New location, first excursion

This one was about dental work...very interesting but probably not for everyone, but it did give me an opportunity to check out some of the neighborhood. 

The roads here are a spaghetti mess so they're taking some time for me to learn, but that does mean that there's little though traffic and not much opportunity to get up speed driving. It really is a quiet little neighborhood. Unlike an HOA, it looks like people live around here. It's not junky but people work on their cars in the yard and the lawns are not homogeneous and manicured. I think I'll like these people.

A short walk from our house, on the street we have been using to get home, is a park that has Little Dry Creek (which I have never seen dry, and is named after the Little that Littleton is named after, not because it is necessarily smaller than Dry Creek) flowing through it. It provides a convenient corridor to the major road that forms the eastern boundary of the neighborhood. 

[Walnut Hill Park]

Part of the South Suburban Parks and Recreation trail system, this trail links up with an extensive network of walking, biking, and connector trails. The trails in the Denver area are intended to be an alternative to vehicular traffic.

This is the second snow of Autumn 2019 and the combination of snow, traffic, and mountains is pretty much iconic for Denver.

[Shots around Centennial]

I caught the RTD light rail from the Dry Creek Station, about a mile and a half walk from my house, but on the return trip I checked out the Arapahoe Station which seems closer. I'm sure I'll have photos of that in later articles.

[Dry Creek Station]

I'll be recuperating from our move for the rest of the week but will start my morning doctor-prescribed walks next week with excursions around the corners of our neighborhood. Hopefully I'll find interesting things to post.

Relocations are irritating and exhausting but, for the adventurer, they mean new environments and opportunities for chance to take you into new territories. If you just have to relocate, take advantage of your new surroundings. New is good.

The Chamberlin Observatory

[Chamberlin Observatory]

Before our recent move, there was an astronomical observatory right down the street from me. Why would there be an observatory in the middle of hazy, light polluted Denver?

Well, when it was built in the late 1800s, it was a good ways outside of Denver, A residence was built nearby so the head astronomer, Herbert H. Howe, would not have to travel to and from Denver to do his work. The observatory was named for a patron of the observatory, Humphrey Baker Chamberlin. For more in-depth reading about the observatory and the Denver Astronomical Society that maintains it, check out their website at

https://www.denverastro.org/

My friend, Mysh, had two tickets to the Observatory's monthly open house (not expensive but they have to limit attendance because the building isn't that big and parking is scarce.) She offered to take me along and it was a timely offer since I will be looking at astronomy and physics next year in my adventures. The trip would make a nice segue.

[The refractor]

The main telescope is a Clark-Saegmuller 20 inch refractor. The telescope itself was built by Alvan Clark & Sons and the mount was built by George Nicholas Saegmuller, thus "Clark-Saegmuller". The objective lens is 20 inches in diameter. The eyepiece in use when we visited gave a magnification of 120 times but greater magnifications are possible. 

Refractor scopes have been around for a long time but they were mostly used for spotting on land and sea until Galileo improved the optics for astronomical use. Since then, many designs have been developed. Still, telescopes use lenses and/or mirrors to focus the image of distant objects and gather the tiny amount of light that reaches the Earth. More recently, antennas have gathered other kinds of electromagnetic waves from space, and satellite based telescopes have escaped the distorting effects of Earth's atmosphere to bring incredibly clear images of deep space objects.

The staff presents a lecture on current astronomical topics before giving a tour of the telescope. This time, the topic was planet-like objects that have been found near Pluto and beyond. The amazing thing is that much of the work has been done from Earth-based telescopes on Mauna Loa in Hawaii. 

There are other interesting artifacts on exhibit in the observatory, such as several old pendulum clocks.

[Pendulum clock]

What does clocks have to do with astronomy. We'll be getting into that in the early part of 2020, but part of the answer is that the tracking mechanisms for telescopes, antique and modern, amateur and professional, are clocks.

The tracking mechanism for the Chamberlin telescope is obviously old but has been well maintained.

The astronomers sighted four objects for us. Saturn is a standard. It's spectacular and easy to find. The blue and gold binaries of Albireo was another pair of cosmic jewels. They also showed s quaternary star system. The fourth object was unexpected. They tried to find it early in the demonstration but couldn't. Later in the evening, one of the astronomers was scanning the sky with binoculars and announced that he thought he had founded it, then he sighted it in with the large refractor and treated my friend and I (everyone else had left earlier) to a hazy, but breathtaking view of the Ring Nebula of Lyra, the remains of an exploded star. 

Speaking of optics, there are two ways to get photographs in low light - add more light (with a flash), or expose the image for longer than usual. The later method is preferred for astronomy - it's hard to illuminate a distant planet or star. The pictures above were made with my Snail Camera app, which allows an extended shutter time. This usually requires a tripod to reduce moving the camera while the image is forming but for large Earth-based objects like the observatory building and telescope, a steady hand might be enough.

In the following months, I will be focusing on (pun intended) inexpensive, portable astronomy with binoculars, spotting scopes, and telephoto lenses designed for use with smartphones, but there are ways for the adventuring, lifelong learner to observe distant sky objects. Planetariums and observatories are viable options (they usually like to show off for the public), but images made by large observatories and satellite-based telescopes are available online for study by the amateur astronomer.

A step back

For those who have found my data analysis package, DANSYS, useful (and have probably also found that some of it doesn't work), I have taken the opportunity presented by the recent turmoil in my life to take a step back and go through all the functions and subroutines. I fixed several bugs and added error handling. Now, if you try to feed a function with data it doesn't allow, it won't crash and open the program editor. It will just sit there staring at you so you can check your input. I have also cleaned up some of my sloppy documentation in case you want to get into the IDE (that's where you actually develop the programs) and do some modifications.

I have the excuse that beta testing would have found these errors much sooner and I haven't had access to beta testers. For those who aren't familiar with the terminology, beta testing is when some people actually use a program that's under development and, when they find problems, or just want to recommend some improvements, they shoot a note to the programmer. I am, by the way, open to suggestions through comments to this blog.

In future months, I will be refurbishing DANSYSX, the user guides, and the LabBooks. I hope you like the changes. For those that haven't looked DANSYS over and want to, you can find it right here:

http://www.theriantimeline.com/excursions/labbooks

Indiana Jones was an archeologist so you can bet that he was into statistics. I've used statistics in some of my studies in these blogs. Data analysis is one of my favorite pastimes. My DANSYS user guides are not just manuals on how to use DANSYS. They also cover the statistics themselves. Check them out and see why I (and Indiana Jones) likes statistics!

Another moving experience

Six years and three moves. It's striking how different, different parts of the Denver area are. We are moving to Centennial now and we will definitely be in the plains. There's still a little rise from the South Platte River but the geography is no longer river valley.

While I adapt to the new location, my blogs will be largely about that but I'm still looking forward to switching gears to astronomy and physics next year. I wonder how light pollution will be in the new neighborhood. 

I've also shifted my October excursions to November. I still plan to take a train out to the airport for the weird Denver tour. And, unless something else interferes, I'll hike Boulder Creek with a friend. I still plan to finish up the Highline Canal Trail, but I've pretty much lost my opportunity for an Autumn hike.

Anyway, I hope you stick with me through some big changes in the future months as I finish up 2019, mathematics, and language with the caveat that the past never really goes away.

Are you one of those folks (like me) who hate moving? Take advantage of it! A move is a great time to take stock of your situation, organize your life, and make all those big changes you've wanted to make but have been putting off.

I once worked on a pipeline barge as a welder helper. I was in pretty good shape and I stayed that way by exercising regularly. I would do push-ups - standard and inverted (with my feet up on the wall). On land, push-ups are one thing - on the Gulf of Mexico, they're something else. Pushing up as the barge rode down the slope of a wave, I would almost lift off the floor, but if I wasn't ready when the barge was lifted by the next wave, I could find my face in a collision with the floor.

Something was changing as the barge bobbed around in the water. Was it my weight? Was it my mass? Does it make a difference?

I have an assortment of tools for measuring weight and mass. Here's a picture of some of it.

[Tools]

There are some weight (or mass) sets in the center. (I apologize but the vocabulary of weight and mass is incurably tangled.) To the left are some tools to measure weight - I'll call those "scales", although the word is also used for things that measure mass. To the right are tools to measure mass - I'll call those "balances" although that word is also used to refer to weight measuring devices.

You might say I have a problem, here. Let's look at the three groups separately.

[Weights]

There are standards of both weight and mass and I have lots of little pieces of metal and other materials that have been created to conform to those standards. For instance, the open black box in the center contains very precise (I had to buy it for lab work when I was in pharmacy school) pieces of metal with gram masses and ounce weights.

The cubes below it are called "density samples" because, despite the fact that they're the same size, they have very different masses. Density is defined as mass per unit volume.

There's also a stack of brass masses on a hook that are just right for hanging.

[Scales]

You've likely seen many scales. The things you use to measure the weight of produce at a grocery store are scales. You also weigh yourself on scales - bathroom scales.

Usually, a scale measures how hard an object pulls on a spring (like the set of spring scales on the lower right, or the Jolly Balance (which is actually a scale), the yellow plastic thing in the upper right corner - it also measures density. Alternately, a scale might measure how hard an object pushes down on an electronic component, like the digital bathroom scales in the picture.

[Balances]

On the other hand, a balance literally balances two objects. If they balance evenly, they are pulling down with equal force. Many science kits include inexpensive balances.

The blue velvet lined box in the picture contains a brass assayer's balance like the ones used long ago to "weigh" gold nuggets. There is also a pocket postal scale (which is actually a balance) and a tiny, three beam balance. It works like the "scales" your doctor uses to weigh you. In that case, the doctor balances you against the slider weights on the bars that are about eye height in front of you. A system of levers magnify the weights of the sliders and the machine calculates your weight when you're balanced. 

Scales measure weight and balances measure mass.

I carried some equipment to the Ross-University Hills branch of the Denver Public Library and rode their elevator to see what would happen when I measured the weight and mass of objects.

[Riding an elevator with a scale]

First, I used a portable electronic scale to weigh a mass. Yeah, I know it's a 20 gram mass that the scale says is 30 grams - I didn't zero the scale, but you can tell that the indicated weight (actually weight translated into grams - more about that below) changes as the elevator goes up and then returns to the first floor.

[Riding an elevator with a balance]

On the other hand, the balance stays balanced. You can tell because the vertical point stays vertical. Why did the weight change but the mass did not?

Mass is simply the amount of matter in an object and that doesn't change as long as the object is intact. The mass of an object is measured by comparing it to another object of known mass.

Weight is actually the force that an object directs straight down vertically. Newton's second law of mechanics, and the one most central to everything, defined force as mass times acceleration, so I need to go over a few technicalities.

When a thing changes position, it moves at a particular speed. In a car, speed is usually measured by a speedometer in miles per hour (at least in America. Everywhere else, it's kilometers per hour.) Speed is measured in distance per time, or distance divided by time.

Physicist do not usually work with speed. They prefer to work with velocity. Velocity is speed in a specified direction. It's called a vector quantity because you have to give more than one measure to fully specify it.

When you're driving a car, you don't maintain a constant speed. Acceleration is how fast you're speeding up or slowing down. Acceleration is measured as speed per time. That means it is measured as the distance traveled per unit time per unit time, or distance per unit time squared. In physics, the most common measure is meters per second squared.

Now we come to force. When I say that force is mass times acceleration, think in terms of pushing an object so that it speeds up faster and faster at a constant rate. Force makes things go faster or slows them down. A common measure of force is the newton which is the amount of push required to accelerate a one kilogram object one meter per second squared.

And weight, being a force, is often measured in newtons (notice that, when "Newton" is a name, it's capitalized, but when it's a unit of force, it's written in lower case.). Weight is mass times acceleration. What acceleration? The acceleration of gravity. That's why the weight of a body can change. The acceleration that gravity imposed on a body in freefall is 9.764 meters per seconds squared...at sea level on the Earth and, although it is different at different places on the Earth's surface, the variance is usually too small to worry about. (Geologists actually do worry about it because large deposits of metal ore will present a slightly different gravitational pull than other rocks and they use of a very sensitive instrument called. "gravitometer" to measure the pull.) As you move out away from the Earth, though, it's pull becomes weaker and your weight also decreases.

The moon is smaller than the Earth and, therefore, has less gravitational pull. Acceleration due to it's gravity is only 1.625 meters per second squared on the moon. I weigh 185 pounds on Earth. On the moon, I would only weigh 185 times 1.625/9.774, or 30.8 pounds.

I recorded my phone's accelerometer on the elevator using Google's Science Journal. It looked like this.

[Elevator ride]

Another digression...it can be confusing which direction is which on a phone. Just remember the graphs you drew in algebra. The x axis went left to right, the y axis went up and down and if you were working with three dimensions, the z axis was into and out of the page. It's the same for the phone. Holding the phone flat in front of me, the direction of the elevator's motion was along the z axis. All of the accelerometers produced jagged lines, but look at the scales. The x and y accelerometers showed accelerations around zero and one m/s2. The z accelerometer measured around 9.5 m/s2. That should look familiar - it's the acceleration due to gravity.

When the elevator starts up, weights in the elevator opposes it's motion with an equal but opposite force, (that's Newton's third law). So, add the elevator's acceleration to that due to gravity. Since the accelerometer measures up to twelve m/s2, the elevator must be accelerating at about two and a half meters per second squared until it reached a constant speed, and the tracing smoothed out. At the top, the elevator slows down at about 1.5 meters per second squared and objects lighten up. As the elevator starts back down, objects in it lose weight again, to regain it at the bottom.

That's actually how the phone's accelerometers work. They are tiny (You might have heard of nanotechnology. Cell phone accelerometers are nanotech.) combs that have tiny weights at the end of their times. As the weights accelerate, they move with the acceleration and sensors pick up the motion.

It's not entirely bogus that my electronic scales claim to measure grams (mass). It actually measures weight but, on Earth, weight is mass times a constant 9.764 acceleration due to gravity so the electronics just have to divide the weight by 9.774 to get the mass….but not on the moon.

Riding in a car, notice how you lean as it slows down, speeds up, or turns a corner. That's forces at work. If you have an elevator handy, you might try riding it with a bathroom scales and see how your weight changes and remember...your mass stays the same.