Federal Center Station to Oak Station

The Eastern Continental Trail, which includes the Florida Trail, the Alabama Roadwalk, the Pinhote Trail, the Appalachian Trail, and the International Appalachian Trail, will carry you from Key West, Florida to Belle Isle, Newfoundland and Labrador, 4,400 miles. But it requires a lot of walking on trails, plus roadwork and waterwork.

Roadwork happens when no foot trails have been developed, like the stretch in Alabama between the end of the Florida Trail and the beginning of the Pinhote Trail near Weogufka, Alabama. They're also places in Canada where there is water that must be crossed.

It's not that I've done all that. I just wanted to introduce some terminology, because even on these short station-to-station hikes, I end up doing a lot of roadwork.

Starting at Federal Center Station in Lakewood, I had to figure out how to get across highway 6 on my hike to Oak Station. Of course, I did my homework before starting out.

There are some parts of the Denver Metro area that are not pedestrian friendly...few street signs, trails, sidewalks. I would prefer not to walk on a busy overpass with no sidewalk. Luckily, the satellite images in Google Maps clearly show sidewalks and the dashed lines of crosswalks and the length of Union  Boulevard and Simms Street from the Federal Center to the trailhead of the Lakewood Gulch Trail was okay.

So, I left the train at Federal Center Station and climbed the hill to Union Boulevard, which was a backtrack from my last hike along the W Line. Crossing the light rail and highway 6 turned out to be easy roadwork.

The arch in the distance is the W Line where it crosses highway 6.

Simms Street and the light rail approach each other near the Lakewood Gulch Trail, then the W Line turns east toward downtown Denver. Collins Road crosses Simms there and the trailhead for the Lakewood Gulch Trail is a few steps down Collins in Bellows Park. 

Looking at the Wikipedia article for Lakewood Gulch, I think that might be my ticket from Oak Station to Auraria West Station.

Like all the "gulches" in the Denver area, Lakewood Gulch is an artificial channel for directing storm water through East Denver.  It has been subject to flashfloods in the past.

Occupying the distance between Simms Street and Oak Street is a large medical equipment manufacturing company, Terumo Global. The Greenway that runs through it's grounds reflects the technological focus.

I'm not sure what molecule the tetrahedral model is supposed to represent but it's appropriate given how many biological compounds have the form. Carbon can bond to up to four other atoms and, since atoms tend to space themselves out as far as they can, the tetrahedron is common in organic compounds.

On the far side of the gazebo is a double helix model, I assume, of DNA.

Parts of the trail give nice views of the surrounding area including green Mountain.

The convenience of Lakewood Gulch (for me, at least) is that it crosses side streets that run short distances north to W Line stations. Oak Street was well marked and I took it to Oak Station.

All of the light rail stations and the larger bus stops in Denver display art by named artists...murals, windscreens, and larger works, like the whimsical, Tread Lightly, by Joshua Wiener. The seven steel boats on legs make me think of Baba Yaga's Marina.

The train ride back ended at my home station, Arapahoe at Village Center, and I was surprised to see the water feature at Village Center Tower One operating, so I took some pictures.

The glow

At some time during my high school years or a little after, my parents and I visited a mine in southeastern Georgia. They mined a fine sand, not for silica, but for ores of elements like titanium, gadolinium, thorium, cerium, neodymium, lanthanum, and others that sound exotic to most people...rare earth elements.

These minerals, primarily zircon, rutile, monazite, and xenotime had been washed out of the ancient Appalachian mountains long ago. The eastern mountains of North America are very old and were, in their youth, much larger than the Rockies. They may have been as tall as today's Himalayas. To be worn down to their present size, a lot of stuff has been washed out and some of it was deposited near the ocean in Georgia.

The sand was scooped up and washed down helical troughs. As it descended the troughs, it moved faster and faster spinning off, first, the lighter sand and, then, heavier and heavier materials, separating the sands nicely by density. Our guide gave us four very generous samples.

The sand was very fine but our microscope revealed wonders. The hard minerals retained their crystal forms, tiny sparkling jewels. The zircon provided the extra of being fluorescent, glowing a dull red in the light of our ultraviolet lamp.

When light meets matter, some of it is absorbed and several things can happen according to the intensity and wavelength of the light, and the kind of matter. The vibrations of infrared and microwave radiation are too big to get into the atoms that make up most materials, but they can certainly shake up the larger particles. That's why infrared and microwave radiation heats things up. Heat is just the motion of particles that make up matter. Shorter wavelengths can move the electrons around in individual atoms and make some interesting things happen.

When visible light hits an atom, the energy it imparts can kick an electron further out from the nucleus of it's atom. When it falls back to it's rest state, it will give the energy back as the same wavelength of light (in a colorless material) or as some other wavelength of light (in a colored material).

There are shorter wavelengths of light. Most people can't see ultraviolet light (aka "black light") but some substances can absorb it and re-emit light of a visible wavelength giving the impression that the material is glowing with its own light. Designers use this phenomenon, called "fluorescence", to make highly visible objects. The terms "dayglow" and "neon" are often used to describe the products. "Dayglow" is especially appropriate since there is enough ultraviolet light in sunlight to set them off and give them a vibrant appearance.

Ultraviolet light is often divided into two categories - long and short wavelengths. The longer wavelengths are close to the visible spectrum. In fact, some people can see some of the longer wavelengths of ultraviolet light. These are the wavelengths targeted by designers because shorter wavelengths...

well, they burn you. Short wavelength ultraviolet light is the part of sunlight that causes sunburn. The shorter the wavelength of light, the more energy it carries, and the larger a push it can give electrons in atoms. Short wavelength ultraviolet is the beginning of the spectrum of ionizing radiation. It is so energetic that it can knock electrons right off atoms. Shorter wavelengths include X rays and gamma rays.

I remember LED lights when they became available to consumers. The Christmas lights were laughable. At that time, you could only get red, green, and yellow LEDs but they were very dim. Later they figured out how to make them much brighter. But the goal was LEDs for illumination because solid state LEDs operate cooler, last longer, and use way less electricity to produce the same amount of light. The problem was...who wants to live in a house lit by red, green, or yellow lights?

LEDs are near-monochromatic light sources. One will only produce light in a very narrow band of colors. After a while, substances were found that emitted all the colors, from infrared to ultraviolet, but white, the color most people want to live in, isn't actually a color. It's a mixture of all the colors.

Engineers found two solutions. When they placed different colors of LEDs together they could mix the colors to give off a reasonable illumination. Then, the problem became a simple matter of aesthetically balancing the color blend.

The other solution became the most common. Here's a picture of the ceiling lamp in my bedroom.

Here it is turned on.

Those are LED bulbs. When I shine my ultraviolet flashlight (with it's single ultraviolet LED) on one of the bulbs, it looks like this.

That's not terribly impressive, but it is white. The secret of the white light LED bulb is that the light element is a printed circuit board with several ultraviolet LEDs plus some other color LEDs to balance the color produced. And the inside of the bulb is coated with a fluorescent material.

The bulbs are well designed and not a lot of the UV light escapes. I know this because even the long wavelengths make my skin tingle. Also, I have some neon paints and they look pretty drab under the house lights.

Sunlight perks them up and the UV flashlight really makes them pop.

Recently, in a dollar store I noticed a disinfectant wand for less than $10. These things put out weak, shortwave UV light, so I bought one. Fluorescence is pretty specific. A material than will glow under one wavelength might not under another, or they might emit a different color. Here's what the paints look like under the short wavelength UV.

The glow is dim but, remember, the wand puts out much less radiation than the flashlight. Still, the colors of the fluorescence are about the same except the blue paint doesn't fluorescence at all under this short wavelength UV.

In 2000, I attended the PathwaysToDarkness party in Atlanta, Georgia. It was a meeting of vampires and weres. Appropriately, it was held at night and the place was dark (some vampires are sensitive to daylight and burn easily.) Except for the bar. There was a blacklight. And, of course, there was tonic water and absinthe. Why, "of course"?

Well, they both fluoresce under blacklight. Absinthe glows green and the quinine sulfate in tonic water blazes a brilliant blue. Want to see it?

Tonic water, for those that don't drink, is a bitter component of various mixed drinks that contains quinine sulfate measured in parts per million, so the glowing substance is present in only a very tiny amount. It became popular in the 1800s when it was found to have a curative affect on malaria. My father, who contracted the disease in southern Georgia began drinking again in old age to ease his leg cramps.

It doesn't fluorescence at all under my disinfectant wand but there are short wavelengths that do cause fluorescence. 

The main fluorescent entity isn't the quinine sulfate but the ions, quinine hydrogen sulfate and quinine dihydrogen sulfate. For that reason, increasing the hydrogen ion concentration of tonic water increases the fluorescence. Tonic water that uses carbonated water as solvent is already slightly acidic but I added some lemon juice to my tonic water to get a blazing blue glow.

Many things glow under black light making the ultraviolet flashlight a useful instrument for field geology. Scorpions, for instance, give off a ghostly white light. Some minerals also give off a characteristic glow and can aid in night prospecting.

When I was collecting, I had a few minerals that would glow brilliantly under a black light. A few were from Franklin, New Jersey, "The Fluorescent Mineral Capital of the World". The zinc mines around there produce excellent specimens. 

The few minerals I have now are so-so.

Fluorescence is named for the second minerals from the left and right in the top row, fluorite, which is  calcium fluoride. The one to its left also commonly fluoresces. It's calcite, the mineral that makes up limestone and marble. The mineral spotlighted on the bottom row is also calcite.

Caves generally form in limestone and the eastern United States is practically a limestone sponge with the Appalachian mountains floating on it. There are a lot of caves.

One favorite trick of cave tour guides is to carry a group deep in a cave and turn off the lights to show what darkness really is like. 

I visited a spectacular cave in northern Alabama called Cathedral Caverns and they apologized. When they turned off the lights, all the rocks glowed dimly. That's called "phosphorescence". 

In fluorescence, the atoms exposed to one wavelength of light absorb the light but immediately re-emit it with another wavelength. In the specimens above, invisible ultraviolet is re-emitted as red light. But in phosphorescence, it takes longer for the electrons in the atoms to calm down, so they are re-emitted over a period of time.

These particular minerals don't do much of anything under the disinfectant wand.

You can't see it in the photo, but the fluorite, second from the right in the upper row, does show a dull brown when exposed to this wavelength.

Sedimentary rocks, while they are often great for fossil hunters, do not usually provide good opportunities for mineral collectors, although some areas have gorgeous calcite crystals, but anywhere on land is an exciting place for a night hike with an ultraviolet light. Ultraviolet flashlights are inexpensive and even more powerful battery powered lights with both long and shortwave light sources can be found for less than $50.

Red Rocks Community College to Federal Center Station

The recent section of my hikes along the W Line was all road work and wasn't very scenic, but it was short (less than two miles - I walked more wandering around Golden to find the pet store before getting on the actual hike.) but there were a few high points.

Leaving Red Rocks Community College Station, I followed the service road along highway 6 over the hill (literally) to the cluster of highrises known as the Federal Center.

Along the way, I saw this bank where one of the small streams flowing out of the foothills had cut into the clay.

It shows a nice soil profile in the stuff that's been laid down by the creek. The dark band is material that's been washed down from the organic topsoil and has stuck in a layer of clay. Just below, it looks like there's a more chunky and less permeable layer that traps the dark material above it.

The rocks and soil here are the same kinds of stuff we have at Walnut Hills.

These pretty burrs, called teasel, are the kind of dried plants florists like to stick in autumn arrangements. They're pretty common in the Denver metro area 

And speaking of Denver, this particular hill provides a good view of downtown Denver.

But I was still in the foothills and, looking back the other direction, I could see Green Mountain.

Most of the buildings in the Federal Center were businesses - dentists, lawyers, lots of restaurants, hotels, and the like. There are still some government offices but it looks like it's been some time since that was the main attraction here. There is the big St. Anthony's Hospital up the hill.

The station is at the edge of the Great Plains and affords an interminable view of...well, plains. I did notice that this station was a hub for bus lines to outlying areas like Conifer. Also, the Bustang, the Colorado Department of Transportation bus to other parts of Colorado, stops here. I'll keep that in mind.

The next section will be somewhat of a puzzle. Just past Federal Center Station is a snarl of multi-lane highways and industrial areas that I will have to navigate.

So... adventure.

Topo

The International symbol for geologist might well be a geologist's pick and a rolled map. These are the primary tools of the field geologist. (Like Rabbit says in Twister, the movie, "don't fold the map," There was a big crease through Wichita.)

There are several kinds of maps that a field geologist may be interested in, but the two main types are topographic maps and geologic maps. Actually, any time you go into the field, for geology, hiking,camping, etc., a topographic map is your friend. It tells you at a glance how the land is shaped.

And topographic maps are not expensive. You can order them from the National Geological Survey for a few bucks. In fact, you can download them here:

https://ngmdb.usgs.gov/topoview/

For free.

Other countries will have other government departments that take care of distributing topographic maps.

Printed maps are usually clearer than digital maps, but they're also awkward. A typical topographic map is about half your height or more and... don't fold it...roll it...right?

Actually, you can clean up a digital map and get a lot of mileage from it. Here's the 2019 1:24000 scale Highlands Ranch topographic map (GNS). It shows my neighborhood, Walnut Hills.

Eh, it also shows a lot more than I need, so I took a screenshot of it, blew it up and cropped it to just Walnut Hills to get this.

I opened that in Google Photo and used the image processing tools to make the contour lines clearer. Specifically, I used the Highlights, Pop, and Sharpen tools and got this. I don't want to be too specific. Different maps will need somewhat different approaches and the Google Photo app provides a variety of tools. For instance, an old yellowed map may need a blue filter to tame some of the yellow background. The trick is to play with an image until it does what you want it to do. Other apps like Photoshop or Gimp has a lot more to work with but the basic photo touch-up utilities do pretty well for maps.

That made me very happy! Now, I have a topographic map of my study area in my phone (that I can actually read!) and I can show you a few tips on how to read one.

What a topographic map adds to, say, a road map, are the light brown squiggles. They're called "contours" and they represent lines of equal elevation. For instance, look at this section.

One of the contours is broken by a number, 5750. That indicates that every point on that line represents a point in the real world where the ground is approximately 5750 feet above sea level. (This is the US, so topographic maps here use the Imperial system of measurement.)

Notice that there are two different shades of contour lines. The ones with numbers are called "major" contours. The lighter ones are not numbered and are called "minor" contours, but you can tell what they represent by counting them. 

The next major contour over is at 5700 feet and there are four minor contours between so each pair of minor contours have a difference in elevation of ten feet. That will be constant on this map. Adjacent major contours represent a difference of fifty feet. Adjacent minor contours differ by ten feet.

But that may differ between two different maps. This is a hilly area. Out on the plains, a few miles to the east, minor contours may only differ by two feet with major contours of ten feet difference. In the Rocky Mountains to the west, major contours may differ by one hundred feet.

The blue and dashed lines near Davies Avenue are Little Dry Creek and Little Dry Creek Trail. Notice how the contour lines form Vs along the creek with the creek flowing down the points of the Vs. But which way does the creek flow?

If you were walking the creek, you would see that streams always flow with the Vs pointing upstream.

Here's another section of the map.

The little rectangle with a flag on top is Walnut Hills Elementary School. The creek runs behind the school in a deep (about 30 feet) valley. You might have noticed that the contour lines are bunched closer together on the north side of the creek than the south. The closer contour lines are on a topographic map, the steeper the gradient is. The north slope of the valley behind the school is considerably steeper than the south side.

You might think of a contour as where the water line would be if the land flooded to that level. By looking at a topographic map, you can easily "see" what the shape of the land is. Can you "see" where the big hill is behind the school? It's where the contour lines loop around South Ulster Circle.

Pick up or download a topographic map of your area and carry it with you when you go out. How well does it show the shape of your area?