August 2008 Archives

Watch

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Turns out I would make a terrible political live-blogger. I wound up watching so much Democratic speechifying that I haven't posted here in days.

While I didn't find his acceptance speech as loftily inspiring as some of his earlier ones, I think that for what he needed to do, Obama knocked this one out of the (large, packed) park.

Meanwhile, today will go down as the day the McCain campaign jumped the shark. Or the polar bear, as the case may be.

Now, of course, the excitement (so to speak) moves to my back yard. Not sure yet what the extent of my involvement in that mess will be.

Veepstakes

Supposedly today is VP Day. I didn't bother to sign up for the extra special find-out-first text message. It's not like I won't find out within hours, anyway.

For the record, I've been saying it should be Sebelius for months.

I'm going to out on a limb and say it'll be her. But I'm quite likely wrong.

[Update, the next day: Yup, I was wrong. I feel pretty okay about not getting a text message at 3 am to tell me that.]

Low-Car Entertainment

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Nothing much to report; had a kind of busy weekend that segued smoothly into a contractor dismantling my house this week. (Actually just the windows, which all need to be replaced, because the city has developed an abundance of concern about lead paint in old windowframes.) Also, my house has been killing entirely too much time squawking at the Olympics. Haven't spotted a single protester yet. That's why NBC gets the big bucks, I assume.

At Streetsblog, I checked out photos of the new Times Square. As part of the "Broadway Boulevard" project the street has been redesigned to prioritize the types of traffic that make the city work -- i.e. primarily foot traffic. And I think the new bike lane aware traffic lights (example shown at left) are too cute.

Speaking of which, who else knew that World Carfree Day falls on my birthday? Sweet.

Two other entertaining bits I ran across in the past few days:

A joke made at an American Geophysical Union meeting has emerged fully formed in Deep Time for Dummies. Why bother memorizing 4,600,000 millennia of geological history when the Bible says you only need six? An expert maps 6,000 years of history onto the geological record, starting with:

* 23 October 4004 B.C.: Hadean Era ends with Lucifer's fall to Earth
* 4003 B.C.: Earth still largely molten , Adam and Eve cover their shame with asbestos waders

and including such world-historical highlights as "48 B.C.: All of Gaul is divided into three parts as Corsica collides with the European Plate" and

A.D. 1492: Panama's rise from sea thwarts Columbus's discovery of Japan.
A.D. 1522: Sneak asteroid attack by Hernan Cortez smashes Aztec Empire

And so on in that vein, although the modern bits of the timeline seem a tad off.

Also, check out the Periodic Table of Awesome. Finally it is revealed that the suggestively similar awesomeness of pirates, zombies, dwarves, robots, and aliens is caused by their common (halogenic) valence number.

I also like the idea of The Idea Vending Machine. It's disappointing that it only occurs to tourists to use it. And since that actually makes three entertaining bits, I hope the Idea Vending Machine includes one that reads "learn to count."

Interesting Stuff

Continuing link dumpage, this time from my reading in the DIY scene. I wonder if I can make EGAD nearly-daily again if I just give up on covering the mid-week.

3-D printers (aka robotic prototypers, rapid fabricators ... a whole category of machines that take in 3-D engineering design files and turn them into physical objects by various means) are trickling down to the mass consciousness and the amateur level. By now I've seen probably dozens of examples of people whipping together such devices, typically winding up with something that is a grotesque hybrid of a moveable stage and a hot-glue gun. One of my favorites will render your designs in Cheez Whiz.

However, the most delightful project -- in a "we're gonna have to listen to techno" sort of way -- RepRap is now self-hosting (mostly). As in, one RepRap can make another RepRap. That is so cool. I want.

Okay, what else?

Here's a short video and write-up about a form of tempered glass that's been known about for centuries and has some quite odd properties -- Prince Rupert's Drops are nearly indestructible until you tweak the end of the tail. Then they violently explode.

If I had more time, I would totally enter the Underhanded C Contest.

Evil Mad Scientist labs has been around for twenty millicenturies.

Josh Marshall ran across and posted about a neat article in The Atlantic about GM's crash program to be first to market with a practical electric car. They're aiming for basically now, in car time, but given the state the company is in it's not clear that even that is enough time.

Titles

Covering all the bases, eh? British Airways lets you pick from a pretty wide array of titles when applying for a frequent flier account. Just take a second to peruse that drop-down menu.

I wonder, how many people so qualified actually feel the need to be addressed by their airline as "Brigadier General"? The hereditary titles I understand, as European nobility does make a rather big deal about such things. I'm rather curious to know who would qualify for the title of "High Chief", though. And seriously, I don't think people going by "His Holiness" or "Her Majesty" generally bother with frequent flier programs. (I checked -- there's no "Her Holiness" option, I'm sorry to say.)

The drop-down list of preferred languages, while impressive (how many people do *you* run into that speak Altaic?) is not quite such a comprehensive overkill.

Overheard

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At my house, yesterday morning, regarding a window fan: "This fan should not be on! It's cold! Winter is coming! It smells like winter outside!"

It may be true that we are past the summer solstice and the climatological summer temperature peak, and we are having an unusually mild summer in general. Nevertheless, given that the date was August 10, I expressed some skepticism.

Walking down University Avenue, this morning: a honky-tonk rendition of Pink Floyd's "Comfortably Numb" blasting from a passing pickup.

I'm not sure how I feel about that one.

Optimization

I'd always heard that compiler optimization1 is uniformly risk-positive -- i.e. turning on optimizations might make your code not run, but never the other way around.

On a seemingly-unrelated note, I'd always heard that you can't do proper tail calls in C, because it is so tightly wedded to the function call paradigm -- with the result that recursive algorithms can't be safely used in C.

The other day, I discovered that, taken together, both of the above statements are under some circumstances false.

Consider the following program:

#include <stdio.h>

int x;

unsigned long long int foo(unsigned long long int a) {
if(a % 2 == 0) ++x;
return a > 0 ? foo(--a) : a;
}

int main() {
unsigned long long int i = 2;
while(1) {
printf("Recursing %llu levels (got x = %d)\n", i, x);
x = 0;
foo(i);
i *= 2;
}
return(0);
}

Formally, you can see that foo() is recursive, so as the variable i gets bigger and bigger, the program should run forever, taking twice as long each time through. In practice, if you compile this program normally, the stack will overflow because it can only hold so many function calls, and the program will abruptly crash after a fraction of a second.

With gcc, turn on "-foptimize-sibling-calls" (which happens by default if you use "-O2" or higher), and the compiler will employ tail call optimization, meaning that the recursive bit (call a function and return the result) gets turned into an iterative operation (jump to a new function and let it return its own result as if it was a simple continuation of this function). As a result, that recursive call at the end of foo() doesn't take up an extra slot in the call stack, so the program really will run forever, exactly like it should. (Eventually the variable i will overflow and wrap around, so you'll get the wrong number, but the program will never crash. And since I used a 64-bit integer (that's what the "long long" thing means), you probably won't be around for the billions of years it will take your computer to actually count that high.)

1: For non-programmers, a compiler is the program that turns a programming language source code -- something that usually looks like written instructions or mathematical formulas -- into the binary instructions that a CPU can run as a program. Compiler optimizations are tricks the compiler can use, that result in binary instructions that don't exactly reflect what you wrote in the source code, but should have the same effect and run faster or take less space. C is one of the older programming languages, and one of the most widespread.

Some Provocative Bits

A great deal of my reading is political in nature, so I have a vast backlog of links to interesting stuff I've read. Here's a selection:

I'm leading off with the article that actually inspired me today to get off my virtual ass and return to the site, because I want to know planetgal's reaction to it. Digby has been writing lately about police violence, with a particular focus on the phenomenon of people being essentially tortured (sometimes to death) with Tasers. However, the post I'm interested in today zooms in on a different, rather specific form of police aggression: it appears that in an encounter with today's trigger-happy cops, it is not too unlikely that they will shoot your dogs.

Not to diminish the horror of a loved one being electrocuted, but at least then there are likely to be some kind of repercussions. But I know several people, planetgal included, who love their dogs like children, so it's a bit striking that if a policeman guns them down essentially for sport they probably won't even feel the need to apologize.

Next topic: someone convinced the government to publish its policy on electronic searches at border crossings. The short version is, they can take your laptop, cell phone, or anything else "capable of storing information" down to the crumpled up receipts in your pockets. For all practical purposes, they never have to give it back, they will share the data with whomever they want, and they don't need a reason.

For this reason among others, I only cross borders with electronics I don't mind losing (I tend to inherit ancient laptops) and keep basically no information on them -- my files cross later via encrypted link (nothing but SSH) from my destination's wireless network. The exceptions are MP3s (which nobody cares about, I want on the plane, and would take too long to download from home anyway) on my player, and stuff like contacts on my cell phone (since I don't know of an easy way to wipe it and remotely restore that, anyway). But seriously, if you're trying to smuggle data in/out of the country, just tuck a SD card or similar in your pocket. They're so tiny now, it could almost certainly pass unnoticed.

On a related note, if I'm not mistaken in this Frontline interview an ex-NSA employee reveals what Bush/Cheney were doing that was so bad Ashcroft's deputies threatened to resign when they found out. Not to mention the fact that Bush was willing to deep-six necessary foreign intelligence revisions unless Congress included retroactive blanket immunity for the telcos that cooperated (and by extension for himself, since if they can't be investigated nobody will ever be able to prove what they did). Why the Democratic leadership rolled over for that one remains a mystery. I'll probably talk at greater length about this one later.

More generally there's been a lot written (here's a good example) this summer about restoring the rule of law and achieving accountability for those responsible for so degrading it -- the many followers of Bush and Cheney who enabled illegal spying, who committed torture, who tried to roll back democratic rights that our ancestors have guarded for the last thousand years. I'll tell you straight up right now, most of them, if confronted, are going to claim that they were just following orders.

Back To It

It appears that my last content-ful post was back in May; it now being August, I'm retroactively declaring that EGAD observes summer vacation this year.

In reality, though, I stepped away from the blog because EBEX, the experiment I've been working on for the past several years, was scheduled for a test flight this fall, and all Hell predictably broke loose as we stretched and struggled to get it ready to fly. As that flight has now been postponed to the spring, I think the pressure has subsided sufficiently that I can go back to blogging, although I don't yet know what the posting schedule is likely to be.

What I can say is that there will be a few posts coming up soon, as I clean up and clear out the half-written posts that have accumulated over the past couple of months. It continues to be the case that I read an enormous amount online, and I'm not even going to try to summarize everything interesting that I read, but I probably will put up a few link-dump posts.

I'm intrigued that my monthly traffic only fell by around 20% over two months of non-posting -- I suspect this is because my archived posts are rather popular with the search engines. However, that other 20% is probably most of my regular readers, which means that it may be a while before anybody actually reads this. (Not actually true, as it will show up in RSS feeds and the LJ feed shortly, but people reading EGAD that way probably don't show up in the site counter, either.)

I bet more of you would click through and visit the site if the comment system was less flaky. I should look into that.

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This page is an archive of entries from August 2008 listed from newest to oldest.

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