Shallow Thoughts : : Mar
Akkana's Musings on Open Source Computing and Technology, Science, and Nature.
Mon, 30 Mar 2020
It was surprisingly hard to come up with a "D" to write about,
without descending into Data geekery (always a temptation).
Though you may decide I've done that anyway with today's topic.
Out for a scenic drive to shake off some of the house-bound cobwebs,
I got to thinking about how so many places are named after the Devil.
California was full of them -- the Devil's Punchbowl, the Devil's
Postpile, and so forth -- and nearly every western National Park
has at least one devilish feature.
How many are there really? Happily, there's an easy way to answer
questions like this: the
Geographic Names page on the USGS website,
which hosts the Geographic Names Information System (GNIS).
You can download entire place name files for a state, or
you can search for place name matches at:
GNIS Feature Search.
When I searched there for "devil", I got 1883 hits -- but many of them
don't actually include the word "Devil". What, are they taking lessons
from Google about searching for things that don't actually match the
I decided I wanted to download the results so I could
count them more easily.
The page offers View & Print all or
Save as pipe "|" delimited file. I chose to save the file.
Read more ...
[ 16:30 Mar 30, 2020
More linux/cmdline |
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Thu, 26 Mar 2020
... You thought C would be coronavirus or COVID-19, I bet!
Well, I won't pretend I'm not as obsessed with it as everybody else.
Of course I am. But, house-bound as we all are now, let's try to
think about other things at least now and then. It's healthier.
One of the distinctive peaks here in northern New Mexico is a butte
called Cabezón, west of the Jemez near Cuba.
It's a volcanic neck: the core of an old volcano, part of the Mt Taylor
volcanic field. Once a basalt volcano stops erupting, the lava sitting
inside it slowly cools and solidifies. Then, over time, the outside
of the volcano erodes away, leaving the hard basalt that used to
be lava in the throat of the volcano. It's the same process that
made Tunyo or Black Mesa, the butte between Los Alamos and Española
that's been featured in so many movies, and the same process that
made the spectacular Shiprock.
Dave and I have driven past Cabezón peak several times, but haven't
yet actually explored it. Supposedly there's a trail and you can climb
to the top (reports vary on how difficult the climb is). One of these
Last week, Dave was poking around in a Spanish dictionary and discovered
that -ón in Spanish is a suffix that denotes something larger.
So, since cabeza means head, cabezón means
(Looking for confirmation on that, I found this useful page on
Spanish Suffixes You’ll Never Want to Let Go Of.)
Apparently it can also mean stubborn, ditzy, or just having big hair.
But hearing that cabezón meant big head took me
back to my childhood, and another meaning of cabezón.
When I was maybe ten, my father decided to take up fishing.
He bought a rod and reel, and brought me along as we headed out
to the docks (I don't remember where, but we were in Los Angeles,
so it was probably somewhere around Santa Monica or San Pedro).
This didn't last long as a hobby; I don't think dad was cut out for
fishing. And mostly he didn't catch anything. But on one of our last
fishing trips, he caught a fish. An amazing fish. It wasn't especially
big, maybe fourteen inches or so. It had a big head and a triangular
body, with a flat belly as the base of the triangle. It had weird fins.
It was dark olive green on two sides of the triangle, with a dull yellow
belly. It looked prehistoric, and sent me running off to the books when
we got home to make sure we hadn't caught a coelocanth.
After some research at the library (this was way pre internet),
my father concluded that he'd caught something called, you guessed it,
Searching for photos now, I'm not so sure that's right. None of the
photos I've found look that much like the fish I remember. But I can't
find anything more likely candidates, either (though I'm wondering
about the Pacific staghorn sculpin as a possibility). I guess fish
identification even now in the age of Google isn't all that much
easier than it was in the seventies.
I don't think we ever ate the fish. It sat in his freezer for quite
a while while he tried to identify it, and I'm not sure what happened
So maybe I've seen a cabezón fish, and maybe I haven't.
But it was fun to learn about the -ón suffix in Spanish,
to find out the meaning of the name for that distinctive butte
out near Cuba. One of these days Dave and I will go hike it.
And if we make it to the top, we'll try not to get big heads about it.
[ 19:17 Mar 26, 2020
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Sun, 22 Mar 2020
The idea of blogging the alphabet came from a conversation during a
hike in Nambe Badlands. It's beautiful a hike that we don't do very often,
about 40 minutes from Los Alamos.
"Badlands" is a term for any sort of soft, dry, eroded terrain:
a place of mostly dirt and loosely consolodated sandstone, where the
terrain erodes into a maze of rounded hills, steep gullies and arroyos,
with occasional pillars where harder rocks emerge.
Badlands are often fairly colorful due to the mixture of different
rock and soil types. Arizona's Painted Desert, with its stripes of
red, white and green, is a famous example. The colors around
Nambe and the rest of the Española valley is more subtle:
mostly reds, tans, yellows with a few bright white veins running through.
One thing you get in the badlands is views. In the image at left, we're
looking southwest past the "barrancas" of Pojoaque. You can see the
Pajarito plateau -- the line of white buildings is part of LANL,
fairly near my house in White Rock -- and beyond it, the Jemez mountains,
Out of the photo behind us are the Sangre de Cristos, running
up toward Taos and eventually Colorado.
The badlands themselves are interesting too. They're mostly Santa Fe
Group sediments, eroded primarily from the Sangres with a little
contribution from the Jemez.
In this area, there's a prominent white layer running through.
Since it's harder than the dirt on either side of it, it tends to make
a "white rim" reminiscent of the famous Canyonlands White Rim, but of
course the rock itself is very different. This white rim, while
harder than the normal badlands dirt, is still relatively
soft, flaky; it erodes to a powder anywhere where it's exposed.
Geology books don't cover this area, but as best I can determine,
from papers online, the white layer is probably an ash layer
that's part of the Skull Ridge group of the Tesuque formation
(those are all finer gradations of the Santa Fe Group).
There are four white ash layers, probably erupted from 13-16 million
years ago (estimates vary quite a bit, but middle Miocene), possibly
So although the white ash is volcanic, it's apparently quite a bit
older than most of the Jemez and comes from somewhere else entirely.
It's hard to be sure: I wish geological papers included better maps.
In the one Field Geology class I had the opportunity to take,
we spent most of our time making maps, and I suspect maps are a
big part of what most professional geologists do; but somehow,
the geology papers online seem remarkably lacking in maps.
We climbed up to a high lookout for lunch, during which Charlie, our
best birder, was scanning with binoculars and discovered an owl
sitting in the tower across from our lunch spot.
Alas, due to coronavirus "social distancing" concerns,
she couldn't pass her binoculars around,
but I was able to see the owl, just barely, with the
little monocular I keep in my pack. After some debate over its
size, and scrutinizing the photos (not good enough to be worth sharing)
afterward, Charlie concluded (and I agree) it was a great horned owl.
Badlands exploring is fun; aside from spectacular views, there are
always interesting hoodooes and other rock formations to inspect.
We did a relatively easy 5.5-mile loop, but there are plenty of other
trails in the badlands that I'd like to explore some day.
A few relevant papers I found:
- Alluvial-slope deposition of the Skull Ridge Member of the TesuqueFormation, Española Basin, New Mexico (Kuhle, Smith)
- Stratigraphy of the Santa Fe Group, New Mexico (Galusha, Blick)
- A PALEONTOLOGICAL SURVEY OF A PART OF THE TESUQUE FORMATION NEAR CHIMAYÓ, NEW MEXICO, AND A SUMMARY OF THE BIOSTRATIGRAPHY OF THE POJOAQUE MEMBER (MIDDLE MIOCENE, LATE BARSTOVIAN) (Aby, Morgan, Koning)
- Geomorphology of Espanola Basin (Kelley)
[ 12:02 Mar 22, 2020
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Wed, 18 Mar 2020
We're "praticing social distancing" with the COVID-19 virus active in
New Mexico ... but fortunately, that doesn't mean we can't hike.
It might be the most healthy thing we can do, as long as we all keep
our distance from each other and don't carpool.
On this week's hike, someone told me about a fun activity:
since a lot of her friends are stuck at home, they're trading emails
where each day, everybody writes about something starting with a new
letter of the alphabet.
Sounds like fun! So I'm going to join the game here on my blog.
I'm not going to try for daily posts; I expect to post roughly twice a
week, usually on light topics, not geeky tech articles.
I'll lead off today with a short note: a reminder to everyone to
sign up for an absentee ballot, if your state allows that,
so you can vote by mail rather than going to a polling place in person.
In this time of social distancing, you don't want to be at a crowded polling
place touching the same screens or pens that everyone else has touched
before you; and it would be better if poll workers weren't required to
be there either. It would be so much better if we all voted by mail.
When Dave and I lived in California, the state had just switched to
what they called "permanent absentee ballots": at least in the bay
area, ballots were automatically sent to all voters. You could fill
the ballot out at home, and then you had the choice of mailing them in
or dropping them off at the nearest polling place. (This was thanks to
our excellent then-Secretary of State Debra Bowen, who also fought
against no-paper-trail voting machines and for increased ballot
New Mexico still uses in-person voting, though I'm happy to
say we use paper ballots and allow absentee voting without requiring
But this year, it looks like New Mexico will be encouraging voting by mail;
our Secretary of State has a
FAQ | ABSENTEE VOTING FOR THE 2020 PRIMARY ELECTION.
page with details on how to sign up, and you must request your ballot for
the primary by May 28.
Check the rules for your state (assuming you're in the US).
If you haven't voted in the primary yet, check now, since time may be
running out! For the November general election, you probably have
plenty of time.
And if your state doesn't allow no-excuse voting by mail / absentee ballots,
this might be time to call your governor or lobby your state legislators
asking for an exception. It's a critical health matter, this year.
[ 20:58 Mar 18, 2020
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Sun, 01 Mar 2020
Galen Gisler, our master of Planetarium Tricks,
presented something strange and cool in his planetarium show last Friday.
He'd been looking for a way to visualize
the "Venus Pentagram", a regularity where Venus'
inferior conjunctions -- the point where Venus is approximately
between Earth and the Sun -- follow a cycle of five.
If you plot the conjunction positions, you'll see a pentagram,
and the sixth conjunction will be almost (but not quite) in the
same place where the first one was.
Supposedly many ancient civilizations supposedly knew about this
pattern, though as Galen noted (and I'd also noticed when researching
my Stonehenge talk), the evidence is sometimes spotty.
Galen's latest trick: he moved the planetarium's observer location
up above the Earth's north ecliptic pole. Then he told the planetarium to
looked back at the Earth and lock the observer's position so it
moves along with the Earth; then he let the planets move in fast-forward,
leaving trails so their motions were plotted.
The result was fascinating to watch. You could see the Venus pentagram
easily as it made its five loops toward Earth, and the loops of all
the other planets as their distance from Earth changed over the course
of both Earth's orbits and theirs.
You can see the patterns they make at right, with the Venus pentagram
marked (click on the image for a larger version).
Venus' orbit is white, Mercury is yellow, Mars is red.
If you're wondering why Venus' orbit seems to go inside Mercury's,
remember: this is a geocentric model, so it's plotting distance from
Earth, and Venus gets both closer to and farther from Earth than Mercury does.
He said he'd shown this to the high school astronomy club and their
reaction was, "My, this is complicated." Indeed.
It gives insight into what a difficult problem geocentric astronomers
had in trying to model planetary motion, with their epicycles and
Of course that made me want one of my own. It's neat to watch it in
the planetarium, but you can't do that every day.
So: Python, Gtk/Cairo, and PyEphem. It's pretty simple, really.
The goal is to plot planet positions as viewed from high
above the north ecliptic pole: so for each time step, for each planet,
compute its right ascension and distance (declination doesn't matter)
and convert that to rectangular coordinates. Then draw a colored line
from the planet's last X, Y position to the new one. Save all the
coordinates in case the window needs to redraw.
At first I tried using Skyfield, the Python library which is supposed
to replace PyEphem (written by the same author). But Skyfield, while
it's probably more accurate, is much harder to use than PyEphem.
It uses SPICE kernels
(my blog post
on SPICE, some SPICE
examples and notes), which means there's no clear documentation or
list of which kernels cover what. I tried the kernels mentioned in the
Skyfield documentation, and after running for a while the program
died with an error saying its model for Jupiter in the de421.bsp kernel
wasn't good beyond 2471184.5 (October 9 2053).
Rather than spend half a day searching for other SPICE kernels,
I gave up on Skyfield and rewrote the program to use PyEphem,
which worked beautifully and amazed me with how much faster it was: I
had to rewrite my GTK code to use a timer just to slow it down to
where I could see the orbits as they developed!
It's fun to watch; maybe not quite as spacey as Galen's full-dome view
in the planetarium, but a lot more convenient.
You need Python 3, PyEphem and the usual GTK3 introspection modules;
on Debian-based systems I think the python3-gi-cairo package
will pull in most of them as dependencies.
Plot your own epicycles:
[ 13:04 Mar 01, 2020
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