Where Are The Robotic Bricklayers?

https://constructionphysics.substack.com/p/where-are-the-robotic-bricklayers

There seems to be a few factors at work. One is the fact that a brick or block isn’t simply set down on a solid surface, but is set on top of a thin layer of mortar, which is a mixture of water, sand, and cementitious material. Mortar has sort of complex physical properties - it’s a non-newtonian fluid, and it’s viscosity increases when it’s moved or shaken. This makes it difficult to apply in a purely mechanical, deterministic way (and also probably makes it difficult for masons to explain what they’re doing - watching them place it you can see lots of complex little motions, and the mortar behaving in sort of strange not-quite-liquid but not-quite-solid ways). And since mortar is a jobsite-mixed material, there will be variation in it’s properties from batch to batch.

Zip - How not to design a file format.

 https://news.ycombinator.com/item?id=27925393

> How do you read a zip file?

> This is undefined by the spec.

> There are 2 obvious ways.

> 1. Scan from the front, when you see an id for a record do the appropriate thing.

> 2. Scan from the back, find the end-of-central-directory-record and then use it to read through the central directory, only looking at things the central directory references.

I was recently bitten by this at work. I got a zip from someone and couldn't find inside the files that were supposed to be there. I asked a colleague, and they sent me a screenshot showing that the files were there, and that they didn't see the set of files that I saw. I listed the content of the zip using the "unzip -l" command. They used the engrampa GUI. At that point I looked at the hexdump of the file. What caught my eye was that I saw the zip magic number near the end of the zip, which was odd. The magic number was also present at the beginning of the file. At this point I suspected that someone used cat(1) to concatenate two zips together. I checked it with dd(1), extracting the sequence of bytes before the second occurrence of the zip magic number and the remainder into two separate files. And sure enough at that point both "unzip -l" and "engrampa" showed the same set of files, and both could show both zips correctly. Turns out engrampa was reading the file forwards, whereas unzip was reading the file backwards. 

‘Scared to Death’ by Arbitration: Companies Drowning in Their Own System

 https://www.nytimes.com/2020/04/06/business/arbitration-overload.html

The hair-dryer incident

 https://slatestarcodex.com/2014/11/21/the-categories-were-made-for-man-not-man-for-the-categories/

The Hair Dryer Incident was probably the biggest dispute I’ve seen in the mental hospital where I work. Most of the time all the psychiatrists get along and have pretty much the same opinion about important things, but people were at each other’s throats about the Hair Dryer Incident.

Basically, this one obsessive compulsive woman would drive to work every morning and worry she had left the hair dryer on and it was going to burn down her house. So she’d drive back home to check that the hair dryer was off, then drive back to work, then worry that maybe she hadn’t really checked well enough, then drive back, and so on ten or twenty times a day.

It’s a pretty typical case of obsessive-compulsive disorder, but it was really interfering with her life. She worked some high-powered job – I think a lawyer – and she was constantly late to everything because of this driving back and forth, to the point where her career was in a downspin and she thought she would have to quit and go on disability. She wasn’t able to go out with friends, she wasn’t even able to go to restaurants because she would keep fretting she left the hair dryer on at home and have to rush back. She’d seen countless psychiatrists, psychologists, and counselors, she’d done all sorts of therapy, she’d taken every medication in the book, and none of them had helped.

So she came to my hospital and was seen by a colleague of mine, who told her “Hey, have you thought about just bringing the hair dryer with you?”

And it worked.

She would be driving to work in the morning, and she’d start worrying she’d left the hair dryer on and it was going to burn down her house, and so she’d look at the seat next to her, and there would be the hair dryer, right there. And she only had the one hair dryer, which was now accounted for. So she would let out a sigh of relief and keep driving to work.

And approximately half the psychiatrists at my hospital thought this was absolutely scandalous, and This Is Not How One Treats Obsessive Compulsive Disorder, and what if it got out to the broader psychiatric community that instead of giving all of these high-tech medications and sophisticated therapies we were just telling people to put their hair dryers on the front seat of their car?

But I think the guy deserved a medal. Here’s someone who was totally untreatable by the normal methods, with a debilitating condition, and a drop-dead simple intervention that nobody else had thought of gave her her life back. If one day I open up my own psychiatric practice, I am half-seriously considering using a picture of a hair dryer as the logo, just to let everyone know where I stand on this issue.

River Runner: drop a raindrop anywhere in the USA, watch where it ends up

 https://river-runner.samlearner.com/

Teardown of a PC power supply

 https://www.righto.com/2021/05/teardown-of-pc-power-supply.html

You might wonder how the controller chip on the primary side receives feedback about the voltage levels on the secondary side, since there is no electrical connection between the two sides. (In the photo above, you can see the wide gap separating the two sides.) The trick is a clever chip called the opto-isolator. Internally, one side of the chip contains an infra-red LED. The other side of the chip contains a light-sensitive photo-transistor. The feedback signal on the secondary side is sent into the LED, and the signal is detected by the photo-transistor on the primary side. Thus, the opto-isolator provides a bridge between the secondary side and the primary side, communicating by light instead of electricity.

Try This One Weird Trick Russian Hackers Hate

 https://krebsonsecurity.com/2021/05/try-this-one-weird-trick-russian-hackers-hate/

DarkSide and other Russian-language affiliate moneymaking programs have long barred their criminal associates from installing malicious software on computers in a host of Eastern European countries, including Ukraine and Russia. This prohibition dates back to the earliest days of organized cybercrime, and it is intended to minimize scrutiny and interference from local authorities.

In Russia, for example, authorities there generally will not initiate a cybercrime investigation against one of their own unless a company or individual within the country’s borders files an official complaint as a victim. Ensuring that no affiliates can produce victims in their own countries is the easiest way for these criminals to stay off the radar of domestic law enforcement agencies.

 

DarkSide, like a great many other malware strains, has a hard-coded do-not-install list of countries which are the principal members of the Commonwealth of Independent States (CIS) — former Soviet satellites that all currently have favorable relations with the Kremlin, including Azerbaijan, Belarus, Georgia, Romania, Turkmenistan, Ukraine and Uzbekistan. The full exclusion list in DarkSide (published by Cybereason) is below:

Simply put, countless malware strains will check for the presence of one of these languages on the system, and if they’re detected the malware will exit and fail to install.

An A.I. Finally Won an Elite Crossword Tournament

 https://slate.com/technology/2021/04/american-crossword-puzzle-tournament-dr-fill-artificial-intelligence.html

Steam's login method is kinda interesting

 https://owlspace.xyz/cybersec/steam-login/

Draw an iceberg and see how it will float

 https://joshdata.me/iceberger.html