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Andrew Reid
Works at NIST
Attended Queen's University
Lives in Washington DC
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Andrew Reid

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A lucid explanation of the Banach-Tarski paradox, making the rounds on Hacker News. This is pleasantly well grounded, with some necessary intro, and a minimum (though not zero) boggled amazement on the part of the presenter.

Also, the "read more" is pretty good, and in keeping with excellent public-speaking practice, opens with a joke -- "What's an anagram of Banach-Tarski? Banach-Tarski Banach-Tarski."
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Andrew Reid

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Today's SMBC propagates one of my favorite fun language facts -- in the 19th century, one of the meanings of "the silent majority" was the dead.

Etymology is not meaning, of course, but it can make for a good joke sometimes.
We'd still like a few more proposals, especially for the Seattle and San Francisco shows! Please consider sending in a proposal! Discuss this comic in the forum. July 25, 2015. It's almost the last second to submit for BAHFest! We especially need more submitters for our West Coast show!
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Speaking of post-blogging, I just now discovered that @ReliveApollo11 is post-live-tweeting the Apollo 11 landing, 46 years afterwards. As I write this, the proverbial Eagle has, indeed, landed, they've taken some pictures, but the astronauts have not stepped out of the LM yet.
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Would have been nice to follow this from just a little earlier!  I think I've previously read through some of the transcripts, which was quite exciting.
https://www.hq.nasa.gov/alsj/a11/a11trans.html
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Haven't watched this yet, but I'm a sucker for more info and background about Chuck Jones and the old Warner Brothers shorts.

I recently discovered that "Animaniacs" are on Amazon instant video, and have been re-visiting them. They're actually substantially more hit-and-miss than I remember, and I think they're a bit more disjointed than the classic Bugs Bunny, it's not Chuck Jones. But they hit some truly magnificent notes from time to time. And the sound, rich orchestral tapestries that complement the action, with auditory references, too, something the classic Warner cartoons also did very well.

Also, classic Warner cartoons and Animaniacs change as you age. When I was a kid, I thought Daffy Duck was pretty stupid, a necessary foil to advance the wackiness. Now he's my favorite -- he has straightforward goals, he's often right, but he never wins, hence the freak-outs. That makes a lot more sense to me now than it did 30 years ago. Odds my bodkins indeed.
Tony Zhou is back with another installment of Every Frame a Painting. In this one, he examines the evolution of Looney Tunes anima
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That whole series of  critical reviews of film is worth watching.I particularly enjoy the breakdown of Michael Bay's techniques
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Andrew Reid

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Apparently the x86 "mov" command is Turing-complete. (h/t +Alan Cox , where I saw this first.)

There are good comments on the original post, and also on the Hacker News comment thread: https://news.ycombinator.com/item?id=9751312

PDF of the paper is here: http://www.cl.cam.ac.uk/~sd601/papers/mov.pdf

I believe the traditional next step is for someone to implement a four-function calculator this way -- it's not a proof, but it can be a good demo of just how (im)practical the Turing-completeness is.
 
This is simultaneously amazing, ridiculous, and terrifying.

As it turns out, the assembly instruction 'mov' is Turing complete.
movfuscator - The single instruction C compiler
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If MOV is turing-complete and most compiled code is about 75% MOVs does that make all apps 75% turing complete?
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Andrew Reid

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Many years ago, I backed this Kickstarter project, the "Revolights" bicycle lighting system. It's a ring of LEDs that goes on the rim of the wheel, and has a microcontroller in it, so that the front wheel is only lit on the front arc, and the back wheel only on the back arc as the wheels spin around.

They exceeded their Kickstarter target by a lot, and through their updates, I had a ring-side seat to the decision to do another design iteration, and then to on-shore the manufacturing to the US, with the attendant surprises, some good and some bad, and some additional delays. I found it all quite fascinating, and besides all that, did get a set of "Mark I" Revolights of my very own.

They finished their Kickstarter in September of 2011, and they're still going, they've subsequently come out with a custom wheel with integrated revolights, added an accelerometer to the rear wheel to make a smart brake light, gotten the products into bike shops, and continued updating their backers.

The most recent update looks pretty high-impact, geek culture wise, they're now featured in an article in Makezine, and are the subject of a short documentary film, linked to in the article, "Life after crowdfunding", which will apparently be Episode 1 of a longer film about crowd-funded startups and their issues.

Obviously, my involvement is pretty small, but I am still enjoying the progress they're making.
A loose consortium of bike-tech startups is collaborating to negotiate the crowdfunding valley of death and innovate urban biking.
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Andrew Reid

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TIL about Baron Rudolph von Ripper, who I had never heard of -- he was an Austrian aristocrat who apparently spent much of WW2 as a soldier of fortune of sorts, seeking revenge against the Nazis for killing his parents. He was also an artist, and seems (based on my Google searches) to be primarily remembered for his many etchings and paintings depicting his war experience.

US Army site with some background (the article is mainly about the family back-story of one particular paintings): http://www.army.mil/article/3442/Portrait_at_Army_Medical_Museum_Links_Generations/

German-language Wikipedia page: https://de.wikipedia.org/wiki/Rudolph_Carl_von_Ripper

A bit more info:
http://www.acgart.gr/acg-collection/ARTISTS/V/VonR/VonR-bio.htm

What is also interesting is the way I learned about this -- I was at the coffeehouse at one of our local independent bookstores today, where they often have local artworks on display and for sale, and the current exhibit is several cartoon-like drawings by local artist Art Hondros, including a set of four, "prelude to a dogfight", which is about Baron von Ripper.

So, you can learn things from cartoons, is what I'm saying.
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Here's a fun map, h/t to thisisnthappiness. The red and blue colored regions each contain 5% of the world's population, and the white area contains the other 90%. Obviously the blue area selects for countries with low average density (Canada, Australia, Scandinavian countries), or sub-national regions like that (the Amazon, the Sahara, Siberia). The red area does not seem similarly selected, Bangladesh is not the most densely populated country (that's Macau), nor does it contain the highest population density city (that's Manila).

In the io9 article, the map-makers marvel that such a high-population-density region can have so little global prominence, so that might be why it was selected. I have noticed this effect with cities in China -- there are cities with 5-10 million people that I've never heard of (obviously a contingent metric, but I just now searched on "most populous cities", and quickly found Shantou, China, population  5,743,719, which I'd not heard of before).

So, it turns out, the world is kind of a big place.
The remaining 90%, of course, inhabit the regions colored white. (That’s how math works!)
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Not exactly related, but the Philippines surprise me as being roughly equivalent to Japan in size & population (offhand, I would have said Japan was much larger and had many more people).
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Andrew Reid

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This article from 2008 just came around on Hacker News, and seems like it deserves a reference here.

Seems it's actually possible to distribute software for an IBM PC and a C64 on the same disk, by clever interleaving of disk sectors. Each machine sees a disk with several "bad" sectors, and doesn't interfere with them.
As an IBM PC historian, one aspect of my hobby is archiving gaming software.  (You can take that statement to mean anything you want -- whatever you think of, you're probably right.)  At the 2008 E...
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+Alan Cox In fact, I even remember one DOS-PC with a boot rom trying FM first, the SIEMENS PC-D ... well, then again, that baby was originally ment to be a Unix Workstation ;)
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Headed home from #scipy2015. Scipy is still my favorite professional meeting. I have a substantial to-do list of things to follow up on, which is one of those "good problems".
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<clicks tag>...., oh, Sci-Py, Scientific Python, I geddit.
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A few days ago, having become frustrated with my Nexus 7 (2012) and its slow decline in performance, combined with feeling generous towards myself, I ordered a Nexus 9.

It arrived today, and I once again have the problem I seem to always have with just about every new wifi device ever -- the thing will not tell me its MAC address.

I have a MAC white-list on my home wifi network. so it is of high utility for me to know the MAC addresses of devices I want to connect to the network before I connect them. A spate of recent devices have had this problem, the Nexus 5 (LG), the Nexus 7 (2012) (Asus), the Nexus 9 (HTC), the Chromecast, the Ouya, my LG DVD player. It's not everything, if I recall correctly, the Roku popped up the MAC address on the screen where you pick the ESSID you want to connect to. Is this really so hard? Shouldn't this be simple basic information? It could be on a sticker on the box, where there is also a serial number and various other device-specific bits of info, or, as for the Roku, it could be discreetly in a corner of the ESSID selection dialog.

And yes, I am familiar with the argument that MAC filters are useless, because MACs can be spoofed and a determined attacker can sniff a valid MAC from routine traffic and spoof it at their leisure. I am not defending against a determined attacker, I am just practicing reasonably simple "defense in depth", in the hopes that maybe the MAC filter will make a non-determined attacker move on to my neighbor and leave me alone. Besides which, it is not, in my opinion, the role of device manufacturers or set-up software authors to dictate network security policy for me. They should provide sufficient info to allow various policies to work.

My solution, incidentally, was rather creative, I thought. I turned on tethering on my phone, and attached the device to the phone, then opened a shell on the phone and looked in the ARP cache (it's in /proc/net/arp, no root access required) to find the MAC address, which I then entered into my home network's white list. The phone tethering does not have a MAC whitelist, because it's not continuously on, so it presents a smaller attack surface.
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+Bill Connor Mine improved slightly from 5.1 to 5.1.1, it got to the point where it could run two apps at once and only freeze occasionally, which was better than the constant random freezing of 5.1, but still enough to make me crazy.
The N9 has made a good first impression,  it's quite zippy, and my aging eyes appreciate the larger screen, it's a better e-reader than the N7. But, it's also noticeably heavier, and in my initial set-up session, featuring downloading lots of apps and content, it got noticeably warm on the back. Also, it's still on 5.0, hopefully 5.1 won't be an issue here....
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Superpowers, energy and entropy, philosophy, and some interesting lateral and long-term thinking. It's even got a nice bit of a twist ending.
. Seen on Tumblr, along with associated discussion: Yellow: People's minds are heartbreaking. Not because people are so bad, but because they're so good. Nobody is the villain of their own life sto...
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Nicely done.
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Work
Occupation
Scientific computing
Employment
  • NIST
    Scientific computing, present
Places
Map of the places this user has livedMap of the places this user has livedMap of the places this user has lived
Currently
Washington DC
Previously
Canada - Calgary - Vancouver - Chicago
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Tagline
Clever. Maybe clever enough.
Introduction
I studied computer science and physics at UBC, and have never really let go of either. I read a lot. Geeky, but not in a debilitating way.
Bragging rights
I know how much wood a woodchuck would chuck, but I'm not telling.
Education
  • Queen's University
    Physics, 1989 - 1994
  • University of British Columbia
    Physics, 1986 - 1989
  • University of British Columbia
    Physics and Computer Science, 1982 - 1986
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Gender
Male