divided by the distance. That means the half width is equal to the tangent of half the angular field of view times the distance, or 14.6 miles. My full field of view at 40 miles is about 29.8 miles.

I figure that my measured distance to the ruler could have been off by 2 inches in either direction, so I can calculate my error by recalculating my field of view at 29 inches and 25 inches and that error turns out to be about ±3°.

I can calculate the resolution of my camera using the same method but, instead of using half the ruler, I use half a millimeter. The distance from the ruler where I can just make out millimeter markings is 31 inches or 787.4 millimeters. That gives me a resolution of 0.07° ± 0.005° . That's a far cry from being able to see binary stars as two stars, but, at least, I can see the sun and moon as a disk instead of just a point source of light.

My camera's electronic zoom does not increase resolution at all but my telephoto lens does. If I wanted to check the resolution of my camera with an optical system like a telephoto lens, binoculars, or a telescope, I wouldn't use trigonometry, I would just see if I could see a pair of stars with a known separation.

Angular field of view is a more flexible measure than width of view at a given distance, but now you know how to find your camera's angular field of view.

Blogger blogs: A little lesson

Ah, well, yes...I see..  

So, this is a lifelong learning blog in which I recount my learning experiences, and I have had a new one.

Some learning experiences are created, others just, sorta...happen to you.

I have learned that you can cut and paste images into a Blogger blog. Just don't expect them to stay there.

File it under "hoisted by my own petard". 

I discovered that I could just compose a whole blog in Google Docs and then copy the text and images over to Blogger, thus circumventing the image insert command in the Blogger editor. I started doing that at the end of 2019 and it worked well until a couple of weeks ago. Then it exploded.

It is frustrating, weird, and sort of interesting.

It seems to be chaotic. Some photos are still there. How are they different from the ones that disappeared? Computers are frustrating (or is that "fasctrating").

In Google's defense, I never saw where they suggested using cut and paste for images.

So, two years worth of photos. They're still in my photo archives. I might take a while to reinsert them, a few at a time. In the meantime, I will go back to inserting pictures via the insert command.

If you want photos from an exploded blog, drop a line and I'll be glad to send them by email.

grph

Survey quest

Have you ever seen one? They're everywhere. They're so ubiquitous, in fact, that you might not notice them.

Survey markers.

Many show where pipes and cables are buried. Some mark property boundaries. The one pictured above is a standard survey marker placed by the National Geodetic Survey of the United States (NGS).

Each survey marker of the NGS is paired with a file in a publicly accessible database that stores a huge amount of geographic data. Other countries have their own versions of the NGS.

Geocaching is a popular pastime worldwide. People establish a container of inexpensive souvenirs for other people to find. Geocachers take an object out and leave one in its place. The fun is in the journey - the searching and finding. There are geocaching websites on the Internet. Check them out...that just might be your next passion.

Survey markers are sorta the postage stamps of geocaching and some geocaching sites have sections about survey markers. Like stamps, they all have more or less interesting backstories on file. For instance, there is a survey marker on a step in the Colorado State Capitol in Denver that shows precisely (and I mean "precisely") where a mile above sea level is.

Last fall, I used a local survey marker as a destination for a hike. I planned to use it for an activity in one of my LabBooks. I found it by using the map search engine, here:

http://benchmarks.scaredycatfilms.com/index.php##

The marker was about two miles away on the other side of nearby Interstate 25. 

The marker is on a little concrete mound on a shoulder between an urban street in the Denver Tech Center and the Interstate. There's a stake there to indicate its position.

It was a reasonable urban hike on a nice day.

If you tap (or click) the marker on the website map, you get a link to the data file.

How much information could be attached to such a little metal plate. You'd be surprised. There is position information - latitude and longitude to five decimal places of seconds, and altitude in millimeters. There's also a detailed description of the site and the buildings and streets in the area.

If you want to know your place in the world, a survey marker will tell you.

The map also gives a link to a geocaching site:

https://www.geocaching.com/mark/details.aspx?PID=AE5259

There are survey markers associated with monuments, mountain peaks and other geological points of interest, and town squares. If you think you might be interested in benchmark hunting (that's what it's called), check out this site:

https://www.geocaching.com/mark/