Sunday, October 13, 2019

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:

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.

Tuesday, October 1, 2019

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.


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.


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.


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.


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 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 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.

Friday, September 27, 2019

Points east

I recently posted a blog about the University neighborhood in Denver. Since then, I've walked over to my local library, the Ross-University Hills branch of the Denver Public Library for a physics demonstration (that will be the next blog here). That walk carried me through the Wellshire neighborhood. Since I frequently visit the library and the shops over on Colorado Boulevard, this is a regular walk for me.

Wellshire is a residential area bordered by University Blvd on the west, Yale on the north, Colorado Blvd on the west, and Hampden Drive on the south. In addition to several churches and a few shops on the west side of Colorado, the large Wellshire Golf Course lies along Hampden and the Highline Canal runs through it.

The South Platte River cuts a hundred foot deep valley into the plains here and Wellshire is the beginning of the plains extending from University neighborhood east until they hit the shallower valley of Cherry Creek, about eight miles east of the river. From there, it's pretty much plains to the Mississippi River.

My walks usually take me along Bates Avenue and Amherst to Colorado, but the trip on Dartmouth, though more demanding, is beautiful and affords some nice views of the mountains.

[Bates in Wellshire neighborhood]

[Busy Colorado Blvd]

The library is in the University Hills neighborhood, east of Wellshire. The building is a modern, two story construction. I arranged to use their elevator to perform a physics demonstration. Most of the rooms used for activities are upstairs. The catwalk like stairs are interesting. They are suspended at one end by cables.

[Library stairs]

Libraries are often built with aesthetic values in mind and usually offer much more than books. Check out your local library and pay particular attention to it's architecture, history, grounds, and exhibitions

Thursday, September 26, 2019


I have recently decided to comply more closely with my physician's dictate to "walk 20 minutes a day.". In the past I have been rather slack in my adherence. Some hikes are several hours. My walks to the grocery might be twenty minutes if the trips both there and back are considered.

Now, since my computer no longer constrains me in the mornings, I am free to take this computer ,(my cell phone) and stroll up to the University campus, or to one of the several parks in the area.

Walking in the same area every day lets me more consistently observe the cyclicity of the changes of my surroundings. This morning I noticed a thistle growing up through a dense shrub and how it changed it's habit to it's situation as it sought the sun light.

Yesterday was the first day of Autumn and today a welcomed, cool breeze Is blowing. Soon there will be snow. Both I and Vincent eagerly awaits it.

Since I walk in the same areas every morning, I'm able to divide my attention and listen to my books as I walk. I'm pretty good at multiplexing and things still catch my attention. I am currently listening to a Librivox recording of James Boswell's Journey to the Hebrides. It's a pleasant account of an eighteenth century gentleman's journey to his homeland with his friend, Dr. Samuel Johnson, the author of England's first dictionary.

I sit on a rock wall surrounding the University of Denver's water gardens as students walk past to their current destinations.

The water gardens have fish

The interior of Mary Reed Hall with it's arches and vaulted ceilings

 This spray of water in the sun caught my eye

Do you have a regular walking routine. Do you just walk or do you augment your time with quality rich activities?

Monday, September 23, 2019

Spanish - a final report

I've enjoyed studying Spanish and plan to continue...just because it's fun, but I suspect that I missed the train on conversational Spanish. It's normal for people to lose the ability to learn new languages easily as they get older, especially if it's not a regular part of their lives but it seems that I have another problem. I've always had auditory processing disorder (APD which makes it hard to process speech, but my jobs in the past have kept me involved with others and their speech. Now that I'm retired, there's less exposure and, with age, my learning disabilities are getting worse.

On the other hand, I can read most of the Spanish signs and labels around town. My ability to read Spanish has improved dramatically. With a little help from the translator in my Kafui Utils Smart Kit app (which I wholeheartedly recommend), I can read Spanish novels like Cien anos de solidad by Gabriel Garcia Marquez (which I also recommend).

The video, Destinos, is educational, entertaining, and pretty and I have a way to go to finish it but it has my attention, so I will.

Are there communities in your town that speak a different language? See if you can learn it. Often, native speakers will be excited to help you with the conversational part, you just have to learn the phrases, "Speak more slowly," and "I don't understand," in their language.

Saturday, September 21, 2019

Harvard Gulch - The rest of the story

I have walked west on Harvard Gulch Trail - East , (Harvard Gulch is on both the east and west side of the river.) And I reported that trip in the August 5, 2017 blog, Harvard Gulch. I began at University Blvd and walked down to Rosedale. From University, the Harvard Gulch Trail continues east to Colorado Blvd.

[University Blvd]

The weather is moderating and some of the trees sense the approach to fall.

[Cherry tree at Cherry Hills III]

Winding through residential areas, the Gulch is more for exercise than scenery, but it offers a nice way to walk between two major streets without dealing with heavy traffic, although the trail crosses several streets.

[The trail at University]

A little further east, it enters Robert McWilliams Park, a good sized greenway with a playground, picnic tables, a water fountain, and restrooms with sinks.

[Robert McWilliams Park]

Robert Hugh McWilliams Jr. (1916-2013) was a judge of the tenth circuit U.S. court of appeals and the Colorado Supreme Court.

At one point, the trail briefly becomes a street sidewalk.


There are some interesting houses along the way.

Judiciously placed rocks along the canal are reminders that Harvard Gulch is primarily a drainage ditch.

Near the Colorado Blvd end, the trail changes from pavement to a crushed gravel trail.

Here is where the Gulch emerges from underground behind the Y.

This is a there-and-back trail unless you want to return on nearby Yale or Iliff, where you can see the Chamberlin Observatory. From University to Colorado, it's 1.2 miles with an elevation gain of 56 feet.

Do you know who the parks, streets, and other places in your area are named after. Often, they're not people whose names would be recognized by everyone, but they often have interesting histories.

Friday, September 20, 2019

Calculus in your life

Mathematics is a language that is ideal for describing how the world works and building models that help understand the underlying processes and make predictions.

As a tutor, I heard a lot of, "I'll never use this. Why do I have to learn it?" and, honestly, I sympathized. I was helping high school students learn concepts that I was taught in college courses. Some intended to go on into technical or theoretical curricula in universities...but not all.

So, why advanced math in high school? Well, first, calculus, as difficult as it's made out to be, is neither advanced nor difficult. Once you understand it, it's no more difficult than any other math. It's a language. It has a vocabulary and it has rules for putting it's "words" together to make sense. The problem is that many calculus teachers don't understand it, at least not well enough to impart understanding to their students.

Further, calculus is the last tool you need to understand the world most people see in everyday life. The sequence goes like this:

Arithmetic gives you the tools to count and measure.

Algebra helps you solve problems in math.

Trigonometry let's you figure out the distance across a river without actually having to get your feet wet - that is, surveying.

Geometry is what you need to design structures that will stand up.

And, calculus...calculus is the tool you use to deal with change, because the two concepts
(only two) at the center of calculus, differentiation and integration, are what we have to deal with rates.

You see, a derivative (that's what you find when you differentiate) is just a slope. Every handyman knows what that is - it's rise over run. Measure a horizontal distance, that's the run, and then measure vertically up to the ramp,  or stairs, or roof, and that's the rise. Divide the rise by the run and that's the slope. Where it gets a little complicated is when the object you're measuring the slope of isn't a straight line. What if it's the trajectory of a bullet or a curved pipe?

The speed of a car, or any other rate, is a slope. The run is the time it takes for the car to go a number of miles. The number of miles is the rise. Rise over run….miles over hours….miles per hour. But cars rarely travel at a constant rate, so it's sometimes nice to know how fast a car is going at any particular time -that's called "instantaneous speed"and you need calculus to figure that out...or a speedometer, but a speedometer is an analog calculus calculator. It adds tiny chunks of speed (of the wheels) to come up with an estimate of current speed. That's the other concept of calculus….integration.

Integration adds tiny pieces of area, volume, rates, what have you, together to get a total. It does the impossible by adding together an infinite number of infinitesimally tiny chunks to get an infinitely accurate total.

For instance, if you knew exactly what the instantaneous velocity of a car is at every instant of a trip, you could add all those rises together to know exactly where the car is at any particular point in the trip.

But does anyone really add infinite quantities? That would take an infinite amount of time. But calculus provided ways of estimating integrals to any degree is accuracy. Those tools are called "numerical analysis".

Want to actually do the addition? Luckily, there is a way, because the integral is the reverse process of the derivative! If you know a derivative, you can just start there and go backwards to find the integral!

Some wag once said, "there are two things in calculus, differentiation and integration. Everything else is application."

So what do I think that everyone should know about calculus? I think they should know what it is and what it's good for. They should also know where to pick up the knowledge of how to use it in case they encounter a problem that requires it.

Carpenters, construction workers, and practical statisticians rarely, if ever use calculus, but the mathematical tools they use are based on calculus and someone had to work those out. If you want to make a career out of fiddling with numbers (that's what theoretical mathematicians and scientists do) or if you want to build the mathematical tools that other people use, then expect lots of calculus. And if you plan to follow me into next year, also expect some calculus.

I'm about to embark on an adventure into the hard sciences, astronomy and physics, and calculus is a big part of their language but, hopefully I can explain well enough for you to catch the passion for lifelong learning while I break open the hood and show you all the workings inside the world.

By the way, if you feel adventurous and want to study calculus or any other advanced math, MIT has some great online courses at

Thursday, September 19, 2019

University neighborhood

[Word cloud]

I've lived at my present location for about three years and it's just recently occurred to me to do a walking tour of my neighborhood. In this case, that would be the University neighborhood in Denver, Colorado.

The University neighborhood is named for the University of Denver, which takes up roughly it's north third. The area is located on the Eastern rim of the South Platte River valley. Using Google Earth, I found that the intersection of University Boulevard and Bates Avenue is 100 feet above the river.

The boundaries of University neighborhood are University Blvd to the east, Dartsmouth Ave to the South, Downing Blvd to the west, and the Valley Highway (Interstate 25) to the north.

The place was once a town in it's own right, South Denver, and was established as a residential area and buffer zone for Denver proper. There's considerably more to University neighborhood than the University and you can read about it here:

And here:

The image at the head of this blog is called a "word cloud" or "tag cloud". It's a method of content analysis and is a visual representation of the frequency of words in a text….in this case, the Denver 9 news article referenced above. The bigger and more central a word, the more often it occurs in the text. Roughly, according to Denver 9 News, these are the things that are important to the University neighborhood.

The University takes center stage, but also notice the relative importance of homes, bars, and coffee. Sitting here, I can count four coffee bars in the neighborhood and there are several pastry shops and restaurants that explicitly advertise coffee. Coffee shops are interesting creatures, each having its own personality. Of my two favorites, La Belle Rosette is the quieter and usually plays lounge music - Sinatra and Dorsey - that sort of thing. Keith's, on Downing, is livelier and leans toward jazz and, occasionally, live music.

I started the walking tour at the bus stop at University and Bates. Just across the street (in the next neighborhood to the east) is the church I attend, the Christ Episcopal Church. There are many churches in the University neighborhood and as many denominations. Almost directly across from Christ Church is the Unity Spiritual Center, an interesting blend of Christianity and Eastern philosophy.

[Christ Episcopal Church]

A visitor might expect to have grand views of the Rockies from this neighborhood since it's on a high rise opposite the Front Range but they would be surprised. Most of the area is fairly dense Urban forest. What they would see are trees. Many of the trees have been planted by developers and residents. The way I visualize this area before the pioneers is like the town in High Plains Drifter. After all, Denver is high plains, cool desert. The climate is changing and, if it hasn't lost it's desert status yet, it's well on its way.

The best views of the mountains are on the east-west streets and on the University campus.

About the best authority on Denver neighborhoods is Chris Englert of Walk2Connect. She has toured every neighborhood in Denver, leads walking tours, and has published a couple of guide books about the Denver area. ( She included a walking tour of the University neighborhood in her "Walking Denver's Neighborhoods" but it focuses on the campus and about two thirds of the area is residential and well worth seeing for anyone who likes residential architecture and gardens.

I headed down University to Dartsmouth. The Korean Emmanuel Methodist Church is at this intersection.

With the large Asian population in Denver, there are several Buddhist and ethnic Christian churches.

The area between Dartsmouth and Downing Street is a residential area called Arapaho Acres. It's composed mainly of small homes but there's a lot of variety and many nice gardens. 


[Twa corbies (two crows)]

The Porter Adventist Hospital is just up Downing. I've seen that they've had some legal and procedural problems in the past but I've used them several times and I've never seen a more professional, competent, friendly staff. I've been impressed every time. They call themselves a "community hospital" and that's exactly what it feels like.

Just past Porter, Harvard Gulch and it's associated trail crosses Downing, so I took it uphill.

[Harvard Gulch]

This trip was also the maiden run of my new Motorola Moto E5 Cruise phone. I've packed it with all my essential equipment and my entire reference library so, since my computer crashed, I really am mobile. It's a great experience. I'm composing this blog on my phone. This was also the tryout for my AllTrails app. It provides tools to record hikes and walking tours and can upload the report to the AllTrails website. My recording told my that I walked 8 miles in 3 hours 48 minutes and 26 seconds. It also said that my total elevation gain was 223 feet. The elevation gain on this section of the Harvard Gulch Trail was 62 feet.

Harvard Gulch isn't a natural stream and it isn't what geologists and geographers are thinking when they say "Gulch". Technically, a Gulch is a steep V shaped valley. The several gulches in Denver are canals intended to drain runoff from the valley slopes into the South Platte River. Harvard Gulch East runs from Colorado Boulevard near Iliff to Rosedale, where it goes underground to emerge again at the river.

Near the Eastern border of University neighborhood, the trail passed through DeBoers Park, a nice greenspace with a playground, park benches and picnic tables, and a water fountain.

[DeBoers Park]

From there, I walked to the University campus.

This campus is an excellent opportunity to see a wide variety of architectures and landscaping. The whole campus is an arboretum with plaques identifying trees. there are also several water gardens. Visitors should also check out the anthropology museum in Strum Hall and Vicki Myhren art gallery near Asbury Street.

The campus is featured in several of the other Adventuring blogs. Currently, there is a lot of construction. 

When I have asked Denverites where to eat, the most common recommendations are for the area around Evans and University. There are many great restaurants, coffee shops, bakeries, Ben and Jerry's Ice Cream shop, and even Deiter's Chocolate.

At Buchtel Avenue is the Ritchie Center with it's golden carillon tower and the Cable Building. The latter is not actually a part of the University of Denver. It was originally intended to be a memorial and museum to the Cable industry and communication in general but ended up as a conference center. The librarian will still provide tours of the archives with advanced notice.

[The Cable Building]

Across the street is University Lightrail Station. Like all the light rail stations in Denver and many of the bus stops, University Station displays original works of art.

[University Station]

The station also had a stacked parking garage with nice views of the urban forest and the Front Range of the Rocky Mountains.

[RTD parking garage and views from the top]

A walk down Buchtel to Downing afford nice views of a quiet residential area and a loud interstate.

Further south, Downing has a surprising shopping area that is reminiscent of small town America with shops, a dinner, and Keith's Coffee Shop.

[Downing Street]

Another walk up Harvard Gulch brought me back to University Blvd.

[High-rise apartments along University Blvd]

[Cherry Hills III gated community]

And to my starting point.

All neighborhoods have histories and points of interest. Some are more in the open - some, you have to dig for. What's in your neighborhood?