this

FAQ
contact
rss/xml
atom/xml
search
spam notice
terms of use


sundries

xkcd
Fripp
Rahul
skippy
Sroyon
pylduck
Dogblog
thistothat
Joe.My.God.
Woolly Days
Futility Closet
Language Log
Bruce Schneier
Dinosaur Comics


archive


From the NY Times web site this afternoon. It was reworded after about 90 minutes.
surprise announcement (thanks Sasha for finding this) When taking pics of the sun or moon near the horizon, it helps to know how much time it takes for objects to rise or set. If you can remember that the apparent diameter of the moon or sun is about ½ of a degree of arc, calculating the rate they set at is easy.

A day is a turn of 360 degrees. Rising-setting motion is 360 ÷ ½ = 720 moon‑or‑sun diameters in a day, or 30 diameters in an hour. So the moon or sun takes roughly two minutes to rise or set the distance of its own diameter.

Roughly. The moon's orbital motion makes it set about 3% more slowly than the sun does, if that matters.

And speaking of orbital motion, sometimes the moon will be approaching a star or planet and I'll want to estimate when it'll be in the spot I want for a pic. If you can remember how many days are in a month, that's about how much slower the moon's motion relative to the stars is than its rising-setting motion. The moon orbits in somewhat less than 30 days so it takes a little less than 30 × 2 minutes = one hour to move a distance of its own diameter.

Last night's eclipse reminded me of all this. The total phase of a lunar eclipse begins a little less than an hour after the start of the umbral phase.
Illustration from US Patent 5023850, "Clock for keeping time at a rate other than human time". The clock could run at 7x in a canine application, thereby reminding humans of "the value to the animal of the duration" of activities. So if time is money, a day is seven times as expensive if you're a dog.

I've wondered how hummingbirds perceive time. We move in slow motion by comparison.
figure 1
From reviews of paintings by our last President:
Mr. Bush has an uncanny ability to translate photographs into more awkward images enlivened by distortions and slightly ham-handed brushwork.
These empty headed daubs look the work of someone you wouldn't trust to mow a lawn without cutting someone's foot off.
(NY Times and The Guardian, respectively) Assuming that
there are intelligent extraterrestrials, and
they write (with symbols on two-dimensional surfaces),
I once said I'd be curious to see what symbol an alien culture used for π, and a friend asked, "How do you know they would have a π in their mathematics?"

My friend knew how ubiquitous π is, not just in geometry/trig but in every branch of mathematics. He just liked to ask questions that made you consider anything you might be overlooking.

Funny thing is, that conversation didn't lead to what I now see as the elephant in the room—namely that it's better to have a symbol for the ratio of a circle's circumference to its radius rather than its diameter. The appearance of 2π in so many formulas in math and physics (e.g., angular frequency is 2π) is a hint that 2π is more fundamental. The case for 2π is laid out in detail in Michael Hartl's The Tau Manifesto, whose arguments I find compelling. Were I designing math nomenclature from scratch, I would so define a symbol for 6.28318... instead of 3.14159... .

Will the world see the light? The weight of literature and tradition behind our definition of π is huge. We're stuck with it like we're stuck with the QWERTY keyboard. As much as I'd like to see the movement to ditch π in favor of τ (=2π) succeed, I think it's a longshot to get much traction in my lifetime. But I'd bet you a nickel that if we ever compare notes with extraterrestrials, they'll have a symbol for τ instead of π. yes, I left out Hawaii
(recreation of a cartoon I saw years ago,
maybe in Harper's but I'm not sure)
California is the best state in the USA for rock climbing, and not just because I am biased. A guidebook for Joshua Tree National Park alone lists 3854 routes.

The first climbing guidebook for the Owens Valley—published in 1988 and long since out of print—listed just ten routes in my neighborhood, dissed the area for having largely crummy rock, and called it a sort of "poor man's Joshua Tree". Well.

There are a lot more than ten routes in my neighborhood now. Fittingly, a few of them have names making reference to J-Tree route names. E.g., Last (and least) is Imaginary Hidden Valley, my silly answer to J-Tree's Real Hidden Valley. I say least because although IHV is in the latest guidebook, it's not popular and it doesn't turn up in a web search. Googling for the phrase returned only four results when I tried this evening, none of them referring to the climbing area. Google's helpful true‑enough count: "About 3 results".

Isaac Asimov told a story of having sat in on a sociology class where the professor classified mathematicians as mystics for believing in imaginary numbers. Asimov spoke up to defend them, and the prof said okay, hand me the square root of minus one pieces of chalk. The rest of the story can be found here.

Imaginary numbers don't come up in conversation often enough. It's been 31 years since the last time someone asked me what complex numbers are good for. Language stuff.

Yesterday, Mike Rogers (R-Alabama) stood by his claims that Edward Snowden is somehow in cahoots with Russian intelligence services. But from sentence to sentence, what Rogers claimed various unnamed officials think wobbled from "can't rule out" to "believe" to a thicket of overnegation:
We know today no counterintelligence official in the United States does not believe that Mr. Snowden, the NSA contractor, is not under the influence of Russian intelligence services.


A recent NY Times article discusses objections to the term "homosexual": it's outmoded, it's loaded, it can have a pejorative tone. It's a decent article as far as it goes, but it never mentions my favorite curious fact about homosexual, to wit: it's a hybrid word (homo from Greek, sexual from Latin).

I like how modern Greek has no truck with various hybrid words common in other European languages, preferring homegrown compounds instead. In Greece, a homosexual is an ομοφυλόφιλος (omofylófilos), an automobile is an αυτοκινήτων (af̱tokiní̱to̱n), and a television is a τηλεόραση (ti̱leórasi̱).

And for those who find typos in subheadlines amusing, I've saved one from the Times article in case they fix it. Goodyear has a new blimp1 and a name the blimp contest. The grand prize winner and up to five friends get to ride the blimp.

Contest rules include (italics mine):
Your Entry MUST2 meet the following qualifications, in the Sponsor's sole discretion:
[...]
(d) MUST NOT contain material that is (or promotes activities that are), in Sponsor's sole discretion, hateful, slanderous, libelous, tortuous, sexually explicit, obscene, inappropriate, vulgar, offensive, sexually explicit, profane, pornographic, discriminatory (e.g., based on age, sex, religion, natural origin, physical disability, sexual orientation or age);
Okay then, I guess they mean it.
1 technically not a blimp but rather a semi‑rigid dirigible
2 MUST and MUST NOT are in all caps, thus presumably to be interpreted as described in RFC 2119
Justin Casquejo, a teenager from New Jersey, has been in the news for sneaking into the not-quite-finished One World Trade Center.

click for original size News reports include pics of Justin from social media websites, but they're all rather tame pics and you'd never know that he and a friend had been posting a few somewhat NSFW pics as well. They've since vanished off twitter—but I saved them. The pics (see also) are composed to be just shy of indecent, but I can see why they've been yanked now that Justin has a measure of fame.

It is entertaining that security was deficient enough to allow a kid to get to the top of the building. (Word is, a guard was asleep.) And there's amusement value in the mentality that drives adolescents to climb through barriers (or post pics about how real men do things). And as readers know, even modest entertainment value is enough to make me post stuff. BUT, the reason I'm bringing all this up is because the episode brings back memories and highlights how much has changed since I was a teenager.

Circa 1977, two friends of mine got caught trespassing on the construction site of the original World Trade Center. They didn't make the news. They didn't end up being prosecuted.

click for larger uncropped version We weren't taking pics of ourselves naked, and we didn't post the naked pics that we didn't take on social media sites that didn't exist. But I did get this shot of one of my friends who got caught at the WTC.

The computer paper on the wall in the upper right had the 6002 digits of the then-largest-known prime number, 219937‑1. The IBM 1130 at my high school had 8192 words of core memory, enough to hold the decimal digits and the (assembler language) program to generate and print them, but not a lot more.

I still have the LP whose album cover is partly visible (leaning) next to my friend's foot. I still have the chessboard that's on the floor. I don't have a reel-to-reel tape recorder anymore although I still have some tapes that maybe I'll arrange to digitize some day.

My friend is playing with a razor blade standing on a speaker magnet. I've generally gotten better results taking pics of people when they're occupied with something else than when they're looking at the camera.
As y'all know, the number 19 has figured in fun coïncidences in my life. As a teenager I thought perhaps they were more than dumb luck but nowadays my best guess is that they are just that. Consider, though, that 19 cropped up more often when I was a teenager. Well, except for a run of nineteens again when I was 38. In a few years I'll be 57, perhaps.

Most of my friends have deemed my nineteens to be insignificant and saw my interest in them as another of my quirks, if a fairly benign one. The only friend who understood had a recurring number of his own—1020—which impressed me because a number that large comes around less frequently than a small number like 19. When I did an experiment to test whether 19 came up more than other numbers, I chose a similarly sized number (17) as a control.

I was there to see some of my friend's 1020 instances firsthand and he told me about others, e.g.:
from a letter Master Lock The lock came with the tag shown here. Strictly speaking, this wasn't an instance of 1020 but rather 10 and 20—but even so.

A well-known "feature" of getting high is that trivial things can seem profound. My brother once wrote down what he at the time thought was a cool observation, but it struck him as less remarkable in the cold light of day the next morning. It said, a combination lock is really a permutation lock.
I've been without my marimba for ten days because I sent the bars out for tuning. I miss it.

If I had more energy I'd consider making another marimba. Not that the one I have is bad, but I have an idea I'd like to experiment with. The bars for the lowest notes are really thin in the center, which makes them more prone to vibrating in undesirable modes. Making them thicker would require making them longer, ideally mounting them on curved rails (akin to how piano strings don't increase in length in a linear progression). Curved rails would be a pain to fabricate and I suspect that has a lot to do with why no one uses them. Branched rails (a piecewise-linear approximation to curved rails) exist but they are uncommon.

Bass notes are special to me.

A local band I used to see in Boulder was scrambling to find a bass player for an upcoming tour (summer 1987 or 1988, I'm not sure). I borrowed an electric bass and started learning their songs, but they got someone else (who also learned the instrument from scratch) instead. But the experience made me start paying more attention to bass lines in songs and increased my appreciation for the role of bass in general.

I envy string players for the expressive qualities of their instruments. There is no vibrato nor bending notes on the marimba. But what is life if not working within limitations.
circle-with-line denotes snap pizzicato
Among the tone colors electric bass is known for is plucking a string so that it rebounds off the fingerboard. Although known as popping in this context, the general effect has another name associated with the composer who invented the symbol for it that's now standard in music notation. If you know me, your first guess as to which composer it is will be correct.