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Sometimes you don't need to see coördinates from a GPS receiver, you just let your phone or other device show your location on a map. But if you're looking to calculate how far apart two places are or to find a spot a mile east of where you are, you may want to use numbers. Latitude and longitude are not great for such purposes because it's a pain to convert them into distances. Better are UTM (Universal Transverse Mercator) coördinates, which are positive decimal (x,y) values in meters ("easting" and "northing"). They're not exactly equal to meters on the ground (because of discrepancies inherent in map projection) but they're pretty close. UTM divides the earth into sixty zones and uses a different projection for each zone. If the area you're working in doesn't straddle a zone boundary, UTM coördinates are easily subtracted to get displacements in meters.

UTM coördinates can have a lot of digits and sometimes they are given in truncated form for simplicity. In this map excerpt, 400000 and 4053000 are in meters; 401, 402, and 4052 are in kilometers. By convention, UTM coördinates are written in small and large digits—the tens and units km digits being large—so that even when they are truncated, you know what units to interpret them as. climbing routes here To get a feel for how UTM works (and how it compares to latitude and longitude), there's a nice tool at that overlays maps with UTM grid lines.

UTM's grid lines curve with respect to due east/west and north/south (in any map projection, something has to give). Topo maps often have a key to show you roughly how much UTM's vertical grid lines diverge from true north in the area mapped (along with how far magnetic north is off). The angles on the map legend shown here are given in degrees+minutes of arc and also in mils (thousandths of radians). In this example, the UTM vertical grid lines diverge from true north by 11 mils. Expressing the divergence in mils makes for convenient adjustments: to move one km true north from a location in this area, add 1000 meters to UTM northing and 11 meters to UTM easting. (An approximation, but close enough for most purposes. For small angles, cos(θ) ≈ 1 and sin(θ) ≈ θ.)

I wish I could stop here because UTM is so sensible, but sometimes one encounters coördinates in MGRS (military grid reference system), a kludgey and cryptic way to express what UTM says directly.

SatStat The screenshot to the right shows a satellite navigation app displaying MGRS coördinates 11SMA0198048176 that correspond to UTM Zone 11, 401980E, 4048176N. MGRS coördinates incorporate digits from the equivalent UTM coördinates, but the rules for encoding/decoding the prefix letters are dopey. The S in 11SMA is a subdivision based on lines of latitude, whereas the M and A are further subdivisions based on UTM grid lines. If a hodgepodge of incongrous methods of subdivision sounds like a recipe for confusion, that's because it is.
A few days after the cover of the New Yorker featured a drawing of (part of) Kim Jong-un's head, in which the artist "tried to capture the mystery—and the deep anxiety—of the moment", North Korea released this surreal-mysterious (undated) photo: click for larger version If the pic had a round table instead of a desk, it would look like a setup for a Colt 45 commercial (the brand ran some truly bizarre commercials on US television in the 1960s). Saturn has two little moons that are roughly in the same orbit, except one is a little closer to Saturn so it makes a revolution in slightly less time—but when it catches up to the slower moon and passes it, the two moons' mutual gravitational attraction transfers some energy between them. The moons continually switch positions: one is closer to Saturn for a while, then the other, ... .

The gravitational field of two moons doing this kind of dance puts spiral lumps into an area of Saturn's ring:NASA photo, taken by Cassini on June 4, 2017 Some music I liked when I was a kid doesn't impress me much anymore, and then there's some that I appreciate all the more as time goes on. Steely Dan is in the latter category—their music has a lot going on under the surface.

I like the early Steely Dan records the best. The later ones sold better and got awards.

I am saddened by Walter Becker's passing today but encouraged by Donald Fagen's tribute in which he affirms his intent to keep playing Steely Dan's music.

I like that Walter Becker's 1994 solo record has 12 tracks despite being named 11 Tracks of Whack and that it includes the song Lucky Henry which I think is an absolute gem. A US Attorney recently moved to postpone a trial because
The case agent in this matter, ATF Special Agent Chad Horst, will be unavailable for trial from August 21 through to August 23, 2017. Agent Horst will be out‑of‑state from August 19 through to August 23, 2017, on a pre‑paid trip to view the total solar eclipse, scheduled to occur on August 21, 2017. The last time such a total eclipse is estimated to have occurred is June 1918.
The path across the USA of the June 8, 1918 eclipse was similar to the one this month but there have of course been various other opportunities to see total solar eclipses since 1918.

The judge denied the request, quoted lyrics from the Carly Simon song You're So Vain, took issue with the description of an eclipse as "total" when you can still see the sun's corona, found the phrase "scheduled to occur" odd when applied to an eclipse, and said
The present motion proposes to subordinate the time and resources of the court, of the opposing counsel, of the witnesses, and of the jurors to one person's aspiration to view a "total" eclipse for no more than two minutes and forty‑two seconds. To state the issue distinctly is to resolve the issue decisively.
The trial ended up being heard yesterday (by the judge; the defendant waived his right to a trial by jury) so maybe Agent Horst went to see the eclipse anyway.

The case was about unlawful possession of firearms. The defendant claimed he hadn't consented to a search of his car but according to the police he said, "Uhhh, sure." The prosecution cited another case as precedent in which a response of "yeah, I guess" was ruled to have expressed consent. I didn't see this week's total eclipse because I didn't feel up to making a long drive. Had I gone, though, I would've liked to have found a spot to be alone during totality. I've seen a total eclipse in the company of others (in 1991) and I'd like to try the alternative. You can't hear how silent an eclipse is when people around you are making all manner of noise.

I like seeing the thin crescent moon after a total solar eclipse (any eclipse, not necessarily one visible near me). I imagine the moon to be discreetly preening, basking in the satisfaction of having contributed to the spectacle a few days before.
It is the punishment of the South that its Robert Lees and Jefferson Davises will always be tall, handsome and well‑born. That their courage will be physical and not moral. That their leadership will be weak compliance with public opinion and never costly and unswerving revolt for justice and right. It is ridiculous to seek to excuse Robert Lee as the most formidable agency this nation ever raised to make 4 million human beings goods instead of men. Either he knew what slavery meant when he helped maim and murder thousands in its defense, or he did not. If he did not he was a fool. If he did, Robert Lee was a traitor and a rebel—not indeed to his country, but to humanity and humanity's God.

Nowadays we have Republican politicians standing by Tr‑‑p lest they fall out of favor with their constituents. I wandered around the grounds of the Googleplex for the first time yesterday. I was underwhelmed.

Google used to number at least some of their buildings with transcendental or imaginary numbers but all the ones I saw this week were numbered with integers (boring).

There weren't many pieces of outdoor art and none that I found interesting.

My favorite part of the campus was an embedded non‑Google property, i.e. a holdout:

Google employees in front of not-so-Google building Fred A discussion in a photography forum got me to thinking about what I like about black and white images (only some of which I can put into words).

Smooth gradation looks awesome in black and white, e.g. an area of sky fading from one gray level to another. Smooth gradation is of course also possible in color but there's something sublime about how it looks in black and white.

Black and white lets you take considerable liberties in altering contrast. When you darken skies with a red filter (or the digital post-processing equivalent), the resulting image is artificial but it doesn't look blatantly, annoyingly artificial.

Sometimes color is a distraction. Some compositions are about form and shape.

In any case, my interest in black and white is not about nostalgia. I don't aim to make pics that look like they were taken 100 years ago, nice though some 100 year old pics are. click for full bird
Roadrunner this morning.
Click on the pic for larger uncropped version.