The Daily Parker

Large areas of the planet are experiencing record heat this week, as predicted by the anthropogenic climate change hypothesis:

No single record, in isolation, can be attributed to global warming. But collectively, these heat records are consistent with the kind of extremes we expect to see increase in a warming world.

• Denver tied its all-time high-temperature record of 105 degrees on June 28.
• Burlington, Vt., set its all-time warmest low temperature ever recorded of 80 degrees on July 2.
• Montreal recorded its highest temperature in recorded history, dating back 147 years, of 97.9 degrees (36.6 Celsius) on July 2. The city also posted its most extreme midnight combination of heat and humidity.
• Scotland provisionally set its hottest temperature on record. The U.K. Met Office reported Motherwell, about 12 miles southeast of Glasgow, hit 91.8 degrees (33.2 Celsius) on June 28, passing the previous record of (32.9 Celsius) set in August 2003 at Greycrook. Additionally, Glasgow had its hottest day on record, hitting 89.4 degrees (31.9 Celsius).

As we reported, Quriyat, Oman, posted the world’s hottest low temperature ever recorded on June 28: 109 degrees (42.6 Celsius).

That's right; in Oman overnight on June 28th, it never got below a potentially lethal temperature.

It's beginning to look a little like Christmas...on Venus.

Amsterdam is building a new subway line directly beneath the Amstel River, so they drained it, as one does. Then they let a team of archaeologists go wild:

The excavations in the Amstel yielded a deluge of finds, some 700,000 in all: a vast array of objects, some broken, some whole, all jumbled together. Damrak and Rokin proved to be extremely rich sites on account of the waste that had been dumped in the river for centuries and the objects accidentally lost in the water. The enormous quantity, great variety and everyday nature of these material remains make them rare sources of urban history. The richly assorted collection covers a vast stretch of time, from long before the emergence of the city right up to the present day. The objects paint a multi-facetted picture of daily life in the city of Amsterdam.

The city has published an online catalog that you can view chronologically or alphabetically.

This past weekend included the Chicago Gay Pride Parade and helping a friend prepare for hosing a brunch beforehand. Blogging fell a bit on the priority list.

Meanwhile, here are some of the things I'm reading today:

• From last week, the Times discusses whether Earth's 23.4° axis tilt was actually a necessary precursor to life.
• New Republic's Josephine Huetlin asks, "Why do populists get away with corruption?"
• One of Chicago's last remaining over-the-tollway oases is slated for demolition.
• Josh Marshall points out why President Trump treating international diplomatic negotiations like flea-market haggling is a huge, long-term problem for the US.
• Writing for JetBrains' blog, developer Dino Esposito looks at how special string handling can be a code smell.
• The owner of the Lexington, Va., restaurant that kicked out Press Secretary Sarah Sanders talked to the Washington Post.

Back to debugging service bus queues...

Meetings and testing all day have put these on my list for reading tomorrow:

• The Atlantic's Carl Zimmer on epigenetics.
• New Republic's David Dayen saying AT&T has proved its critics right in only a week.
• London plans to spend £1.5 bn ($2 bn) to get enough trains on its four most-crowded lines just to keep up with demand.
• Jennifer Rubin says, contra the President, America is strong and he is weak.
• Andrew Sullivan says, fuck it, give Trump his wall.
• And pity the poor Trump Administration staffers who can't get dates in DC.

And with that, it's the weekend.

For day 15 of the Blogging A-to-Z challenge I want to talk about something that computer scientists use but application developers typically don't.

Longtime readers of the Daily Parker know that I put a lot of stock in having a liberal arts education in general, and having one in my profession in specific. I have a disclosed bias against hiring people with computer science (CS) degrees unless they come from universities with rigorous liberal arts core requirements. Distilled down to the essence, I believe that CS majors at most schools spend too much time on how computers work and not enough time on how people work.

But CS majors do have a lexicon that more liberally-educated developers don't really have. For example, when discussing how well code performs, CS majors use "Big O" notation.

In Big O notation, the O stands for "order of growth," meaning how much time could the algorithm could grow to take up given worst-case inputs.

The simplest notation is O(1), where the code always takes the same amount of time to execute no matter what the inputs are:

int q = 1;
int r = 2;
var s = q + r;

Adding two integers in .NET always takes the same amount of time, no matter what the integers are.

The titular notation for this post, O(n), means that the execution time grows linearly based on the input. Each item you add to the input increases the time the algorithm takes by exactly one unit, as in a simple for loop:

public long LoopExample(int[] numbers)
{
	long sum;
	for(var x = 0; x < numbers.Length; x++)
	{
		sum += numbers[x];
	}
	return sum;
}

In that example, each item you add to the array numbers increases the time the loop takes by exactly one unit of time, whatever that unit may be. (On most computers today that would be measured in units of milliseconds, or even hundreds of nanoseconds.)

Other algorithms may be slower or faster than these examples, except that no algorithm can be faster than O(1). The parenthetical can be any expression of n. Some algorithms grow by the logarithm of n, some grow by the double of n, some grow by the square of n.

This notation enables people to communicate precisely about how well code performs. If you find that your code takes O(n²) time to run, you may want to find a fix that reduces it to O(log n). And you can communicate to people how you increased efficiency in just that way.

So as much as I want application developers to have broad liberal educations, it's worth remembering that computer science fits into a liberal education as well.

About a year ago, a number of American diplomats and their families in Cuba were injured by what our military speculated might be a sonic weapon. A sonic weapon directs sonic energy at a target to disable, but not necessarily permanently damage, the person. Over a few months, people reported "blaring, grinding noise," hearing loss, speech problems, nausea, disequilibrium...exactly what a sonic weapon could cause.

Via Bruce Schneier, a team at the University of Michigan working in association with the IEEE has published a paper speculating on the variety of weapon how it might have worked:

On the face of it, it seems impossible. For one thing, ultrasonic frequencies—20 kilohertz or higher—are inaudible to humans, and yet the sounds heard by the diplomats were obviously audible. What’s more, those frequencies don’t propagate well through air and aren’t known to cause direct harm to people except under rarefied conditions. Acoustic experts dismissed the idea that ultrasound could be at fault.

Then, about six months ago, an editor from The Conversation sent us a link to a video from the Associated Press, reportedly recorded in Cuba during one of the attacks.

To make the problem tractable, we began by assuming that the source of the audible sounds in Cuba was indeed ultrasonic. Reviewing the OSHA guidance, Fu theorized that the sound came from the audible subharmonics of inaudible ultrasound. In contrast to harmonics, which are produced at integer multiples of a sound’s fundamental frequency, subharmonics are produced at integer divisors (or submultiples) of the fundamental frequency, such as 1/2 or 1/3. For instance, the second subharmonic of an ultrasonic 20-kHz tone is a clearly audible 10 kHz. Subharmonics didn’t quite explain the AP video, though: In the video, the spectral plot indicates tones evenly spaced every 180 Hz, whereas subharmonics would have appeared at progressively smaller fractions of the original frequency. Such a plot would not have the constant 180-Hz spacing.

Of course, to this day, no one knows exactly why the attacks occurred, and even to say "attacks" makes a reasonable but not certain assumption.

An article in this month's Atlantic points out that we humans can wonder how we got here only because we got here:

After all, there are 100-mile impact craters on our planet’s surface from the past billion years, but no 600-mile craters. But of course, there couldn’t be scars this big. On worlds where such craters exist, there is no one around afterward to ponder them. In a strange way, truly gigantic craters don’t appear on the planet’s surface because we’re here to look for them. Just as the wounds of the returning planes could reflect only the merely survivable, so too for our entire planet’s history. It could be that we’ve been shielded from these existential threats by our very existence.

“Observer selection effects are really the kind of effects where the data you get is going to be dependent, in some sense, on survival, or that you as an observer exist,” [Anders Sandberg, a senior research fellow at University of Oxford’s Future of Humanity Institute] says. “Now this gets really interesting and scary when we apply it to our own survival.”

“Maybe the universe is super dangerous and Earth-like planets are destroyed at a very high rate,” Sandberg says. “But if the universe is big enough, then when observers do show up on some very, very rare planets, they’ll look at the record of meteor impacts and disasters and say, ‘The universe looks pretty safe!’ But the problem is, of course, that their existence depends on them being very, very lucky. They’re actually living in an unsafe universe and next Tuesday they might get a very nasty surprise.”

If this is true, it might explain why our radio telescopes have reported only a stark silence from our cosmic neighborhood. Perhaps we’re truly extreme oddballs, held aloft by a near-impossible history—one free from lifeless water world.

We see this on smaller scales when, for example, extremely lucky people start to think they succeeded entirely because of their own efforts. But that's a different topic. Sort of.

Saturday and Sunday, the Apollo Chorus sang Verdi's "Requiem" three times in its entirety (one dress rehearsal, two performances), not including going back over specific passages before Sunday's performance to clean up some bits. So I'm a little tired.

Here are some of the things I haven't had time to read yet:

• I always read Andrew Sullivan's weekly column but I haven't had a chance yet.
• Democratic candidate Conor Lamb might win in a heavily-Republican district in Pennsylvania. (Disclosure: I have contributed to Lamb's campaign.)
• The Telegraph UK reports that there is now a genetic test for intelligence.
• Jeet Heer returns to political reporting, suggesting that the President's ideas aren't as bad as his execution of them.
• Now that we're back on Daylight Saving Time in North America, The Daily WTF reminds us how much fun it is to debug software implementations of time zones.
• Microsoft's Raymond Chen started a series of blog posts on advanced Git management.
• Cranky Flier says American's most recent changes to its scheduling practices are good for customers.
• Closer to home, the city of Chicago and the Chicago Transit Authority have started construction aimed to fix one of the biggest bottlenecks on the El.
• Crain's Chicago Business reports that, for the first time in its existence, Groupon has had a profitable quarter.
• Chicago History Today has side-by-side photos of Dearborn and Jackson from 1936 and 2017.
• And finally, NASA has launched two new weather satellites that will significantly advance weather forecasting.

Other stuff is going on, which I'll report when I have confirmation.

In all seriousness, self-cloning crayfish are kind of freaky:

In 2003, scientists confirmed that the marbled crayfish were indeed making clones of themselves. They sequenced small bits of DNA from the animals, which bore a striking similarity to a group of crayfish species called Procambarus, native to North America and Central America.

For nearly two decades, marbled crayfish have been multiplying like Tribbles on the legendary “Star Trek” episode. “People would start out with a single animal, and a year later they would have a couple hundred,” said [German biologist Frank] Lyko.

Many owners apparently drove to nearby lakes and dumped their marmorkrebs. And it turned out that the marbled crayfish didn’t need to be pampered to thrive. Marmorkrebs established growing populations in the wild, sometimes walking hundreds of yards to reach new lakes and streams. Feral populations started turning up in the Czech Republic, Hungary, Croatia and Ukraine in Europe, and later in Japan and Madagascar.

Cloning works in the short term, but not for very long. Sex is useful in fighting disease:

If a pathogen evolves a way to attack one clone, its strategy will succeed on every clone. Sexually reproducing species mix their genes together into new combinations, increasing their odds of developing a defense.

The marbled crayfish offers scientists a chance to watch this drama play out practically from the beginning. In its first couple decades, it’s doing extremely well. But sooner or later, the marbled crayfish’s fortunes may well turn.

“Maybe they just survive for 100,000 years,” Dr. Lyko speculated. “That would be a long time for me personally, but in evolution it would just be a blip on the radar.”

One question the Times did not answer: how do they taste?

The Atlantic reports on some new research in why animals all do this thing that could get them eaten:

There are a handful of substances clearly demonstrated to cause sleep—including a molecule called adenosine, which appears to build up in certain parts of the brains of waking rats, then drain away during slumber. Adenosine is particularly interesting because it is adenosine receptors that caffeine seems to work on. When caffeine binds to them, adenosine can’t, which contributes to coffee’s anti-drowsiness powers. But work on hypnotoxins has not fully explained how the body keeps track of sleep pressure.

For instance, if adenosine puts us under at the moment of transition from wakefulness to sleep, where does it come from? “Nobody knows,” remarks Michael Lazarus, a researcher at the institute who studies adenosine. Some people say it’s coming from neurons, some say it’s another class of brain cells. But there isn’t a consensus. At any rate, “this isn’t about storage,” says [Japanese researcher Masashi] Yanagisawa. In other words, these substances themselves don’t seem to store information about sleep pressure. They are just a response to it.

Unfortunately...they still haven't figured it out. But there is a cute video at the bottom of the article.